Study On The Conversion Properties Of Porous Metal Oxide Loaded Hollow Membrane Lignin

With the development of society,the energy crisis has become a major challenge for mankind.It is imminent to develop and utilize the energy structure of green sustainable development.As a part of green energy,lignin biomass has gradually aroused people's attention,and has been developed and utilized as a chemical raw material.The development of lignin biodegradation technology has become the focus of scholars' research.This paper attempts to study the oxidative degradation of lignin from the aspect of Fenton oxidation technology,focusing on the performance and stability of metal loaded mesoporous materials and membrane materials in the process of heterogeneous Fenton oxidative degradation of lignin.The main contents of this paper are listed as follows:1.Using SBA-15 as template,mesoporous Fe-Cu catalyst was prepared by hard template method.Through XRD SEM,TEM and N2 adsorption desorption isotherm characterization,it can be seen that the catalyst maintained regular regular pore structure and large pore volume and specific surface area.Iron copper metal are transition metals,iron and copper may have redox synergistic effects during the reaction,accelerate the iron cycle,the heterogeneous Fenton reaction can be continuously carried out quickly.Through lignin degradation experiments,it was found that mesoporous Fe-Cu catalyst showed good catalytic and reusing performance in the degradation of lignin by heterogeneous Fenton.The optimum conditions for the test are lignin concentration of 50 mg.L-1,catalyst concentration of 1 g.L-1,H2O2 360 mg·L-1,pH=3,and reaction temperature 70 ?.2.Chelating agent co-assembly method was used to prepare iron loaded mesoporous carbon(Fe/Meso-c)precursor.Then the Fe/Meso-c precursor material was evenly dispersed on the hollow alumina ceramic tube carrier by stacking and coating,and the modified Fe/Meso-c@CM ceramic membrane was successfully prepared.The metal loaded mesoporous carbon precursor materials were characterized by XRD,SEM,TEM and FTIR.The results showed that the metal particles were successfully loaded into the pores of mesoporous carbon and maintained the pore arrangement and structure of mesoporous carbon.Through the SEM characterization of the modified ceramic membrane,we can see that the precursor material has been loaded onto the surface and inner channel of the ceramic tube successfully,forming a dense and smooth active layer on the surface of the carrier,and the metal particles are immersed in the channel of ceramic tube carrier.Compared the mesoporous carbon activity on lignin degradation properties of different metal load,and the Fe/Meso-c@CM ceramic membrane as the research object,in the process of lignin degradation by heterogeneous Fenton,the degradation of lignin in 540 min still can reach 70%,and the carrier shows good reusing performance.The optimum conditions for the test are pH=5,Fe:H2O2=1:20,metal load 0.2 g,transmembrane pressure 0.02Mpa,and lignin concentration 50 mg·L-1.