Development And Industrial Application Of Catalyst For Ethylbenzene Hydrogenation

In view of some problems and shortcomings existed in the catalyst applied at the current styrene plant of Lanzhou Petrochemical Company, the new improved styrene catalyst and concerned production technology are developed, its industrial application has carried out successfully. This achievement can improve the domestic production technology for ethyl benzene dehydrogenation to styrene, provided mature technology and precious experience for the styrene production in China.Styrene monomer(SM) is a very important raw material for synthesis of some polymers and macromolecule materials. In our country, styrene is mainly manufactured via the technological route of ethyl benzene dehydrogenation. The ethyl benzene dehydrogenation catalyst is one of core techniques in styrene production, and its performances may determine the economical feasibility of process. The performances of a ideal dehydrogenation catalyst should meet follow requirements, such as lower mass ratio of steam to oil, high ethyl benzene conversion activity, high styrene selectivity, long service life, ideal stability and mechanical strength. In this work, the proper composition of catalyst is investigated in detail, the balance between each Fe-K-Ce-Mo-Mg compounds in the K-contained catalyst is adjusted carefully, and some new promoters and structural stabilizer are introduced, thus the new generation of dehydrogenation catalyst is developed, its optimized activation conditions are found, and the reproducibility of catalytic performances have been tested. Under the conditions of negative pressure and adiabatic operation, the test on pilot plant and 1000 hours test on the scale plant are carried out. The comprehensive performances of the modified catalyst type of LH365M has been improved apparently, which is of lower average pore size of 160? and higher specific surface area of 4.0 cm2/g, the conversion of ethyl benzene can reached to more than 70%; the selectivity for styrene is 94.7%, the losing rate of potassium content is as low as 50%, the performances under the conditions of lower temperature ana lower mass ratio ofsteam to oil can be enhanced obviously. The technical index of new catalyst is reached to the advanced international level. Based on this work, the new catalyst has been applied in the industrial styrene plant of SRPLP, and the very favorable effect has been obtained: Using MAX-5 catalyst in the first stage of reactor, the conversion of ethyl benzene increases by 4%, and using LH365M catalyst in the second stage of reactor, the conversion increases by 2%.