Pig manure is one step away from a transformation of metamorphic proportions. The lowly waste product, notorious for its impact on the environment and on human olfactory nerves, is on the verge of becoming an important alternative to petroleum now that scientists at the University of Illinois have developed a process for converting raw pig manure to crude oil. With further development, the process may even yield biodiesel.
If successful commercially, the process would help reduce greenhouse gas emissions and other pollutants from pig farms and many other types of livestock operations. In particular, it could help protect drinking water supplies in livestock farming areas.
Pig Manure and Oil Supplies
When it comes to providing an alternative source of oil, pig manure ain’t no small potatoes. According to an article by Steve Giegerich in the St. Louis Post-Dispatch, one pig generates up to 8 pounds of manure per day. The research team estimates that a 10,000-hog farm could produce about 5,000 barrels of crude oil per year. The bottom line: instead of ending up with a manure waste disposal nightmare, hog farms could see an increase in income of up to $15 per hog.
Make Oil, Not Manure
The manure-to-oil process uses thermochemical conversion, in which heat and pressure act on organic compounds in a revved-up, tightly controlled imitation of the much longer process that occurs in nature. In order to develop a commercially viable method, the research team ditched the catalyst required by the conventional process, and they figured out a way to keep pig hair and dander from fouling the equipment. The team also skipped the conventional first step, which would be to dewater the manure. Instead, their process uses raw manure containing 80% water. The use of raw manure requires more heat to activate the conversion, but the researchers note that could be captured and recycled with a heat exchanger.
The Future of Manure Oil
As Giegerich reports, for now the manure oil is being tested as a low grade binder for asphalt on a stretch of road near I-44 in Illionis. The team has also refined the product to an oil that could compete with diesel fuel. If the process can be made cost-effective, it will be the latest in a series of fast-breaking developments in converting manure to an important alternative to fossil fuels in the U.S. It’s already happening with manure and methane gas conversion. In particular, the dairy industry is already advancing quickly along the cow manure-to-methane road, partly in a water quality preservation effort.
Image: Pig by lastquest on flickr.com.
Tina Casey specializes in military and corporate sustainability, advanced technology, emerging materials, biofuels, and water and wastewater issues. Tina’s articles are reposted frequently on Reuters, Scientific American, and many other sites. You can also follow her on Twitter @TinaMCasey and Google+.