Erythritol: Another C4 Platform Chemical in Biomass Refinery

Abstract

The potential of erythritol as a platform chemical in biomass refinery is discussed in terms of erythritol production and utilization. Regarding erythritol production, fermentation of sugar or starch has been already commercialized. The shift of the carbon source from glucose to inexpensive inedible waste glycerol is being investigated, which will decrease the price of erythritol. The carbonbased yield of erythritol from glycerol is comparable to or even higher than that from glucose. The metabolic pathway of erythritol biosynthesis has become clarified: erythrose-4-phosphate, which is one of the intermediates in the pentose phosphate pathway, is dephosphorylated and reduced to erythritol. The information about the metabolic pathway may give insights to improve the productivity by bleeding. Regarding erythritol utilization, chemical conversions of erythritol, especially deoxygenation, have been investigated in these days. Erythritol is easily dehydrated to 1,4-anhydroerythritol, which can be also used as the substrate for production of useful C4 chemicals. C−O hydrogenolysis and deoxydehydration using heterogeneous catalysts are effective reactions for erythritol/1,4anhydroerythritol conversion.

Recent advances in the valorization of plant biomass

“…Recently, several methods have been proposed that could be used to directly produce isosorbide from lignocellulose or cellulose biomass [ 110 , 111 ]. Glucose can be converted into 1,2-propylene glycol by hydrogenolysis, which can selectively cleave the C–C and C–O bonds of glucose [ 112 ] or hexane via hydrodeoxygenation [ 109 ], and glucose can also be fermented by microorganisms into ethanol, erythritol [ 113 , 114 ], lactic acid [ 115 ], organic acid [ 116 , 117 ], polyhydroxyalkanoate (PHA) [ 118 , 119 ], and polyhydroxybutyrate (PHB) [ 120 ]. In addition, glucose can also be fermented into furfural, which, as an inhibitor of the next fermentation, can be produced during the pretreatment of biomass feedstocks, and furfural is also a platform compound for fuel additives, medical drugs, and other bulk chemicals [ 121 – 123 ].…”

Selective Hydrogenolysis of Erythritol over Ir−ReOx/Rutile‐TiO2 Catalyst

“…Selective hydrodeoxygenation of glycerol to 1,2‐ or 1,3‐propanediols [7] and deep hydrodeoxygenation of xylitol or sorbitol to alkanes or mono‐alcohols [8] are typical reactions investigated in these years. In contrast, a C4 sugar alcohol, namely erythritol, has not been regarded as a platform chemical, [9] and there have been much fewer reports for erythritol conversion than those for conversion of other sugar alcohols. However, erythritol is widely found in fruits and fermented foods and is easy to obtain by fermentation on an industrial scale [10] .…”

Hydro(deoxygenation) Reaction Network of Lignocellulosic Oxygenates

“…In this regard, formic acid, as one of most used biomass‐based hydrogen sources, can be explored for HDO‐based upgrading and oxygen removal processes, of which lignin valorization is used in addition to thermal energy production . In recent approaches, C 4 platform chemicals are derived from C−O hydrogenolysis and deoxygenation, which involves erythritol/1,4‐anhydroerythritol conversion …”