Sequential Production of Levulinic Acid and Porous Carbon Material from Cellulose

Abstract

A sequential production of levulinic acid (LA) and porous carbon material (CM) from cellulose was conducted by a two-step process. The cellulose was first acid hydrolyzed, and the preferred reaction conditions required a severity factor of 4.0–4.5, in which the yields of LA, formic acid, and solid residue were 38 ± 3 wt%, 17 ± 3 wt%, and 15 ± 3 wt%, respectively. The solid residue was further used for CM preparation through pyrolysis, with or without ZnCl2 activation. The ZnCl2 activation promoted the formation of CMs with improved thermal stability, high surface area (1184–2510 m2/g), and excellent phenol adsorption capacity (136–172 mg/g). The used CM can be easily regenerated by a simple methanol Soxhlet extraction process, and a comparable phenol adsorption capacity of 97 mg/g was maintained for the 5th reusing. Finally, 100 g cellulose produced 40.5 g LA, 18.9 g formic acid and 8.5 g porous CM, with a total carbon utilization ratio reaching 74.4%.

Keywords

• cellulose
• levulinic acid
• porous carbon material
• pyrolysis
• hydrolysis
• adsorption