Catalytic co-pyrolysis of hydrolyzed lignin and waste tires over NiMo modified HZSM-5/MCM-41 composite molecular sieve in microwave fluidized bed for monocyclic aromatic hydrocarbons

Abstract

High oxygen content is unfavorable for the deoxygenation process during the thermal conversion of hydrolyzed lignin into liquid fuel. This study investigated the effects of nickel and molybdenum supported on molecular sieves, as well as temperature, on the catalytic co-pyrolysis of hydrolyzed lignin and waste tires in a microwave fluidized bed for the production of monocyclic aromatics. Results indicated that the hydrocarbon radicals generated by the added waste tires quenched the oxygen radicals from hydrolyzed lignin, improved the distribution of co-pyrolysis products and mitigated the coking of the catalyst. Compared to the composite molecular sieve carrier, under the action of the bimetallic co-loaded catalyst, at 550 °C and with a Ni:Mo ratio of 2:1, the ideal bio-oil yield reached the highest of 42.64 wt%, and the selectivity of MAHs is 46.15 %. The microwave fluidized bed catalytic co-pyrolysis process provides an efficient approach for converting organic solid wastes, such as hydrolyzed lignin and waste tires, into high-value products, including monoaromatic hydrocarbons.