摘要:
A method for minimizing the loss of xylenes in an ethylbenzene conversion/isomerization process by adding toluene to the feedstock. The concentration of toluene in the feedstock is increased by co-feeding toluene or by recycling toluene separated from the ethylbenzene conversion reactor effluent. The increased toluene concentration reduces the loss of xylenes during the ethylbenzene conversion reaction and under preferred operating conditions increases the amount of xylenes in the product.
摘要:
There is provided a process for the alkylation of ethylbenzene with ethylene to selectively produce para-diethylbenzene over a catalyst which has been selectivated by multiple treatments with a siliceous material.
摘要:
There is provided a process for shape selective xylene disproportionation that involves contacting a feedstream which includes xylene under conversion conditions, with a molecular sieve catalyst that has been surface modified. The xylene disproportionation process has a selectivity for pseudocumene of over 85%.
摘要:
A method for increasing the efficiency of xylene isomerization by using a two stage isomerization process. In the first stage of the process, a C.sub.9.sup.+ aromatics feedstock is subjected to ethylbenzene conversion and xylene isomerization. Non-C.sub.8 aromatics are removed from the effluent, which is then processed in a second stage of the process to remove para-xylene and isomerize the para-xylene depleted effluent. The effluent from the second stage isomerization unit is then recycled into the inlet of the second stage of the process and a slip stream from the para-xylene separator is recycled to the feedstock and to the effluent of the ethylbenzene conversion unit. In this way, the production of para-xylene is maximized. In a preferred embodiment, toluene is co-fed into the feedstock to minimize the loss of xylenes during the ethylbenzene conversion reaction.
摘要:
A porous crystalline material has a tetrahedral framework comprising a general structure, M1-IM-M2, wherein M1 comprises a metal having a first valency, wherein M2 comprises a metal having a second valency different from said first valency, and wherein IM is imidazolate or a substituted imidazolate linking moiety.
摘要:
The management of hydrogen in hydrogen-containing streams associated with petrochemical process units wherein the hydrogen-containing stream is subjected rapid cycle pressure swing adsorption to increase the concentration of hydrogen therein.
摘要:
The present invention relates to engineered structured adsorbent contactors for use in pressure swing adsorption and thermal swing adsorption processes. Preferably, the contactors contain engineered and substantially parallel flow channels wherein 20 volume percent or less of the open pore volume of the contactor, excluding the flow channels, is in the mesopore and macropore range.
摘要:
A catalyst system that exhibits a ratio of ethylene saturation to aromatics ring saturation of greater than 3,500. The catalyst system comprises two components and each component comprises a crystalline molecular sieve having a Constraint Index of from about 1 to about 12 and an effective amount of Group VIII metal. The catalyst system finds particular application in ethylbenzene conversion/xylenes isomerization reactions. The catalyst system can be prepared by incorporating the Group VIII metal into the molecular sieves by competitive ion exchange.
摘要:
An ethylbenzene conversion catalyst is described which comprises a molecular sieve and a hydrogenation metal, wherein the catalyst exhibits a benzene hydrogenation activity at 100° C. of less than about 100 and a metal dispersion, as measured by hydrogen chemisorption, greater than 0.4 and wherein the molecular sieve is steamed to an alpha value of less than 400 prior to incorporation of the palladium with the molecular sieve.
摘要:
There is provided a zeolite catalyst, which is first selectivated with a siliceous material and then treated with an aqueous solution comprising alkaline earth metal ions under ion exchange conditions.