Patent GB-466066-A (GB)
Title: Improvements relating to the polymerization of olefins
IPC: C07C2/08
Filed: 1936-05-15
Abstract: Mixtures of iso- and normal olefines such as a butane cut from cracked oils are passed over a solid catalyst at a temperature below 200 DEG  C., preferably between 50 and 150 DEG  C., the reaction time being so limited that the polymers produced are predominantly iso-olefine polymers.  When temperatures above 150 DEG  C. are employed, it is desirable to use pressures of, e.g. 50--100 lb./sq. in.  The time varies according to the temperature and catalyst employed but should be sufficient to give a yield of 75--125 per cent of the iso-olefine present.  Below about 100 DEG  C., 3--50 secs., and above about 150 DEG  C., 5--30 secs. are suitable. The preferred conditions are 80--100 DEG  C. and 5--40 secs., giving a yield of about 100 per cent of the iso-olefines present in a butane cut.  Any butadiene in the initial material is preferably removed before the polymerization.  Suitable catalysts are difficultly reducible oxides of Groups 2--4, especially Al, La, and Zr oxides supported on silica or the like, rare earths alone or mixed with oxides of Al, Zr, or Zn, phosphoric acid on carriers, aluminium chloride on pumice or silica, or Al+Cd on silica.  The remaining olefines may be polymerized in a second stage, preferably at higher temperatures and pressures, and with or without catalysts, 200--500 DEG  C. for 100--10 secs. is suitable. The first polymer is used in producing high octane motor fuel. The second polymer is less valuable and may be blended with the first in varying proportions.  Examples are given of the polymerization of a C4 hydrocarbon mixture containing about 40 per cent total olefines, 10,7 per cent iso-butylene, using diatomaceous earth impregnated with phosphoric acid (1) at atmospheric pressure, reaction time 5 secs.; (2) at 60 lb. pressure, average time 20 secs. the selectivity, i.e. the fraction of the iso-olefines polymerized over the fraction of the normal olefines polymerized, being given for temperatures of 80--240 DEG  C. In example (3), the gases are contacted for 4,7 secs. at 100 DEG  C.  The remaining gases are treated with the same catalyst at 150 lb./sq. in. and 225 DEG  C. for 100 secs.  The polymers are added to gasoline.ALSO:The octane no. of gasolene is improved by adding polymers obtained by passing mixtures of iso- and normal olefines, such as a butane cut from cracked oils, over a solid catalyst at a temperature below 200 DEG  C., preferably between 50 and 150 DEG  C., the reaction time being so limited that the polymers produced are predominantly iso-olefine polymers.  When temperatures above 150 DEG  C. are employed, it is desirable to use pressure, e.g. 50--100 lb. per sq. in.  The time varies according to the temperature and catalyst employed but should be sufficient to give a yield of 75--125 per cent of the iso-olefine present.  Below about 100 DEG  C. 3--50 secs., and above about 150 DEG  C. 5--30 secs., are suitable. The preferred conditions are 80--100 DEG  C. and 5--40 secs. giving a yield of about 100 per cent of the iso-olefines present in a butane cut.  Any butadiene in the initial material is preferably removed before the polymerization.  The remaining olefines may be polymerized in a second stage preferably at higher temperatures and pressures, and with or without catalysts 200--500 DEG  C. for 100--10 secs. is suitable.  The first polymer is added to gasolene to produce aeroplane or other high octane motor fuel.  The second polymer alone or blended with the first is also used to improve gasolene.