Hydrogen-Rich Syngas Production through Synergistic Methane-Activated Catalytic Biomass Gasification

Abstract

The abundance of natural gas and biomass in the U.S. was the motivation to investigate the effect of adding methane to catalytic nonoxidative high-temperature biomass gasification. The catalyst used in this study was Fe− Mo/ZSM-5. Methane concentration was varied from 5 to 15 vol %, and the reaction was performed at 850 and 950 °C. While biomass gasification without methane on the same catalysts produced ∼60 mol % methane in the total gas yield, methane addition had a strong effect on the biomass gasification, with more than 80 mol % hydrogen in the product gas. This indicates that the reverse steam methane reformation (SMR) reaction is favored in the absence of additional methane in the gas feed as the formation of H 2 and CO shifts the equilibrium to the left. Results showed that 5 mol % additional methane in the feed gas allowed for SMR due to formation of steam adsorbates from oxygen in the functional groups of aromatic lignin being liberated on the oxophilic transition metals like Mo and Fe. This oxygen was then available for the SMR reaction with methane to form H 2 , CO, and CO 2 . This study was not a detailed catalytic activity evaluation, but it was exploratory research to ascertain the synergy presented in the co-gasification of biomass and natural gas.

Direct Conversion of Syngas Produced from Steam Reforming of Toluene into Methane over a Ni/Biochar Catalyst

“…Syngas produced from renewable energy ( e . g ., biomass gasification) is considered a sustainable and promising technology because of the less release of CO 2 and environmental pollution compared with fossil fuels. − However, tar formation during biomass gasification should be considered, and advanced catalysts, especially Ni-based catalysts with economic feasibility, are the common catalysts for tar removal. , Furthermore, some literature studies calculated the H 2 /CO ratio of the produced gas and mentioned that the produced gas is suitable for downstream utilization, but most of them have not properly addressed the issues of downstream conversion . Among all of the technologies of syngas conversion, syngas (even contains trace CO 2 ) can be converted into methane (CO + 3H 2 → CH 4 + H 2 O, CO 2 + 4H 2 → CH 4 + 2H 2 O) under atmospheric pressure at low temperatures, and therefore, store renewable energy in the form of high energy density .…”

Biomass Valorization Under Methane Environment

“…Wang et al [34] developed a valorization process of furfural under methane environment using Zn-Ga/ZSM-5 catalysts and proved that methane could be used in an effective way to produce more valuable aromatic products. In 2019, Lalsare et al [35] used FeMo/ZSM-5 catalyst for methane-activated gasification of hardwood and found that the introduction of methane led to high hydrogen yield, in contrast to high methane yield with the absence of methane in feed gas, making the product gas more profitable. Wang et al [36] studied the deoxygenation process of phenol under methane environment with Zn/ZSM-5 catalyst.…”

“…Moreover, isotope-labelling experiments proved the participation of methane, which favorably occurred at benzylic site or meta position of the benzene ring. Wang et al [33] also found that a moderate acidity of support was advantageous for lignin conversion under methane In 2019, Lalsare et al [35] claimed that oxophilic metals such as Fe and Mo facilitated the conversion of oxygen in lignin-containing biomass together with methane to form CO and hydrogen. Furthermore, they suggested that the acid sites and metal species in FeMo/ZSM-5 favored water-gas shift and steam methane reformation reaction to produce high H 2 /CO value in gas product.…”

Deoxygenation-enhanced chemical looping gasification: a new pathway to produce hydrogen from biomass

“…1 There is a desire to utilize clean, sustainable, and renewable energy resources instead of fossil fuels. 2 Biomass is considered a carbon-neutral resource because CO 2 in the atmosphere can be fixed through photosynthesis, which shows the characteristics of renewability and environmental friendliness. 3 Therefore, renewable bioenergy is seen as the substitution of fossil fuels, and plays a pivotal role in value-added fuel production and carbon dioxide emission reduction.…”