Cobalt-supported activated biochar in the co-pyrolysis of cattle manure and rice husk

It is crucial to develop an efficient catalyst for catalytic co-pyrolysis. In this paper, the catalytic co-pyrolysis of cattle manure and rice husk over a catalyst loaded with cobalt (Co) using potassium hydroxide-activated biochar as the support was conducted in a two-stage fixed-bed reactor. The results showed that the cobalt/potassium rice husk char (KRHC) catalyst displayed a good catalytic pyrolysis process with a large specific surface area and a developed pore structure. Loading with cobalt not only improved the quality of syngas but also increased syngas yield. Hydrogen content increased from 4.55 to 13.68% and carbon monoxide content increased from 19.78 to 32.25%, whereas carbon dioxide content decreased from 7.32 to 5.3% and methane content decreased from 8.01 to 6.07%. Syngas yield increased from 3.68 to 4.58 N m³/kg. The catalyst promoted the breaking of C–C and C–O bonds in tar, increased the content of phenols, ketones and aldehydes, and reduced the content of oxygen in the syngas. The catalysts also maintained good performance after five catalytic cycles, with hydrogen and carbon monoxide contents of approximately 10 and 27.5%, respectively.