07 February 2008

Peak Oil: Meet Moorella and Her Friends

Bioethanol has the inside track in the race for sustainable alcohol biofuels. While those of us who are salivating for the development of economical bio-butanol processes will have to wait, the race for the best bio-ethanol process is shaping up nicely. The current dark horse is Zeachem, the California startup that is using moorella thermoacetica--the termite gut microbe--to convert cellulose to acetic acid (acetate), then on to ethanol. The hybrid process is illustrated above.
The process can yield 50 percent more ethanol from a given amount of biomass than conventional processes. The net energy ratio of biofuel produced this way is between 10 and 12, compared with first generation biofuels like corn ethanol, which come in at around 1.5. The new net energy ratio benchmark radically changes any biofuel policy debate....The company has demonstrated the new method in a laboratory setting and is now drawing up plans for an ethanol plant that will produce about two million gallons of ethanol a year. Construction could begin as early as this year, says Dan Verser, a founder and vice president of research and development at ZeaChem.

...ZeaChem replaces yeast with a type of bacteria called Moorella thermoacetica, which can be found in a number of places in nature, including termite guts and the ruminant of cows, where it helps break down grass. Instead of making ethanol and carbon dioxide, the bacteria convert sugars into a component of vinegar called acetic acid, a process that releases no carbon dioxide....To convert acetic acid into ethanol, ZeaChem turns to chemistry. First, the company's researchers convert the acid into a common solvent called ethyl acetate - something that chemists have long known how to do. The final step - making ethanol - requires adding energy to the system in the form of hydrogen.___More details at Source___
The frontrunner in competition with Zeachem is Coskata, which claims to be in a position to produce US $1 a gallon bio-ethanol by 2010.
Using patented microorganisms and efficient bioreactor designs, Coskata uses a unique three-step conversion process that turns virtually any carbon-based feedstock, including biomass, municipal solid waste, bagasse, and other agricultural waste into ethanol (schematic, click to enlarge). The technology is globally applicable. The process is environmentally sound, reducing carbon dioxide emissions by as much as 84 percent compared to gasoline, as well as generates up to 7.7 times as much net energy as is required to produce the ethanol, according to Argonne National Laboratory____Source
The Coskata process is illustrated in the graphic below:
Both ethanol processes above involve multi-step hybrid processes to yield between 7.7 times and 10 times the energy consumed in the process. Compare those yields to the 1.5 times input from maize (corn) bio-ethanol. Maize is not even in the running.

Finally, there is the algal biodiesel/bio-alcohol hybrid process from Green Star Products, Inc.
First generation algae production can produce 4,000 gallons of oil per acre per year (versus 50 to 100 gallons for other oil crops) and later generations will produce 10,000 gallons or more per acre.”___Green Star
Some of the claims should be taken with a grain of salt, but eventually science will unlock the promise of abundant energy from biology. Whether the key production breakthroughs will occur within 5 or 10 years, the actual high volume production of quality biofuels should occur within 20.

If the newer in situ processes for producing oil from shales and tar sands pay out, there is enough liquid fossil fuel to power world industry for approximately 100 to 200 years. We should not depend on those promises, but conventional oil yields alone should be sufficient for 30 years at current consumption. If prices go too high, economies will slow and consumption will go down. Price drops will follow reduced demand. It is a cyclic process, with negative feedbacks.

Biofuels are scalable far above current projections. Earth's biosphere is extremely expandable and contractible. But it is unlikely that biofuels will be the main long-term solution to human energy needs. Transportation is another story, but aside from aircraft, alternatives to liquid fuels and solid fossil fuels will probably take over within 50 years.

Electricity can drive automobiles, and other forms of transportation aside from aircraft. Electric power is versatile, and better methods for producing electricity are being developed on an almost daily basis.

Nuclear fission energy will provide a necessary bridge to nuclear fusion energy, large scale geothermal, and massively interconnected renewable energy power grids (HVDC HT superconductor transmission interconnect) of much improved reliability and stability. Utility scale storage (eg redox flow cells) will provide further stability.

De-centralised production and storage of energy will also become more economical and feasible, for those living "off the grid." Residential renewable energy generators (wind, solar, neo-bio etc) paired with both electrical storage and fuel cell backups, should provide remote haciendas with clean, safe, reliable power.

The long term goal is technology that allows humans to roam the solar system and beyond, carrying with them all they need for life support and other needs for thriving in the universe.

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