Patent GB-1001767-A (GB)
Title: Process and apparatus for the conversion of hydrocarbons by treatement with a liquidcatalyst
IPC: C07C5/27
Filed: 1963-04-01
Abstract: The invention comprises a process and apparatus for the conversion of hydrocarbons, wherein the hydrocarbons are treated with a liquid catalyst containing a mixture of molten metal halides, e.g. a mixture of aluminium chloride and antimony chloride, and in which the used catalyst is continuously withdrawn from the reaction zone and passed to an extraction zone in which it is contacted with the hydrocarbons to be treated in order to dissolve in the said hydrocarbon's metal halides from the said catalyst, a sludge remaining, after which the resultant solution is passed to said reaction zone in which it is treated with liquid catalyst, the sludge remaining behind in the first extraction zone being extracted batchwise in a second extraction zone with hydrocarbons to be treated.  In preferred embodiments:  (1) a portion of the hydrocarbons to be treated are passed through both extraction zones and (2) the supply of hydrocarbons to the bottom of the second extraction zone is interrupted when the sludge in the second extraction zone is spent, and the said hydrocarbons are passed to the bottom of the first extraction zone, the sludge being withdrawn batchwise from the bottom part of the second extraction zone. Conversion processes specified are isomerization, alkylation, polymerization, reforming and refining. Hydrocarbon starting materials specified are alkanes having 4 to 9 carbon atoms, e.g. butane and pentane, and cyclic hydrocarbons, e.g. methyl cyclopentane, dimethylcyclopentane and methyl cyclohexane. Commercial hydrocarbon mixtures obtained from natural gases, petroleum distillates and cracked distillates having butane and pentane components and straight run gasoline and casing head gasolines are also used.  The hydrocarbon mixtures used are preferably freed from excess amounts of alkenes, alkadienes and other impurities by mineral acid refining or hydrogenation.  The catalyst materials used are mixtures of Friedel-Crafts type catalysts, e.g. aluminium chloride with halides of Li, Na, K, Cu, Zr, Nb, Mn, Pd, Mg, Zn, Cd, Sn, Pb, As, Sb, Hf, Ta, V, W, Tl, Bi, Cr, Fe, Co and Ni which may be liquids below 100 DEG  C.  The conversions are carried out at 60 DEG  to 120 DEG  C. and pressures of 9 kg./sq. cm. to 35 kg./sq. cm. and when isomerization takes place up to 25% HCl by weight based on the hydrocarbon feed may be used. After conversion the reaction products are separated off by distillation.  In additional procedural steps: (1) catalyst drawn from the first extraction zone, may be stirred before passing to the second extraction zone, (2) only a portion of the hydrocarbon feed may be passed through the second extraction zone which may be wholly or partly passed to the first zone and (3) additional hydrocarbon feed may be passed directly to the reaction zone.  As shown in Fig. 1, used catalyst from an isomerization reactor (not shown) is passed through line 1 into extraction zone 2 which may be fitted with disc and doughnut trays and contacts hydrocarbons supplied through line 3 and open valves 4 and 5.  Hydrocarbons containing dissolved metal halides pass through line 6 to the isomerization reactor.  After closing valve 5 and opening valve 8, sludge passes through line 7 to second extraction zone 9, hydrocarbons now being passed through the latter from line 10 and subsequently to extraction zone 2 via line 11 and 12.  When the catalyst has been freed from metal halides valve 4 is closed and hydrocarbons are introduced directly via valves 13 and 14 and line 12 into extraction zone 2. Sludge is drained off through line 15, valves 8, 14 and 16 are closed and valves 4 and 5 opened to repeat the cycle. In a modification, a column 20 contains extraction zones 21 and 22, separated by plate 23 provided with standpipe 24 and a horizontal plate 25 fitted above the standpipe.  Zone 21 is fitted with disc and doughnut trays.  Used catalyst supplied to extraction zone 21 through line 37 contacts hydrocarbons which have passed through the standpipe 24.  Plate 25 prevents sludge from passing into the second zone 22 and line 26 and pump 27 are provided for passing the sludge into said second zone wherein extraction of the catalyst material again takes place with hydrocarbon supplied <PICT:1001767/C4-C5/1> into the upper part of zone 22 and then through the standpipe 24. Valve 34 is now opened and sludge is removed via lines 33 and 35. The cycle is restarted by closing valves 32 and 34 and opening valve 30.  The example describes the through lines 28, 29 and 33, valves 32 and 34 being closed.  When the sludge in zone 22 is free from metal halides, valve 30 is closed and valve 32 opened so that hydrocarbons now flow <PICT:1001767/C4-C5/2> regeneration of a molten catalyst consisting of 95% SbCl3 and 5% AlCl3 by weight at 85 DEG  C. over a period of twelve hours wherein less than 0.02% of SbCl3 contained in the used catalyst is lost.