Effect Of Modified Catalysts On Pyrolysis Of Biomass

The catalytic pyrolysis technology is considered as a promising strategy of waste and biomass management due to its advantages on reducing and recycling.Recently,porous materials like molecular sieve have attracted much attention because they have high surface area,specific structure and active sites.The Ni and Cr modified HZSM-5 zeolites were prepared via impregnation method and the effect of the modified catalysts on the pyrolysis of biomass was studied by using fixed bed and gas chromatography mass spectrometry?GC/MS?.Pyrolysis of cellulose over Ni modified HZSM-5 produced less aldehyde and chain-like products.Moreover,the yield of phenols increased during pyrolysis of lignin and the yield of long chain-like products decreased.The effect of Ni and Cr modified HZSM-5 on the yield of phenol in lignin pyrolysis products was strong.The effect of Ni modified graphene on pyrolysis products components of typical combustible solid waste were studied by pyrolysis-chromatography mass spectrometry?Py-GC/MS?.Graphene oxide?GO?and dispersion liquid of reduced graphene oxide?RGO?were selected for preparation of catalysts.The pyrolysis with adding modified graphene produced more yield of 1,6-dehydration.The yield of phenol in the pyrolysis products of modified graphene was increased.The decrease of alcohol content and the increase of phenol showed that the modified graphene displayed a significant effect on the removal and recombination of hydroxyl groups.The modified graphene promoted the production of long carbon chain products.The main compositions of coal gangue are Al₂O₃,SiO₂ which are main compositions of molecular sieve.Coal gangue which has some active metal element is selected as additive in pyrolysis.The effects of major actors?temperature,ratio of gangue to corn,particle size?on co-pyrolysis of coal gangue and corn stalk were studied in fixed bed.The reaction conditions for maximum yield of bio-oil were a gangue to corn ratio of 9 at 600?and the material diameter is 100 mesh.The maximum reaction rate starting time of gas production was slightly delayed with coal gangue content increasing,and the percentage of CO,CO₂,C_nH_m,CH₄ and H₂ in the products decreased obviously.The higher temperature and smaller particle size produced more CO,CO₂,C_nH_m,CH₄ and H₂.