Catalytic Processes from Biomass-Derived Hexoses and Pentoses: A Recent Literature Overview

Abstract

Biomass is a plentiful renewable source of energy, food, feed and chemicals. It fixes about 1–2% of the solar energy received by the Earth through photosynthesis in both terrestrial and aquatic plants like macro- and microalgae. As fossil resources deplete, biomass appears a good complement and eventually a good substitute feedstock, but still needs the development of relatively new catalytic processes. For this purpose, catalytic transformations, whether alone or combined with thermal ones and separation operations, have been under study in recent years. Catalytic biorefineries are based on dehydration-hydrations, hydrogenations, oxidations, epimerizations, isomerizations, aldol condensations and other reactions to obtain a plethora of chemicals, including alcohols, ketones, furans and acids, as well as materials such as polycarbonates. Nevertheless, there is still a need for higher selectivity, stability, and regenerability of catalysts and of process intensification by a wise combination of operations, either in-series or combined (one-pot), to reach economic feasibility. Here we present a literature survey of the latest developments for obtaining value-added products using hexoses and pentoses derived from lignocellulosic material, as well as algae as a source of carbohydrates for subsequent transformations.

An overview of the biphasic dehydration of sugars to 5-hydroxymethylfurfural and furfural: a rational selection of solvents using COSMO-RS and selection guides

“…1, after the corresponding chemical pretreatment of biomass, the cellulosic and hemicellulosic fractions give rise to the so-called C5 and C6 platforms since they are polymers from whose hydrolysis hexoses like glucose or fructose and pentoses like xylose, most abundantly, can be obtained. Such sugar units are very attractive platform chemicals from which a number of routes can originate by direct oxidation, 11 hydrothermal processing, 12 fermentative pathways 4 or by one-pot reactions through furans, 13 to name a few. Furans originate as a consequence of the catalytic dehydration of glucose (via fructose) to 5-hydroxymethylfurfural (5-HMF) and xylose to furfural•5-HMF occurs in human diet being formed from the thermal decomposition of carbohydrates, hence being a good indicator of non-enzymatic browning and used as a reference for deterioration of food that has undergone excessive heating or been stored for too long.…”

“…A number of other reviews have covered the topic of the production of furans from sugars and other biomass derived substrates, 11,13,14,[55][56][57][58][59] in a couple of cases addressing specifically the use of biphasic systems for this purpose. 31,32 However, the emphasis of such studies has been put mostly on catalytic and mechanistic considerations.…”

Multi-Step Exploitation of Raw Arundo donax L. for the Selective Synthesis of Second-Generation Sugars by Chemical and Biological Route

“…These alternative renewable resources include lignocellulosic biomass [1,2], animal manure and human sewage [3,4], meat processing waste [5,6] and aquatic biomass [7,8], which can be employed as biorefinery feedstocks. Among them, the lignocellulosic biomass represents a key feedstock, being abundant, safe, and cheap and it is mainly composed of three biopolymers (cellulose, hemicellulose and lignin), which are precursors of very valuable bio-products and biofuels [9,10]. For this reason, the selective fractionation of the lignocellulosic biomass is of paramount importance, in order to optimise the recovery and the valorisation of each biopolymer, adopting a multi-step approach.…”

A sustainable system for maleic acid synthesis from biomass‐derived sugar

“…It cannot be produced though biochemical pathway at present, and is industrially derived from fossil materials like butane and benzene at reaction temperatures from 450 to 500 °C with vanadium oxides or vanadium‐phosphorous oxides as catalyst . Recently, sustainable and green routes from the oxidation of renewable biomass‐sugars into valuable organic acids like formic acid, acetic acid, lactic acid, gluconic acid, succinic acid, maleic acid and xylonic acid have received considerable attention . There are two types of routes for organic acids synthesis from sugars, non‐furan related and furanic pathways.…”

“…The process of maleic acid production is a typical furan related route, which takes 5‐hydroxymethylfurfural (HMF) or furfural as a building block starting from glucose/xylose . Compared with the catalytic conversion of hexoses for producing HMF, there is a higher overall yield of furfural from pentoses, accompanied by lower energy consumption . Therefore, furfural has been considered as a cost effective starting material for the production of maleic acid.…”