Research On Preparation And Properties Of Alumina Membrane Coated Activated Carbon Support

With expansion of industrial production of the vinyl chloride from acetylene, it is advanced and economical to use fluidized bed reactor. Research on fluidized bed technology about production of the vinyl chloride from acetylene has attracted much attention. However, currently, the mechanical strength of effective activated carbon catalyst particles is not enough, which have seriously affected the economy and industrial development of the technology.Currently, there are two kinds of methods to improve the mechanical strength of the catalyst. That is catalyst shaping and heat treatment. But these methods often depress catalyst activity and are inapplicable to mercury chloride impregnated activated carbon catalyst. For this purpose, this thesis plans to coat alumina membrane on activated carbon. The membrane has good mechanical strength and transmission performance and expects to enhance the attrition resistance of activated carbon.In this paper, we studied the preparation of activated carbon coated with the alumina membrane firstly. Then its attrition strength property, pore structure property, corrosion resistance property and adsorption property were discussed. We mainly got the following achievements:(1) Coconut shell activated carbon was chosen as the substrate, and stable clarification of alumina sol as a coating fluid. Adopting repetitious slip-cast method, activated carbon coated by a layer of dense, uniform and smooth Y-Al2O3 membrane was prepared, the thickness of which was about 550nm.(2) Compared to activated carbon, the pore structure property of activated carbon coated by Y-Al2O3 membrane had a slight change. After coated by Y-Al2O3 membrane, BET surface area, pore volume, micropore surface area, micropore volume decreased slightly and the average size and surface area of pore, mesopore volume increased slightly. The coating of alumina membrane did not affect transmission and adsorption property of acetylene and hydrogen chloride on activated carbon. Hydrogen chloride did not erode the alumina membrane.(3) The alumina membrane with good mechanical strength could effectively prevent the activated carbon from being attrited, which greatly enhanced the attrition resistance property of activated carbon. In addition, the attrition rate of activated carbon particles coated byγ-alumina membrane was 2.90%, which nearly approached to the attrition rate of the pureγ-Al2O3 particles and almost reached the minimum value.