Conversion of Fructose to HMF in a Continuous Fixed Bed Reactor with Outstanding Selectivity.

Eric Weingart,Ulf Prüße,Sarah Tschirner,Linda Teevs

doi:10.3390/molecules23071802

Eric Weingart, Ulf Prüße + Show 2 more

Open Access

https://doi.org/10.3390/molecules23071802

Copy DOI

Abstract

5-Hydroxymethylfurfural (HMF) is a very promising component for bio-based plastics. Efficient synthesis of HMF from biomass is still challenging because of fast degradation of HMF to by-products under formation conditions. Therefore, different studies, conducted mainly in monophasic and biphasic batch systems with and without water addition have been published and are still under investigation. However, to produce HMF at a large scale, a continuous process is preferable. Until now, only a few studies have been published in this context. In this work, it is shown that fluorous alcohol hexafluoroisopropanol (HFIP) can act as superior reaction solvent for HMF synthesis from fructose in a fixed bed reactor. Very high yields of 76% HMF can be achieved in this system under optimized conditions, whilst the catalyst is very stable over several days. Such high yields are only described elsewhere with high boiling reaction solvents like dimethylsulfoxide (DMSO), whereas HFIP with a boiling point of 58 °C is very easy to separate from HMF.

Highlights

Renewable resources are promising alternatives to dwindling fossil resources for the production of important platform chemicals
Such high yields are only described elsewhere with high boiling reaction solvents like dimethylsulfoxide (DMSO), whereas HFIP with a boiling point of 58 ◦ C is very easy to separate from HMF
In our previous work [13,14], we showed in a batch system that hexafluoroisopropanol hexafluoroisopropanol (HFIP, (HFIP, Scheme 1) in combination with water and with the use of an acidic ion exchanger

Summary

Introduction

Renewable resources are promising alternatives to dwindling fossil resources for the production of important platform chemicals. Because of its versatile functionality, HMF is an important key intermediate in the production of various bio-based chemicals. Promising results with HMF yields and selectivities up to 90% are achieved using organic solvents or biphasic reaction systems [1,2,3,4]. Tuercke et al [5] used a continuous microreaction process for HCl catalysed dehydration of aqueous fructose In this single phase, a fructose conversion of 71% with an HMF yield of 54% and a selectivity of 75% could be achieved. Jeong et al [6] used continuously generated HMF as an intermediate to produce different heterocyclic furan chemicals. They used a functionalized capillary micro reactor for catalytic dehydration of fructose in DMSO. Schön et al [7] used a monophasic continuous

Methods

Discussion

Conclusion