Alkylation process and catalyst therefor

#In one aspect, this invention relates to a novel composition of matter, which is effective as an alkylation catalyst, comprising trifluoromethanesulfonic acid and an inorganic solid support material. In another aspect, this invention relates to the alkylation of alkanes (paraffins) with alkenes (monoolefins), in the presence of a novel solid catalyst composition comprising trifluoromethanesulfonic acid and a solid support material.

#The use of supported trifluoromethanesulfonic acid catalyst for the alkylation of alkanes with alkenes is known and has been described in the patent literature (e.g., in European Patent Application having Publication No. EP 0 433 954 A1). The present invention is directed to a novel, effective alkylation catalyst composition comprising trifluoromethanesulfonic acid and specific inorganic support materials, and to the use of said catalyst composition in an alkylation process.

#It is an object of this invention to provide a novel solid composition of matter which is active as an alkylation catalyst. It is another object of this invention to alkylate alkanes with alkenes in the presence of a novel solid catalyst comprising trifluoromethanesulfonic acid and an inorganic support material. Other objects and advantages will be apparent from the detailed description of the appended claims.

#The composition of matter of this invention comprises CF.sub.3 SO.sub.3 H on an inorganic support material which contains BPO.sub.4 and/or B.sub.2 (SO.sub.4).sub.3. Generally, the support material contains about 20 to about 100 weight-% BPO.sub.4 and/or B.sub.2 (SO.sub.4).sub.3 and up to about 80 weight-% (preferably about 0.5-80 weight-%) SiO.sub.2. Other inorganic solids, such as alumina and activated carbon, may be used in lieu of or in addition to silica. The BET/N.sub.2 surface area of these support materials generally is in the range of about 200 to about 400 m.sup.2 /g. Preferably, the particles of the composition of matter have a size in the range of smaller than 20 mesh and larger than 40 mesh.

#The composition of matter of this invention can be prepared in any suitable manner. Preferably, the BPO.sub.4 -containing support material is prepared by the reaction of a boric acid ester B(OR).sub.3 wherein each R can be independently selected from alkyl radicals containing 1-5 carbon atoms (more preferably tri-n-propyl borate) and orthophosphoric acid (H.sub.3 PO.sub.4), with SiO.sub.2 either being absent during this reaction (so as to prepare a 100% BPO.sub.4 material) or SiO.sub.2 being present during this reaction in an amount as to provide a material containing up to about 80 weight-% SiO.sub.2 (preferably about 0.5-80 weight-% SiO.sub.2). When a B.sub.2 (SO.sub.4).sub.3 -containing support material is used, it is preferably prepared by the reaction of a boric acid ester (such as tri-n-propyl borate) and sulfuric acid, either in the absence of or in the presence of up to 80 weight-% SiO.sub.2 (preferably about 0.5-80 weight-% SiO.sub.2). The thus-obtained support material is then preferably calcined (generally for about 2-5 hours at a temperature of about 250.degree.-500.degree. C., either in air or in a N.sub.2 atmosphere). The CF.sub.3 SO.sub.3 H catalyst component can be applied to the support material in any suitable manner. Generally, it is added in liquid form to the top layer of the solid support material (preferably being present in a catalyst bed) just prior to the alkylation reaction, generally at a weight ratio of CF.sub.3 SO.sub.3 H to said support material in the range of about 0.02:1 to about 0.4:1.

#The solid compositions or matter described above are employed as catalysts in the alkylation process of this invention. The process for alkylating C.sub.2 -C.sub.7 alkanes (preferably isoalkanes, i.e., branched alkanes) with C.sub.2 -C.sub.7 alkenes (preferably those containing an internal double bond) can be carried out in any suitable manner. The contacting of a mixture of at least one feed alkane and at least one feed alkene, generally at a molar alkane/alkene ratio of about 6:1 to about 12:1 (preferably about 8:1 to about 10:1), with one of the above-described catalyst compositions can be carried out at effective alkylation conditions, preferably at a relatively low temperature of up to about 100.degree. C., preferably about -10.degree. to about 100.degree. C., more preferably about 0.degree.-30.degree. C., most preferably about 0.degree.-5.degree. C., preferably at a pressure of about 2-6 atm.