Alkanolamines as Dual Functional Solvents for Biomass Deconstruction and Bioenergy Production

Abstract

This work demonstrates the feasibility of applying dual functional solvents called alkanolamines for biomass pretreatment, deconstruction, and conversion into biofuels.

In Situ Synthesis of Protic Ionic Liquids for Biomass Pretreatment

“…Ethanolamine and most organic bases are also effective for pretreatment; however, they have characteristically also resulted in hemicellulose removal due to their high pH. 19 This is consistent with the results depicting the lower xylose yields with pure ethanolamine (Figure 2), and is a confirmation that the PIL performance is also different from that of the original reagents. Both glucose and xylose yields were significantly lower in acetic acid and fresh biomass, at less than 35% sugar yields.…”

“…To demonstrate this synthesis method, the PIL hydroxyethylammonium acetate ([Eth]-[OAc]), also known as ethanolamine acetate, was utilized due to its previously demonstrated effectiveness for biomass pretreatment via lignin removal. 8,18,19 [Eth][OAc] is a wellstudied PIL that has significant benefits related to its ability to selectively extract lignin from biomass, release high yields of monomeric sugars, biocompatibility with enzymes and microbes, recyclability/recovery, and scalability. 8,[13][14][15]18 PILs are easily synthesized via a stoichiometric Brønsted acid−base reaction involving proton transfer, and in this study, we develop a method to perform the PIL synthesis in situ while simultaneously pretreating the lignocellulosic biomass.…”

Amine-based pretreatments for lignocellulose fractionation and lignin valorization: a review

“…A wide range of alkanolamine solvents, such as ethanolamine, 1-amino-2-propanol, 2-methylamino ethanol, N , N -dimethylethanolamine, 1,3-diamino-2-propanol, and 2-amino-1,3-propanediol was employed for biomass deconstruction and bioenergy production. 102 The alkanolamines displayed the effectiveness of promoting lignin removal and improvement of the total sugar yield. Both experimental and computational analysis unveiled similar trends with respect to the degree of substitution on the amino groups, lignin removal, and sugar release efficiency.…”

“…Furthermore, amino groups dominated alkanolamines exhibited better dissolution towards lignin than hydroxyl groups dominating alkanolamines, owing to the superior affinity of amino groups with H-bond donor groups of lignin. 102…”

“…Furthermore, amino groups dominated alkanolamines exhibited better dissolution towards lignin than hydroxyl groups dominating alkanolamines, owing to the superior affinity of amino groups with H-bond donor groups of lignin. 102 Monoethanolamine, diethanolamine, and triethanolamine have shown effective sulfur-free delignification in the wood pulping and biomass deconstruction. 100,[103][104][105] Similarly, the presence of diethanolamine in the hydrothermal treatment of rice straw resulted in cellulosic pulps with desirable properties.…”