There are many types of organic crops that can be used to produce ethanol. Here in the US, big Agricorps and Bushco decided it was best for them to make corn based ethanol the organic crop based fuel of choice.
Why?
And forget about buying carbon offsets, once again the small family farmer is leading the way to carbon negative fuel production.
How? Read on for simple primer on crop-based fuels, and a quick shout out to the family farmer, making a bigger corrective impact on global warming than any UN program, or any country on the planet...
Corn
An acre of good land (class A or B soils) averages about 330 gallons of corn based ethanol. It costs slightly less in energy to make than it yields in fuel energy, so it has a near break even/negative 1:1 field-to-wheel ratio, so that means big government handouts- hundreds of millions at last budget look- to make it work. Refining corn based ethanol is firmly in the grasp of big Agricorps like ADM and Cargill, so they control the market and market pricing. That means no pesky competition, just like Big Oil enjoys. Almost all corn seed are patented, primarily by Monsanto, so there’s little opportunity for farmers to crib their own seed stock.
The massive government handouts are at the middle, at the refining process. That means ADM, Cargill and BigAg are the big winners. Corn needs nitrogen and ammonia to grow. Farmers get higher prices, but as I’ve diaried before, they pay it all back in higher production and fertilizer costs.
Soy
Biodiesel primarily comes from beans. Soybeans to be exact, another crop controlled by BigAg. Soy based biodiesel is not new; Rudolph Diesel’s first engines in the 1890’s ran on soy based fuel (or coal dust). Soy based biodiesel doesn’t have the sulfur emission by-products that petrol based diesel has. Even a 2% biodiesel additive to regular diesel cuts sulphur emissions.
Bacteria present in soybean root nodules will fix nitrogen from the atmosphere, normally supplying most or all nitrogen needed by the plant. That’s why many farmers rotate corn and beans; the bean root system with the nitrogen gets put back into the soil as fertilizer for the corn. Some soils need phosphate and potash for maximum yields, but generally soybeans need far less fertilizer for maximum yields when compared to corn, and cost far less to produce.
An acre of good land (class A or B soils) averages about 100 gallons of soy based biodiesel. The distilling process is pretty straightforward; soybeans and methanol go in, biodiesel and glycerin come out at near 100% conversion efficiency, and at a 1:3 field-to-wheel energy gain, making it more desirable than corn as a fuel source. Right now the government subsidies here are to the back end big users instead of the middle man producers. Fleet owners get the tax credits and breaks for using it, not the producers. Why? BigAg makes more income from corn, less from beans, so there’s less incentive to crank up soy based biodiesel. With 35mpg fleet goals, that may change. A couple billion dollar investment and the US could be producing more than 20% of its fuel needs via soybeans. Beans that give that kind of gas are good.
Sugar
Brazil gets about 660 gallons of ethanol per acre of cane sugar. The part of the sugarcane left over after the sugar is extracted can be used as fuel to power the refining process, contributing to a fantastic 1:8 field-to-wheel energy gain.
Brazil, locked out of selling the US market sugar (we’re forced to buy it from US Big Sugar for a premium), increased production of wheat, corn, and oats to pound down US grain imports in retaliation. And they also increased cane sugar production exponentially, and are now self sufficient organic fuel producers.
Sugar beets produce energy too. An acre of sugar beets in France yields about 700 gallons of ethanol. It has about a 1:2 energy conversion rate, which is pretty good. Here in the US, livestock and pet feeds consume most sugar beet production.
Grass
Switchgrass is a native prairie grass that can produce up to 1,000 gallons of ethanol per acre. It has a very good 1:4 field-to-wheel energy conversion rate. It grows on less than optimum soils quite well, and requires little to no fertilizers of any kind. As a prairie native, it is resilient to rain and drought. It does not need to be replanted each year. The root system is permanent: you simply mow it once a year (or more, maybe) to get the raw material.
There is not much in the way of government investment so far, but biomass refineries are starting to come on line. The process is more complex, but the results are impressive. In 2002 The University of Illinois(shameless plug here) College of Agriculture (kills USC’s Ag program BTW) experimented with miscanthus, a tall reed that grows like a weed. Miscanthus Gigantus needs almost no fertilizers, has a permanent root system, grows well in poorer soils, and yields about 1,500 gallons of ethanol per acre, at a very good 1:6 field-to-wheel energy conversion rate.
The worlds largest carbon sinks
The farmers growing biomass, in particular the grasses, trap and fix carbon (as carbon dioxide) into the soil. Grasses have a negative carbon footprint; they absorb more carbon dioxide when they are growing than they give off as fossil carbon dioxide when burned as ethanol, and they do it to the tune of a couple tons of carbon (absorbed as carbon dioxide) per acre per year. That means a couple million acres of switchgrass or miscanthus scours several million tons of carbon (as carbon dioxide) out of the atmosphere every year. In the process, autos using grass based ethanol exhaust up to 87% less carbon by-products.