Poultry poop could replace coal

Treated excrement from turkeys, chickens and other poultry, when converted to combustible solid biomass fuel, could replace approximately 10% of coal used in electricity generation, in turn reducing greenhouse gases and providing an alternative energy source, according to a new study by researchers from Ben-Gurion University of the Negev (BGU).

A statement from American Associates BGU notes that biomass accounts for 73% of renewable energy production worldwide. However, crops grown for energy production burden land, water and fertiliser resources.

“Environmentally safe disposal of poultry excrement has become a significant problem,” the researchers write. Converting poultry waste to solid fuel, a less resource-intensive, renewable energy source is an environmentally superior alternative that also reduces reliance on fossil fuels.”

The researchers evaluated two biofuel types, biochar and hydrochar, to determine which is the most efficient poultry waste solid fuel. Biochar is produced by slow heating the biomass at a temperature of 450°C in an oxygen free furnace. Hydrochar is produced by heating wet biomass to a much lower temperature of up to 250°C under pressure using a process called hydrothermal carbonisation (HTC).

“We found that poultry waste processed as hydrochar produced 24 percent higher net energy generation,” says student researcher Vivian Mau and Professor Amit Gross, chair of the Department of Environmental Hydrology and Microbiology at BGU’s Zuckerberg Institute. 

“Poultry waste hydrochar generates heat at high temperatures and combusts in a similar manner to coal, an important factor in replacing it as renewable energy source.”

 

Methane reduction

Another key finding of the research, which has been published in the journal Applied Energy, is that higher HTC production temperatures resulted in a significant reduction in emissions of methane and ammonia and an increase of carbon dioxide and carbon monoxide.

“This investigation helped in bridging the gap between hydrochar being considered as a potential energy source toward the development of an alternative renewable fuel,” Gross explains. “Our findings could help significantly reduce greenhouse gas emissions associated with electricity generation and agricultural wastes. Field-scale experiments with HTC reactor should be conducted to confirm the assessments from this laboratory-scale study.”

The research article is available here.