Production of biogas from poultry litter mixed with the co-substrate cow dung

Peer review under responsibility of Taibah University.

Abstract

Poultry litter (a mixture of rice hulls, sawdust and chicken excreta of broilers) mixed with the co-substrate cow dung and poultry droppings was evaluated under anaerobic conditions for the production of biogas (methane). Four laboratory scale reactors, R1, R2, R3 and R4, were set up with different proportions of waste poultry litter, cow dung and poultry droppings and had a 6% total solid concentration. Digestion was carried out for 50 days at room temperature, 32 ± 3 °C. Volatile solid degradation and specific gas production in the four reactors was 46%, 51.99%, 51.96%, 43% and 0.263, 0.469, 0.419, 0.221 l/g, respectively, based on the volatile solid (VS) feed. The methane yields were 71%, 72.5%, 72.6% and 70%, respectively. The COD reductions were 46.1%, 50.76%, 48.23% and 45.12%, respectively. A kinetic analysis showed that the anaerobic digestion of poultry litter with a co-substrate followed first order kinetics. Among the experimental reactors, R2 (25% cow dung, 75% poultry litter) gave the optimum results: a VS reduction of 51.99%, a specific gas yield of 0.469 l/g and a methane yield of 72.5%.

Keywords:

• Poultry litter
• Co-substrate
• C/N ratio
• Anaerobic digestion
• Biogas

Acknowledgments

This work was supported by the Ministry of Science and Technology, Bangladesh, under the project “Direct catalytic conversion of biogas to methanol” (No. 39.009.006.01.00.049/2013-2014/EAS-15/292; Date: 06/11/2013). We would like to acknowledge the help from Department of Chemistry, Jagannath University and BCSIR.

Notes

Peer review under responsibility of Taibah University.