Fen Peng

Roles Investigation of Promoters in K/Cu–Zn Catalyst and Higher Alcohols Synthesis from CO2 Hydrogenation over a Novel Two-Stage Bed Catalyst Combination System

A novel two-stage bed catalyst combination system composed of a low-temperature RWGS catalyst and another high-temperature modified F–T synthesis catalyst was developed to higher alcohols synthesis from CO2 hydrogenation in this work. Firstly, the roles of K2O and ZnO promoters in Cu-based catalyst were investigated by N2 adsorption/desorption, XRD, H2-TPR, CO2-TPD and RWGS reaction test. Results showed that K2O plays a positive role in improving the CuO–ZnO interaction and ZnO acts as a support for promoting the dispersion of copper species and improving the unit surface area of copper metal. Well dispersed copper in contact with the surface of ZnO particles leads to the ideal performances for RWGS reaction accompanying with methanol synthesis over CuZn1.0K0.15 catalyst due to the synergetic promotion effect between K2O and ZnO promoters. Then, the optimization of loading mode and loading volume ratio of catalyst combination system was conducted. It was indicated that the higher alcohols can be effectively synthesized from CO2 hydrogenation over the optimal CZK(1.5)//CFCK(4.5) two-stage bed catalyst combination system due to the thermal coupling effect and product conversion coupling effect of these catalysts.Graphical AbstractThe higher alcohols synthesis from CO2 hydrogenation was effectively conducted over the CZK(1.5)//CFCK(4.5) two-stage bed catalyst combination system due to the thermal coupling effect and product conversion coupling effect.

Extraction and characterization of wax from sugarcane bagasse and the enzymatic hydrolysis of dewaxed sugarcane bagasse

ABSTRACT Extraction of high-value products from agricultural wastes is an important component for sustainable bioeconomy development. In this study, wax extraction from sugarcane bagasse was performed and the beneficial effect of dewaxing pretreatment on the enzymatic hydrolysis was investigated. About 1.2% (w/w) of crude sugarcane wax was obtained from the sugarcane bagasse using the mixture of petroleum ether and ethanol (mass ratio of 1:1) as the extraction agent. Results of Fourier-transform infrared characterization and gas chromatography–mass spectrometry qualitative analysis showed that the crude sugarcane wax consisted of fatty fractions (fatty acids, fatty aldehydes, hydrocarbons, and esters) and small amount of lignin derivatives. In addition, the effect of dewaxing pretreatment on the enzymatic hydrolysis of sugarcane bagasse was also investigated. The digestibilities of cellulose and xylan in dewaxed sugarcane bagasse were 18.7 and 10.3%, respectively, compared with those of 13.1 and 8.9% obtained from native sugarcane bagasse. The dewaxed sugarcane bagasse became more accessible to enzyme due to the disruption of the outermost layer of the waxy materials.