Three items out of New Mexico,  recently,  point to the focus that state is putting on desalination.

The new El Paso/ Ft Bliss water desalination plant is opening this year. It will be the world’s largest inland water desalination plant.

The desalination facilities will increase El Paso Water Utilities’ fresh water production by approximately 25%, based on current demand, and will include a state-of-the-art desalination plant, a learning center, groundwater wells, transmission pipelines, storage and pumping facilities and the disposal of concentrate, the residual that remains after the desalination process.

The second item out of New Mexico is the opening of a new 16,000 sq ft  ground water desalination research facility. The facility called the National Inland Groundwater Research Center headed up by Mike Hightower from San Dia Labs–will offer permits & several different concentrations of brackish water for desalination research purposes.

To address the development of the “next generation” of desalination technologies needed to realistically impact future fresh water supplies, a federal partnership between Sandia National Laboratories and the Bureau of Reclamation was established by Congress in 2001 to evaluate and coordinate the development of a brackish ground water desalination research facility in the Tularosa Basin of New Mexico. While significant efforts have been devoted to address coastal or seawater desalination issues, this facility has been designed to address the unique research needs, such as system performance and environmental impact, of desalination and effective utilization of brackish ground water in inland areas. The goal of this facility is to become a national and international leader in the research, testing, evaluation, and demonstration of novel technologies for cost-effective ground water desalination and environmentally sound concentrate management.

Conceptual design of the facility was completed in September 2002, and final design completed in April 2004. Construction on the water supply system for the facility was initiated in October 2003, while groundbreaking for the facility was held in June 2004.

This last article involves students being involved in a research contest that involves desalination related problems. It occurs to me that they might do their bench scale demonstrations at the new facility mentioned above. One of the problems calls for the students to “Develop an inland desalination operation” Too bad they won’t have those cheap photovoltaic cells that I mentioned in last week’s post. Those won’t come out until this fall. However, a couple  ideas mentioned in this blog would  be great student projects.  One would be  distillation desalination using low pressure.  Another would would be using greenhouses for water desalination.

Anyhow here is the contest.

Environmental Design Contest to focus on water and renewable energy

Under the recently formed Institute for Energy and the Environment (IEE) and the College of Engineering, New Mexico State University is advancing applied engineering solutions to critical environmental challenges through its Environmental Design Contest, an annual international competition set for April 1-5 this year.

The Design Contest, sponsored by private and public entities such as Intel, the U.S. Department of Energy (DOE), the Food and Drug Administration and the American Water Works Association and Research Foundation, has deployed seven student-developed technologies at industrial and DOE sites over the 17-year course of the contest.

The design challenges presented in the upcoming competition relate to water and renewable energy – two areas critical to the state’s legislative initiatives symbolized by Gov. Bill Richardson’s call to be the “clean energy state” as he declared 2007 the “Year of Water.”

The 2007 international challenge will engage 34 teams from 22 universities. Almost 170 students from across the U.S., as well as teams from Budapest, Hungary, Universidad de Las Americas in Mexico, and the University of Manitoba, Canada, will compete. In a concurrent high school design contest, 125 students from eight schools will develop solutions to the same design challenges with various options for the younger competitors. NMSU has two teams competing for cash prizes, traveling trophies and worldwide recognition.

Government agencies, industrial affiliates and academic partners play a key role in the design contest, assisting IEE in the development of design problems and evaluation criteria, providing financial support for site-specific issues and serving as judges for the final competition. Design teams showcase their work through research papers, oral and poster presentations and bench-scale demonstrations. Their scientific approach must consider regulatory guidelines, public opinion and cost.

“The institute fosters an inter-disciplinary research agenda to address environmental sustainability,” said Abbas Ghassemi, IEE director. “Our flagship event, the International Environmental Design Contest is evolving into its 17th year addressing immediate areas of concern, and it is as timely and relevant as ever. We continue to evolve the application of real solutions to real problems affecting quality of life for everyone.”

Steven Castillo, dean of the NMSU College of Engineering, is excited about the contest and the engineering solutions that result from it.

“Providing inexpensive, clean sources of energy to support continued economic growth is one of the biggest challenges we face in the coming years,” Castillo said. “IEE is becoming a focal point for NMSU faculty from disparate disciplines to solve difficult technical problems and support the production of world-class engineers in these important areas.”

This year’s Design Contest tasks include:

• Develop a photovoltaic (solar panel) system performance indicator to determine that a residential utility-interactive PV system is operating properly and that the AC power output is following the solar power available to the PV array.

• Develop an inland desalination operation and disposal system (for water) in rural, isolated communities to demonstrate a low-cost, simple and reliable system.

• Convert a biomass resource to useful forms of energy and other products to demonstrate options using biogas or liquids.

 

 

As I have mentioned before, water desalination costs consist roughly of 1/3 each of capital, maintenance and energy. The most promising technology so far — carbon nanotube membranes show promise of collapsing capital maintenance and energy costs by replacing a 30 million dollar desalination plant with a <2 million dollar membrane tipped pipe you stick in the ocean. (More on that later.)

However, there will still be energy costs involved with pumping water. Those costs increase as you contemplate pumping water hundreds —even thousands of miles inland.

So what about electricity costs?

There is a serious power generation paradigm shift afoot which will result in lower electricity prices.

Current solar generation efforts underway might well provide a way to offload all the construction and maintenance costs of the electrical infrastructure onto private contractors — Leaving water utilities just the consumer’s cost of metered electricity–all along the inland pipeline.

Here’s How.

Low cost high volume electricity will be generated from next generation solar plants going up in the deserts of Southern California. In fact, it looks like they will be able to bring in electricity at the current cost of coal fired electricity.

None of the companies would give a price for building the solar sites or disclose the rates the utilities will pay for power, but both said the cost would be similar to traditional coal or gas.

It looks like the solar power operators in Southern California have come up with a seriously innovative way to mainstream solar power using net metering.

January 20, 2007

Is the Sun finally rising on Solar Power?

An Interview with Rob Styler of Citizenre

Press Release from Affordable Photovoltaics LLC

 

In the past, solar power has been too expensive and too complicated. To switch to solar, people had to invest their children’s college fund or sell their second car. The average consumer pays $40,000 to convert their home to solar-plus you are responsible for the installation, maintaining the equipment, getting permits-who has the time (or the money)?

A company called Citizenre has a bold plan to remove all of the traditional barriers to solar power. They offer: No system purchase. No installation cost. No maintenance. No permit hassles. No performance worries. No rate increases. No way!?

(My comment:So what if this were a water utility–)

When we first heard about this, we were so intrigued that we contacted the company. It seemed almost too good to be true. Like most innovations, their model is so simple it makes you wonder why no one thought of it before.

You simply pay Citizenre the same rate per kilowatt for power that you used to pay your utility company-but it gets even better. Citizenre will guarantee that your rate per kilowatt will not go up for 25 years. With ever increasing electricity rates, this gives consumers peace of mind and can add up to significant savings. They even have a solar calculator on their website that shows exactly how much you will save over 1, 5, and 25 years. I saved over $13,000 and by using clean energy, it was the equivalent of taking 24 cars off the road or planting 400 trees. Nice.

In the past, “going green” usually implied sacrifice. You get to feel good about saving the planet but most “green” products are more expensive than their “dirty” counterparts. With Citizenre, going green can actually save you money.

This is all made possible by net metering laws that require the utility companies to allow renewable energy to flow into the grid and then allow the consumer to pull that same amount of energy off of the grid at no cost to the consumer. Basically the grid becomes a huge battery. The meter spins backwards during the day when the sun is shining and forwards at night when the consumer pulls that power back off the grid.

(My comment: Ok. So what happens if all along the canal/pipeline into the desert you installed solar electricity generating systems– installed for free by franchisees of Citizenre-that generated twice as much energy as the canal pumps need–so that at night when the solar cells weren’t working–the pumps could still draw power from the network–for free–because they had produced twice as much as they needed during the day. The answer is that there is still a rental fee whose total is still calculated by the amount of energy produced by the solar cells. However, it won’t be anything like the retail rates of .10-.20 a kilowatt retail rates)

These laws were passed because residential energy production was the number one cause of pollution in the US last year, but there are still 9 states that have not joined the party. If you live in Alaska, Tennessee, South Carolina, Mississippi, Alabama, Missouri, Kansas, Nebraska, or South Dakota, the Citizenre Solution is not an option for you yet.

We were still a little skeptical, so we asked Rob Styler, the president of their marketing division, some hard questions.

Q. How can Citizenre afford to install this complete solar system with no upfront cost to the consumer?

A. Because we handle everything ourselves from the solar grade silicon to the final installation, we create savings at each stage of the production. Plus we are building the largest plant for solar power in the world. When you combine our vertical integration with our economies of scale, we are able to produce the final product at half the cost of our competitors.

Q. This sounds like Citizenre required a large amount of money to make all this happen?

A. $650 million.

Q. Now I know why no one did this before you guys. So the customer does not have to give any money to have this complete solar system installed on their house?

A. We require a security deposit, typically only $500, at the time of installation. They get this deposit back, with interest, at the end of the contract. If they don’t pay their bill and walk away from the contract, they lose their deposit and we come take the system off their roof. They are also required to pay a monthly rental for the solar energy system.

Q. And how is that rent calculated?

A. By the amount of energy that the system produces.

Q. But they are paying the same rate they were paying before, right?

A. Often it is actually less. We base our rates on the yearly average for their utility. So we have to base our rates on the prior year. Since rates tend to go up each year, many customers will save money on their first bill, and this will only increase as the years pass. We provide a calculator on our website that will tell specifically what they will save with their particular utility and their monthly usage. Many customers save over $10,000 just by switching to the sun. Our whole mission is to help people join the solution and stop being part of the problem.

(My comment: So a California water utilitiy could go to their web site and calculate on the spot how much they would save by having a solar system installed.Ok here is the web page you go to. Click on the lower left hand corner.)

Q. I like that. How long of a contract do they have to sign?

A. One year, five years, or 25 years. Over 70% of our customers sign the 25-year contract because that locks in their rate for the entire term of the contract. If they sign a shorter contract, their rate is recalculated according to current energy rates at the end of their term.

Q. What happens if I sign a 25-year contract and I want to sell my house in 10 years?

A. You have three options. First, you can ask us to move the system to your new house. We do that one time for free. Second, you can transfer the contract to the new owner. This can potentially add value to your house because if energy rates keep going up like they are and they are 60% higher in 10 years, then your buyer would get a 60% decrease on their energy bill because of your foresight. The final option is that you can contact us, tell us that you just want to end the contract and we will remove the unit. With this third option you do lose your security deposit.

Q. So is my security deposit the most I can lose?

A. Obviously if you don’t pay your bill there will be late fees or if one of our franchisees comes out to your house to remove the unit and you greet him with a shot gun and pit bull, we will have to take legal steps to recover our property. But if the customer is cooperative they should have no worries.

Q. Say I want a system on my house. How does it work? What is the process?

A. One of our Independent Ecopreneurs will help you each step of the way. There are some simple questions to answer about your amount of shade, the direction of your roofline, etc. After you sign the contract, a solar engineer will come to the house to design your system.

Q. What if I don’t like the design? Am I still obligated to the contract?

A. No. You can back out of the contract with no penalty. You don’t even pay the deposit until after you approve the design.

Q. Okay. I like the design. I want the system. What’s next?

A. The installation usually takes about half a day. The permit process can take as much as 90 days depending on how cooperative the local utility is, but we handle everything. All you do is sit back and feel good knowing you are using clean energy to power your home.

Q. What happens if something breaks or goes wrong?

A. We have a complete worry free performance guarantee. If the unit ever stops working, one of our franchisees will rush out to fix it for free. The customer has no rental charges until the system is working again so we are motivated to get it fixed fast.

Q. What if my kid hits a baseball through one of the panels?

A. It is just like renting a car or a TV. You are responsible for returning it in good condition. We recommend that customers contact their homeowners insurance to double check that the unit will be covered under their policy. Usually there is not a problem.

Q. Wouldn’t I save money in the long run if I just bought the system?

A. Actually, no. Renting can save you a significant amount of money, and it protects you from a large investment risk. We can help the consumer evaluate their options so they can make a solid decision. Our goal is to have solar power producing 25% of our residential energy supply in the year 2025. To make that happen, we removed every barrier we could find to solar entry. We make solar simple.

Q. I understand that your manufacturing plant is not completed yet, is that right?

A. Correct. The first systems will be ready to install in September of 2007.

Q. So why would someone sign up now?

A. First because they lock in their rate as soon as they sign up. Second, they get in line so they can get their system sooner once the plant is producing. Third, it also helps us show the market how many people will go green if we provide an offer that makes sense on every level, including economically. To quote Ghandi, “Be the change that you want to see in the world.”

Q. So how does someone sign up?

A. They just go to http://www.affordablephotovoltaics.com and they can sign up for free right now

………………………….

Nice interview.

So for the purposes of a pipeline — local solar franchises could install and maintain the photovoltaic equipment along the pipeline that fed electricity at low fixed predictable costs to the generators that ran the pumps that pumped the water inland.

Kind of nice — don’t you think — that they lock in prices for twenty five years so that the consumer is protected from rising electricity prices….But what if future photovoltaic electricity prices fell rapidly and dramatically. That’s what Nano Solar has in mind. “Tomorrow’s solar panels may not need to be produced in high-vacuum conditions in billion-dollar fabrication facilities. If California-based Nanosolar has its way, plants will use a nanostructured “ink” to form semiconductors, which would be printed on flexible sheets. Nanosolar is currently building a plant that will print 430 megawatts’ worth of solar cells annually—more than triple the current solar output of the entire country.” And prices will fall substantially. According to Wikipedia.

Estimates by Nanosolar of the cost of these cells, fall roughly between 1/10th and 1/5th ^[3] the industry standard per kilowatt. A significant cost reduction which, if true, is expected to drastically affect, if not revolutionize the modern energy market.

Current costs for photovoltaics are +-.18@kilowatt hr vs +-.03@kilowat hr for coal generated electricity. So 1/10 of .18 would be .018 cents@kilowatt hour. Operating & maintenance costs add another .01 cent@kilowatt hour

That 1/10th number is not a fluke either. Another company called Innovalight with similiar technology — claims it will be able to do the same thing.

Innovalight has developed a silicon nanocrystalline ink that holds the promise to bring flexible solar panels to cost that could be as much as ten times cheaper than current solar cell solutions.

In fact according The Energy Blog:

Their [Inovalight]technology is similar in some respects to others that are developing thin-film silicon photovoltaics. Kyocera, Unaxis , Ovonics, Sanyo, Energy Photovoltaics , Konarka, Nanosys and Nanosolar are companies in this field that I have written posts about. It seems with all these companies and all the companies developing non-silicon thin-film products, a few should emerge as leaders with low cost solar products.

I think that its safe to say the costs of producing photovoltaics are going to come down substantially in the near future. Basically, we’re talking about electrical generation going through a paradigm shift.

Now remember we are talking about two kinds of solar power generation here. The first is the large scale thermal solar plants located in remote desert locations and the second is photovoltaic systems which are usually small scale affairs located on roof tops. (However, with photovoltaic costs falling so dramatically–next generation solar farms may use phtovoltaics rather than thermal solar power generation.)

A company like Citizenre is using both the large scale thermal solar plants and the small photovoltaic systems by way of net metering to gain enormous economies of scale.

One hidden cost of building the large power generation plants in remote sites is the costs of building electrical lines back to the main grid. To offset these costs

California ISO asks feds to back plan for greening the grid

Folsom, CA, Jan. 26, 2007 — The California Independent System Operator Corp. (California ISO) filed with its regulator, the Federal Energy Regulatory Commission (FERC), to approve in concept a financing plan for transmission trunklines to remote locations in order to get green power from multiple users on to the grid.

If the new payment mechanism is approved and implemented, it would be a means of removing financial barriers that can hinder development of wind, solar, geothermal and other renewable energy resources, said the California ISO.

This is a good idea and should be implimented in other states beside California.

Finally, from Moss Landing in Monterey California, an interesting method for drawing water from the ocean is being considered. Rather than stick a pipe out in the ocean planners are contemplating digging a diagonal well from the shore at a cost of 2 million dollars.

Cal Am estimates well drilling to cost $2M

PUC asked water company to research method seen as less invasive way to cool desalination plant

By KEVIN HOWE

Herald Staff Writer

If California American Water is required to draw seawater from wells rather than Moss Landing’s once-through water cooling system for a pilot desalination plant, the cost will be about $2 million, the company has told the state Public Utilities Commission.

The purpose of the diagonally drilled test wells, Bowie said, would be to see if they could draw enough water to support a full-scale desalination plant, a process that would involve water quality testing and may include experimental desalination.

The company’s estimate for all of that work, including some pilot water treatment, is $2 million, she said, “and they may not ask us to do all of that.”

Subsurface intakes are diagonally-drilled wells that extend below sea level toward the ocean floor. They are the favored desalination technology of many environmental groups that object to the open ocean-water intakes employed at Moss Landing and other coastal power plants, because they can trap plankton, larvae and other small organisms.

Subsurface intakes collect water after it has passed through layers of sand, soil and gravel, thereby avoiding impacts to marine life and reducing the need for pre-treatment before the water goes through the desalination process.

In Marina, a subsurface test well would draw water from the seawater-intruded, 180-foot aquifer. Engineers have posed the theory that drawing water at this location could actually help prevent the advancement of seawater intrusion.

Mark Lucca, general manager of the Marina Coast Water District, said district officials and Cal Am representatives have been talking in general terms about possible test wells and sites, “but I’ve not heard about an ‘X’ on the map.”

No decision has been made to drill test wells, Bowie said.

If the PUC requests additional subsurface research, Bowie said, installation of the test well could begin as early as July. The company would need appropriate permits from the Coastal Commission and other agencies for the well.
As currently proposed, the Cal Am pilot plant would divert seawater from the Moss Landing plant’s once-through cooling system. It would then discharge the remaining brine from the desalination process into the power plant’s system to be returned to the bay.

The state Lands Commission early last year adopted a resolution to phase out once-through cooling systems for coastal power plants.

Using the diagonal wells would eliminate the environmental objections of once-through cooling systems and avoid making desalination plants dependent on them.

Desalination, combined with aquifer storage and recovery, Bowie said, has been identified by the Public Utilities Commission as the most viable and environmentally sensitive supply project for the area.

For the full article click here.

2 Million Dollars to drill a diagonal well out into the ocean. That looks like the future cost of a desalination plant– –someday — when all that’s needed is a pipe stuck out in the ocean — with a semipermiable membrane attached to the cnd. Except that they won’t need to drill diagonal well. They’ll just need to lay pipe out into the water. Which should be cheaper than 2 million.

Update:

In December I blogged about peak oil predictions of the collapse of production of Saudi oil production.

A couple of things happened in the last month that I think will result in the collapse of demand for oil in the next 10 years. First GM introduced the hybrid Volt at their auto show in January. The car goes 40 miles on a charge and then switches over to gas. It costs an extra $5000 to make. It can be recharged in 6 hours overnight. (Since standard commutes are <=33 miles daily most cars can be charged overnight without using gas.) The DOE released a study saying that 85% of the US could run off hybrids without need of upgrading the current US electrical system because cars would be charged at night–during a period of low demand. Finally, Bush signed an executive order mandating that federal vehicles use uses plug-in hybrid (PIH) vehicles. So GM will have enough demand to justify investments to ramp up production that will leverage economies of scale to bring down prices that will make the car attractive the public.

 

As much as a third of the cost of water desalination is made up of maintenance costs. So a fair amount of thought has to be put into making surfaces that come in contact with air & water clean. I have mentioned in a previous post called The Pipeline that there is a product called Sharkote-– a US navy funded coating announced in 2005 that immitates the skin of a shark. Sharkote might be used inside the pipes that carry water. (barnicles & algae don’t grow on shark skin like they do on whale skin so Sharkote would also serve well to reduce maintenance in algae farms)

Recently, a number of other possible kinds of surface applications have come out of the labs. This first application looks like its more suitable for places inside desalination plants– surfaces that are damp but not directly connected to fresh water production.

Spiky surface ‘kills infections’

 

The coating inactivated the influenza virus

Adding a special “spiky” coating to surfaces can kill bacteria and viruses, research suggests. US scientists found painting on spike-like structures kept the surfaces infection-free.

The spikes, they believe, rupture bacteria and virus particles on contact, inactivating them.

The team, writing in the Proceedings of the National Academy of Sciences, suggest their findings could help to fight the spread of diseases.

Given the simplicity of the coating procedure, it should be applicable to various common materials Massachusetts Institute of Technology

The researchers painted glass with long chains of molecules, called polymers, which anchored to the surface to form tentacle-like spikes.

When the team then applied the surfaces with E. coli and Staphylococcus aureus (both common disease-causing forms of bacteria) and the influenza virus, they found the coating killed them with 100% efficiency within minutes.

Click here for the rest of the article.

This next product might be used for outside surfaces of desalination plants that face the sun– or green houses used for biodiesel and desalination production.)

 

Eco glass cleans itself with Sun

 

By Jo Twist BBC News Online science and technology staff

Normal glass (left) and Activ (right) makes for clear views

A revolutionary kind of glass that needs little cleaning could mean soap and chamois are banned for good. The Pilkington Activ glass has a special nano-scale – extremely thin – coating of microcrystalline titanium oxide which reacts to daylight.

This reaction breaks down filth on the glass, with no need for detergent. When water hits it, a hydrophilic effect is created, so water and dirt slide off.

It is one of four finalists for the eminent MacRobert engineering award.

The prize is given out by the UK’s Royal Academy of Engineering for technological and engineering innovation.

‘Nano’ cleaning

“Pilkington Activ is based on titanium dioxide, which is used in foodstuffs, toothpastes, and sun cream,” explained Dr Kevin Sanderson, one of the team members who developed Activ at Pilkington’s technical research centre.

“But usually it is a white powder which is not ideal for glass because you can’t see though it.

Each time harsh chemicals are used, they are washed off into ground, which produces contamination. What we say here is that you can just spray water on top Dr Kevin Sanderson, Pilkington

“So we used it in a thin film form – 15 nanometres thick – so that it appears as close to normal glass as it can.”

Although not strictly nanotechnology, the special coating and the chemical reactions happen at the nano-scale (one thousand millionth of a metre).

The titanium dioxide coating on the glass had two properties that made it special, said Dr Sanderson.

Click here to see how the glass works

 

Click here to read the rest of the article.

This last coating is like the coating that is activated by the sun. However, it works in wavelengths that would be suitable for light bulbs. So it would prevent the growth of fungus and the build up of dirt on the damp inner surfaces of a desalination plant.

 

Self-cleaning bathroom on the way

 

By Marina Murphy

Few of us enjoy the weekly blitz on the bathroom

Nanotechnology may yet rescue us from the drudgery of the weekly ritual of blitzing the bathroom.

Scientists in Australia have developed an environmentally friendly coating containing special nanoparticles that could do the job of cleaning and disinfecting for us.

“If you have self-cleaning materials, you can do the job properly without having to use disinfectants and other chemicals,” says researcher Rose Amal at the Particles and Catalysts Research Group, University of New South Wales, where the coating is being developed.

Previously self-cleaning materials were limited to outdoor applications because ultraviolet light was required to activate the molecules in the coatings.

Less time cleaning the bathroom is rather appealing Mary Taylor, Friends of the Earth

These surfaces contain tiny particles of titanium dioxide, which become excited when they absorb ultraviolet light with a wavelength of less than 380 nanometres.

Light activated

This gives the particles an oxidizing ability stronger than chlorine bleach. The excited particles can break down organic compounds and kill bacteria.

The new coating contains modified particles of titanium dioxide, which are doped with other cations like iron or vanadium and anions like oxygen, nitrogen or carbon.

This coating can absorb light at the higher wavelengths in visible light, such as the bathroom light.

The coating can kill bacteria such as E. coli

Lab experiments revealed the surface of coated glass could kill the bacteria E. coli (Escherichia coli) and degrade volatile organic compounds in visible light.

The oxidising properties also mean fungus cannot grow on the surface. And because the coating is hydrophobic – it does not like water – the water simply slides away carrying any dirt with it, rather than gathering as droplets.

Using the coating in baths and sinks would not pose any problems with skin irritation, according to Amal.

“When the bath is filled, the water would attenuate the light so I don’t think the surface would activate. It will only be active if the light can reach the surface,” she says.

For the rest of the article click here.

 

Will someone kindly do the math that shows the energy needed to raise the temperature of water to steam vs the energy needed to lower the pressure on water to near vacume state so that it flashes to steam. Email the formula to me at cakilmer at yahoo.com and I’ll post it.

(See below for updated formula.)

Why?

Well it would be helpful to verify the claim that its more energy efficient to lower the pressure around water so as to flash it to steam than to raise the temperature of water to boil it to steam.

I first heard about this from one of the tenor guys in my community chorus last fall. He was doing consulting work for some outfit or other. I never got the details. They were looking into temperature differentials between say water at the surface and water +1000 feet down to power their vacume pumps. But the whole thing worked out to be too expensive. Recently, a report was published in New Scientist about some UK researchers who are working on a device which will use wave action to power a pump which will lower pressure and thus the temperature needed to evaporate (and then distill) water.

I mention this by way of introducing some Florida Atlantic University Grad Students who claim they can reduce the cost of water desalination by a factor of ten by using waste heat as an energy source to lower the pressure on water so that it will flash to steam. ( The key concept here is using heat to lower pressure on water to flash it to steam — rather than using the heat to raise the temperature of water to boil it.)

“I’ve been able to build this incredibly eccentric machine, spill gallons of water everywhere, and generally act like the mad scientist I always wanted to be as a kid,” said Eiki Martinson, one of the students involved. “Best of all, we solved one of the biggest problems of today — with an invention that can save millions of lives around the world.”

Martinson and Brandon Moore developed a process estimated to be 10 times more efficient than existing desalination technologies.

Sounds like these guys are having fun.

Moore and Martinson have been working in conjunction with their advisor, Dr. Daniel Raviv, an electrical engineering professor, to create a process that depends on recycling waste energy to distill water at a near vacuum and at room temperature. The project was initiated and sponsored by inventor Michael R. Levine, who currently holds 76 patents.

Levine said he came up with the first version of the distillation process on paper, and the FAU team took it to another level, augmenting the inventor’s idea — and creating the working apparatus.

The FAU team and Levine are working with power and water agencies to scale up the project so it can provide a million gallons of fresh water per day.

The students entered the project in the 2006 Collegiate Inventors Competition, a program of the National Inventors Hall of Fame Foundation. They were among the top seven finalists in the United States/Canada competition. This honor recognizes the innovations, discoveries and research by college and university students and their advisors for projects leading to inventions that can be patented.

How might this be incorporated into current tech.

Well– as I mentioned in Greenhouses For Desalinised Water and Oil — Aquasonics technology is currently using waste heat to power a special nozzle that breaks water into a very fine mist. This mist is then hit with hot air. Instead of using waste heat to hit the mist — maybe the waste heat could be used to create a vacume. The question is–is the energy used to create the vacume orders of magnitude lower than the energy used to heat the water. And is the equipment needed to create the vacume relatively simple/inexpensive.

Update:

P=Pressure V=Volume T=Temperature

PV=nRT

PV/T=nR

P1V1/T1 = P2V2/T2=P3V3/T3

Darn, it seems these days that just about as fast as you can think of something — there’s a researcher around working on it. I’ve mentioned that it would be nice to shape a carbon nanotube filter into a pipe so that you could just stick it out in the ocean and fresh water would flow in. Here’s a researcher who has developed a carbon nanotube pipe for a purpose that might be adapted to water desalination.

Savvy Sieve: Carbon nanotubes filter petroleum, polluted water

http://www.sciencenews.org/articles/20040814/fob7.asp

Alexandra Goho

Bridging the gap between the nanoworld and the macroworld, researchers have created a membrane out of carbon nanotubes and demonstrated its potential for filtering petroleum and treating contaminated drinking water.

Scientists have long valued carbon nanotubes for their high strength and thermal properties (SN: 6/5/04, p. 363: Available to subscribers at http://sciencenews.org/articles/20040605/bob10.asp), yet it’s been a challenge to assemble nanotubes into useful materials large enough for people to hold in their hands.

CLEAR PASSAGE. The wall of this tube-shaped filter is made of a single layer of densely packed carbon nanotubes. Ajayan

Researchers at Rensselaer Polytechnic Institute in Troy, N.Y., and Banaras Hindu University in Varanasi, India, have now devised a method for making such large-scale structures and found an application for them.

The researchers injected a solution of benzene and ferrocene—the materials needed to assemble the carbon nanotubes—into a stream of argon gas and then sprayed the mixture into a quartz tube. The tube was located inside a furnace heated to 900°C.

A dense forest of carbon nanotubes formed on the inner walls of the quartz tube, yielding a hollow black cylinder. The researchers carefully removed the cylinder, which measured several centimeters long and up to a centimeter in diameter. It was composed of trillions of nanotubes. Each nanotube was only a few hundred microns long, essentially the thickness of the carbon cylinder’s wall.

“It’s a pretty amazing structure if you think about it,” says lead investigator Pulickel Ajayan of Rensselaer.

To test their cylinder as a filter, the researchers capped one end and let petroleum flow into it. As the oil passed through the cylinder’s wall, the membrane caught the large and complex hydrocarbons—a necessary step in making gasoline.

In a second experiment, Ajayan and his colleagues tested their filter on contaminated water. The researchers had added Escherichia coli, the bacterium responsible for a common intestinal disease, to a sample of water and passed the sample through the filter. Analysis of the filtered water showed that it was devoid of E. coli. More surprising, when the researchers tried water contaminated with the poliovirus, which is much smaller, not one virus made it through the sieve.

The researchers describe their results in the September Nature Materials.

“It’s very encouraging to see the development of new applications like these for carbon nanotubes,” says Alan Windle, a materials scientist at the University of Cambridge in England. “This is a nice piece of work.”

However, because the researchers didn’t compare their material’s performance with that of conventional ceramic or polymer filters, it’s difficult to gauge how competitive a carbon-nanotube filter would be, Windle adds.

Ajayan considers the new study just a first demonstration of nanotube filtration. However, he says, because the pore sizes in his team’s membrane are more uniform than those in conventional membranes, a carbon-nanotube filter could be especially effective at filtering out selected chemicals or microorganisms. What’s more, because carbon nanotubes can tolerate much higher temperatures than polymers can, periodic doses of heat could unclog the membrane without destroying it.

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A later generation carbon nanotube filter might be shaped into the form of a house sized mushroom that sits on the ocean floor not too far from the coast. The carbon nanotube filter would be on the dome of the mushroom. A ram pump would be on the stem. The ram pump would use the weight and momentum of falling water to push the water ashore.

Ram pumps have only two moving parts, making them virtually maintenance-free. The basic idea behind a ram pump is simple. The pump uses the momentum of a relatively large amount of moving water to pump a relatively small amount of water uphill. To use a ram pump, you must have a source of water situated above the pump. For example, you must have a pond on a hillside so that you can locate the pump below the pond. You run a pipe from the pond to the pump. The pump has a valve that allows water to flow through this pipe and build up speed.

Ram pump in action

Once the water reaches its maximum speed this valve slams shut. As it does so the flowing water develops a great deal of pressure in the pump because of its inertia. The pressure forces open a second valve. High-pressure water flows through the second valve to the delivery pipe and the pressure in the pump falls. The first valve can then reopen to allow water to flow and build up momentum again, and so the cycle repeats.

Kind of a neat idea I think. But a couple years from now the cost of photovoltaics might come down sufficiently to make a solar pump an attractive low maintenance option or  carbon nanotube membranes may be able to cheaply extract hydrogen from water so as to make it dirt cheap to pump the water using hydrogen as an energy source. That way you don’t have a big contraption out in the ocean. All you have is a pipe. But a Ram Pump might serve as an intermediary step.

Matthew R. Simmons, Chairman of the energy-industry investment banking firm Simmons & Company International has written extensively on peak oil. He was interviewed on the subject by Foreign Policy Magazine back in 2005. And again by Energy Bulletin in June 2006

His firm has completed for its clients’ investment-banking projects that have valued over $65 billion. He has given 75 speeches since publishing his book on Saudi Oil, Twilight in the Desert (2005). “As I study the oil situation, the problems get worse… [but] the peak oil movement has grown from being a pimple to a pandemic,”

While the Peak Oil scare has died back a bit recently — Mr. Simmons has been quietly scaring the bejeebers out of Pentagon, DOE and Intelligence types for the last two years. (Mr. Simmons views were validated this week by a spate of news stories that reported the reason for Iran’s current production being below their OPEC quotas — was simply that they were running out of oil.)

Recently Mr. Simmons has decided to create “a new international water energy research center” in Rockland, Maine. According to Mr. Simmons

“What I’ve started is getting interested parties to get interested, hopefully, in Rockland, to create an institute in Rockland, an institute of water, and allowing 200 to 300 of the best scientists in the world, backed by maybe 20 universities, and 20 corporations and 20 think tanks, come here as a water fellow, and under one roof get all these people doing wave energy and tidal energy and desalination and so forth,” said Simmons.

Sounds like he could pull it off. But he could likely use some encouragement.

Certainly, I like any big idea that combines energy and water.

For several months I have been looking for work that might follow up on the Lawrence Livermore carbon nanotube break through annouced in May that promises in 5-10 years — to enable manufacturers to develop semipermiable membranes that cheaply desalinise water.

A couple weeks ago I posted a piece called Honey I shrunk the carbon nanotubes .

Recently some Japanese researchers figured out how to pack carbon nanotubes together effficiently.

Here are a couple more links to experimental work I’ve posted in the last several months that might follow up on the Livermore work. 1.) 2.) 3.) 4.) 5.) 6.) . This last #7.) discusses how charge could be used for semipermiable membranes.

The reason I mention this, is because according to reports widely published in provincial newspapers from Australia in October it seems that the Livermore team’s solution has already addressed all the problems for which I presented possible solutions. Did their solution come from some exotic process that’s not scaleable? Nope . They said they used “standard microfabrication techniques that in theory can be scaled.” Did the carbon nanotubes successfully filter out salt? Yup. They said current results showed that “nanotube membranes could remove up to 95 per cent of the chloride”–with better results in the offing. Was there any leakage around the sides of the carbon nanotubes? Nope. They said they deposited “a filler material – a matrix material that can fill the tiny gaps between the tubes to allow us to make a stable membrane.” Won’t these little nanotubes clog up quickly? Nope. The carbon nanotube “also showed that they have inherent anti-fouling characteristics.” Here’s the kicker. How come the larger carbon nanotubes were able to reject the smaller sodium ions. Guess. uh huh. Twas charge. “The fact that most of the sodium was not trapped by the experimental membrane pointed to the electrical charge mechanism being the active factor.” (There’s some serious implications here for hydrogen filtration as well.)

So why is this membrane 5-10 years away from a beta mass production model–and not, say, 18 months away?

Question 7 – How long do you think it will be before the technology you have been discussing becomes, if not everyday, at least usable?

Jason Holt – That’s a good question and one we often get. I think it depends on the kind of investment and partnering that we do with companies. There has been a lot of interest in the States from some of the big water treatment companies like GE and Culligan. They have contacted us and are interested in scale-up and commercialisation of the technology. If we get their involvement, a five-year time line will probably be overly optimistic – it’s more likely to be 10 years.

So it sounds like Mr. Holt is interested in working with smaller production companies that have already mastered the mass production of nanotubes with a a scaled up methodolgy simliar to his own methods for producing carbon nanotubes. Here are two possible candidates that I’ve pulled from back blogs that I’ve posted here and linked to above. One Nanovip.com and the other is NanoH20. There’s likely a couple more mentioned in my blog.

Finally a point should be made as to the real potential cost cutting here. According to the piece.

“The take-home message here is that the combination of fast flow and the small pore size suggests that we could use these membranes to significantly lower the energy cost of nanofiltration or desalination. A 100-fold higher permeability can reduce the energy costs by more than 80 per cent.”

If you just stuck a pipe in the ocean with a carbon nanotube filter on the end– the only enery costs would be pipeline pumping costs. Further, there wouldn’t be a big desal plant that would need to be built. What’s more the carbon nano tube membranes seem to have some anti fouling characteristics. So what the hey. Between collapsed energy, maintenance and capital costs — don’t you think perhaps 10 fold cost reductions can be done in 10 years– and maybe lot less?

Anyhow, this stuff is fun to consider. Here’s link to the brief article. In the meantime I’ve copied and pasted below a detailed article that covers the same event.

Australian Academy of Science | Conferences and lectures
Transcripts of lectures and speeches

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Forthcoming conferences and lecturesConference proceedingsTranscripts of lectures and speeches PUBLIC LECTURE: Desalinating water cheaply – exploring technologies
Fast water transport through carbon nanotubes and implications for water treatment
The Shine Dome, Canberra, 26 October 2006 Dr Jason K Holt
Chemistry and Materials Science Directorate, Lawrence Livermore National Laboratory, California, USA

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Introduction (Professor Kurt Lambeck) – I am pleased to introduce Dr Jason Holt who will speak on something that is very much on everybody’s mind – water! But what will be different from most of the recent water discussions, is that he does not see the solutions in terms of market forces and water trading, beloved by economists. He will be addressing new technologies that promise to produce more of the drinkable form through the use of nanotube membranes and desalination.

Dr Holt is a research scientist at the Lawrence Livermore Laboratory in California with experience in nanomaterials, nanoscale devices and analytical chemistry. His interests are very much in the application of this experience to alternative energies and the environmental sector, including nanotube membranes for water treatments.

Recently his research featured on the cover of Science and this brought his work to our attention. In the press release accompanying the article, he promised that a nanotube membrane on a silicon chip would offer a cheap solution for desalinisation. This is something that our coastal cities are most interested in and this is why Jason will be joining the Academy’s High Flyers Think Tank in Adelaide this coming week.

So without further ado, I invite you Jason to talk about Desalinating water Cheaply.

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Jason Holt
(Click on image for a larger version) Thank you very much for that introduction and thanks to all of you for coming here this evening. Thanks also to Sophia Dimitriadis for arranging my visit here.Tonight I will tell you about some of our recent work, our recent discovery of enhanced water transport through carbon nanotubes, and what implications that has for water treatment. What I hope to demonstrate today is that this is one of the areas in which nanotechnology can really benefit the environment. I know that there have been some concerns raised about potential environmental or health consequences of nanotechnology. I hope to show you that water treatment is an area where nanotechnology can really lend itself.I want to acknowledge some of my co-workers within our BioNanoSciences Group at the laboratory – in particular, Hyung Gyu Park who is a University of California Berkeley graduate student who has worked with me closely on this project – and also I want to acknowledge our two group leaders, Aleksandr Noy and Olgica Bakajin.
(Click on image for a larger version) I will start off with some background information about the water shortage problem and present some relevant facts and figures that most of you will probably be familiar with.I will then introduce available desalination technologies, desalination being one of the technologies that can potentially address the water shortage issue.And then I will discuss our concept of a nanoengineered membrane, based on carbon nanotubes, which I think can address many of the shortcomings that conventional membranes, specifically reverse osmosis (RO) membranes, currently suffer from.

I will present some of our preliminary performance data showing how, in principle, implementing these nanoengineered membranes into an existing RO facility could significantly reduce the costs associated with water treatment.

Then I will wrap up my talk and show you where we are intending to go in the future.

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So what is the problem that we are trying to address? This is nicely summarised by the three quotes on this slide. The general theme here is that to us globally, in the 21st century, water is going to be what oil was in the 20th century: a precious commodity. And the key thing to emphasise here when considering water versus oil is that there are a number of viable alternatives to oil but there really is no substitute for fresh water.

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Our fresh water supplies have always been scarce – as you can see, just a very small fraction of the total amount of water on the planet is fresh water – and these supplies are dwindling. It is estimated that, if current projections hold, there will be a huge increase in the number of people around the world facing water scarcity, reaching as high as 18 per cent of the world’s population in the coming decades.

I also want to emphasise that 70 per cent of water usage is for agricultural purposes, often in very water poor areas – I think this is a global figure but the percentages probably look very similar in Australia. A case in point is China, the northern part of the country has two-thirds of the cropland but only has one-fifth of the water.

I myself am relatively new to the water treatment field and I am astounded by some of these statistics.

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So then where should we go for additional water? You see here a list of the various alternatives, prioritised by relative cost.

One obvious choice is water re-use: recycling water from treatment plants and then potentially injecting that into aquifers for later use, or having a dual distribution where you separate out the non-potable water for use in irrigation and other applications where high purity water is not essential.

Next on the list is the treatment of marginally impaired waters. These are water sources that have maybe one or two species in solution, such as nitrate or arsenic, and none of the other impurities that you would have in, say, sea water. Some of the local water supplies in the Bay Area of San Francisco, where I live, are marginally impaired waters because they have high nitrate levels. Because of this, researchers within our Energy and Environment laboratory are developing so-called ‘smart’ membranes that can selectively remove nitrates from solution.

Finally there is desalination of sea water and brackish water, which has a salinity about one-tenth that of sea water. In the US, desalination of brackish water is more prevalent than desalination of sea water, although the US only uses a very small percentage of the total brackish water reserve.

Sea water desalination has not been widespread. This is because of the energy needed to drive water across the conventional low-permeability, reverse osmosis membranes. In fact, energy use is about 50 per cent of the cost of sea water desalination. If we can significantly reduce that energy figure we can potentially make sea water desalination more widespread.

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We have here a list of the conventional desalination technologies that are available.

In reverse osmosis, a saline solution is pressurised, driven across a membrane – which prevents the sodium and chloride ions from permeating – and fresh water is produced.

Another membrane-based technology is electrodialysis. With this technique cation- and anion-selective membranes, along with electrodes, drive the positive and negative ions to opposite sides, producing demineralised permeate.

Another technique, which is commonly used in arid regions like north Africa and the Middle East, is thermal-based distillation, where heat is used to distil the water. Some of that heat is recaptured from vapour condensation.

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So what do the energy figures look like? This graph shows the salinity, for both reverse osmosis and electrodialysis, plotted against the cost in megajoules per cubic centimetre.

Reverse osmosis, as I have mentioned, involves significant energy costs because of the high pressures needed to push the saline water across the membrane. The natural osmotic pressure has to be overcome, and the water needs to be driven across the membrane at significant flow rates: this is very energy intensive.

Electrodialysis suffers from similar problems. The membranes that are used are not very permeable to the ions; they have high resistivity. And electrodialysis is not very efficient except for brackish water. As you can see from the cost curves, at higher salinities, as represented by sea water, RO is the more cost effective alternative.

The thermal methods require significantly higher energy expenses. Theoretically, the minimum amount of energy required to separate water from the saline solution is about 1000 kW per acre foot. The amount of energy needed to distil saline water is 800 times more than that. This is why thermal distillation isn’t plotted on the curve. It is the most energy intensive of all the techniques and is really only suitable in regions like north Africa and the Middle East.

So, I would argue that of these technologies RO – because it can be used across a range of salinities – is the preferred option if we can improve the existing membrane technologies.

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Listed here are the current problems that we face with reverse osmosis membranes, one of which is low permeability. I will show you later, with our concept of nanotube membranes, where we can have the greatest impact is in developing a high-permeability membrane.

Chemical degradation of conventional RO membranes is also a problem. The membranes are susceptible to fouling, which means that it is essential to pre-treat the water. Polyamide membranes can be degraded by chloride ions, which is a problem given that chloride is one of the major ionic species in sea water. Another type of polymer RO membrane, cellulose acetate, is susceptible to degradation when the pH is outside the target range.

I think nanoengineered membranes offer a potential solution to many of these problems, not just in permeability but also chemical compatibility.

So now I’ll tell you about carbon nanotubes and how we are using carbon nanotube membranes to tackle some of these problems.

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For those of you who are not familiar with carbon nanotubes: nanotubes are atomically-smooth, molecule-sized channels. The tubes that we make are of the order of a nanometre (1 nm) in diameter. To offer a size perspective, 1nm is about 50,000 times thinner than a human hair and just a few water molecules in diameter.

The interesting thing is that water behaves very differently when it is confined within a carbon nanotube. This has been simulated for many years but not measured experimentally until very recently. Researchers predict that water forms unique structures within carbon nanotubes, and under the right conditions, it can actually form a one-dimensional chain of water molecules.

Perhaps because of the water ordering that takes place, it has long been predicted that the water would flow extremely fast through the channels. The best real world analogy we can come up with is that the water flow in these channels is like getting the same flow through a garden hose as you would get through a fire hose or a channel that is ten times larger.

On the bottom right-hand side of this slide you see an enhancement of the flow rate, of several orders of magnitude, through these channels. This is what had been predicted but it had not been measured until very recently.

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How can we make a membrane out of carbon nanotubes? How can we take these interesting properties that the individual nanotubes possess and make a membrane that will allow us to test these predictions?

Our fabrication process is illustrated here schematically. I won’t go into all the details but I am happy to answer questions about the particulars at the end of the lecture.

In brief, we start out with a prepatterned silicon wafer. We deposit a thin bimetallic metal layer on the surface and heat it to a high temperature to form nanoparticle ‘seeds’. These serve as the catalytic seeds to nucleate the growth of carbon nanotubes. And because of the high density of these particles, the tubes that then grow from the nanoparticles are vertically aligned. They have a little bit of ‘squiggle’ in them, as is illustrated in this schematic, but the nanotubes do span from top to bottom.

The next step in the fabrication is to deposit a filler material – a matrix material that can fill the tiny gaps between the tubes to allow us to make a stable membrane. For that purpose we use silicon nitride (Si₃N₄). We have also demonstrated vapour-phase polymer deposition between the nanotubes, but for the membranes that I will talk about here we have used Si₃N₄ exclusively.

We coat the nanotubes, use a series of etching processes to open up the channels on either side, and the result is a nanotube membrane where the only pores in the structure are the carbon nanotubes themselves. The 2 x 2 cm square test chip that we made is shown here. I want to emphasise that although thetest chip is extremely small in scale, the techniques that we used are inherently scalable. We are using standard microfabrication techniques that in theory can be scaled up to a size that would be suitable for making a real reverse osmosis membrane.

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I also want to show some microscopy to give you a sense of what the individual nanotubes look like and what the membrane itself looks like. These are transmission electron microscopy (TEM) images of carbon nanotubes. Image A shows bare carbon nanotubes and the inset shows an individual carbon nanotube with an inner channel diameter of less than 2 nm. It was essential to verify the size because the nanotube transport simulations that I mentioned earlier all focused on a regime less than 2 nm in size. Interesting physics happen at that scale and fortunately our TEM expert Yinmin (Morris) Wang went through the images to come up with a size distribution – it turns out that we have an average channel diameter of 1.6 nm.

Image C is a thin slice of the membrane, looking at it down the axis of the nanotubes. We wanted to verify that the only pores in the membrane were the nanotubes themselves and that there were no voids in the Si₃N₄, because we want to focus on transport through the nanotubes exclusively and ensure that there are no cracks in the structure. The bright spots correspond to holes in the membrane, and all the spots circled in yellow are individual nanotubes which have a channel diameter of less than 2 nm.

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But the question is: how does the membrane perform in real life? What are its filtration characteristics? Can we actually filter out particles that are nominally larger than the 1.6 nm channel that we have measured?

So we carried out a series of filtration experiments where the membrane is mounted in a flow cell and placed in a solution of nanoparticles (the nanoparticles are upstream of the membrane). We apply pressure and collect what comes out.

We started out with a solution containing 5 nm gold particles – these particles are about three or four times larger than the pore size – and we saw no evidence that these particles permeated through the structure. This gave us a good indication that there are no large cracks or voids in the membrane.

We then tried smaller particles, at 2 nm – just nominally larger than the nanotube pore size – and again we saw no evidence for passage of these particles through the membrane.

The only species that we saw permeate through the membrane was a 1.3 nm organometallic dye. Again, this gave us a good indication that the membrane is indeed void-free.

As a control, we also looked at a multiwall carbon nanotube membrane. This has a much larger pore size, about 6 to 7 nm in diameter. It also showed filtration characteristics consistent with the measured pore size; allowing 5 nm particles to permeate but not 10 nm gold metal particles.

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After confirming that the membrane was void-free, we wanted to tackle the physics question: what is the flow rate through an individual carbon nanotube? We needed to answer this so we could compare it to the simulation predictions that had been made several years ago. We also wanted to find out how the nanotube pores compare with those of conventional membranes.

We looked at a series of three carbon nanotube membranes, as well as a polycarbonate membrane – a conventional membrane with a pore size about 10 times larger than our nanotubes and the smallest pore size commercially available. I should emphasise, that to quantify the flow rate per nanotube we need to know how many pores are actually open and expanding the membrane structure and being wetted with water. As you might imagine, this is difficult to pinpoint exactly, but we can come up with an upper limit by using the microscopy images that I showed you earlier.

So, going through and counting the number of pores in several different regions, we come up with an extremely high pore density at 250 billion pores per square centimetre. If we use this pore density as our upper limit, it will allow us to come up with a minimum flow rate per nanotube.

We found that the flow rate per nanotube is orders of magnitude higher than what conventional hydrodynamic theory would suggest. By comparison, the polycarbonate membrane that we measured showed only a very slight enhancement.

Another way of trying to capture this is in terms of what is called slip length – I won’t go into the theory or the equations, but the slip length is an indication of how frictionless the flow is: large values would indicate that the flow through the nanotubes is nearly frictionless. This is something that simulations have long predicted, but it is a matter of being able to measure it experimentally on this scale – less than 2 nm. The flow rates that we measured are comparable with what the simulations have long predicted.

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What does the physics of the flow rates mean in practical terms, particularly for membrane developments and desalination?

I have plotted the permeability for the nanotube membranes and compared it with the permeability for conventional polycarbonate membranes. Permeability is what people in the membrane community care about – that is, the volumetric flow rate per unit area, divided by the pressure drop.

As you might expect from the enhanced flow seen through the tubes and the high packing density, we see a significant enhancement in water permeability when compared to conventional membranes – in fact, about a 100-fold higher water transport rate.

As an aside: we also see enhanced flow of gases. I haven’t discussed this because the application that I am focusing on is water treatment, but if anyone is interested in discussing that afterwards I would be glad to.

The take-home message here is: the combination of fast flow and the small pore size suggests that we could use these membranes to significantly lower the energy cost of filtration – nanofiltration or desalination, in this case.

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So how would this carbon nanotube membrane perform in reverse osmosis applications? We worked with systems modellers to ask the question: what effect would this higher-permeability membrane have on a reverse osmosis facility? The schematic of the model is shown here. We consider the feed stream as well as the permeate stream, and then the brine or concentrated stream.

One thing I should mention is that, unlike a real facility where energy recovery takes place in the high-pressure brine stream, we don’t take this into account in the model. But, in terms of showing how the energy costs scale with permeability, the inclusion of the energy recovery is not really important.

This table shows the impact of enhanced permeability on energy costs. For a typical polymer RO membrane permeability is 10-¹¹ m3/m2-sec-Pa. Our nanotube membranes, as I mentioned, are about 100-fold higher. The cost which is shown here is the energy cost of desalinating, in terms of kilowatt/hours per cubic metre. We include here not only the energy costs of operating the pumps to produce the required pressure but also the energy to pump in the water from the source. You can see that a 100-fold higher permeability can reduce the energy costs by more than 80 per cent. So there is potentially a very significant impact on the energy costs of treating sea water.

In this model we fixed the flow rate, but what if you keep the pressure the same, what effect will higher permeability have on energy cost? Another way of looking at the problem is to ask: if we operate at the same energy or same pressure, what effect would that have? And, as you might imagine, from 100-fold higher permeability at the same pressure we would get 100-fold higher flow rate of water through the membrane. Which way a given plant should operate is perhaps not such a straightforward optimisation problem and may depend on the particular peculiarities of that region. But it shows you that, either way, with the high-permeability membrane we can, in principle, have a large impact.

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What does this mean in dollar terms? A way to look at this is the permeate costs per cubic metre. Here we have included both the cost of the membrane and electricity. On the left hand graph we show permeate costs versus membrane area for three curves in order of increasing permeability and we find a minimum in the permeate cost at about 8000 m². In the graph on the right hand side, we took that 8000 m² value and applied it to cost versus permeability and we see a significant reduction in the cost – from about $1 per cubic metre down to 40 cents.

So, in addition to the significant reduction in energy costs, we can reduce the actual dollar cost of treating a given volume of water by about 60 per cent.

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The other question is: what kind of selectivity does this membrane exhibit? It is great to have fast water flow through the tubes, but if we can’t reject salt to any significant level then it is obviously not very useful for desalination.

These are very preliminary data that we obtained just in the last month, but our initial findings are that the membranes show very encouraging salt rejection levels. It is important to note that for these experiments we only do a single pass through the membrane. A conventional RO membrane which you might be familiar with is essentially a spiral-wound membrane around the feed tube, so the water has multiple chances to pass through the membrane structure. In effect, it is like having many membranes in series so in a single pass almost all of the chloride is rejected.

With our membrane, the rejection of sodium is slightly less but, in principle, if we had a number of these membranes in series or, if we formatted it as shown on the right-hand side of this slide, the sodium rejection levels could approach 90 or 95 per cent.

What we don’t know at present is the mechanism: why is the membrane behaving in this fashion? Is there physical size exclusion of these ions from the pores, or is it due to surface charge effects? The initial results suggest surface charge effects dominate, but other experiments that we have performed under slightly different conditions show different rejection characteristics. These results are still very preliminary.

The nanotube membranes have some other properties that I would like to point out. They seem to have inherent antifouling characteristics. They don’t readily clog, and when they do we can regain the original permeability just by briefly washing the membrane with deionised water. There are additional parametric studies we would like to carry out, to see how the rejection characteristics vary with the size of the ion and the effect of pH and ionic strength.

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To conclude: reverse osmosis desalination has long been touted as one of the viable solutions for our water scarcity problem, but there have really been no major developments in membrane technology for decades. I think that is what has made sea water RO economically infeasible. In fact, in the US there is really only one large-scale sea water RO facility that has been built, and it has been tied up in a series of legal and technical problems. In principle, it is supposed to come online later this year. The fact that we only have one such facility in the US highlights that operation of these plants is not economically feasible.

I would offer that the carbon nanotube membranes that we have developed show unprecedented water permeabilities and if they can be scaled up we can significantly reduce energy costs associated with reverse osmosis.

So we are taking a two-pronged approach here. One addresses the issue of scale-up: can we make these membranes on an industrially relevant scale? I think the answer to that is yes because we are using conventional fabrication techniques that are amenable to scale-up.

The other approach is to also tackle some of the science questions. We recently started a project to look at some of these issues, and the main question that we want to tackle is: why are we seeing these transport rate enhancements in nanotubes? Is it a consequence of structural ordering that occurs within the tubes? We don’t know yet, but we will use experimental X-ray based techniques to hopefully answer some of these questions. The science we are doing here is not just for science’s sake but because we think that by answering these questions we can actually design better membranes.

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I would like to acknowledge the intellectual and technical contributions from the people listed here, as well as the three year internal funding we received from our Laboratory Directed Research and Development Fund to get this project to the stage it is at right now.

Thank you for your time, and I would be happy to answer any questions.

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Discussion Kurt Lambeck – Thanks very much, Jason, for a very stimulating and informative talk. Question 1 – Jason, could you go back to your slide entitled ‘What kind of selectivity does a CNT membrane exhibit?’, where you discussed the size of the membrane. You mentioned there that a water molecule was 0.3 nm in diameter. The CNTs were 1.6 nm. That means that the water would go through. But it seems to me that not only the water but also the sodium ions and the chloride ions would go through. The nanotube is much bigger than any of those.
(Click on image for a larger version) Jason Holt – Yes, that’s true. If the membrane was working on the basis of size exclusion alone, we would in principle see no preferential rejection of chloride. But that’s why I made mention of surface charge effects. What may be happening is preferential rejection of ions that are the same charge as the surface of the membrane. That is perhaps the reason why we see such a high level of rejection of chloride relative to sodium.Question 1 (cont.) – So the sodium ions and the chloride ions remain on the surface of the membrane. Don’t they clog it up? Jason Holt – No. On the figures that I mention here, we frequently see preferential rejection of the chloride – most of it still remains in the feed stream, but we only see a small rejection of sodium. So the sodium actually, by and large, can pass through. But over the course of these experiments we haven’t seen significant clogging of the membrane. It seems reasonable to expect some accumulation of those ions near the surface of the pores but we don’t see any reduction in the flow rate, at least over the duration of these experiments that we have carried out.Another thing to mention here, in terms of practical use of this membrane, is that ordinarily you would decide that there is cross-flow occurring, which would really help to prevent accumulation of ions near the surface. We are doing these experiments on the research scale with just a single pass of the membrane, but in practice you would have cross-flow. There are other engineering designs that you can use to minimise the effect of ion concentration near the surface of the membrane.Question 1 (cont.) – The permeate then would have a high sodium ion level?

Jason Holt – Yes. In these initial experiments so far we see high sodium content but a low concentration of chloride.

Question 1 (cont.) – Is it possible to remove that sodium concentration?

Jason Holt – Yes. I think one way of doing that is to change the surface charge on the membrane. So, instead of the membrane having the negative charges shown on the slide, there are simple chemical routes to converting those to positively charged groups. So in practice what we might have is a multilayered membrane: one like the electrodialysis membranes that I mentioned before, where you have alternating cation- and anion-selective membranes so you can achieve rejection of both species.

Question 2 – There has been criticism that the salt by-product will be discharged back into the sea, with environmental effects. Have you had any thought about that process, or is there any way of preventing that salt from being discharged back into the sea?

Jason Holt – As far as I know, the Tampa Bay ecosystem – where the only large-scale sea water RO plant in the US is located – appears to allow for it. But the brine is not being discharged directly. As I understand it, the brine is being diluted by a factor of 50 and then discharged into the Gulf of Mexico. But the environment is something that has to be considered wherever a plant is going to be operated. I am not aware myself of any alternatives to discharge, but I know that is a concern regarding the sea water at really concentrated high-salinity RO facilities.

Question 2 (cont.) – I have another question. You opened with the scarcity of fresh water, and how it is disappearing. There is a school of thought that the amount of fresh water we received at the time when the earth was formed is what we always have, and our use of it doesn’t diminish that supply very much. It is a question of that quantity of fresh water being unevenly distributed around the world: we are not getting any here in Australia while someone else is getting our share. But basically the volume of fresh water remains constant.

This is not your area, I suspect, but I am just wondering whether anyone has any comments about that, and whether or not that in fact is proven – or thought – to be the case.

Jason Holt – I don’t have any insights myself. Does the question relate to the distribution of fresh water?

Question 2 (cont.) – Well, it is not the question of quantity but the question of distribution that we need to tackle. I don’t know how factual that is.

Kurt Lambeck – The total water is more or less conserved but there is no reason why the fresh water should be conserved. Take a case where we just make a mess of all the fresh water we have. I can think of no reason for all of that to be conserved.

Question 3 – Jason, you made mention of the use of Si₃N₄ as the filler material in the carbon nanotube forests. I am aware of other people using organic-based materials, rather than the material that you use. Would you care to comment on the pros and cons of Si₃N₄?

Jason Holt – We started using Si₃N₄ because that was the deposition process available to us. And it turns out that Si₃N₄ actually forms a very conformal coating around the nanotubes. I don’t have the SEM image to show this, but it does a nice job of filling the gaps between the tubes, which is really the key to making it a stable membrane. It is true that for making RO membranes we wanted to go the polymer route, and I had done some preliminary work looking at vapour-phase deposition of polyimide and parylene. It turns out parylene might be the best choice. It is very resistant to chemical degradation and you can actually reflow parylene at extremely high temperatures, up to 300 or 350°C. So that might be the route that we take in the future – use the same process but with polymer deposition and, essentially, make a flexible nanotube membrane.

Question 4 – Do you need the matrix material? Could you pack the tubes together to allow the water to flow around the outside of the tubes?

Jason Holt – It’s a good question. Our feeling is that the flow rate enhancements that we see are unique to the interior of the nanotube: flow through the interior of the nanotube is not necessarily going to be the same as the flow between a bundle of nanotubes. That’s part of the answer.

The other, I think, is an issue with the fragility of the membrane. Even a densely packed bundle of nanotubes with no filler material in between them is extremely fragile. You can easily tear a densely packed bundle of nanotubes. So for practical reasons I think we have to use a matrix material approach.

Question 5 – Just following on from those last two questions about the membrane: I was wondering, as a consumer of desalinated water, what might happen if I swallowed a bit of your membrane. Would there be a risk from ingesting a nanotube?

Jason Holt – That’s another good question. I think a lot of the health concerns about nanotubes, and other nanoparticles for that matter are about free nanoparticles or nanomaterials in solution – and in the United States there are a number of projects looking into health effects in nanotechnology. With this structure here, in particular the nanotubes are firmly embedded in the membrane; they are not free to move. Unless we are working at extreme pressures where we can actually fracture the membrane – which we are not currently doing and it’s not how we would be operating these membranes in a plant – I think there’s minimal concern with respect to the nanotubes becoming dislodged and getting into the water supply.

Question 6 – Jason, you’ve got the membrane there; on a single pass you’ve got the negative surface charge, so presumably that would retain the sodium; and then you’d have to have the second pass, which would be positive charge and would repel the chloride ion. How do you put these charges on the membrane? You would have to have some dialysis system, or how do you do that?

Jason Holt – This would be done by changing the surface chemistry. We don’t know this for certain, but most likely the negative surface charge on the membrane is due the presence of acid groups – you have carboxylic groups on there, COO- – and with that kind of surface charge there are easy chemical routes to switch that over to a positively charged group, something like an amine group or a basic group. Although we haven’t done that yet, I don’t think it’s a huge barrier to alter the surface chemistry to make a membrane that will reject cations.

Question 6 (cont.) – So you have to have two passes?

Jason Holt – Yes, that’s what I think. I think that in practice, unless you can make a membrane with pores that are so small that you’ll be able to reject both species just on the basis of size, it’s going to be hard to make a membrane that will achieve similar rejection levels for both positive and negative ions. I think that practically speaking it may be easier to adopt a multi-layered approach.

Question 7 – How long do you think it will be before the technology you have been discussing becomes, if not everyday, at least usable?

Jason Holt – That’s a good question and one we often get. I think it depends on the kind of investment and partnering that we do with companies. There has been a lot of interest in the States from some of the big water treatment companies like GE and Culligan. They have contacted us and are interested in scale-up and commercialisation of the technology. If we get their involvement, a five-year time line will probably be overly optimistic – it’s more likely to be 10 years.

Question 8 – If I might just briefly get to the gas filtration properties of your membranes: I read in your paper in Science that there was a differential selectivity between carbohydrate and non-carbohydrate gases. I wasn’t exactly sure whether that meant that the carbohydrate gases were preferentially passing through the membrane or whether it was the other way around.

Jason Holt – In addition to higher transport rates for all gases, we also see an enhancement of the overall flow rate, with preferential diffusion of hydrocarbons, if you look at C1 through C5 – methane, ethane, all the way up to pentane. We actually see an enhancement in the transport of those gases, compared to what conventional diffusion theory would predict. And it kind of makes sense, based on what is out there in the simulation literature. One idea is that, because of the similarity in structure between a hydrocarbon molecule and the nanotube surface, it may be that these gases actually adsorb onto the nanotube surface and then can diffuse along the surface, as opposed to simply bouncing off the nanotube walls, so to speak. In addition to the water experiments we are also doing some more detailed measurements to try to better understand the gas transport mechanism, because at this stage it is still speculation as to why you see the enhancement in hydrocarbon diffusion.

Question 8 (cont.) – It could also be that it has got more intimate interaction with the carbon nanotube inside. It seems that it is slipping through more easily.

Jason Holt – Yes, that is a possibility.

Question 9 – I am just wondering what awareness you have of interest or understanding by water supply authorities or industry in Australia in relation to this technology. What sort of understanding or interest is there in Australia?

Jason Holt – We haven’t been contacted, at least in the past few months, by anyone regarding the technology, although we had a discussion today with Ken Matthews from the National Water Commission and he seemed very interested in the technology.

Question 10 – Jason, I gather from some of the acronyms in your earlier slides that these are double-wall nanotubes. How tight is the control over that? Are they all double-wall, or do you have some single and some multiwall mixed in?

Jason Holt – I glossed over that subtlety because for the purposes of making the membrane all we really care about is the innermost tube. But in reality, the tubes that we are making are, essentially, concentric single-wall tubes. From what we have seen in TEM – of course, it’s hard to get statistics on these things – we have counted about 500 of these tubes and looked at different regions in the TEM, and they all appear to be double-wall tubes with the size distribution that I showed earlier – about 1.5 nm inner diameter and the size cut-off is at about 2 nm. We don’t see any diameters larger than that.

The way we can control that is by tailoring the thickness of the catalyst layer. We are using, as I mentioned in the paper, an iron and molybdenum catalyst layer supported on aluminum, and by adjusting the thicknesses of these catalyst layers we can in turn affect the size distribution of the nanotubes. In fact, just recently we have been able to make similarly structured single-wall nanotubes – we found a recipe that allows us to make this same kind of membrane but comprising single-wall tubes, also vertically aligned and have a slightly smaller pore size – 1.3 to 1.4 nm instead of 1.6 nm.

Kurt Lambeck – Thank you very much, Jason. This has been a very nice example of how basic science can be put to good practical use. I wish some of our masters were present to hear that. Thank you very much.

Jason Holt – Thank you.

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GE Global Research and Texas Tech University announced this week that they are teaming up to work on another kind of desalination/energy combo.

GE to Develop Wind-Powered Water Purification

November 29, 2006

NISKAYUNA, NY — GE Global Research, the centralized research organization of the General Electric Company, today announced it is partnering with Texas Tech University to develop affordable water desalination systems to increase the quantity and quality of clean water available in arid areas around the United States and globally.

The GE-Texas Tech partnership will focus on the integration of renewable energy systems, such as wind turbines, with membrane desalination processes. The development of the integrated renewable energy-water system has the potential to significantly reduce the cost of creating new sources of freshwater from impaired resources, such as brackish water, by directly addressing the major component of operating cost of desalination systems – energy.

Again, notice that while there’s not much money available for desalination research–there’s plenty available for energy research.

The partnership is part of GE’s company-wide ecomagination initiative, in which GE has pledged to more than double its level of investment in the development of cleaner energy technologies, from $700 million to $1.5 billion, over the next five years.

btw why did GE choose Texas and why wind energy?

The answer is that Texas has recently become the largest wind energy producer in the USA with more soon to come online:

Texas has mandated that at least 5,880 megawatts of energy used in the state come from renewable-energy sources by 2009 and 5,000 more megawatts by 2015.

By the numbers

2,700 Megawatts of wind energy that could be added to the Texas grid by the end of 2007.

2,631 Megawatts of wind energy currently operating in Texas.

2,044 Turbines currently in Texas.

Top wind-energy states

1. Texas

2. California

3. Iowa

SOURCES: ERCOT, American Wind Energy Association

Wind power is expected in 2006 to provide 18% to 20% of the new capacity installed in the country — making it the second-largest source of new power generation after new natural gas plants according to the Energy Information Administration.

wind energy is one of the most economical forms of utility-scale renewable energy available, with a “bus bar” price (which does not include transmission and distribution costs) of 3 to 6 cents per kWh at good wind sites.

By contrast, power generated by oil-, gas- and coal-powered plants feeding into the PJM Interconnection — the grid operator covering most of the country from the Hudson River to the Chicago area and as far south as North Carolina — costs 2 to 3 cents a kilowatt-hour, the report said. PJM supplies power to 51 million customers.

Also, as I’ve mentioned before west Texas has a lot of brine aquifers below the windy desert that could see some benefit from desalination. These aquifers are currently being tapped by gas drillers. In some places the water used for drilling is being recycled and desalinated. These might also be good places for greenhouses.

 

 

 

This week, let’s take a more in depth look at using greenhouses to tap oceans or briny aquifers to produce desalinised water and energy.

Several weeks back I posted about a British Company that used greenhouses for water desalination to produce high value fruits and vegetables. Another thing those green houses could produce is biocrude/biodiesal from algae. Why?

Consider this from Wikipedia.

Oil Yield

• Cultivating Algae for Liquid Fuel Production (http://oakhavenpc.org/cultivating_algae.htm)

Gallons of Oil per Acre per Year

Corn . . . . . . . 18

Soybeans . . . .48

Safflower. . . . . 83

Sunflower . . . 102

Rapeseed. . . 127

Oil Palm . . . . 635

Micro Algae . .5000-15000

The yield from oil bearing algae per acre is many orders of magnitude higher than the yield of ethanol from corn. Say the algae produces 10,000 gallons of biodiesel@acre. If the producer can get $1@ gallon of biodiesel then there’s $10,000@acre. Work is underway to improve the oil yields of the algae. There is reason to believe that in the future yields can be increased to 50,000 gallons of biodiesel@acre (and $50,000 revenue@acre).

Current estimates of costs are sketchy. According to this April 2005 report:

These estimates showed that algal biodiesel cost would range from $1.40 to $4.40 per gallon based on current and long-term projections for the performance of the technology.

Researchers in Utah say their algae-biodiesel will be cost competitive by 2009.

(Update:

Tasios Melis, a professor of enzymology at the University of California at Berkeley, has created genetically modified strains of algae that speed growth rates of naturally occurring algae and increase its hydrocarbon content, which could boost the biodiesel yield of bioreactors from 10,000 gallons per acre to 20,000 gallons or more. Melis originally developed the supercharged algae as a way of improving the harvest of hydrogen as a fuel source, and he believes its long-term benefits are greatest in developing clean-burning hydrogen as a ubiquitous energy source. But Melis says genetic information on hydrogen production could enable development of algae for specific types of fuel.”The potential is really superior to natural algae,” Melis says. “It is essentially a problem of biology, but we have a blueprint and I’m confident it can be done.”) End of update.

Consider a joint project of the DOE San Dia Labs and LiveFuels Inc. They aim to convert algae-to-oil. I mentioned they could also desalinize briny aquifers in greenhouses in West Texas or New Mexico while turning algae-to-oil. — There might be a market for salt and minerals as well. (I’ve been salting my eggs & oatmeal in the morning with smoked applewood flavored salt I bought from that Maine company I mentioned a couple weeks back. Its pretty good.)

Before I go further down the algae-to-oil path it should be noted that a couple years from now solar photovoltaic plastic will be available which could cost effectively be used in greenhouses. As well, sunlight could be used for water splitting.

Nanotech-based photoelectrochemical materials could lower the cost of hydrogen production “somewhere between a factor of 4 and 10,”

But that’s likely even further in the future. The most interesting currently available solar tech is this pairing of an efficient solar dish with a 200-year-old Stirling engine design. This solar plant is going up in the Mohave Deserts of Southern California. These plants will produce electricity at or below the costs of coal powered plants. A scaled down version of this might be used to pump water in the desert–but it might be more expensive.

The advantage of working with solar is that there is plenty of capital available that’s looking for tax advantaged opportunities. As well, a number of major counties in California have served notice to their coal fired electrical generating plants–they will not be renewing their contracts in…2027.While that date is far in the future, the push is on for lowering carbon emissions worldwide. One way to reduce carbon emissions would be to pump carbon dioxide into the British greenhouses — filled with algae — mentioned above that used desalinised water pulled from the underground aquifers of West Texas. FutureGen is currently working on a coal gassification project around Odessa that uses waste heat for desalination. The idea currently is to pump the carbon dioxide into the ground–so that at some point — the extra pressure will enable more oil extraction. Perhaps a better way to use the carbon dioxide would be to pump it into greenhouses filled with green algae. As well, underground brine water could be pumped into the greenhouses and where it would be desalinated to water the algae.

In fact, some tests in arizona currently are moving from large test tubes to a greenhouse environment:

The Arizona power plant project includes putting algae in tubes as part of the biodiesel production process.

For a year, researchers watched algae multiply in huge, bubbling test tubes beneath the hot Arizona sun so they could find just the right strand of the microscopic single-celled plant.

The experiment has been so successful that it’s about to expand into greenhouses on the plant grounds, and in time, be grown in such large quantities that it could be converted into fuel, cutting down on harmful greenhouse gases.

The new thing here to understand is not that the algae-to-oil angle. Algae-to-oil is being tested extensively already. The company doing the work above is an MIT associated company called GreenFuel .

GreenFuel has already garnered $11 million in venture capital funding and is conducting a field trial at a 1,000 megawatt power plant owned by a major southwestern power company. Next year, GreenFuel expects two to seven more such demo projects scaling up to a full pro- duction system by 2009.

Rather, the new thing that I’m suggesting here is that LiveFuels/GreenFuel — technology be wedded to the British Greenhouses to produce oil and desalinised water.

Update: Additional profits could be garnered by way of carbon credits that are gaining traction worldwide. ie when coal plants take carbon dioxide out of their waste–these credits can be resold. Here is how Wall Street is doing this now.
That said, the problem I could see with the greenhouses might be that it would be expensive to clean out their salt accumulations.

One way to reduce the problem of salt cleanup in the greenhouses would be to jury rig a cheap low tech solution for desalination using the efficient solar dish with a 200-year-old Stirling engine mentioned above and Aquasonics technology.

At the heart of the Aquasonics technology is a special nozzle that breaks water into a very fine mist. This mist is then hit with hot air. The steam rises where its cooled and collected and the salt falls to the floor where its collected and easily moved. Aquasonics has been using waste heat from power plants as a heat source. But it would be relatively simple and cheap to aim the solar dishes mentioned above at two black boxes. One black box heats brine or salt water to pressurize it for expulsion through the nozzle — and one black box heats the air used to blast the nozzle spray from the water box.

Anyhow here is a full list of algae-to-oil companies.

According to Michael Briggs, University of New Hampshire, Physics Department — a 250 acre algae farm producing 10,000 gallons@acre could produce oil for $18.56@barrel. And with a net profit of .10 the farm could yield $250,000 per year net earnings.

So the idea is to add pure clean water to the output of the already profitable mix.

Additional algae links:

Fatty acids & Hydrocarbons (oil) and liquid fuels

More algae candidates for high lipid yields

Reef Algae Web Site or http://www.botany.hawaii.edu/reefalgae

The Phycological Society of America http://www.psaalgae.org (most of the following links came from this page)

Guide to Pressing Seaweeds http://www.cryptogamicbotany.com/lm_press_seaweed.html

Desmid website (www.desmids.nl)

AlgaeBase website – information on taxonomy of all algae (http://www.algaebase.org)
Portuguese Seaweeds Website – Portal das Macroalgas Portuguesas (http://www.uc.pt/seaweeds)
PISCO Marine Algae Database: an online collection of images (http://www.piscoweb.org/cgi-bin/qml/newalgaequery.qml)
Desmid Information, including beautiful photos (http://www.desmids.info/)
Algae associated with sea turtles in Hawaii (http://www.turtles.org/limu/limu.htm)
The Phytoplankton Image Library (http://www.cedareden.com/phyto.html) by Michael R. Martin
The Latz Research Laboratory with information on dinoflagellates and bioluminescence (http://siobiolum.ucsd.edu/)
The International Research Group on Charophytes with information on living and fossil charophytes (http://www.life.umd.edu/labs/delwiche/Charophyte.html)
A Checklist of Fijian marine algae (http://www.usp.ac.fj/marine/fijilist.htm)
Jeremy Pickett-Heaps’ web site for Cytographics with information on algal videos, preparation of live cells, etc (http://www.cytographics.com)
Web-based
multimedia course entitled “A phylogenetic survey of photosynthetic
organisms” focusing mainly on algae by Derek Keats (http://kewl.uwc.ac.za/)
Algal Images (especially diatoms) from Rex Lowe’s lab (Bowling Green University) (http://www.bgsu.edu/Departments/biology/algae/index.html)
Great Lakes Diatom Home Page (http://www.umich.edu/~phytolab/GreatLakesDiatomHomePage/top.html)
Algal images for teaching and ecological data from southeastern Ohio from Morgan Vis’ lab (Ohio University) (http://vis-pc.plantbio.ohiou.edu/algaeindex.htm)
Smithsonian
Institution Algae Web page with information on algae in general, recent
publications, how to preserve algae and herbarium collections (http://www.nmnh.si.edu/botany/projects/algae)
The University of California Museum of Paleontology with general information: Green Algae (http://www.ucmp.berkeley.edu/greenalgae/greenalgae.html), Chromista (http://www.ucmp.berkeley.edu/chromista/chromista.html), Red Algae (http://www.ucmp.berkeley.edu/protista/rhodophyta.html), and Dinoflagellates (http://www.ucmp.berkeley.edu/protista/dinoflagellata.html)
Mike Guiry’s seaweed page (http://www.seaweed.ie)
CYANOSITE with information on Cyanobacterial research (http://www-cyanosite.bio.purdue.edu/index.html)
The Harmful Algae Page with photographs, news stories and information (http://www.redtide.whoi.edu/hab/)
ECOHAB: Florida – Ecology and Oceanography of Harmful Algal Blooms (http://floridamarine.org/features/view_article.asp?id=9024)

Dang. I was working on nice thoughtful post on the relationship between water and energy across a range R&D projects. Sounds good? I brushed it aside. Why? ANOTHER big breaking bit of nanotube news hit the wires. Get this. Scientists at UC Berkeley & Lawrence Berkeley National Labratory have figured out how to alter the diameter of individual carbon nanotubes … at will!

Alex Zettl and colleagues at the University of California, Berkeley and the Lawrence Berkeley National Laboratory say carbon nanotubes’ ability to conduct electricity and other electrical and mechanical properties depends heavily on their size. However, current methods for making CNTs cannot reliably control nanotube diameter, making it more difficult to fabricate devices from nanotubes.

“We have developed a method to shrink individual nanotubes to any desired diameter,” the researchers report. “The process can be repeated in a highly controlled fashion, yielding a high-quality CNT of any pre-selected and precise diameter.”

The method, involving a high-temperature that shrinks regular-sized CNTs and reforms them into high-quality tubes of a smaller diameter, is to be detailed in the Dec. 13 issue of the journal Nano Letters.

	Image: COURTESY OF TOM YUZVINSKY
	SEE HOW THEY SHRINK: A computer-generated images of the process for shrinking nanotubes.

Think this could be used to create a carbon nanotube shrunk to the diameter of H20? Think this might be a boost for desalination?

Give that carbon nanotube the right charge and you could do some serious seperations. Heck, you might not even have to consider charge. The researchers even claim that they can automate the process.

Anyhow, this looks to be another cool tool for the toolkit.

Speaking of the relationship between energy and water…a smaller diameter membrane created by the above process — could as well be used to sort out hydrogen in carbon reformation or various thermal depolymerization processes.

Also this, week a group of chemists at Rice University figured out how to grow carbon nanotubes.

    Rice University chemists today revealed the first method for cutting carbon nanotubes into “seeds” and using those seeds to sprout new nanotubes. The findings offer hope that seeded growth may one day produce the large quantities of pure nanotubes needed for dozens of materials applications.

In more nano news NASA’s Goddard Space Flight Center says they have developed a cheap way to make carbon nanotubes that are either conducting or semiconducting.

Goddard researchers Drs. Jeannette Benavides and Henning Leidecker developed a simpler, safer, and much less costly process to make these carbon nanotubes. The key was that they figured out how to produce bundles of these nanotubes without using metal, which reduced the costs tremendously and made a better quality product.

They’ve already lisenced the procedure to a company in Idaho that’s making products.

Earlier this year, NASA Goddard licensed its patented technique for manufacturing these high-quality “single-walled carbon nanotubes” to Idaho Space Materials (ISM) in Boise, Idaho. Now the carbon nanotubes based on this creation process are being used by researchers and companies that are working on things that will impact almost every facet of life, such as new materials with ceramics and polymers.

Maybe next week I’ll do that piece on energy and water.

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