Scientists at the University of Idaho have developed a method, which they say is actually quite simple, to turn cow manure into a fully biodegradable plastic. The continual push for renewable energy and products has also recently resulted in Florida’s trash-to-ethanol plant, off-shore wind farms, and even plans to turn pig manure into asphalt.
Plastics are an integral part of daily life and according to the EIA, about 3% of petroleum demand in the United States is used for making plastic. That’s about 200 million barrels based on data from 2010, in addition to the 65 billion kilowatt-hours of electricity also needed in the process.
Thankfully, the state of Idaho is home to about 1 million cows, each of which produce 100 to 150 pounds of manure daily. In a simple process, the manure is fermented into a type of slurry which is then fed to naturally occurring bacteria. When the individual bacteria cells consume too much (they always do) they convert excess into carbon polymers (much like our bodies turn excess food into fat). After a few days, the bacteria are killed with chlorine and the slurry is left to dry. What remains is a “a semi-crystallized, natural, biological, biodegradable plastic” compound polyhydroxyalkanoate, or PHA.
Those involved claim the process to be simple and efficient and an average dairy farm could oversee the plastic production easily with only two people. In such a scenario, tanks could hold 2 million gallons of the manure slurry which would equate to 400,000 to 1 million pounds of plastic, assuming the current ratios are scalable.
With PHA selling at a premium, significant economic return could be generated from dairy manure…Dairy manure is a great untapped biomass resource in Idaho..