Effect of Steam on the Tar Reforming during Circulating Fluidized Bed Char Gasification

Abstract

In this work, the real tar was introduced into the circulating fluidized bed gasifier by pre-mixing tar and char. The effect of steam on the tar reforming characteristics at both 850 and 900 °C was investigated by combining the analysis of the rate of tar conversion, the change of tar content, and char physical structure. The test results indicated that steam could effectively promote the tar conversion. Therefore, the content of tar in the final gas could be reached as low as 32 mg/Nm 3 . It was found that the effect of steam on the different components of tar was in difference. Among the various components, polycyclic aromatic substances were more inclined to decompose. The results of BET confirmed that the distribution and structure of pore were obviously developed at the presence of steam, and the abundant pore structure further improved the catalytic performance of the char on the tar conversion in turn.

Review on Catalytic Biomass Gasification for Hydrogen Production as a Sustainable Energy Form and Social, Technological, Economic, Environmental, and Political Analysis of Catalysts

“…(used in physical purification). 155 Even though physical purification methods are simpler, they have some drawbacks. For instance, these techniques require heating and cooling steps; they produce large amounts of liquid waste or wastewater when a scrubber is used; and the tar energy is not utilized.…”

“…Wet and dry purifications are techniques that include filtration, aqueous or organic liquid scrubbing, absorbing, cyclone separation, etc. (used in physical purification) . Even though physical purification methods are simpler, they have some drawbacks.…”

H2-rich syngas production from gasification involving kinetic modeling: RSM-utility optimization and techno-economic analysis

“…In addition to it, in steam gasification process, there is a tendency of reducing tar content, which is one of the major challenges during gasification. 3 Apart from the technological and designing aspects of gasifier there are other factors that influence H 2 yield in biomass gasification such as feedstock type, quality and inherent moisture content, particle size and density, reaction temperature, bed height, heating rate, environment, flow of medium, steam flow rate, addition of catalyst, sorbent to biomass ratio, etc.…”