Description of the biofuel production

The effects of corn and soybean production in the Midwest include massive topsoil erosion, pollution of surface and groundwater with pesticides, and fertilizer runoff that travels down the Mississippi River to deplete oxygen from a portion of the Gulf of Mexico called the dead zone that has, in the last few years, been the size of New Jersey.

As ethanol use pushes corn prices higher, farmers are increasingly abandoning the traditional corn-soybean rotation to what's known in farm country as corn-on-corn. High prices have encouraged farmers to plant corn year after year, an intensification that boosts fertilizer and pesticide requirements.

Description of the biofuel production

 
Firstly the biomass goes through a step that reduces the size of the material so that it is easier to handle and to make the production process more efficient. It is much like the grinding process that the agricultural residues go through so that the particles have uniform size.

The next step is to treat the biomass in which the hemicellulose fraction of the biomass is broken down into simple sugars. It happens with the help of a simple chemical reaction called hydrolysis, which occurs when dilute sulfuric acid is mixed with the biomass feedstock. In this reaction, the complex chains of sugars in the hemicellulose are broken and that results in the releasing of simple sugars. The complex hemicellulose sugars are transformed into a mix of soluble five-carbon sugars, xylose and arabinose, and soluble six-carbon sugars, mannose and galactose. Small portion of the cellulose is also transformed into glucose. There are few enzymes that are used like the cellulase enzymes, which hydrolyze the cellulose part of the biomass. These enzymes are either produced in the last mentioned step or are to be bought.

After the hydrolysis of cellulose, the glucose and pentose are fermented which gives "ethanol broth" as an output. A final step of dehydration has to be done to remove the excess water from ethanol and this step is therefore called Ethanol Recovery. Then the other by-products that include products like lignin are used to produce electricity that is required for the production of ethanol.


Presently this whole process is quite expensive therefore scientists are working hard to find out a way out and a cheaper process so that the production becomes cost effective that would also lead to a considerable increase in the usage of Biofuel.


Water use has also become a concern as corn production expands into drier areas like Kansas, where the crop requires irrigation. The ethanol boom has sent water demands skyrocketing, putting pressure on already suffering sources like the Ogallala aquifer. And according to a recent report by the World Resources Institute, stepped-up corn ethanol production means not only increases in soil erosion and water pollution, but increases in greenhouse-gas emissions.