Plastic is gaining ground as the next sustainable energy source, despite its reputation as a major polluter.
Environmentalists are looking for new ways to reduce pollution from landfills, and power plants are looking for energy sources that produce fewer greenhouse gas emissions.
Some believe that burning plastic could solve both of these problems.
Convergen Energy, based in Wisconsin, creates fuel pellets from pre-consumer paper and plastic. This is the waste that industrial manufacturers would otherwise throw away due to product printing errors or other issues.
MU tested a sample of Convergen fuel pellets at the campus power plant on East Stewart Road. About 5% of the campus’s energy comes from coal, and MU’s director of energy management, Gregg Coffin, hopes pellet can replace it.
Campus energy workers are now seeking approval from the Missouri Department of Natural Resources to be able to fully implement the process at the power plant.
The tests were conducted for a year, ending in November. If approved by the state, the plant could start operating this fall.
A major positive result is the reduction of plastic pollution in landfills and the oceans. The plastic recycling rate in the United States was less than 9% in 2018, according to the United States Environmental Protection Agency.
Ted Hansen, CEO of Convergen, said more than a billion pounds of materials have been kept out of landfills since sustainability efforts began more than a decade ago.
So how do pellets produce energy? They are similar to coal in the way they are handled and burned, but they produce less greenhouse gas emissions.
Once granulated, the mixture is tested for contaminants such as chlorine. When burned, chlorine can produce emissions such as hydrogen chloride, which forms an acid with available moisture.
MU has found that the residual amount of chlorine in the granules can be controlled with its existing emission control systems, Coffin said.
The granules are then placed in boilers fitted with water tubes. As the pellets are burned, the heat turns water into steam. The steam spins a turbine, which turns the generator and creates energy.
Like most environmental issues, the issue of air pollution has been the subject of much debate. Mark Haim, director of Mid-Missouri Peaceworks, said he was skeptical of the energy of plastic.
“We believe that we should phase out the use of petroleum-based plastics and switch to bioplastics, which are compostable or biodegradable,” he said. “If we were to do this, we wouldn’t have a source of plastic to use the incineration model.”
The Missouri Department of Natural Resources said Convergen pellets tested at MU “contain more volatiles than charcoal” and “less chlorine, mercury, nitrogen and sulfur than charcoal,” according to a report. air pollution control program.
Volatile organic compounds contain chemicals that pollute the air. They can contribute to the formation of ozone and are therefore regulated by the EPA.
The Air Pollution Control Program report said the pellets would likely increase volatile organic compounds and carbon monoxide emissions, but “the increase should be less than 100 tonnes” and therefore meet the safety standards of the industry. ‘EPA.
The plastics are also not PVC or polyvinyl chloride. PVC is a major safety concern because it can create harmful dioxins which are usually produced by the incineration of waste. The pre-consumer non-PVC plastic used by Convergen significantly reduces this problem.
While MU waits to receive approval for full use of the fuel pellets, Convergen is now looking to expand the idea to other power plants in Missouri.