Catalytic Conversion of Xylose to Furfural by p-Toluenesulfonic Acid (pTSA) and Chlorides: Process Optimization and Kinetic Modeling.

Muhammad Sajid,Muhammad Rizwan Dilshad,Dehua Liu,Xuebing Zhao,Muhammad Saif Ur Rehman

doi:10.3390/molecules26082208

Abstract

Furfural is one of the most promising precursor chemicals with an extended range of downstream derivatives. In this work, conversion of xylose to produce furfural was performed by employing p-toluenesulfonic acid (pTSA) as a catalyst in DMSO medium at moderate temperature and atmospheric pressure. The production process was optimized based on kinetic modeling of xylose conversion to furfural alongwith simultaneous formation of humin from xylose and furfural. The synergetic effects of organic acids and Lewis acids were investigated. Results showed that the catalyst pTSA-CrCl3·6H2O was a promising combined catalyst due to the high furfural yield (53.10%) at a moderate temperature of 120 °C. Observed kinetic modeling illustrated that the condensation of furfural in the DMSO solvent medium actually could be neglected. The established model was found to be satisfactory and could be well applied for process simulation and optimization with adequate accuracy. The estimated values of activation energies for xylose dehydration, condensation of xylose, and furfural to humin were 81.80, 66.50, and 93.02 kJ/mol, respectively.

Highlights

Furfural is a high-value furan aldehyde, with a wide range of industrial uses, especially in the production of pharmaceuticals, polymers, resins, solvents, fine chemicals, fuel additives, and biofuels [1,2,3,4]
Only a 50% furfural yield has been achieved in the industrial mineral acid-catalyzed furfural production process [20]
Catalytic transformation of xylose into furfural was elaborated over different organic acids in aqueous as well as in organic solvent medium

Summary

Introduction

Furfural is a high-value furan aldehyde, with a wide range of industrial uses, especially in the production of pharmaceuticals, polymers, resins, solvents, fine chemicals, fuel additives, and biofuels [1,2,3,4]. Mineral acids [8,9], modified solid acids [10], metal oxides [11], and some organic acids [12], have been used for the production of furfural from xylose by employing water, organics, ionic liquids, and their combinations as solvents. Mineral acids are applied in organic synthesis because of the higher process yields, and heterogeneous solid acids are used because of their high recycling efficiencies [9,13]. Besides these advantages, mineral acids are less selective owing to associated environmental concerns [14]. Only a 50% furfural yield has been achieved in the industrial mineral acid-catalyzed furfural production process [20]

Methods

Results

Conclusion