A highly stable waste animal bone-based catalyst for selective nitriles production from biomass via catalytic fast pyrolysis in NH3

The selectivity and stability of catalysts have always been a challenge in the field of catalytic fast pyrolysis (CFP). Herein, a series of waste animal bones collected from local market were employed as catalyst to convert biomass, with only acetonitrile and propionitrile in bio-oil, via catalytic fast pyrolysis and ammonization (CFP-A) process. Combined with characterization and control experiments of calcium-based components in bone, it was found that hydroxyapatite (HAP) was the catalytic active phase, while NaCl and KCl inorganic salts in bone inhibited the production of nitriles. Under the optimized conditions, the selectivity of acetonitrile and propionitrile from cellulose were 74.9 % and 25.1 % in bio-oil, respectively. Importantly, for the raw biomass, it still maintained high nitriles selectivity. The carbon yield of nitriles did not decrease after 10 cycles with HAP. Such a stable catalyst is first reported in the field of CFP, which is important for CFP to be economically sustainable.