Selective Production of 1,2‐Propylene Glycol from Jerusalem Artichoke Tuber using Ni–W₂C/AC Catalysts

Abstract

A series of Ni-promoted W(2) C/activated carbon (AC) catalysts were investigated for the catalytic conversion of Jerusalem artichoke tuber (JAT) under hydrothermal conditions and hydrogen pressure. Even a small amount of Ni could greatly promote the conversion of JAT to 1,2-propylene glycol (1,2-PG), whereas the pure W(2) C/AC catalyst resulted in the selective formation of acetol. The product distribution profiles involving the reaction temperature, time, and H(2) pressure indicated that 1,2-PG formed as a result of acetol hydrogenation, which was catalyzed by Ni. Thus, there was a synergy between W(2) C and Ni, and the best performance yielded 38.5% of 1,2-PG over a 4%Ni-20%W(2) C/AC catalyst at 245°C, 6 MPa H(2) , and 80 min. To understand the reaction process, some important intermediates, such as inulin, fructose, acetol, glyceraldehyde, and 1,3-dihydroxyacetone, were used as the feedstock. Based on the product distributions derived from these intermediates, a reaction pathway was proposed, where JAT was first hydrolyzed into a mixture of fructose and glucose under the catalysis of H(+) , then the sugars underwent a retro-aldol reaction followed by hydrogenation catalyzed by Ni-W(2) C.

Mechanism and Kinetic Analysis of the Hydrogenolysis of Cellulose to Polyols

“…The cost of catalysts was greatly reduced due to the convenience in the preparation and the better reusability of catalysts without decay in the performance [28,115]. The feedstock involved microcrystalline cellulose and raw biomass, in detail including corn stover [22], birch wood [24], miscanthus [119], concentrated glucose [116,120], and Jerusalem artichoke [121]. The product distributions were tuned between EG, erythritol, and hexitols by varying the ratio of tungsten and hydrogenation metals [88].…”

“…The product distributions were tuned between EG, erythritol, and hexitols by varying the ratio of tungsten and hydrogenation metals [88]. Alternatively, the dominant product was altered from EG to 1,2-PG by changing the feedstock from glucose-based biomass to fructose-rich biomass such as Jerusalem artichoke [121]. On the basis of extensive studies, the reaction route and mechanism of this process were identified [17,28,29,115,122], and reaction kinetics are preliminarily modeled for the essential reactions [123][124][125].…”

Temperature-controlled phase-transfer catalysis for ethylene glycol production from cellulose

“…Compared with the blank test, the yield of glycolaldehyde over tungsten compounds was increased by a factor of 4-6. According to our recent study on the conversion of differently structured sugars over W 2 C catalysts, 7 glycolaldehyde arose from C-C bond cleavage of glucose via a retro-aldol reaction pathway. Considering that hot water could promote the dissolution and hydrolysis of cellulose, with the assistance of H + , to form glucose or cellooligosaccharides, 1b,8 we propose the reaction pathway as shown in Scheme 1.…”

Advances in selective catalytic transformation of ployols to value-added chemicals

“…They found that WO3 crystallites efficiently promoted the hydrolysis of cellulose to sugar intermediates and also promoted the selective cleavage of the C-C bonds. Recently, Zhang and coworkers [193][194][195] extended the feedstock from microcrystalline cellulose to lignocelluloses (such as corn stalk, birch and other woody biomass) and Jerusalem Artichoke Tuber. These studies provide a better understanding of the biomass transformation.…”