Fuels, derived from plant or other bio-mass.
Where liquid fuels are by and far away the most cost effective, low mass density, low volume per unit available energy, large scale store for concentrated energy for vehicles of all kinds. (Batteries are very heavy. Indeed, there is a move to create a liquid fuelled battery for portable appliances such as computers or cameras etc. This is done by creating a fuel cell, an electric battery that works by exploiting the chemistry of a liquid (or, perhaps gaseous) fuel.)
I especially noted on alcohols, biodiesel fuels made through esterification, and butanol.
This last is a higher order alcohol than the familiar ethanol, is used in paint thinners etc., and is capable of being used as a direct replacement for gasoline in the familiar, conventional four stroke Otto Cycle engine.
I had also looked at the possibilities for algae based fuels.
I believed and still believe that liquid fuels are the likeliest technology to succeed the fossil fuels, at least in part (though Hydrogen may well be the ultimate "fuel," especially on a transition to high efficiency fuel cell electric drive technologies).
So, I stressed that we should look at some initial exploration and deployments in partnership with other players and support agencies, to develop initial technical capacity.
All of this was several years back.
Then, the other day, I ran across a development that is noteworthy, the use of insect gut bacteria enzymes, to break down lignin (one of the constituents of woods), which would release a lot of the chemical potential in woody materials. (This is similar to Holtzapple's mixed alcohol fuel process -- now branded MixAlco -- that looked to digest woody waste to make fuels. As I recall, there was some talk as well of bacteria from catfish guts in such a fermentation process.)
The insect gut bacteria enzyme possibility is well worth headlining, through SciDev.Net:
About 50 million tonnes of lignin are produced every year worldwide, mostly as waste after the sugar, or cellulose, in a plant has been converted into ethanol.
Finding a way to process this tough molecule could boost biofuel production and cut the greenhouse gases that are emitted when it is burned as waste.
Insects harbour natural catalysts that could be exploited to convert plant material into biofuels more efficiently, report scientists in a paper in PLoS Genetics this month (10 January). Herbivorous insects often rely on microbes in their guts using these molecules to digest plant materials such as cellulose and lignin.
By comparing the genomes of gut microbes from grasshoppers, termites and cutworm caterpillars, the scientists found that the diversity of gut microbes present and their ability to break down plant materials are linked to what the insects eat. These findings could be used to guide future searches for enzymes for use in the biofuel industry, they say . . . .
In addition, the researchers found that grasshoppers might be a good target for biocatalyst discovery because their guts harbour enzymes that can break down cellulose.
The new enzymes could be used to reverse design biorefineries for more efficient biomass degradation, according to Yuan.
Yuan's laboratory has received a US$2.4 million grant from the US Department of Energy to try to use enzymes found in termite guts and microbes to design a way of turning lignin into biofuel.
"You can make anything but money out of lignin," Yuan says. Yet, so far there have been no good commercial uses for lignin waste, he says.[Research paper, here.]
That last sardonic comment is an apt summary of the story of lignin to date.
But, if a breakthrough can be had on lignin and/or on cellulose, the potential may be highly significant (not least, by transforming geopolitics through breaking the dominance of oil on the global economy).
Accordingly, we should further note from the article, how:
Li Shi-Zhong, executive director of the MOST-USDA Joint Research Center for Biofuels from Tsinghua University, China, says: "Biofuels are the only practical and competitive large-scale substitute to petroleum."
Let us see, and let us hope, let us work -- and let us pray. END