Patent GB-840825-A (GB)
Title: Producing lubricating oils by irradiation
IPC: C08F10/00
Filed: 1957-10-28
Abstract: Hydrocarbon mixtures, defined below and boiling in the range 300 DEG to 700 DEG  F. are irradiated with neutrons and g -rays having an energy above 1 Mev. obtained from a nuclear reactor, at 100 DEG  to 600 DEG  F. and a dose rate above 1 equivalent megaroentgen per hour, until 100 to 1000 equivalent megaroentgens have been absorbed, to obtain a lubricating oil.  The hydrocarbon mixture comprises 60 to 95% of saturated hydrocarbons, 5 to 40% of unsaturated straight chain hydrocarbons, less than 2% of aromatics and less than 25% of naphthenes.  Preferably there is separated from the irradiated mixture a fraction boiling above 700 DEG  F. having a viscosity above 35 SSU at 210 DEG  F. and a viscosity index above 125 which may be used as a lubricating oil; a portion of said fraction boiling at 800 DEG  to 1000 DEG  F. may be blended with another lubricating oil to comprise 1-15% of the composition whereby an improved lubricating composition having a viscosity in the range of 40 to 60 SSU at 210 DEG  F. and a viscosity index above 115 may be obtained. The latter portion of said fraction preferably has a viscosity in the range of 1000 to 10,000 SSU at 210 DEG  F. and may lower the pour point by at least 10 DEG  F.  The initial hydrocarbon subjected to irradiation may be obtained by catalytic cracking, e.g. at 850 DEG  to 1050 DEG F., or by fluid coking, delayed coking, thermal cracking or steam cracking, e.g. at 800 DEG  to 1400 DEG  F.  Where a catalytically cracked distillate is used it may be first separated by distillation and then treated to remove aromatics by a conventional liquid extraction process and then further cleaned up with a solid absorbent; where thermal cracking is employed, it is preferred to extract the desired straight chain paraffins and olefins from the cracked mixture with a molecular sieve.  A starting mixture of the desired composition may be obtained in other ways, e.g. by modifying a paraffin wax by the addition of olefins having from 12 to 24 carbon atoms, or by reducing the olefin content of olefin-rich feed stocks by means of sulphuric acid or hydrogenation.  The irradiation may be performed batchwise or continuously, and the material may be placed in suitable containers or conduits in or near the irradiation source or the material can serve as a moderator in the nuclear reactor. Preferably at least 30% of the energy received is obtained from neutrons.  The pressure during irradiation may if desired be up to 500 p.s.i. or more to maintain condensed phase conditions. Isotopes giving rise to secondary radiation upon capture of neutrons (e.g. boron 10, lithium 6 and cadmium 113) may be present during irradiation as solutes, as discrete solids contained in the irradiated mixture or can be present on the container walls; 0.001 to 1% of such isotopes based on the composition treated may be employed.ALSO:Hydrocarbon mixtures, defined below and boiling in the range 300 DEG  to 700 DEG  F. are irradiated with neutrons and g -rays having an energy above 1 Mev obtained from a nuclear reactor, at 100 DEG  to 600 DEG  F. and a dose rate above 1 equivalent megaroentgen per hour, until 100 to 1000 equivalent megaroentgens have been absorbed, to obtain a lubricating oil.  The hydrocarbon mixture comprises 60 to 95% of saturated hydrocarbons, 5 to 40% of unsaturated straight chain hydrocarbons, less than 2% of aromatics and less than 25% of naphthenes.  Preferably there is separated from the irradiated mixture a fraction boiling above 700 DEG  F. having a viscosity above 35 SSU at 210 DEG  F. and a viscosity index above 125 which may be used as a lubricating oil; a portion of said fraction boiling at 800 to 1000 DEG  F. may be blended with another lubricating oil to comprise 1-15% of the composition whereby an improved lubricating composition having a viscosity in the range of 40 to 60 SSU at 210 DEG  F. and a viscosity index above 115 may be obtained.  The latter portion of said fraction preferably has a viscosity in the range of 1000 to 10,000 SSU at 210 DEG  F. and may lower the pour point by at least 10 DEG  F.  The initial hydrocarbon subjected to irradiation may be obtained by catalytic cracking, e.g. at 850 DEG  to 1050 DEG  F., or by fluid coking, delayed coking, thermal cracking or steam cracking, e.g. at 800 DEG  to 1400 DEG  F. Where a catalytically cracked distillate is used it may be first separated by distillation and then treated to remove aromatics by a conventional liquid extraction process and then further cleaned up with a solid absorbent; where thermal cracking is employed, it is preferred to extract the desired straight chain paraffins and olefins from the cracked mixture with a molecular sieve.  A starting mixture of the desired composition may be obtained in other ways, e.g. by modifying a paraffin wax by the addition of olefins having from 12 to 24 carbon atoms, or by reducing the olefin content of olefin-rich feed stocks by means of sulphuric acid or hydrogenation.  The irradiation may be performed batchwise or continuously, and the material may be placed in suitable containers or conduits in or near the irradiation source or the material can serve as a moderator in the nuclear reactor. Preferably at least 30% of the energy received is obtained from neutrons.  The pressure during irradiation may if desired be up to 500 p.s.i. or more to maintain condensed phase conditions. Isotopes giving rise to secondary radiation upon capture of neutrons (e.g. boron 10, lithium 6 and cadmium 113) may be present during irradiation as solutes, as discrete solids contained in the irradiated mixture or can be present on the container walls; 0.001 to 1% of such isotopes based on the composition treated may be employed.