Ryan ChartrandBiofuels and biomass programs are touted as a major solution to the problem of America’s addiction to petroleum by allowing us to grow carbon neutral fuel domestically. Can fuels such as biodiesel and ethanol offset the huge amount of energy that our economy and lifestyle demands? Some even say that it takes more energy to make these biofuels than the amount of energy you get out of them.
Well, the last one is wrong. A comprehensive look shows that for every one unit of energy you put into growing the soy bean to crushing the oil to converting it to biodiesel you get 2.2 back out. Ethanol has a lower return of about 1.2 but it is still a positive return. This article will take a closer look at these biofuels and offer solutions that are in the works.
Our industry runs on diesel fuel, from trucks and trains to busses and tractors (To learn the basics of what biodiesel is visit biodiesel.org). Almost all of our biodiesel comes from virgin soy bean oil produced in the Midwest in biodiesel plants that can only process this one feedstock. The total amount of biodiesel produced in this nation was 250 million gallons in 2006. Compare this to the 50 billion gallons of petroleum diesel consumed. The National Biodiesel Board is pushing to meet 5 percent of the nation’s demand by 2010. But, according to the USDA only about 450-500 million gallons of soy oil is available for biodiesel which currently can’t compete with food prices.
Soy can not be the only solution since soy beans only produce about 50 gallons of oil per acre annually, meaning we would need 1 billion acres to supply our need. Some researchers and soy bean lobbyists suggest that we will be able to genetically modify soy beans to yield more oil, the perfect solution to diversifying our energy sources. Other available feedstocks include waste vegetable oil from restaurants, canola (120 gal/acre), mustard (100 gal/acre), palm (200 gal/acre), or pretty much any plant that produces oil. Since we can’t grow plants like palm in the U.S., the best solution available is to develop biodiesel manufacturing out of waste vegetable oil from restaurants locally, (one is almost complete in Gonzaga), as well as implementing crop rotations of canola, mustard or camelina and providing farmers with incentives to do so.
Most of our liquid fuel that is consumed in the U.S. is gasoline at 140 billion gallons per year. Ethanol is the natural replacement for this and additional corn is being planted and investments are being made in ethanol plants all over the country. Ethanol is easily produced from the fermentation of sugar. Sugar is hard to grow in the U.S. but we do have a lot of subsidized corn which has starch that can be converted into sugar and then into ethanol. The reason ethanol only has a net energy yield of 1.2 is because most of the energy demand in creating it comes first from growing the crops and second from the multiple stages of distillations that are required to remove water that is created in fermentation. Not only does this create a huge amount of heavily polluted wastewater, but most of the new ethanol plants being built use coal as their energy source.
There are future hopes for converting wood waste and grasses, which mostly consists of lignocelluloses and are easily grown, into cellulosic ethanol. However, you must now convert the lignocelluloses to starch and then sugar to ferment. This has yet to be proven economical outside of laboratory studies.
The overall question still remains, is there enough land to grow traditional crops to provide for the current energy consumption? The answer is no. Reducing consumption is the first thing on the list. Through moderation a balance of developing our waste streams will be key to a successful biofuels future. We have to push for multi-feedstock biodiesel plants that produce fuel from WVO locally, diversification of our farming to include crop rotations, and development of more oil seed extraction facilities including incentives for farmers and research in future crops to combine waste streams such as algae (which grows far faster than terrestrial plants and is used as wastewater treatment to remove nutrient pollution).
We must also look at other ways of using biomass. Anaerobic digestion of agricultural wastes to create methane and direct burning of biomass for energy requires far fewer hurdles in technology. Decentralized cogeneration heat and power systems (CHP) not only convert biomass into electricity, but harnesses the heat created for water and radiant heating and, through tri-generation, even cooling in homes and businesses in the surrounding area.
The Netherlands are catching on to the efficiencies of systems like this, and in Canada, they are beginning to investigate growing crops of switchgrass for burning, not fermentation.
In conclusion, John Benemann puts it quite well, “The advantages of biofuels and other solar and renewable energy sources is that they will be limited, and will be expensive; we will need to use them frugally instead of wasting them wantonly, like we do with fossil fuels.”
Ian Woertz
Civil and Environmental Graduate Student
Minor in Sustainable Environments
Founder of the Biodiesel Club
Research in wastewater treatment with algae and the lipid yield for use as biodiesel.
Please send questions and comments to iwoertz@calpoly.edu