Renewable Production of Methane from Woody Biomass by Catalytic Hydrothermal Gasification

Abstract

Production of synthetic natural gas (SNG) from wood by a catalytic hydrothermal process was studied in a laboratory batch reactor suitable for high feed concentrations (10-30 wt %) at 300-410 °C and 12-34 MPa with Raney nickel as the catalyst. A maximum methane yield of 0.33 (g of CH 4 )/(g of wood) was obtained, corresponding to the thermodynamic equilibrium yield. The carbon gasification efficiency was a function of the reaction time, and for reaction times long enough (∼90 min), complete gasification was achieved. At supercritical conditions, the remaining liquid phase always was tar-free, was colorless, and contained less than 2 wt % of the feed carbon. Analysis of the spent catalyst revealed a slight increase of carbonaceous deposits on the surface (15 atom % vs 10 atom % for the fresh catalyst).

SunCHem: an integrated process for the hydrothermal production of methane from microalgae and CO2 mitigation

“…We have previously demonstrated the feasibility of hydrothermal gasification of swine manure and woody biomass to produce synthetic natural gas (SNG; Waldner and Vogel 2005;Vogel and Hildebrand 2002). The wood was completely gasified in a batch reactor without forming tars or coke.…”

Perspectives on Resource Recovery from Bio-Based Production Processes: From Concept to Implementation

“…• Competing process technologies such as biochemical conversion [11,12] or hydrothermal processing [15,141] can become more economically lucrative than the separation technologies discussed in this work. There is also likelihood chance that a new technology makes a leapfrogging discovery that would provide more lucrative economic incentives.…”

“…To this end, this work will focus on identifying promising separation technologies with the purpose of achieving resource recovery from bio-based production processes, as many economically lucrative raw materials are already present in these waste streams and can be recovered without the need for other conversion processes. In situations where raw materials need to be converted into a more economically lucrative form, other processes such as bio-conversion [11,12] or hydrothermal processing [13][14][15] can be applied. After establishing the economics of resource recovery and identifying the platform technologies, the techno-economic considerations that need to be considered when developing a resource recovery platform technology from a concept to an implementation are discussed in Section 4.…”

“…To our opinion, the overall TRL of the technologies surveyed in Section 4 is relatively high in comparison to other competing technologies such as bioconversion [11,12] and hydrothermal processing [13,15]. As such, from an industrial point of view, the resource recovery through extraction/separation can be a more established technology choice.…”

Hydrothermal gasification of different agricultural wastes in supercritical water media for hydrogen production: a comparative study

“…Connections between cellulose and hemicellulose make networks that stabilize the plant cell wall and lignin covers them. Sugars obtained from cellulose and hemicellulose will be further dehydrated into 5-HMF (5-hydroxymethylfurfural) which in a suitable condition can be converted into acids, alcohols and aldehydes [33]. Lignin is a three-dimensional phenyl propane polymer with ester bond links.…”