Syngas Production from Biomass Gasification: Influences of Feedstock Properties, Reactor Type, and Reaction Parameters

Syngas from biomass gasification can be used in downstreamprocessindustries such as city gas, hydrogen production, etc. In this review,the effects of biomass feedstock properties, and gasification reactionconditions (temperature, gasifier type, etc.) on syngas propertiesare systematically reviewed. In summary, the cracking and reformingof volatile fractions in the gasification process and the catalyticeffect of alkali and alkaline earth metals in the ash on the gasificationhave a direct impact on the syngas yield. And biomass pretreatment(i.e., terrifying/hydrothermal carbonization) can reduce the moisturecontent, which can effectively reduce the energy required for gasificationand enhance the calorific value and syngas yield further. The fixed-bedgasifiers produce lower amounts of syngas. The concentration of H-2 is significantly increased by adding steam as a gasificationagent. Additionally higher gasification temperatures produce moresyngas, and an equivalence ratio of about 0.2-0.3 is consideredsuitable for gasification. For the influence of feedstock on syngas,this paper not only reviews the feedstock properties (volatile, ash,moisture) but also compares the influence of two pretreatments onsyngas yield and proposes that the combination of torrefaction/hydrothermalcarbonization and a multistage air bed gasifier is an important researchdirection to improve the combustible components of syngas. In additionto the summary of commonly used single gasification agents, two ormore gasification agents on the concentration of syngas componentsare also discussed in the gasification parameters, and it is suggestedthat further research into the use of more than one gasification agentis also important for future syngas production.