Hydrogen Ion Transport Mechanism in the Acid-Catalyzed Hydrolysis of Cellulose

Amid escalating global energy demands and tightening environmental constraints, sustainable resource conversion has become increasingly critical. However, the conversion of cellulose to levulinic acid (LA) is hindered by challenges such as coking and inefficient hydrogen ion (H+) transport. In this study, a 3D lattice Boltzmann model is employed to simulate cellulose hydrolysis in pretreated lignocellulose, yielding novel insights into how the Reynolds number (Re), particle radius, acid concentration, and temperature modulate reaction efficiency, H+ transport, and coking behavior. Specifically, distinct stages of the coking process are delineated based on flow field characteristics. At Re = 75, reaction efficiency is maximized by regulating H+ transport and intermediate residence time, while a particle radius of 12 l.u. (lattice units) effectively balances mass transfer. An inlet acid concentration of 6% optimizes LA output and minimizes coking, whereas concentrations exceeding 6% or temperatures above 180 °C induce severe coking, thereby impeding LA production and H+ transport. These findings underscore the utility of the model in enhancing cellulose-to-LA conversion through coking regulation.