Novel study on catalytic pyrolysis of chitin biomass using waste cathode material recovered from spent Li-ion battery.

Waste cathode (BC) from spent lithium-ion battery (LIB) was preliminarily studied for the catalytic pyrolysis of chitin biomass using thermogravimetric and pyrolysis-gas chromatography/mass spectrometry analysis. Compared with the dry-mixing method (BC1), the wet-impregnation method (BC2) significantly increased the decomposition rate of chitin pyrolysis and decreased the apparent activation energy from 85 kJ/mol to 76 kJ/mol. BC2 had a superior catalytic effect on the conversion of heavy components into light fractions. In particular, the selectivities for acetamides and acetonitrile were improved. Furthermore, BC2 enhanced the cleavage of glucosidic, C-O, and C-C bonds, thereby improving the thermolysis of chitin to acetamido acetaldehyde. The production of acetamides, acetonitriles, and other light components (e.g., ketones) was further enhanced via deoxygenation and hydrogenation reactions. Additionally, the selectivity of N-heterocycles (pyridine and pyrrole) and their derivatives (tar-N surrogates) decreased, indicating that tar was significantly reduced during the catalytic pyrolysis and gasification of chitin biomass.