Treated excrement from chickens, turkeys and other poultry, when converted to combustible solid biomass fuel, could replace coal as a renewable energy source, says a study.
The study, published in the journal Applied Energy, showed that treated poultry excrement could replace approximately 10 per cent of coal used in electricity generation, reducing greenhouse gases and providing an alternative energy source.
While biomass accounts for 73 per cent of renewable energy production worldwide, crops grown for energy production burden land, water and fertiliser resources.
The researchers from Ben-Gurion University of the Negev (BGU) in Israel noted that environmentally safe disposal of poultry excrement has become a significant problem.
“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 said.
They evaluated two bio-fuel types to determine which is the more efficient poultry waste solid fuel.
They compared the production, combustion and gas emissions of biochar, which is produced by slow heating of the biomass at a temperature of 450 degrees Celsius in an oxygen-free furnace with hydrochar.
Hydrochar is produced by heating wet biomass to a much lower temperature of up to 250 degrees Celsius under pressure using a process called hydrothermal carbonisation (HTC). HTC mimics natural coal formation within several hours.
“We found that poultry waste processed as hydrochar produced 24 per cent higher net energy generation,” said Professor Amit Gross.
“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,” Gross said.
“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 explained.