Catalytic co-pyrolysis of oil sludge and biomass over ZSM-5 for production of aromatic platform chemicals

Hazardous oil sludge (OS) poses a great challenge to the environment, whereas conventional treatment methods (i.e., incineration or pyrolysis-incineration) are relatively less value-added and will bring about air pollution problems. To realize the high-value utilization of OS, catalytic co-pyrolysis with waste biomass to produce platform chemicals was studied using TG-FTIR and Py (pyrolyzer)-GC/MS methods. Results showed that for the non-catalytic co-pyrolysis of RH (rice husk) and OS, the main synergy on weight loss was the greatly lowered initial pyrolysis temperature of RH (for similar to 55 degrees C) at the lower temperatures and the reduced weight loss ratio of OS (similar to 10-18 wt%) within the higher temperature range. ZSM-5 catalyst promoted the degradation of OS and RH mixtures at < 150 degrees C, yet showed minor effects on their weight loss at higher temperatures. The oxygenated and aliphatic compounds from non-catalytic co-pyrolysis were efficiently converted, resulting in an increased relative yield of aromatics to the highest of 46% and an elevated selectivity to BTX (as high as 60%). Despite the rela-tively short carbon chain length of OS components, ZSM-5 was proved effective to activate the OS pyrolysis products, thus enhancing the further aromatization reactions with biomass pyrolysis intermediates. This study provides a novel method for value-added co-utilization of hazardous OS waste and abundant biomass waste, and thus is beneficial to producing renewable chemicals while reducing the environment pollutant.

Automated summary

This study investigates the catalytic co-pyrolysis of hazardous oil sludge and waste biomass to produce renewable chemicals. The results show that ZSM-5 catalyst promotes the degradation and aromatization reactions, resulting in increased yields of aromatics and selectivity to BTX. This novel method allows for the high-value utilization of hazardous waste while reducing environmental pollution.