Thermal Cracking of Sugars for the Production of Glycolaldehyde and Other Small Oxygenates

Abstract

Thermal cracking of sugars for production of glycolaldehyde, a potential renewable platform molecule, in yields up to 74 % with up to 95 % carbon recovered in the condensed product is demonstrated using glucose as the feed. The process involves spraying an aqueous sugar solution into a fluidized bed of glass beads. Continuous operation is carried out for more than 90 h with complete conversion and stable product selectivity. Besides glycolaldehyde, the other identified condensed products are pyruvaldehyde (9 %), formaldehyde (7 %), glyoxal (2 %), acetol (2 %), and acetic acid (1 %). The effects of temperature, glucose feed concentration, and type of sugar feedstock are investigated. Cracking the monosaccharides fructose and xylose leads to very different product distributions from glucose, but similar carbon recovery. A reaction network in agreement with the main observed products from cracking of monosaccharide sugars is proposed.

Sustainable access to renewable N-containing chemicals from reductive amination of biomass-derived platform compounds

“…Glycolaldehyde is a renowned bio-based platform molecule which can be synthesised from retro-aldol reaction of glucose under subcritical hydrothermal conditions [176,177]. Glycolaldehyde shows promise as a key starting material raw for the synthesis of many interesting and important industrial chemicals, such as ethylene/propylene glycols, ethanolamine, glyoxal, formic acid, glycolic acid and tetrose sugars [178][179][180].…”

Kinetic Modeling of Gas Phase Sugar Cracking to Glycolaldehyde and Other Oxygenates

“…Particularly, products not considered in their work are observed experimentally, such as pyruvaldehyde, acetol, glyoxal and permanent gases. 3,4 Additional reactions were therefore proposed and modelled in this work in order to develop a kinetic model for the sugar cracking process. A simplified reaction network of the kinetic model developed in this work is shown in Figure 2, based on the work of Seshadri & Westmoreland 24 with the further reactions modelled in this work.…”

“…Most noticeably, only small amounts of anhydrosugars are formed (<1%), and the yield of glycolaldehyde is much higher (up to 73-74%). 3,4 Seshadri & Westmoreland 24 calculated gas phase kinetic parameters for pyrolysis of sugars based on quantum-chemical and statistical mechanics calculations and discussed the implications for cellulose pyrolysis. They calculated kinetic parameters for a number of reactions relevant to sugar cracking, including isomerization with the effect of water partial pressure and decomposition reactions by retro-aldol reactions.…”

Toward Replacing Ethylene Oxide in a Sustainable World: Glycolaldehyde as a Bio‐Based C2 Platform Molecule

“…More recently, Schandel et al. successfully applied this process to a range of sugars, including glucose, fructose, xylose, and sucrose [160] . However, a yield higher than 70 % of GA, could only be obtained using glucose as the feedstock.…”