Catalytic Pyrolysis of Cellulose Using Acidic Ionic Liquids at Low Temperatures and Explanation of the Catalytic Mechanism and Product Evolution Model

Abstract

In this paper, we investigated the catalytic pyrolysis process of cellulose (MC) at temperatures of 140 °C, 180 °C, 260 °C and 300 °C with acidic [Bmim]OTf ionic liquids as catalysts. Characterization of the pyrolysis products by SEM, XRD, FTIR and GC-MS showed that the initial pyrolysis temperature of MC was significantly reduced from 315 °C to 140 °C with a temperature interval of nearly 200 °C, and the crystalline structure of MC was rapidly destroyed, which might be due to the synergistic catalytic effect of CF3SO3- and [Bmim]+. The molecular potential distributions of cellulose and ionic liquids were analyzed from a microscopic perspective, and a novel mechanism model for the synergistic catalytic pyrolysis of MC by [Bmim]OTf was developed. This study provides a reference for the targeted product's targeted regulation mechanism, and finally achieves the efficient and low consumption utilization of biomass.

Keywords: cellulose, acidic [Bmim]OTF, low-temperature pyrolysis, synergistic catalytic effect, mechanism model