Catalytic Pyrolysis Of Tar On Nickel Support On Biomass Carbon

People pay more and more attention to the development and utilization of renewable clean biomass energy because of the growing shortage of fossil energy and the serious environment questions. The gasification for producing syngas is regarded as the most promising technology for the utilization of biomass energy. But in the process of gasification for gas, tar impurity will also be created and tar has complex composition and great harm, so removing the tar produced during gasification is urgently needed. In this paper, we conducted a series of research for toluene, a model compound of biomass tar using catalytic pyrolysis method, which is the most economic and efficient. Carbon catalysts have been widely used as catalyst support because of their high specific surface area, developed pore structure, low cost and biocompatibility. Nickel catalysts have the best catalytic performance for steam reforming of tar. So in this paper, we prepared a new kind of catalyst with activated carbon as a support and nickel nanoparticles as active component, and made a series of research for the performance of the catalysts.The main research contents are as follows:(1) The equipment building:Build the fixed bed reactor device used for catalyst activity test, and improve and debug the equipment.(2) The determination of analysis detection method:Internal standard method and external standard method were used respectively to test the liquid phase and gas phase, and established the calculation method of the toluene conversion and gas composition.(3) Preparation and characterization of catalysts:The effects of different catalyst preparation methods (such as the pretreatment of the carbon support, nickel source, impregnating solvents, different load method, the catalyst calcination atmosphere and reduction temperature, etc.) on the Ni nanoparticles size and performance of catalysts were studied, and the various physical characterizations of XRD, BET, H2-TPR, TEM, FTIR were tested. Controllable synthesis of supported Ni catalysts was realized and the mean diameter of Ni nanoparticles varied from 5.1 nm to 9.1 nm with Ni loading amount increased from 9 wt.% to 18 wt.%(4) The influence of reaction conditions:The effects of different reaction conditions on toluene conversion and the gas composition were systematically studied, such as system of mass transfer, reaction temperature, residence time, S/C, and nickel loadings. Ni/AC showed high catalytic activity and good stability for toluene steam reforming: 97.8% conversion of toluene was obtained with the Ni content of 9 wt.% (flow rate of toluene was 5 mL/h and S/C was 3) and the conversion just decreased from 100% to 92% after 700 min (flow rate of toluene was 3 mL/h and S/C was 2). Because of the high activity, stability and low cost, the as-prepared catalyst opens up new opportunities for tar removing.