Effect of CO2-rich atmosphere on nitrogen configuration of char and bio-oil during nitrogen-rich pyrolysis of cellulose

Different volume ratios of carbon dioxide and nitrogen were mixed into the nitrogen-rich pyrolysis of cellulose , resulting in the production of nitrogen-doped biochar and nitrogen-containing bio-oil. When the urea mixture ratio was greater than 50%, the added CO 2 promoted the production of nitrogen-containing bio-oil, reaching a maximum of 26.03% ( M  = 50%) at 10 vol% CO 2  + 90 vol% N 2 . Pyridine , pyrrole , and amines were the main nitrogen-containing compounds produced when using atmospheres of pure nitrogen and carbon dioxide. Upon increasing the volume ratio of CO 2 , the nitrile content increased significantly, becoming one of the main nitrogen-containing compounds. In addition, due to chemical stability, the thermal conversion of CO 2 demands a significant input of energy, so the required activation energy also increased. Adding CO 2 to simulate high-temperature anoxic flue gas is a promising method for biomass pyrolysis to obtain nitrogen containing chemicals with high added value and high nitrogen doped Biochar.