Patent GB-949935-A (GB)
Title: Isomerization process
IPC: C07C5/27
Filed: 1960-06-28
Abstract: Paraffin hydrocarbons having 4-7 carbon atoms, and/or cycloparaffin hydrocarbons having 5 or 6 nuclear carbon atoms and a total of 6-9 carbon atoms, are isomerized at - 18 to 82 DEG  C. by contact with a solid particulate catalyst comprising 5-90% of aluminium chloride and a solid salt of an inorganic acid or an absorbent solid, the aluminium chloride being positioned on the surface of the solid salt or the absorbent solid; the feed mixture must not contain more than 0.5% by volume of aromatic hydrocarbon but must contain (as an inhibitor) at least 2% by volume of cycloparaffin hydrocarbon, which may be one of those specified above.  The feed may also contain 0.01-3% by weight of hydrogen chloride. The proportion of aluminium chloride in the catalyst must be sufficient to form a mono layer over the entire surface of the absorbent solid.  Specified inorganic salts are various calcium and magnesium phosphates, dicalcium arsenate, acid lithium arsenate, sodium aluminium phosphate, dibasic dimanganese phosphate, zirconium, manganese and titanium sulphates, basic aluminium chromate, basic nickel arsenite, basic cobalt borate, nickel silicotungstate or silicomolybdate and cadmium borotungstate. Specified absorbent solids are activated charcoal, fuller's earth, porous clay, silica gel, alumina, bauxite or magnesia.  The catalyst may be supported on a carrier, e.g. pumice or porcelain chips. Examples are given, in some of which 0.6% by volume of pentene-2 is added to the feed as an activator. The used catalyst may be regenerated by a process comprising (1) washing with an inert liquid hydrocarbon, preferably a naphthene or isobutane, at 38-150 DEG  C., (2) re-washing at a higher temperature, (3) treating at 38-150 DEG C., with inert liquid hydrocarbon saturated with aluminium chloride, (4) cooling to the reaction temperature, and (5) purging inert liquid hydrocarbon from the reactor.  Alternatively, treatment of the spent catalyst with a large volume of hot isobutane or a naphthene containing dissolved aluminium chloride may suffice.ALSO:An isomerization catalyst (see Division C5) comprises 5-90% of aluminium chloride and a solid salt of an inorganic acid or an absorbent solid, the aluminium chloride being positioned on the surface of the solid salt or the absorbent solid; the proportion of aluminium chloride in the catalyst must be sufficient to form a mono-layer over the entire surface of the absorbent solid. Specified inorganic salts are various calcium and magnesium phosphates, dicalcium arsenate, acid lithium arsenate, sodium aluminium phosphate, dibasic dimanganese phosphate, zirconium, manganese and titanium sulphates, basic aluminium chromate, basic nickel arsenite, basic cobalt borate, nickel silicotungstate or silicomolybdate and cadmium borotungstate. Specified absorbent solids are activated charcoal, fuller's earth, porous clay, silica gel, alumina, bauxite or magnesia.  The catalyst may be supported on a carrier, e.g. pumice or porcelain chips.  The used catalyst may be regenerated by a process comprising (1) washing with an inert liquid hydrocarbon, preferably a naphthene or isobutane, at 38-150  DEG C., (2) rewashing at a higher temperature, (3) treating at 38-150  DEG C., with inert liquid hydrocarbon saturated with aluminium chloride, (4) cooling to the reaction temperature and (5) purging inert liquid hydrocarbon from the reactor. Alternatively, treatment of the spent catalyst with a large volume of hot isobutane or a naphthene containing dissolved aluminium chloride may suffice.