In-situ Catalyzed Pyrolysis Of Pine Wood Pellets By Molten Salt Experimental Study

Pyrolysis technology has become one of the most promising methods to convert biomass into different substances.However,due to the adhesion of biomass structure and complex components,the composition of biomass pyrolysis products is complex and the product yield is low.The introduction of the catalyst can effectively increase the yield of pyrolysis products and improve the quality of the products.In recent years,some scholars have applied molten salt as a catalyst to biomass pyrolysis technology.However,due to the diverse types of molten salt and the large proportion of composition,more extensive and further research is needed to enrich the role of molten salt in biomass pyrolysis.application.(1)Through the reaction platform and self-made reactor,around the pyrolysis temperature factor,the characteristics of the pyrolysis products of pine wood particles are discussed.The experimental results show that: when the ratio of KNK mixed molten salt system is 3:5:2,the gas production of pine wood particles by catalytic pyrolysis increases with the increase of temperature,the liquid phase product yield,the tar yield and the solid The yield decreases with the increase of temperature.The salt-to-mass ratio is 3:1.When the reaction temperature is 850℃,the gas production is 662.50ml/g,the H2 yield is 24.83%,and the liquid phase product yield,tar yield,and solid yield are 24.54%,3.78% and respectively.35.07%,compared with 650℃,the gas production increased by 320 ml/g,and the liquid phase product yield,tar yield and solid yield decreased by 2.33%,0.94% and 7.39%,respectively.(2)Analyze the change law of pyrolysis products in the range of 650℃ to 850℃ by focusing on the ratio of salt to mass.The experimental results show that the yield of pyrolysis gas and solid yield in the range of 650℃ to 850℃ decrease with the decrease of the salt-tomass ratio,and the liquid phase product yield and tar yield decrease with the decrease of the salt-to-mass ratio.increase.At 700℃,the pyrolysis gas yield with a salt to mass ratio of 3:1is 394.50ml/g,the H2 yield is 22.38%,the liquid phase product yield and tar yield are 25.7%and 4.49%,and the solid yield is 36.92%.Compared with the same working conditions without molten salt catalysis,the gas production has increased by 77 ml/g,the liquid phase product yield and tar yield have been reduced by 16.19% and 6.14%,and the solid yield has increased by 7.32%.(3)Focusing on the component ratio factors of KNK mixed molten salt,analyze the change rule of the pyrolysis products under the conditions of 3:1 salt-to-mass ratio and 700 ℃reaction temperature.The experimental results show that when the KCl content is relatively large,the gas production of pyrolysis reaction is the highest.The proportion of each component in the mixed molten salt KNK system has little effect on the yield of each component of the pyrolysis gas,and only affects the total pyrolysis gas.The yield is affected by.When the KCl content accounts for a larger proportion of the components,it will promote the formation of small molecular products from cellulose,and reduce the yield of liquid products and tar.The mixed molten salt KNK(5:2:3)is compared with the liquid product without molten salt catalysis.The rate and tar yield decreased by 18.3% and 6.42%,respectively.