Lignite improved biogas production during anaerobic digestion of swine manure

• Anaerobic digestion (AD) converts organic waste into biogas, a renewable fuel which is a potential solution for mitigating greenhouse gas emissions and energy crisis.

• Poor operational stability, caused by the variable (or low) quality of the manure such as high total ammoniacal nitrogen (TAN), and low C:N ratio, results in inefficient AD.

• Lignite is an intermediary product between peat and black coal and has been found to reduce ammonia emissions from animal manure. • High cation exchange capacity of lignite can reduce TAN.

• The objective of this study was to investigate the impact of lignite on the performance of anaerobic digestion of nitrogen (N) rich swine manure.

• Key words: Anaerobic digestion, Ammonia, Biogas, Lignite, Methan