Study On Hydrogenation Of Naphthalene To Decalin In A Fixed Bed Reactor

Decalin is a very strong solvent, which makes it can dissolve super high molecular weight polyethylene at low temperature. And decalin has a strong volatility, it can be drived away from fibre by 80 centigrade nitrogen, so it can be reclaimed. Decalin has been the best solvent of super high molecular weight polyethylene in the process of dry filature. Besides, decalin can be used as the best endothermal fuel of dehydrogenation and cracking in ramjet and as a hydrogen source for fuel-cell vehicle.There is no synthetical technology and production installation of decalin in China now. The production decalin needs to be imported, and it is expensive. There are a few corporations produce and sell decalin overseas. Due to naphthalene resource is abundance in China, we can produce decalin by catalyzed hydrogenation naphthalene immediately. Therefore developing the best catalyzed hydrogenation technics to produce decline matching the quality criterion of foreign production is the innovation of this research. The major works of this research including: 1) the selections of catalyst of hydrogenation and solvent of naphthalene, 2) determinations of the best reactor temperature, pressure and liquid hourly space velocity, 3) improving the conversion and reducing byproduct percents.We selected catalysts in a high pressure kettle reactor, which are Pt/Al2O3 and Ni/Al2O3 produced by ourselves. We compared the performances of these catalysts at the same react condition, and determined Ni/Al2O3 as the hydrogenation catalyst finally; Then the selected catalyst was used in a fixed bed reactor to optimize the react condition, we discussed the influence of variety react conditions to the conversion of the reactant and the selectivity of production.We regressed our experiment data by using process optimize software, ascertained the react conditions and technic parameters of synthesizing decalin in a fixed bed reactor: the concentration of naphthalene in feed stock is 18～20%; the concentration of trans-decalin in feed stock is 40～70%; liquid hourly space velocity is 0.6～0.8 ml/ml.h; react temperature is 443～463K; react pressure is 7～8MPa. In the light of optimized react conditions and technic parameters we carried out the experimentation of continuous synthesizing decalin in the fixed bed reactor. After rectifying we can gain eligible decalin production. The purity of decalin is above 98%; The concentration of trans-decalin in production is under 60%; The conversion...