| 摘要 |
<p>Aromatic hydrocarbons are mono-alkylated by reactng an excess with an alkylating agent in the presence of boron trifluoride and a boron trifluoride-modified, solid, refractory inorganic oxide to effect alkylation, adding to the effluent a recycle stream of polyalkylated aromatic hydrocarbon and passing with boron trifluoride over a boron trifluoride modified inorganic oxide to effect transalkylation and recovering from the product unreacted aromatic hydrocarbon which is recycled to the alkylation, monoalkylated hydrocarbon product and polyalkyl hydrocarbon which is recycled to the transalkylation. The aromatic hydrocarbon may have one or more rings and may contain alkyl groups and the alkylation agent may be an olefin, polyolefin, cycloolefin, acetylene or an alkyl ester e.g. alkyl halide, sulphate or phosphate, and may be diluted with nonreactive components, e.g. in a refinery stream. The alkylation of benzene with ethylene is exemplified. The molar ratio of aromatic to alkylating agent may be 4-20:1 and boron trifluoride is added in amounts of 0.1 milligram to 0.8 gram per gram mol of alkylating agent. An inert diluent may be present. The inorganic oxide may be of aluminium, zirconium, silicon, magnesium, boron, phosphorus, mixtures of such oxides or diatomaceous earth or bauxite and may be premodified or modified in situ during the reaction. The alkylation may be effected at 50-250 DEG C., 1-100 atmospheres maintaining the aromatic hydrocarbon liquid, and a space velocity of 0.1-20 vol./vol./hr. The transalkylation is preferably effected under more severe conditions, e.g. at a higher p temperature in the range 100-300 DEG C., by adding further boron trifluoride or by using more modified oxide.</p> |
