Review of Hydrogen Production by Catalytic Aqueous‐Phase Reforming

Abstract

Catalytic aqueous‐phase reforming (APR) produces higher quality hydrogen (with less carbon monoxide) and carbon dioxide from weak solutions of bio‐carbohydrates in a single reactor at low temperatures. It provides a good opportunity for the effective valorisation of biomass‐derived products. It is advantageous than steam reforming because it saves energy by avoiding vaporization of the biofeed and lowers cost by precluding an extra water gas shift reactor. As evident from the numerous published works during the past decade, there is growing academic and industrial interest in the APR process. This review updates recent literature on APR of many biomass surrogates such as glycerol, ethylene glycol, sorbitol, ethanol and glucose. Most works focused on the development of efficient catalysts for selective hydrogen production and they were deliberated comprehensively. Key insights into improved catalysts and reaction conditions were highlighted. New inferences on the thermodynamic, kinetic and reactor engineering aspects of the APR process were analysed too. This thorough appraisal of the current literature, which is hitherto missing, will surely contribute to the development of the next generation of catalysts and reactors for commercial applications of the APR process.

Catalytic Transfer Hydrogenation of Biomass‐Derived Substrates to Value‐Added Chemicals on Dual‐Function Catalysts: Opportunities and Challenges

“…Metal−H bonding strength has been extensively used as a descriptor to characterize the electron configuration of metallic sites for a variety of different applications. It is particularly important for describing the H 2 generation behavior for reforming and WGS reactions –,. Metal−H bonding strength significantly impacts on dehydrogenation and H 2 spillover rates on the catalyst surface.…”

Recent Advances in Glycerol Catalytic Valorization: A Review

“…The production of H 2 has gained a huge amount of interest in the last decades, as it is a potential clean energy fuel [57]. In this route, there are several technologies employed, such as gasification, steam reforming [211,255], dry reforming [100,256], pyrolysis, and aqueous phase reforming [257] (see Section 3.3). The drawbacks of reforming are the drastic reaction conditions (atmospheric pressure and temperature < 800 • C) and many side reactions and the production of CO 2 .…”

Microemulsion Derived Titania Nanospheres: An Improved Pt Supported Catalyst for Glycerol Aqueous Phase Reforming

“…The aqueous phase reforming reaction (APR) of oxygenated hydrocarbons was firstly introduced in 2002 by Dumesic et al [ 1 ] This approach represents an interesting step for the upgrading of sugars and polyols towards the production of hydrogen and liquid products in water at relatively low temperatures (150–250 °C) and pressures (15–60 bar) [ 2 , 3 , 4 ]. Among the use of ethylene glycol [ 3 , 5 , 6 , 7 , 8 ], glucose [ 9 , 10 , 11 , 12 ], and biomass-derived polyols [ 11 , 13 , 14 , 15 , 16 , 17 , 18 , 19 ] as starting raw materials, glycerol represents an interesting substrate due to its availability as coproduct of biodiesel manufactures. In this context, glycerol conversion to high added value products is considered a key factor to boost the economic viability of biodiesel production.…”

“…In addition, platform molecules such as lactic acid, 1,2-propanediol, and propionic acid are co-produced in liquid phase [ 3 , 8 , 14 , 25 , 26 , 27 , 28 ]. Glycerol aqueous phase reforming (APR) is an endothermic reaction (ΔH 0 25 °C = 128 kJ/mol), for this reason the majority of the scientific literature are focussed in the range 200–250 °C in order to overcome thermodynamic limitations and foster the kinetics [ 3 , 8 , 14 , 26 ]. On the other hand, higher temperatures are not commonly investigated due to both glycerol relatively low boiling point and to the possibility of degradation reactions to oligomers and carbonaceous species.…”