Open AccessExploring the Thermodynamic Limits of Enhanced H2 Recovery With Inherent Carbon Removal From Low Value Aqueous Biomass Oxygenate Precursors
Author(s) -
Prince Ochonma,
Claire Blaudeau,
Rosalie Krasnoff,
Greeshma Gadikota
Publication year - 2021
Publication title -
frontiers in energy research
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.734
H-Index - 30
ISSN - 2296-598X
DOI - 10.3389/fenrg.2021.742323
Subject(s) - oxygenate , alkalinity , chemistry , biomass (ecology) , aqueous solution , methanol , carbon fibers , chemical engineering , ethylene glycol , inorganic chemistry , organic chemistry , catalysis , materials science , oceanography , composite number , engineering , composite material , geology
Rational integration of chemical pathways at the molecular scale to direct thermodynamically favorable enhanced H 2 production with inherent carbon removal from low-value substrates can be guided by exploring the thermodynamic limits of feasibility. The substrates of interest are biomass oxygenates that are water-soluble and uneconomical for separation from water. In this study, we investigate the thermodynamic feasibility of recovering H 2 with inherent carbon removal from biomass oxygenates such as ethanol, methanol, glycerol, ethylene glycol, acetone, and acetic acid. The influence of biomass oxygenate-to-water ratios, reaction temperature of 150°C–325°C, and CaO or Ca(OH) 2 as the alkalinity source on the yields of H 2 , CH 4 , CO 2 , and Ca-carbonate are investigated. By maintaining the fluids in the aqueous phase under pressure, energy needs associated with vaporization are circumvented. The hypothesis that enhanced alkalinity favors the preferential formation of CO (precursor for CO 2 formation) over CH 4 and aids the formation of calcium carbonate is investigated. The findings from these studies inform the feasibility, design of experiments, and the tuning of reaction conditions for enhanced H 2 recovery with inherent carbon removal from biomass oxygenate sources.