Fuel and chemical products from biomass syngas: A comparison of gas fermentation to thermochemical conversion routes

Abstract

Increasing demand for renewable feedstock‐based biofuels is driving the interest and rapid development of processes to produce fuels and chemicals from biomass‐generated syngas. Biomass is gasified to produce syngas that can be converted via thermochemical routes to fuels and chemicals such as alcohols, olefins, and fuel grade hydrocarbons. An alternate route to produce liquid products from syngas is through gas fermentation, a hybrid thermochemical/ biochemical process. Biomass gasification, thermochemical syngas conversion routes, and gas fermentation are described including a comparison for converting biomass to ethanol via thecurrent thermochemical route versus gas fermentation. © 2012 American Institute of Chemical Engineers Environ Prog, 2012

Commercial Biomass Syngas Fermentation

“…Limitations in the robustness, flexibility and selectivity of the metal catalysts used in the FT process are thought to result in a production cost disadvantage when compared with gas fermentation [36]. High levels of syngas purity are required to prevent catalyst poisoning; for example, the presence of certain chemical species in the syngas such as sulphur or CO 2 may interfere with, or permanently deactivate the catalysts used [37].…”

REVIEW OF BIOFUEL PRODUCTION – FEEDSTOCK, PROCESSES AND MARKETS — Review Article

“…pressing and extraction and/or milling and grinding takes place (Abubackar et al, 2011;Griffin and Schultz, 2012;Dutta et al, 2011) to unlock the required biomass component. For example, before lignocellulosic biomass can be utilised for an alcoholic fermentation to bioethanol the molecules have to be disaggregated via hydrolysis to receive sugar monomers (Humbird et al, 2011).…”

“…Alternatively to the heat induced and catalyst driven methanol synthesis syngas can also be converted to methanol based on bio-chemical processes (i.e. syngas fermentation); the latter option is still in an early research status (Griffin and Schultz, 2012). Until today, methanol is mainly produced via a synthesis process based on synthesis gas provided by reforming of natural gas or by gasification of coal (Höhlein et al, 2003).…”

“…Another possibility to produce bio-methane is via biomass gasification and the subsequent methanation of the produced and conditioned synthesis gas (Larson and Katofsky, 1993;Griffin and Schultz, 2012). The thermo-chemical gasification process of solid biofuels into a synthesis gas as well as the subsequent gas cleaning is described in detail in the section fuels derived from lignocelluloses; therefore it is not described in detail here.…”

Syngas Fermentation: A Microbial Conversion Process of Gaseous Substrates to Various Products

“…The economy of the fermentation process is enhanced through improvements in efficiency that conserve energy and increase product yield. Energy efficiency represented by retaining the higher heating value from the products, through gasification [5] and as increased product yield from fermentation [6], and the use of energy efficient separation technologies, such as membrane separation, are very important to achieve a profitable commercial process for fuels or chemicals.…”