A process is described for producing paraxylene, in which an aromatic hydrocarbon feedstock comprising benzene and/or toluene is contacted with an alkylating reagent comprising methanol and/or dimethyl ether in an alkylation reaction zone under alkylation conditions in the presence of an alkylation catalyst to produce an alkylated aromatic product comprising xylenes. The alkylation catalyst comprises a molecular sieve having a Constraint Index≤5, and the alkylation conditions comprise a temperature less than 500° C. Paraxylene may then be recovered from the alkylated aromatic product.

A process is described for producing paraxylene, in which an aromatic hydrocarbon feedstock comprising benzene and/or toluene is contacted with an alkylating reagent comprising methanol and/or dimethyl ether in an alkylation reaction zone under alkylation conditions in the presence of an alkylation catalyst to produce an alkylated aromatic product comprising xylenes. The alkylation catalyst comprises a molecular sieve having a Constraint Index≤5, and the alkylation conditions comprise a temperature less than 500° C. The alkylation catalyst may be selectivated to produce a higher than equilibrium amount of paraxylene by using a molar ratio of alkylating agent to aromatic of at least 1:4.

A process is described for producing paraxylene, in which an aromatic hydrocarbon feedstock comprising benzene and/or toluene is contacted with an alkylating reagent comprising methanol and/or dimethyl ether in an alkylation reaction zone under alkylation conditions in the presence of an alkylation catalyst to produce an alkylated aromatic product comprising xylenes. The alkylation catalyst comprises a molecular sieve having a Constraint Index≤5, and the alkylation conditions comprise a temperature less than 500° C. The alkylation catalyst may be selectivated to produce a higher than equilibrium amount of paraxylene by using a molar ratio of alkylating agent to aromatic of at least 1:4.

The invention relates to the field of gas chemistry and, more specifically, to methods and devices for producing aromatic hydrocarbons from natural gas, which involve producing synthesis gas, converting same into methanol producing, from the methanol, in the presence of a catalyst, a concentrate of aromatic hydrocarbons and water, separating the water, air stripping hydrocarbon residues from the water, and separating-out the resultant concentrate of aromatic hydrocarbons and hydrogen-containing gas, the latter being at least partially used in the production of synthesis gas to adjust the ratio therein of H.sub.2:CO 1.8-2.3:1, and can be used for producing aromatic hydrocarbons. According to the invention, the production of aromatic hydrocarbons from methanol in the presence of a catalyst is carried out in two consecutively-connected reactors for synthesizing aromatic hydrocarbons: in a first, low-temperature isothermal reactor for synthesizing aromatic and aliphatic hydrocarbons, and in a second, high-temperature adiabatic reactor for synthesizing aromatic and aliphatic hydrocarbons from aliphatic hydrocarbons formed in the first reactor, and the subsequent stabilization thereof in an aromatic hydrocarbon concentrate stabilization unit. At least a portion of the hydrogen-containing gas is fed to a synthesis gas production unit and is used for producing synthesis gas using autothermal reforming technology. The installation carries out the method. The achieved technical result consists in increasing the efficiency of producing concentrates of aromatic hydrocarbons.

This disclosure relates to the production of xylenes from syngas, in which the syngas is converted to an aromatic product by reaction with a Fischer-Tropsch catalyst and an aromatization catalyst. The Fischer-Tropsch catalyst and aromatization catalyst may be different catalysts or combined into a single catalyst. The aromatic product is then subjected to selective alkylation with methanol and/or carbon monoxide and hydrogen to increase its p-xylene content.

This disclosure relates to the production of xylenes from syngas, in which the syngas is converted to an aromatic product by reaction with a Fischer-Tropsch catalyst and an aromatization catalyst. The Fischer-Tropsch catalyst and aromatization catalyst may be different catalysts or combined into a single catalyst. The aromatic product is then subjected to selective alkylation with methanol and/or carbon monoxide and hydrogen to increase its p-xylene content.

This invention relates to an alkylating process for alkyl benzenes, including the steps of: a) an alkyl benzene and a first stream of alkylating agent being fed into a first reaction zone, contacting with a catalyst A, to produce a process stream I; b) the process stream I and a second stream of alkylating agent being fed into at least one second reaction zone, contacting with a catalyst B, to produce a process stream II; and c) the process stream II being fed into at least one third reaction zone, contacting with a catalyst C, to produce a process stream III containing an alkylate. The present alkylating process can improve the utilization efficiency of the alkylating agent.

This invention relates to an alkylating process for alkyl benzenes, including the steps of: a) an alkyl benzene and a first stream of alkylating agent being fed into a first reaction zone, contacting with a catalyst A, to produce a process stream I; b) the process stream I and a second stream of alkylating agent being fed into at least one second reaction zone, contacting with a catalyst B, to produce a process stream II; and c) the process stream II being fed into at least one third reaction zone, contacting with a catalyst C, to produce a process stream III containing an alkylate. The present alkylating process can improve the utilization efficiency of the alkylating agent.

In a process and system for treatment of feed stocks comprising alkylating agent and metal salts, the metal salts are removed from the feedstock by an efficient combination of separations processes. The processes may take place in one or more stages, each stage taking place in one or more vessels. Such treatment processes may remove 99.9% or more of metal salts from a feedstock, while recovering 99.9% or more of the alkylating agent from the feedstock for use in an alkylation reaction, especially of aromatics such as toluene and benzene. Preferred alkylating agents include methanol and mixtures of carbon monoxide and hydrogen, for methylation of toluene and/or benzene. The methylation proceeds over an aluminosilicate catalyst and preferably yields para-xylene with 75% or greater selectivity.

In a process and system for treatment of feed stocks comprising alkylating agent and metal salts, the metal salts are removed from the feedstock by an efficient combination of separations processes. The processes may take place in one or more stages, each stage taking place in one or more vessels. Such treatment processes may remove 99.9% or more of metal salts from a feedstock, while recovering 99.9% or more of the alkylating agent from the feedstock for use in an alkylation reaction, especially of aromatics such as toluene and benzene. Preferred alkylating agents include methanol and mixtures of carbon monoxide and hydrogen, for methylation of toluene and/or benzene. The methylation proceeds over an aluminosilicate catalyst and preferably yields para-xylene with 75% or greater selectivity.