Papers by Keyword: Ethylbenzene

Abstract: The process of oxidation of hydrocarbon with oxygen proceeds with formation of the corresponding hydroperoxide as the primary product [1,2]. A catalyst is the most important factor that influences on the direction of flow of the oxidation reaction. Catalysts based on metals of variable valency, and their derivatives are the most active in reactions of oxidation of hydrocarbon [3].

Abstract: The oxidative ethylbenzene dehydrogenation to styrene with CO₂ has been studied using various catalysts to enhance its activity and stability. The type of V₂O₅-Fe₂O₃/A_l2O₃-TiO₂ catalyst is studied to fit for this process. It is found that different TiO₂ loadings can lead to the activity difference. Compared with the results happened in N₂ atmosphere, both activity and selectivity were lower than that in the CO₂. Hence, CO₂ was chosen as a soft oxidant by improving activity and selectivity in the process of oxidative ethylbenzene dehydrogenation to styrene with CO₂ over the investigated catalysts.

Abstract: Cr-substituted mesoporous aluminophosphate molecular sieve (Cr-MAP) was prepared and characterized. Cr-MAP is a typical mesoporous molecular sieve with long-range ordered structure, providing effective molecular sieve for fabricating acetophenone by selectively oxizing ethylbenzene with tertiary butyl hydro peroxide (TBHP). When the reaction is at 100 °C for 8 h, using chlorobenzene as solvent and TBHP as oxidant, ethylbenzene conversion, acetophenone selectivity and acetophenone yield reach 72.8 %, 85.4 %, and 62.2 %, respectively.

Abstract: The mathematical model for multicomponent diffusion in styrene production is given considering all six reactions involved in styrene production. The diffusion coefficients for catalyst pellet are calculated for unimodal and bimodal pore size distributions using trapezoidal rule of integration. The effects of standard deviation and average pore size on the diffusion coefficient are determined. The differential equations are converted to algebraic equations and solved by the orthogonal collocation method. The effectiveness factor of catalyst pellet in styrene production is calculated for various pore sizes. It is seen that the average pore size and pore size distribution affects the production rate and effectiveness factor significantly.

Abstract: This article demonstrates the design and industrial operation results of the ethylbenzene(EB) production technology from FCC dry gas by a combination of gas-phase alkylation and liquid-phase transalkylation, developed and commercialized by Dalian Institute of Chemical Physics (DICP), CAS. Based on the high active modified ZSM-5/ZSM-11 co-crystalline zeolite alkylation catalyst and modified β zeolite transalkylation catalyst, both the alkylation and transalkylation reactions are performed under much milder conditions, resulting in low energy cost and low content of xylenes impurities in the EB product. Also, the novel process for EB production, developed by DICP recently, through alkylation of dilute ethylene with gas-liquid mixed phase benzene and transalkylation feed is optimized. The results show that the transalkylation feed addition into the middle-lower part of the reactor improves the EB selectivity from about 90% to more than 99%, and the alkylation and transalkylation reactions are unified into a single reactor. Moreover, the alkylation reaction temperature decreases from more than 320 °C to about 170 °C, and the content of the xylenes impurities in the EB product is further decreased to less than 100 ppm.

Abstract: The effective diffusion coefficients for a single catalyst pellet were determined by numerical integration of the Johnson-Stewart equation for bimodal and unimodal pore size distributions assuming a transitional diffusion regime. The effectiveness factors of a spherical catalyst pellet were determined at various pore size distribution probability density functions. Using effectiveness factors the production rates were determined. The results showed that the effectiveness factor and production rate are sensitive to catalyst pore size distribution and diffusion coefficient.