Sulfonic Acid Anchored Heterogeneous Acid‐Catalyst DIC_AT‐3 for Conversion of Xylose into Furfural in Biphasic Solvent System

Abstract

Furfural is most exigent biomass‐derived furanic molecule used for the production of renewable chemicals, fuels and polymers. In the present study, a series of sulfonic acid anchored heterogeneous catalysts (DICAT‐3) were synthesized for cyclodehydration of xylose into furfural in a biphasic solvent. The profound effect of catalyst backbone, solvent and reaction conditions were witnessed. Xylose dehydration in the presence of DICAT‐3 in the toluene/water biphasic solvent system provides high yield and conversion. The use of the biphasic solvent system in presence of DICAT‐3 offers ease of product and catalyst separation, respectively. Furthermore, the process intensification study was performed for the influence of reaction parameters on furfural yield and xylose conversion. Under optimized reaction conditions DICAT‐3 gave > 88% furfural yield with >99% of xylose conversion at 120 °C in toluene/water. The structural and surface morphological features of DICAT‐3 were investigated by FTIR, SEM/EDX, XRF and TGA analysis. The DICAT‐3 was tested for five consecutive recycle runs and it shows the consistent performance for xylose conversion and furfural yield without loss of catalytic activity. The exploration of DICAT‐3 offers specific advantages such as robust and recyclable catalysts, ease of product separation and non‐stringent reaction conditions with high yield. Thus, the reported process provides a platform for the development of a sustainable and economically viable process.

Dehydration of Xylose to Furfural over Imidazolium-Based Ionic Liquid with Phase Separation

“…The low furfural yield of the dehydration of xylose to furfural in water was reported for the prolonged reaction time due to the formation of byproducts, polymerization, resinification, and condensation reactions, etc. [21]. Thus, 728 was attributed to (-CH-)n (n > 4).…”

“…The low furfural yield of the dehydration of xylose to furfural in water was reported for the prolonged reaction time due to the formation of byproducts, polymerization, resinification, and condensation reactions, etc. [21]. Thus, The acid-catalyzed dehydration of xylose to furfural usually proceeds via the consecutive protonation of hydroxyl groups (forming H 2 O + groups) and cleavage of the C-O bonds, leading to the liberation of water molecules (three overall) and formation of trivalent carbocation intermediates which undergo deprotonation, resulting in C=C bond formation [4].…”

“…The low furfural yield of the dehydration of xylose to furfural in water was reported for the prolonged reaction time due to the formation of byproducts, polymerization, resinification, and condensation reactions, etc. [21]. Thus, the influence of reaction time on xylose conversion and furfural yield was studied between 30-240 min at 160 • C. The results are shown in Figure 3a.…”

A Polyethylenimine‐Functionalized Protic Ionic Liquid (PolyE‐IL) Catalyst for Conversion of Aqueous 2,3‐Butanediol into Methyl Ethyl Ketone (MEK)

“…In order to maintain the liquidity of aqueous reaction mixture above 100 °C, inert gas pressure can be applied to the reactor. [43] For catalytic reactions the inert gas pressure also promotes the effective interaction between catalyst and reactive substrate. Thus, the influence of N 2 pressure has been studied for dehydration of 2,3-BDO in order to test the effect of pressure on BDO conversion and selectivity of MEK.…”