SO42−/Sn-MMT Solid Acid Catalyst for Xylose and Xylan Conversion into Furfural in the Biphasic System

Qixuan Lin,Junli Ren,Chuanfu Liu,Xiaohui Wang,Longfei Jian,Runcang Sun,Huiling Li

doi:10.3390/catal7040118

Abstract

A sulphated tin ion-exchanged montmorillonite (SO42−/Sn-MMT) was successfully prepared by the ion exchange method of montmorillonite (MMT) with SnCl4, followed by the sulphation. This catalysis was applied as a solid acid catalyst for the heterogeneous catalytic transformations of xylose and xylan into furfural in the bio-based 2-methyltetrahydrofuran/H2O biphasic system. These prepared catalysts were characterized by X-ray powder diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), temperature programmed desorption of ammonia (NH3-TPD), pyridine adsorbed Fourier transform infrared spectroscopy (Py-FTIR), element analysis (EA) and Brunauer-Emmett-Teller (BET) method. Their catalytic performance for xylose and xylan into furfural was also investigated. The reaction parameters such as the initial xylose and xylan concentration, the amounts of catalyst, the organic-to-aqueous phase volume ratio, the reaction temperature and time were studied to optimize the reaction conditions. Results displayed that SO42−/Sn-MMT contained both Brønsted acid and Lewis acid sites, and SO42− ions were contributive to the formation of stronger Brønsted acid sites, which could improve the reaction efficiency. Reaction parameters had significant influence on the furfural production. The substitution of water by the saturated NaCl solution in the aqueous phase also had an important effect on the xylose and xylan conversion. The highest furfural yields were achieved up to 79.64% from xylose and 77.35% from xylan under the optimized reaction conditions (160 °C, 120 min; 160 °C, 90 min). Moreover, the prepared catalyst was stable and was reused five times with a slight decrease (10.0%) of the furfural yield.

Highlights

With the rapid development of industrialization in the world, toxic pollutant in water remains a great concern to the environment
Beechwood xylan (AR, ≥90%) and standard reagents such as D-xylose and furfural were provided by Sigma-Aldrich (Saint Louis, MO, USA)
The results showed that SO4 2− /Sn-MMT

Summary

Introduction

With the rapid development of industrialization in the world, toxic pollutant in water remains a great concern to the environment. The heterogeneous catalyst was from widely in the lignocellulosic production of biomass furfural,with which is a production capacity of more than [3], and which can be advantageous in many fields, renewable bio-based chemical derived from the pentosan-rich lignocellulosic biomass with an annual such as oil refining, plastics and agrochemical. Solidcan acid such as production capacity of more than. 2 of heterogeneous catalyst, which generally appears in solid form, acts in a dissimilar phase in the liquid and is strongly desired to be developed due to its outstanding advantages such as environmental reaction mixture [1], and is strongly desired to be developed due to its outstanding advantages such benefits, reusability, benefits, efficient reusability, conversion,efficient easy separation andeasy purification of and the product [2]. of the as environmental conversion, separation purification

Methods

Results

Conclusion