The Research Of Catalytic Gasification Of Phenol In Supercritical Water With Ni-based Bimetallic Catalysts

With the dwindling of fossil fuels and the deterioration of environmental pollution,taking biomass as raw material to produce biofuel or biogas is considered as one of the most effective ways to alleviate these problems.This paper is on using phenol as a model compound for biomass in supercritical water gasification with bimetallic nanoparticles as catalyst and analyzing the reaction products to explore the mechanism of biomass gasification in supercritical water.Ni and Ru on CeO2 in different ratios prepared by the impregnation method for the gasification of phenol in supercritical water were tested.The results show that bimetallic nanoparticle has better activity than single metal nanoparticle and 10Ni-1Ru/CeO2 shows the highest activity for producing CO2 and CH4 and the phenol conversion.The GC-MS results confirm that 10Ni-1Ru/CeO2 catalyst can effectively suppress the formation of dimers and char,leading to the efficient gasification of phenol in supercritical water.Kinetic model of the gasification process gives the activation energy as 110 ± 17 kJ/mol and the frequency factor(lnA)as 16.7±2.6 for gaseous product formation,while for char formation,the activation energy and frequency factor are 38 ± 5 kJ/mol and 3.9 ± 0.8,respectively.10Ni-1Ru/CeO2 can be successfully reused twice,indicating stability in supercritical water at temperatures below 550?.A 10Ni-1Ru/CeO2 SCWG system may be a potential way to treat phenols.A simple and green method of depositing bimetallic nanoparticles(Co-Ni)on activated carbon in supercritical water is described.Water-soluble metal precursors.nickel nitrate and cobalt nitrate,were used in the experiments.The mechanism of bimetallic nanoparticle formation was discussed.Sequential deposition and simultaneous deposition lead to different catalytic activity and the deposition sequence of Ni and Co also have different catalytic activity and selectivity for gasification of phenol in supercritical water.The carbon gasification efficiency of phenol in SCW beyond 95%with Co-Ni/AC catalyst,indicating that Co-Ni/AC is a potential catalyst to eliminate phenols.Repeated use of bimetallic catalyst has shown the high stability of Co-Ni/AC catalyst.