Biotreibstoff – nur Skandal oder auch Chance?
30.April 2008
Mais in riesigen Mengen wird mit rasanten Wachstumsraten zu Treibstoff verarbeitet – mit skandalösen Folgen für die Lebensmittelpreise. Die Ärmsten hungern, weil die Reichsten ihre überdimensionierten Tanks scheinbar umweltfreundlich füllen wollen. Mit Recht formiert sich Widerstand gegen diesen Unsinn.
Anders wäre es, wenn der Sprit aus Algen hergestellt würde, die in Wüstengegenden gezüchtet werden könnten. Genau das ist das Ziel einer Start-up Firma in Vancouver. Das Bild zeigt Glen Kertz, den Präsident dieser Firma vor seiner Versuchsanordnung.
Photo: Valcent Products
Der Prozess arbeitet kontinuierlich. Mit Algen versetztes Wasser zirkuliert zwischen unterirdischen Tanks, in denen CO2 zugesetzt wird und den gezeigten Plastikgefässen, in denen die Algen vom Sonnenlicht bestrahlt werden. CO2 und Sonnenlicht ist es was die Algen zum Wachsen brauchen. Ab einer gewissen Algendichte wird der Zuwachs laufend geerntet.
Kertz extrapoliert, dass sein Verfahren 48 000 l Treibstoff pro Hektar liefern kann, gegen nur 40 l beim Mais. Ein weiterer Vorteil ist der praktisch geschlossene Wasserkreislauf. Mit aus Mais gewonnenem Treibstoff ist hingegen ein exzessiver Wasserverbrauch verbunden: 3500 Liter Wasser pro Liter Biosprit.
Extrapoliert man noch weiter, dann würde mit diesem Verfahren ein Zehntel der Fläche von New Mexico genügen, um den gesamten Treibstoffverbrauch der USA zu erzeugen. Das ist natürlich eine verfrühte Zukunftsspekulation aber die Experten sind sich einig, dass nichts Grundsätzliches gegen diese Vision spricht.
Über die Kosten werden noch keine Angaben gemacht. Der Prozess und die verwendeten Materialien weisen aber auch diesbezüglich in eine praktikable Richtung. Trotzdem wird der Treibstoff vermutlich deutlich teurer sein als das heutige Niveau. Treibstoffeinsparungen werden deshalb auch unter dieser Perspektive zwingend nötig sein. Und damit sollte sofort begonnen werden – anstelle des unsinnigen Biotreibstoffs aus Mais.
Nähere Angaben zu diesem Prozess finden sich im IEEE Spektrum.
Autor: Klaus Ragaller
Artikel gespeichert unter: Klima
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1. Prof. Hans-Jürgen Franke - CTO La Wahie Biotech - Brasil | 16.September 2008 at 13:38
ETHANOL-PRODUCTION WITH BLUE-GREEN-ALGAE
University of Hawai’i Professor Pengchen “Patrick” Fu 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, he said.
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 UH in January, 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 headquarter in Hawaii and branch-office in Brazil.
PLAN FOR AN EXPERIMENTAL ETHANOL PLANT
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.
He 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. That would prevent carbon dioxide release into the atmosphere, where it has been implicated as a
major cause of global warming.
Honolulo – Hawaii/USA and Aracaju – Sergipe/Brasil – 15/09/2008
Prof. Pengcheng Fu – E-Mail: pengchen2008@gmail.com
Prof. Hans-Jürgen Franke – E-Mail: lawahiebiotech.brasil@gmail.com
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