Ethanol & Water

In previous posts we’ve expressed concern – to put it mildly – over the role emerging biofuel markets are having in accelerating tropical deforestation. In our posts “Deforestation and Global Warming,” “Biofueled Ethanol,” “Reforest the Tropics,” “IPCC 2007 & Deforestation,” “Is Biofuel Carbon Neutral?,” “Biofueled Global Warming,” and many others, we make the case that tropical deforestation is the most significant cause of desertification and droughts on earth, it is a major cause of extreme weather, and, along with other changes in land use, may actually have as much or more to do with global warming than industrial CO2 emissions.

Now we have a story in the St. Louis Post, dated April 15, 2007, entitled “Ethanol Plants Come With Hidden Costs: Water,” which surveys the impact ethanol refineries may have on fresh water supplies. Here’s an excerpt:

“The ethanol industry says it takes about 3 gallons of water on average to produce a gallon of ethanol and that recycling and other water-saving innovations will reduce that amount. Sometimes that consumption is understated: In Minnesota, one of the few states that require reporting of water use, a state study in 2005 found that ethanol plants used an average of 4.5 gallons for every gallon of ethanol. The water drawn for ethanol is a cost borne by communities — or whole regions — and a price sometimes ignored in the planning stages for new plants, experts say.”

Not mentioned in this story, of course, is the cost in water to irrigate the corn to produce the feedstock – the 3.0 to 4.5 gallons of water required for ethanol refining doesn’t include the water required to grow the corn, and corn is a relatively water-intensive crop.

Another cause of global warming we believe to be grossly understated to-date by climate scientists is the impact of depleted water tables, which increases the thermal conductivity of any land where the water tables have dropped significantly. Notwithstanding the potential global warming impact of depleted aquifers, the health of aquifers is an important and under-recognized factor influencing general environmental health, imperiling springs that feed aquatic ecosystems, as well as supplies of water for people. And often once these aquifers are depleted too much, it becomes difficult if not impossible to replenish them.

Ethanol proponents have correctly debunked the notion that ethanol is not energy-positive. While not as energy-positive as sugar cane, corn ethanol does embody more energy than is required to make it. But the impact of ethanol production on land use, the impact of ethanol production on water consumption, and the impact of ethanol production on water tables and aquifer health is not sufficiently understood.

Many forms of ethanol and biofuel production in general are very promising – but environmentalists are way behind in developing proper certification for biofuel crops, and as a result, for now it is probably accurate to say that biofuel mania is doing more harm than good to our global environment.

Categorized | Consumption, Energy, Other, Recycling
3 Responses to “Ethanol & Water”
  1. Prof.Hans-Jürgen Franke & Prof. Pengcheng Fu says:

    Ethanol from blue-green algae: University of Hawaii Professor Pengchen “Patrick” Fu has developed an innovative technology to produce high amounts of ethanol with modified cyanobacterias, as a new feedstock for ethanol, without entering in conflict with the food and feed-production.

    Fu has developed strains of cyanobacteria — one of the components of pond scum — that feed on atmospheric carbon dioxide, and produce ethanol as a waste product.

    He has done it both in his laboratory under fluorescent light and with sunlight on the roof of his building. “Sunlight works better,” said Fu.

    It has a lot of appeal and potential. Turning waste into something useful is a good thing. And the blue-green-algae needs only sun and wast- recycled from the sugar-cane-industry, to grow and to produce directly more and more ethanol. With this solution, the sugarcane-based ethanol-industry in Brazil and other tropical regions will get a second way, to produce more biocombustible for the worldmarket.

    The technique may need adjusting to increase how much ethanol it yields, but it may be a new technology-challenge in the near future.

    The process was patented by Fu and the University of Hawaii in January 2008, but there’s still plenty of work to do to bring it to a commercial level. The team of Fu foundet just the start-up LA WAHIE BIOTECH INC. with headquarters in Hawaii and branch-office in Brazil.


    Fu figures his team is two to three years from being able to build a full-scale
    ethanol plant, and they are looking for investors or industry-partners (jointventure).

    He is fine-tuning his research to find different strains of blue-green algae that will produce even more ethanol, and that are more tolerant of high levels of ethanol. The system permits, to “harvest” continuously ethanol – using a membrane-system- and to pump than the blue-green-algae-solution in the Photo-Bio-Reactor again.

    Fu started out in chemical engineering, and then began the study of biology. He has studied in China, Australia, Japan and the United States, and came to UH in 2002 after a stint as scientist for a private company in California.

    Fu is working also with NASA on the potential of cyanobacteria in future lunar and Mars colonization, and is also proceeding to take his ethanol technology into the marketplace. A business plan using his system, under the name La Wahie Biotech, won third place — and a $5,000 award — in the Business Plan Competition at UH’s Shidler College of Business.
    Daniel Dean and Donavan Kealoha, both UH law and business students, are Fu’s partners. So they are in the process of turning the business plan into an operating business.

    The production of ethanol for fuel is one of the nation’s and the world’s major initiatives, partly because its production takes as much carbon out of the atmosphere as it dumps into the atmosphere. That’s different from fossil fuels such as oil and coal, which take stored carbon out of the ground and release it into the atmosphere, for a net increase in greenhouse gas.
    Most current and planned ethanol production methods depend on farming, and in the case of corn and sugar, take food crops and divert them into energy.

    Fu said crop-based ethanol production is slow and resource-costly. He decided to work with cyanobacteria, some of which convert sunlight and carbon dioxide into their own food and release oxygen as a waste product.

    Other scientists also are researching using cyanobacteria to make ethanol, using different strains, but Fu’s technique is unique, he said. He inserted genetic material into one type of freshwater cyanobacterium, causing it to produce ethanol as its waste product. It works, and is an amazingly efficient system.

    The technology is fairly simple. It involves a photobioreactor, which is a fancy term for a clear glass or plastic container full of something alive, in which light promotes a biological reaction. Carbon dioxide gas is bubbled through the green mixture of water and cyanobacteria. The liquid is then passed through a specialized membrane that removes the ethanol, allowing the water, nutrients and cyanobacteria to return to the photobioreactor.

    Solar energy drives the conversion of the carbon dioxide into ethanol. The partner of Prof. Fu in Brazil in the branch-office of La Wahie Biotech Inc. in Aracaju – Prof. Hans-Jürgen Franke – is developing a low-cost photo-bio-reactor-system. Prof. Franke want´s soon creat a pilot-project with Prof. Fu in Brazil.

    The benefit over other techniques of producing ethanol is that this is simple and quick—taking days rather than the months required to grow crops that can be converted to ethanol.

    La Wahie Biotech Inc. believes it can be done for significantly less than the cost of gasoline and also less than the cost of ethanol produced through conventional methods.

    Also, this system is not a net producer of carbon dioxide: Carbon dioxide released into the environment when ethanol is burned has been withdrawn from the environment during ethanol production. To get the carbon dioxide it needs, the system could even pull the gas out of the emissions of power plants or other carbon dioxide producers.
    Honolulo – Hawaii/USA and Aracaju – Sergipe/Brasil – 15/09/2008

    Prof. Pengcheng Fu – E-Mail:
    Prof. Hans-Jürgen Franke – E-Mail:

    Tel.: 00-55-79-3243-2209

  2. Ed Ring says:

    The thermal content of lands where aquifers have been depleted and water tables have fallen is a grossly under-researched area of climate science. Perhaps we need to desalinate simply to recharge aquifers and raise water tables, which in-turn would cool the earth. Virtually all the aquifers on the 10+ million square miles of farmland and grazing land on earth are depleted – and the water flow from these aquifers needs to turn negative, and we need to fill them up again – with water, not CO2.

  3. Derek Petrie says:

    when water is removed from the ground either the soil shrinks or the water is replaced by air which has a far lower thermal conductivity than water. Which way is the heat going into the ground or from the middle of the earth into the atmosphere?
    With reference to water usage.From what you write one would assume that the water disappears. It is transferred ( to be evaporated to come down as rain) Some the figures quoted as usage is used as a cooling media in heat exchangers and the heated water in turn cooled in cooling towers by evaporation. More rain some where. You need to carry out a deeper analysis of figures quoted in the media, who in my experience never get things right!


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