Patent GB-816984-A (GB)
Title: Improvements in or relating to processing of hydrocarbons
IPC: B01J27/06
Filed: 1955-12-13
Abstract: In the treatment of hydrocarbons with a liquid HF-BF3 agent, the surfaces exposed to the agent are of pure aluminium or of aluminium containing a minor proportion of alloying elements. The apparatus may be made wholly of aluminium or of steel coated with aluminium. Aluminium alloy containing chromium, copper, magnesium, manganese, silicon, or tantalum may be used.  An aluminium alloy substantially free from silicon or copper is preferred for use above 100 DEG  C., and pure aluminium at above 150 DEG  C.  A series of tests is described in which corrosion by liquid HF-BF3 agent of aluminium and aluminium alloys is compared with that of nickel, steel, stainless steel, and the alloys known under the Registered Trade Marks "Hastelloy," "Monel," and "Multimet."  Apparatus is described in which a mixture of xylene isomers is reacted with ethylbenzene in the presence of liquid HF-BF3 catalyst to produce 3,5 - dimethyl - 1 - ethylbenzene, metaxylene, and benzene (see Group IV (b)). Other treatments of hydrocarbons are referred to, including the removal of aromatic hydrocarbons and sulphur compounds from petroleum distillates.ALSO:<PICT:0816984/IV (b)/1> In the treatment of hydrocarbons with a liquid HF-BF3 agent, the surfaces exposed to the agent are of pure aluminium or of aluminium containing a minor proportion of alloying elements. The apparatus may be made wholly of aluminium or of steel coated with aluminium.  Aluminium alloy containing chromium, copper, magnesium, manganese, silicon, or tantalum may be used.  An aluminium alloy substantially free from silicon or copper is preferred for use above 100 DEG  C., and pure aluminium at above 150 DEG  C.  A series of tests is described in which corrosion by liquid HF-BF3 agent of aluminium and aluminium alloys is compared with that of nickel, steel, stainless steel, and the alloys known under the Registered Trade Marks "Hastelloy," "Monel," and "Multimet".  In the apparatus shown, a mixture of xylene isomers (prepared by extractive distillations of a naphtha reforming product) is reacted with ethylbenzene in the presence of liquid HF-BF3 catalyst to produce 3.5-dimethyl - 1 - ethylbenzene, meta - xylene and benzene.  The hydrocarbon feed is mixed with HF and BF3 in vessel 13 and passes through line 26 to reactor 29 and thence to decomposer 32, from which HF and BF3 are removed to recovery zone 37 and recycled.  The liquid product passes to fractionation system 49 where the various products are separated.  The exposed surfaces in vessels 13, 29, 32 and 37, and the connecting lines are of aluminium. Other reactions involving a liquid HF-BF3 catalyst are the reaction of toluene and carbon monoxide to product tolyl aldehyde, the alkylation of butylene and isobutane, the isomerization of paraffins, the alkylation of xylene with ethylene, and the disproportionation of ethylbenzene to diethylbenzene or xylene to mesitylene.  Liquid HF-BF3 agent may also be used to remove aromatic hydrocarbons and sulphur compounds from petroleum distillates, or to separate metaxylene from ortho- and para-xylene as described in U.S.A. Specification 2,528,892.