Alkylation Process Using Catalysts With Low Olefin Skeletal Isomerization Activity

PATENT
Alkylation Process Using Catalysts With Low Olefin Skeletal Isomerization Activity
Patent number: 8158839
Issue date: Apr 17, 2012
Application number: 13/101,450
Inventors: Mark G. Riley, Deng-Yang Jan, Stephen W. Sohn, Jaime G. Moscoso
Original Assignee: UOP LLC

A process is presented for the production of linear alkylbenzenes. The process includes contacting an aromatic compound with an olefin in the presence of a selective zeolite catalyst. The catalyst includes two zeolites combined to improve the linearity, and to produce detergent grade LAB. The two zeolites are selected to limit skeletal isomerization while producing a desired 2-phenyl content for the LAB.

FIELD OF THE INVENTION

The present invention is directed to highly selective, modified catalysts and the process of using the catalysts. The catalysts are for use in the alkylation of aromatic compounds.

BACKGROUND OF THE INVENTION

Alkylation of benzene produces alkylbenzenes that may find various commercial uses, e.g., alkylbenzenes can be sulfonated to produce surfactants, for use in detergents. In the alkylation process, benzene is reacted With an olefin the desired length to produce the sought alkylbenzene. The alkylation conditions comprise the presence of homogeneous or heterogeneous alkylation catalyst such as aluminum chloride, hydrogen fluoride, or zeolitic catalysts and elevated temperature.
 
Various processes have been proposed to alkylate benzene. One commercial process involves the use of hydrogen fluoride as the alkylation catalyst. The use and handling of hydrogen fluoride does provide operational concerns due to its toxicity, corrosiveness and Waste disposal needs. Solid catalytic processes have been developed that obviate the need to use hydrogen fluoride. Improvements in these solid catalytic processes are sought to further enhance their attractiveness through reducing energy costs and improving selectivity of conversion While still providing an alkylbenzene of a quality acceptable for doWnstream use such as sulfonation to make surfactants.
 
Alkylbenzenes, to be desirable for making sulfonated surfactants must be capable of providing a sulfonated product of suitable clarity, biodegradability and eflicacy. With respect to eflicacy, alkylbenzenes having higher 2-phenyl contents are desired as they tend, When sulfonated, to provide surfactants having better solubility and detergency. Thus, alkylbenzenes having a 2-phenyl isomer content in the range from about 30 to about 40 percent are particularly desired.
 
Improvements in the catalysts have facilitated the production of linear alkylbenzenes, as shoWn in U.S. Pat. No. 6,133, 492, U.S. Pat. No. 6,521,804, U.S. Pat. No. 6,977,319, and U.S. Pat. No. 6,756,030. HoWever, problems exist With many existing catalysts, and a better understanding, can lead to further improvements in the catalysts.

SUMMARY OF THE INVENTION

The present invention provides for a process for producing a monoalkylated aromatic compound having an increased linearity of the alkyl group. The process comprises reacting an aromatic feedstock With an olefinic compound in an alkylation reactor at reaction conditions using a catalyst comprising tWo zeolites.
 
The first zeolite comprising a microporous crystalline zeolite having a layered frameWork of at least AlO2 and SiO2 tetrahedral units and a composition on an as-synthesized and anhydrous basis
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