Experimental Study On Pyrolysis Of Volatiles From Corn Straw By Ca/Fe Enhanced Biomass Carbon Catalytic Reforming

The existence of biomass pyrolysis oil is the bottleneck in the process of biomass thermochemical utilization.Catalytic cracking is an effective way to remove pyrolysis oil.The use of biomass-based carbon as a catalyst for catalytic reforming of pyrolysis oil has attracted the attention of researchers at home and abroad.Based on the catalytic effect of biomass-based carbon on the pyrolysis of corn straw granules,Fe₂O₃ and CaO were used as additives to prepare biomass carbon-Fe and biomass carbon-Ca catalysts to enhance the in-situ catalytic activity of biomass-based carbon.It is to explore the influence of different modified biomass-based carbon on the catalytic cracking of pyrolysis oil,and use water vapor to realize the technical route of reforming the corn leaf straw pyrolysis volatiles to improve the gas quality of combustible products.This test yielded the following results:（1）The catalytic performance of biomass-based carbon was studied on a self-built reaction platform.The test results showed a good cracking effect on the condensable liquid phase in the pyrolysis volatiles of corn stover particles.21.49%,a decrease of 38.71%compared to the absence of catalyst under the same test conditions.The gas production rate increases with the increase of temperature,up to 50.72%.（2）The catalytic effect of the enhanced biomass-based carbon was studied.Under the experimental conditions,the yield of the liquid carbon-Fe catalyst could reach 20.24%and the gas production rate reached 51.44%.The addition of the Ca-based catalyst can achieve a liquid phase product yield of 20.01%at 800°C,and a gas production rate of up to51.96%.The change of the components of the pyrolysis gas is mainly reflected in the increase of the proportion of combustible gas.Among them,biomass carbon-Fe contributes to the increase of H₂ volume fraction in product gas,while biomass carbon-Ca can promote the formation of CH₄ in pyrolysis gas and reduce the proportion of CO₂.And the difference in the height of the catalytic bed also has a certain influence on the liquid phase yield and gas production rate.Under the experimental conditions,the catalytic activity of biomass-based coke on the pyrolysis volatiles of corn stover particles was as follows:Biomass carbon-Ca>Biomass carbon-Fe>Biomass-based carbon>No catalyst.（3）Based on the pyrolysis test,the effect of water vapor addition on the volume and composition of biomass pyrolysis gas was studied.The results show that the introduction of water vapor can effectively increase the volume of product gas and promote the formation of H₂.Among them,the catalytic effect of biomass carbon-Fe is the most obvious.Under the condition of water vapor,the product gas volume and H₂ content of 5g corn stover granules can reach 2987ml and 50.89%respectively under the reforming operation of biomass-based carbon.Fe₂O₃ can be used as a good additive for the production of hydrogen-rich gas.