Ethanol, from corn

Production of ethanol from corn received a lot of attention worldwide, and especially in the US. Special subsidies were immediately created and distributed to the corn growers, if they use their corn for the fuel production. Unfortunately, the obvious results of it was shortage of food-grade corn, and spike in the food prices in general.

From environmental point of view, the ethanol from corn is, at best, mixed blessing. Growing corn requires vast tracts of natural habitat turned into monoculture corn fields, enormous amounts of irrigation water redirected form rivers and underground aquifers, and significant amounts of oil being used for fertilizers, chemicals, and fuel for farm equipment. Distillation of ethanol from corn is also quite unfriendly. It uses water, natural gas and electricity in quite significant amounts. Luckily, the corn leftovers are utilized as feed for cattle and other commercial use. Thus we are able to classify them as recycled waste, that has no negative impact on the environment.

The data here is from University of Nebraska. The "depreciable capital", that is, the energy required to build and operate the ethanol plant is represented here as an additional quantity of electricity.

The liquid waste data was obtained from this paper. The BOD (measure of the sewage quantity) was cited at 20 kg/ 1000 L of corn ethanol, and sewage volume given as 13 L/L of ethanol.