Daniel Gibbs’s Recent Comments

• Click here to view comment in original post

  Cellulosic ethanol

  There is no question that large-scale production of cellulosic ethanol will be difficult to achieve, but it's worth it. Here's why: we need liquid hydrocarbon fuels to replace gasoline, jet fuel, and diesel. These need to come from carbon-neutral or carbon-negative sources, and that means sugar and lignin from biomass.

  The problems: (1) the carbon balance does indeed depend on the process used, and deteriorates as the distance between feedstock collection (e.g. harvest) and fuel production sites increases. Biomass is much less dense than coal or oil, and we need to develop ways to produce biofuels and chemicals in a much more dispersed fashion. It takes 27 truckloads of switchgrass to produce one truckload of ethanol. The ratio for corn is about 3.6 to 1. This means we need to solve the problems of building many smaller plants vs. fewer large plants, which have the current technology benefit of economies of scale. This is a tough problem.

  (2) The molecular problem is that cellulose is inherently a crystalline stuctural material, built to last thousands of years in some environments. Starch is an ephemeral storage material, designed to be readily broken down by tiny plant embryos. Both cellulose and starch are made from the same monomer: glucose. This is the reason the U.S. ethanol industry started with corn starch - now it must evolve, and do so rapidly. We need to get very large quantities of glucose (and xylose) from a two-by-four, figuratively speaking.

  The benefits: global warming has come upon us rather suddenly, and will almost certainly reach unacceptable levels no matter what we do. It is very much in our interest to begin replacing fossil fuels with realistic biofuels now. Green plants absorb solar energy and carbon dioxide for a living. They are the only practical means of removing CO2 at the atmospheric concentration of 0.04% (400ppm soon). They also store that carbon in glucose, and the solar energy in chemical bonds, something which current solar technologies cannot do.

  A second benefit is that we may begin to reduce the massive transfer of wealth from the U.S. and other oil consumers to oil producers. When oil prices reach $70/bbl, our oil trade deficit reaches $300 billion per year, not quite a billion dollars a day. Not counting Iraq at $9 billion per month.

  Both global warming and oil prices are likely to get worse. In 1998, I wrote a paper titled "Global Warming and the Need for Liquid Fuels from Biomass" - linked at our website www.generalbiomass.com. The data at that time (ca. 1993) indicated that China had 9.5 million vehicles with a 6-year doubling time. India had 6.2 million with a 7-year doubling time. I read today in Fortune that China has 33 million automobiles, and is projected to increase to 130 million by 2015. You do the math, but that suggests a doubling time of about 4 years for China's autos. For reference, the doubling time for all world vehicles was 26 years in 1993.

  Against that backdrop, I hope there will be more public and private support for cellulosic fuels than has so far been evident. Clearly they should be sustainably produced and used to power hybrids, not SUVs. Congress can do this if it has the will. Cellulosic ethanol comes out very well in greenhouse reductions in LCA (Life Cycle Analysis) studies by Kammen at Berkeley and Wang at Argonne.

  Finally, we should think beyond agriculture. In North America, dozens of paper mills have shut down due to foreign competition. Some of these could be refitted as forest biorefineries, making ethanol and other feedstocks to displace oil. More than half the world's people will live in cities in 2008, generating lots of waste paper which could be made into ethanol.

  Daniel Gibbs, Ph.D.

  On Venture capitalist predicts posted 2 years, 9 months ago 4 Responses