Selective Hydrogenolysis of Biomass‐Derived Xylitol to Glycols: Reaction Network and Kinetics

Abstract

The conversion of bio‐based xylitol to ethylene glycol (EG) and propylene glycol (PG) was studied to replace the petrochemical production route and achieve a sustainable process. The reaction network for aqueous‐phase catalytic hydrogenolysis of xylitol over a supported Pt catalyst with Ca(OH)2 as promotor was identified and the reaction kinetics was determined. The effects of reaction conditions such as educt concentration, H2 pressure, and temperature were investigated. With the developed kinetic model, the composition of the product mixture regarding the desired products (EG, PG) and by‐products can be described. The maximum EG yield was achieved at high pressure and low temperature, while high pressure and temperature favored PG production.

First-principles study on the design of nickel based bimetallic catalysts for xylose to xylitol conversion

“…Xylitol is an alcohol sugar frequently used in the pharmaceutical and food industries as a sucrose alternative due to its sweetness and low-calorie content. 8,9 It can also serve as a platform chemical for producing ethylene/propylene glycol, 10,11 which are frequently used as a feedstock for generating hydrogen. 12,13 A significant challenge for effective biomass utilization and upgrading is catalysis.…”

Ru/ReOx/TiO2 Selective and Reusable Catalyst for C−O Hydrogenolysis of C4 Polyols

“…can lead hydrogenolysis towards the breaking of CÀ C or CÀ O bonds. [8][9][10] On the glycerol (GLY) hydrogenolysis, the most studied within the polyols or sugar-alcohols derived from biomass, the first work using solid catalysts based on Ru/C [11] reported the formation of 1,2propanediol (12PDO), ethylene glycol (EG) and ethane as main products indicating the promotion of both types of hydrogenolysis, CÀ O and CÀ C at 493-533 K and 40 bar of H 2 . Catalysts based on Ir [12][13][14] or Rh [15,16] , on the other hand, has presented good activity and selectivity to products with a lower O/C ratio than the starting raw material, i. e. propanediols (PDO) in the presence of 20-120 bar of H 2 and 373-513 K. [17] The combination of an oxophilic promoter (Re, Mo or W) with a highly reducible noble metal (Ru, Rh, Ir, etc) was previously reported that improved the selective CÀ O bond hydrogenolysis of GLY avoiding the CÀ C cleavage.…”

“…However, the nature of selected support and the addition of a co‐catalyst of a different nature (acids, basic, metal oxides, etc.) can lead hydrogenolysis towards the breaking of C−C or C−O bonds [8–10] . On the glycerol (GLY) hydrogenolysis, the most studied within the polyols or sugar‐alcohols derived from biomass, the first work using solid catalysts based on Ru/C [11] reported the formation of 1,2‐propanediol (12PDO), ethylene glycol (EG) and ethane as main products indicating the promotion of both types of hydrogenolysis, C−O and C−C at 493–533 K and 40 bar of H 2 .…”

Ru on N‐doped Carbon for the Selective Hydrogenolysis of Sugars and Sugar Alcohols

“…As a result, a wide range of products is obtained. To enhance selectivity, many monometallic catalysts based on Cu, Ni, Pt or Ru were developed and tested in combination with a homogeneous base [8–14] . Additionally, recent research focused on the development of bimetallic catalysts to facilitate reactions with the addition of a solid base, without external hydrogen pressure or to further enhance selectivity [15–24] …”

“…To enhance selectivity, many monometallic catalysts based on Cu, Ni, Pt or Ru were developed and tested in combination with a homogeneous base. [8][9][10][11][12][13][14] Additionally, recent research focused on the development of bimetallic catalysts to facilitate reactions with the addition of a solid base, without external hydrogen pressure or to further enhance selectivity. [15][16][17][18][19][20][21][22][23][24] Nevertheless, selectivity and activity control remains a major challenge.…”