Patent GB-918967-A (GB)
Title: Process for the alkylation of hydrocarbons and catalyst therefor
Inventor: PFEFFERLE WILLIAM CHARLES
IPC: B01J21/12
Filed: 1960-10-18
Abstract: Alkylation of aromatic or isoparaffin hydrocarbons with mono-olefins is effected in presence of a solid catalytic material which comprises at least one refractory oxide other than aluminium oxide supported on a base having a large pore structure and being composed essentially of gamma alumina modifications resulting from the drying and calcination of a mixture of precursor hydrous alumina phases containing at least 65% of trihydrate, the base after calcining and before use having a surface area of 350 to 550 sq. metres per gram. Specified refractory oxides include silica, magnesia, thoria, zirconia, and mixtures of these.  In an example, an alumina base was prepared as described in Specification 832,200.  The alumina gel was washed, dried, and calcined in a current of air at 480 DEG C.  The calcined pellets had a surface area of 500 sq. metres per gram.  They were impregnated with boric acid solution, dried and calcined.  The boria-alumina catalyst was used for the alkylation of benzene with ethylene and for the alkylation of isobutane with propylene.  In another example, the alumina pellets were impregnated under vacuum with an alcoholic solution of ethyl orthosilicate and then treated with hydrochloric acid, and the pellets were subsequently dried and calcined to form a silica on alumina catalyst.  Specification 735,390 also is referred to.ALSO:An aromatic or isoparaffin hydrocarbon is alkylated with a mono-olefin in the presence of a solid catalytic material which comprises at least one refractory oxide other than aluminium oxide supported on a base having a large pore structure and being composed essentially of gamma alumina modifications resulting from the drying and calcination of a mixture of precursor hydrous alumina phases containing at least 65% of trihydrate, the base after calcining and before use having a surface area of 350 to 550 sq. metres per gram.  Specified refractory oxides include silica, magnesia, thoria, boria, zirconia, and mixtures of these.  The temperature of alkylation may be in the range 250-650 DEG F. and the pressure may be from atmospheric to 1,000 p.s.i.g. or more.  The weight of total feed per weight unit of catalyst per hour may be from 0.1 to 10.  The process may be used in the alkylation of isobutane, isopentane, benzene, toluene, or mixtures thereof, with ethylene, propylene, butene, pentene; propylene dimer, trimer or tetramer; or butene dimers.  In an example, an alumina base was prepared as described in Specification 832,200.  The alumina gel was washed, dried, and calcined in a current of air at 480 DEG C. The calcined pellets had a surface area of 500 sq. metres per gram.  They were impregnated with boric acid solution, dried, and calcined.  The boria-alumina catalyst was used for the alkylation of benzene with ethylene, ethyl benzene being formed.  Isobutane was similarly alkylated with propylene.  In another example, the alumina pellets were impregnated while under vacuum with an alcoholic solution of ethyl orthosilicate and then treated with hydrochloric acid, and the pellets were subsequently dried and calcined to form the catalyst material.  If desired, there may be introduced into the reaction zone together with the isoparaffin and mono-olefin, an aromatic hydrocarbon of not more than 10 carbon atoms so as to reduce the formation of olefin polymers.  In this case lower temperatures e.g. as low as 30 DEG F. may be used. The aromatic hydrocarbon may be benzene, toluene, ethyl benzene, mesitylene, or durene.  The formation of olefin polymers may also be substantially reduced by introducing into the reaction zone together with an alkylatable hydrocarbon such as isobutane and the monoolefin, a small proportion of a paraffin hydrocarbon containing 5 or 6 carbon atoms including a tertiary carbon atom e.g. 2-methyl pentane, or diisopropyl. Specification 735,390 also is referred to.