Aromatic alkylation process
AssigneeSaudi Basic Industries Corporation
InventorsFrederick Merrill Galloway, Jr., Ashim Kumar Ghosh, Mohammad Shafiei, Peter N. Loezos
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Abstract
The present invention is for a process for the alkylation of aromatic compounds, with a shape-selective zeolite catalyst. The process has reactors in series with C8+ aromatics being separated from the product stream effluents from each reactor before passing the reactor effluent to the next reactor with an additional input of methanol. The C8+ aromatics are separated into para-xylene and other C8+ aromatics. This process is applicable for toluene methylation having a molar excess of toluene:methanol. i.e., greater than 1:1, with a shape-selective catalyst of an aluminosilicate zeolite, such as ZSM-5 which has been modified with phosphorus, to produce para-xylene (p-xylene).
Claims17
A method of alkylation of an aromatic in a series of reactors comprising:
- a) contacting in a first reactor an aromatic compound and an alkylating agent under reaction conditions suitable for aromatic alkylation in the presence of a shape-selective zeolite catalyst;
- b) withdrawing a product stream from the first reactor;
- c) separating a stream comprising at least 50 mole % of all C8+ aromatics produced in the first reactor from the product stream from the first reactor;
- d) introducing additional alkylating agent and the remaining product stream from the first reactor to a second reactor;
- e) withdrawing a product stream from a last reactor;
- and
- f) separating para-xylene from the product stream of the last reactor and the separated steam(s) comprising at least 50 mole % of all C8+ aromatics produced in the reactor(s).
A method of alkylation of an aromatic in a series of reactors comprising:
- a) contacting in a first reactor toluene and methanol in a mole ratio range from 2:1 to 20:1 under reaction conditions suitable for methylation of toluene in the presence of a phosphorus-modified ZSM-5 catalyst;
- b) withdrawing a product stream from the first reactor;
- c) separating C8+ aromatics from the product stream from the first reactor;
- d) introducing additional methanol and the remaining product stream from the first reactor to a second reactor;
- e) withdrawing a product stream from a last reactor;
- f) separating para-xylene from the product stream of the last reactor and the separated steam(s) comprising at least 50 mole % of all C8+ aromatics produced in the reactor(s).
Dependencies are inferred from the claim text.