Preparation of Core-Shell Structure Magnetic Carbon-Based Solid Acid and its Catalytic Performance on Hemicellulose in Corncobs

Abstract

Solid acid catalysts show good catalytic depolymerization behavior for lignocellulose. A stable core-shell structured magnetic solid acid catalyst (MSAC), Fe3O4/C-SO3H, was prepared from glucose, concentrated sulfuric acid, and modified magnetic particles of Fe3O4, which was used as the core. The effects of the carbonization and sulfonation processes on the activity of the catalyst were investigated. The results showed that preparation conditions had great influence on the quantity of the acidic groups (sulfonic, carboxyl, and hydroxyl groups) and the stability of magnetic catalysts. The best preparation conditions for MSAC were 3 h of carbonization time, 450 °C as the carbonization temperature, 9 h of sulfonation time, and 90 °C as the sulfonation temperature. Its surface topography, functional group, chemical composition, and magnetic properties were characterized by analysis instrument. Furthermore, the catalyst was stably dispersed in the reaction system, quickly separated from the reaction system using an external field, and reused many times; 44.3% of xylose yield was obtained at 160 °C for 16 h. The catalyst was used repeatedly more than 3 times, and the recovery over 89%. The depolymerization of corncobs was achieved by magnetic catalyst, representing the depolymerization characteristics of real lignocellulose. This data can be used as a reference for the subsequent use of biomass resource.

Carbon-Based Solid Acid Pretreatment in Corncob Saccharification: Specific Xylose Production and Efficient Enzymatic Hydrolysis

“…When the catalyst preparation time exceeded 6 h, the total acid amount of the catalyst decreased and the total yields of xylose, arabinose, and glucose decreased. Longer catalyst preparation times might reduce the hydroxyl and carboxyl groups, which was not conducive to the hydrolysis reaction …”

Enhanced Enzymatic Hydrolysis of Corncob by Synthesized Enzyme-Mimetic Magnetic Solid Acid Pretreatment in an Aqueous Phase

“…These catalysts can be divided into three types: the first is Amberlyst-15, a synthetic resin bearing only −SO 3 H groups; the second is the catalyst bearing −COOH, −OH, and −SO 3 H groups; and the third is the catalyst synthesized in this work bearing −COOH, −OH, and C–Cl groups. Compared with Fe 3 O 4 /C-SO 3 H, the yield of xylose from C350-Cl is much higher than that with Fe 3 O 4 /C-SO 3 H under mild reaction conditions. Compared with C-SO 3 H and Gp-SO 3 H-H 2 O 2 , a similar xylose yield was achieved in a shorter reaction time.…”

Preparation and investigation of highly selective solid acid catalysts with sodium lignosulfonate for hydrolysis of hemicellulose in corncob

“…In the study of hydrolysis of hemicellulose in biomass catalyzed by carbon-based solid acid, Zhang prepared the solid acid catalyst Fe 3 O 4 /C-SO 3 H to catalyze corncob hydrolysis; only a 44.3% xylose yield was obtained when the hydrolysis was carried out at 160 C for 16 h. 22 Xu used glucose and p-toluenesulfonic acid as raw materials to prepare a solid acid (Gp-SO 3 H-H 2 O 2 ), 23 and a xylose yield of 78% (aer sulfuric acid post-hydrolysis) was obtained when the hydrolysis of corncob was carried out at 140 C for 14 h. Zhong prepared the SO 4 2À / Fe 2 O 3 solid acid catalyst and catalyzed the hydrolysis of wheat straw at 140 C for 4 h; the yield of xylose was 63.5% (aer sulfuric acid post-hydrolysis). 24 In our study, the xylose selectivity was signicantly improved, and the reaction condition was mild.…”

“…Due to the complicated structure of lignocellulosic biomass, unsatisfactory results were oen obtained in the application of carbon-based solid acids for lignocellulose saccharication or fractionation. Zhang prepared the solid acid catalyst Fe 3 O 4 /C-SO 3 H to catalyze corncob hydrolysis; 44.3% xylose yield was obtained at 160 C for 16 h. 22 Xu 23 used glucose and p-toluenesulfonic acid as raw materials to prepare solid acid (Gp-SO 3 H-H 2 O 2 ) for corncob hydrolysis and obtained a 77.5% xylose yield under the optimal condition. Zhong 24 prepared the SO 4 2À /Fe 2 O 3 solid acid catalyst and catalyzed the hydrolysis of wheat straw; 63.5% of xylose was obtained aer the treatment of hydrolysate with 1 M H 2 SO 4 at 100 C for 1 h. In this study, we used sodium lignosulfonate, a waste material from sulphite pulp, to prepare highly selective carbonbased solid acid catalysts, which can directly catalyze hemicellulose from biomass into xylose.…”