Solid combustible biomass made from poultry excrement has the potential to replace around 10 percent of coal-generated electricity globally according to a new study from the Zuckerberg Institute for Water Research (ZIWR) at Ben-Gurion University of the Negev (BGU) in Israel.
While biomass accounts for 73 percent of renewable energy production worldwide, crops grown for energy production burden land, water and fertilizer resources. According to the researchers and authors of the study, Professor Amit Gross and PhD candidate Vivian Mau from the Zuckerberg Institute for Water Research (ZIWR) at Ben-Gurion University of the Negev (BGU) in Israel, the “environmentally safe” disposal of poultry excrement has become a significant problem whereas converting it into a solid fuel makes it an environmentally superior alternative that also reduces reliance on fossil fuels.
Entitled “Energy conversion and gas emissions from production and combustion of poultry-litter-derived hydrochar and biochar” and published in the journal Applied Energy, the study evaluated two biofuel 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°C (842°F) in an oxygen-free furnace with hydrochar. Hydrochar is produced by heating wet biomass to a much lower temperature of up to 250 °C under pressure using a process called hydrothermal carbonization (HTC). HTC mimics natural coal formation within several hours.
We found that poultry waste processed as hydrochar produced 24 percent higher net energy generation. Poultry waste hydrochar generates heat at high temperatures and combusts in a similar manner to coal, an important factor in replacing it as a renewable energy source, said student researcher Vivian Mau.
For the first time, the researchers also showed that higher HTC production temperatures resulted in a significant reduction in emissions of methane (CH4) and ammonia (NH3) and an increase of carbon dioxide (CO2) and carbon monoxide (CO), a result of the HTC process being conducted at higher temperatures.
This investigation helped in bridging the gap between hydrochar being considered as a potential energy source toward the development of an alternative renewable fuel. Our findings could help significantly reduce greenhouse gas (GHG) 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, explained Prof. Gross chair of the Department of Environmental Hydrology and Microbiology (EHM) at BGU’s Zuckerberg Institute. explains.
The study was funded by the Israeli Ministry of Environmental Protection, the Rosenzweig-Coopersmith Foundation. BGU Ph.D. candidate Vivian Mau received financial support from the Israeli Ministry of National Infrastructures, Energy and Water Resources, the Rieger Foundation and the Zuckerberg Scholarship Fund at BGU’s Zuckerberg Institute for Water Research.
