Abstract:
The invention is a process for producing paraxylene, benzene and/or toluene is alkylated with methanol in the presence of a catalyst under conditions effective to convert said benzene and/or toluene to xylene and produce a product stream containing water, xylene and one or more phenolic impurities. The said product stream is separated into a water-rich stream and a xylene-rich stream containing one or more phenolic impurities and at least a portion of the xylene-rich stream is contacted with an aqueous solution of a base under conditions to remove at least some of the phenolic impurities from the xylene-rich stream portion.
Abstract:
In a hydrocarbon upgrading process, a hydrocarbon feed is treated in at least one of a steam cracker, catalytic cracker, coker, hydrocracker, and reformer under suitable conditions to produce a first stream comprising olefinic and aromatic hydrocarbons. A second stream composed mainly of C4+ olefinic and aromatic hydrocarbons is recovered from the first stream and is fed together with a methylating agent to a reaction zone containing a catalyst under reaction conditions including a temperature of about 450° C. to about 700° C., such that aromatics components in the second stream undergo dealkylation, transalkylation and/or methylation and aliphatic components undergo cracking and aromatization to produce a third stream having an increased xylene content compared with said second stream and a C3− olefin by-product. The C3− olefin by-product is recovered and para-xylene is removed from at least part of said third stream.
Abstract:
The present inventors have surprisingly discovered that paraxylene selectivity is found to increase as the amount of coke on catalyst increases. In embodiments the paraxylene selectivity and productivity is maximized by controlling the amount of coke on the catalyst while maintaining xylene yield at an acceptable value. The control of coke may be achieved by one or a combination of the following techniques: increasing catalyst on-oil time, decreasing catalyst residence time in the regenerator, reducing the air or oxygen supply to the regenerator, and decreasing catalyst circulation rate, or a combination thereof.
Abstract:
In a process for the production of para-xylene, methanol is preheated to a first temperature, an aromatic feedstock comprising toluene and/or benzene is preheated to a second temperature and the preheated methanol and aromatic feedstocks are fed to a reactor at a first methanol to aromatic feedstock molar ratio. The preheated aromatic feedstock is contacted with the preheated methanol under alkylation conditions in the reactor in the presence of a catalyst so that the methanol reacts with the aromatic feedstock to produce an effluent comprising para-xylene. During the reaction, a temperature is measured within the reactor and is compared with a predetermined optimal temperature. The methanol to aromatic feedstock molar ratio is then adjusted in a manner to reduce any difference between the measured and predetermined optimal temperatures in the reactor.
Abstract:
In a hydrocarbon upgrading process, a hydrocarbon feed is treated in at least one of a steam cracker, catalytic cracker, coker, hydrocracker, and reformer under suitable conditions to produce a first stream comprising olefinic and aromatic hydrocarbons. A second stream composed mainly of C4+ olefinic and aromatic hydrocarbons is recovered from the first stream and is fed together with a methylating agent to a reaction zone containing a catalyst under reaction conditions including a temperature of about 450° C. to about 700° C., such that aromatics components in the second stream undergo dealkylation, transalkylation and/or methylation and aliphatic components undergo cracking and aromatization to produce a third stream having an increased xylene content compared with said second stream and a C3− olefin by-product. The C3− olefin by-product is recovered and para-xylene is removed from at least part of said third stream.
Abstract:
The invention relates to the production of paraxylene by an alkylation process that also produces oxygenates. The process is controlled to utilize recycle to minimize said oxygenates.
Abstract:
In a process for the regeneration of a coked metal-containing catalyst, the coked catalyst is contacted in a regeneration zone with an atmosphere which contains carbon dioxide and carbon monoxide at a temperature of at least 400° C.
Abstract:
The invention is a process for producing paraxylene, benzene and/or toluene is alkylated with methanol in the presence of a catalyst under conditions effective to convert said benzene and/or toluene to xylene and produce a product stream containing water, xylene and one or more phenolic impurities. The said product stream is separated into a water-rich stream and a xylene-rich stream containing one or more phenolic impurities and at least a portion of the xylene-rich stream is contacted with an aqueous solution of a base under conditions to remove at least some of the phenolic impurities from the xylene-rich stream portion.
Abstract:
The invention relates to the production of paraxylene by an alkylation process that also produces oxygenates. The process is controlled to utilize recycle to minimize said oxygenates.
Abstract:
In a process for the regeneration of a coked metal-containing catalyst, the coked catalyst is contacted in a regeneration zone with an atmosphere which contains carbon dioxide and carbon monoxide at a temperature of at least 400° C.