Patent GB-896020-A (GB)
Title: Improvements in or relating to the purification of liquid hydrocarbons
IPC: C10G25/00
Filed: 1959-01-02
Abstract: Adsorbents of acid character are rendered selective towards the dissolved organic nitrogen compounds (in preference to unsaturates) contained in liquid hydrocarbons derived from cracking or thermal reforming, by pretreatment with a polar organic liquid having an adsorptive affinity for the adsorptive agent between that of dioxane and methanol.  The adsorbent is regenerated by treatment with a polar liquid of the same type, preferably the same liquid.  The adsorbents may also be used to remove nitrogen compounds from oil derived from shale and from tar distillates, e.g. crude benzene.  Adsorbents specified are inorganic compounds of acid character comprising silicon and/or aluminium, e.g. silica gel, alumina, spent silicaalumina cracking catalyst, and activated clay.  Polar organic liquids specified are oxygen-containing compounds such as dialkyl ketons, e.g. acetone and butanone; alkyl esters of fatty acids, e.g. ethyl acetate; dialkyl ethers, e.g. diethyl and diiosopropylethers; cyclic ethers, e.g. dioxane; and alkanols, e.g. methanol, ethanol and isopropanol.  In examples a 40 DEG C. to 205 DEG C. gasoline is obtained by the catalytic cracking of a mineral oil and treating the product with dilute aqueous caustic soda solution followed by the air solutizer sweetening process of Specification 775,015.  This gasoline is treated with (i) Silica gel pretreated with acetone which may be regenerated with equal volumes of water and acetone, the water passing through after the gasoline but before the acetone thus facilitating separation; (ii) silica gel pretreated and regenerated with ethyl acetate; and (iii) spent silica-alumina cracking catalyst pretreated and regenerated with acetone.ALSO:Adsorbents of acid character are rendered selective towards the dissolved organic nitrogen compounds (in preference to unsaturates) contained in liquid hydrocarbons derived from cracking or thermal reforming by pretreatment with a polar organic liquid having an adsorptive affinity for the adsorptive agent between that of dioxane and methanol.  The adsorbent is regenerated by treatment with a polar liquid of the same type, preferably the same liquid.  The adsorbents may also be used to remove nitrogen compounds from oil derived from shale and from tar distillates, e.g. crude benzene.  Adsorbents specified are inorganic compounds of acid character comprising silicon and/or aluminium, e.g. silica gel, alumina, spent silica-alumina cracking catalyst, and activated clay.  Polar organic liquids specified are oxygen-containing compounds such as dialkyl ketones, e.g. acetone and butanone; alkyl esters of fatty acids, e.g. ethyl acetate; dialkyl ethers, e.g. diethyl and diiosopropylethers; cyclic ethers, e.g. dioxane; and alkanols, e.g. methanol, ethanol and isopropanol.  In examples a 40 DEG C. to 250 DEG C. gasoline is obtained by the catalytic cracking of a mineral oil and treating the product with dilute aqueous caustic soda solution followed by the air solutizer sweetening process of Specification 775,015.  This gasoline is treated with (i) Silica gel pretreated with acetone which may be regenerated with equal volumes of water and acetone, the water passing through after the gasoline but before the acetone thus facilitating separation; (ii) silica gel pretreated and regenerated with ethyl acetate; and (iii) spent silica-alumina cracking catalyst pretreated and regenerated with acetone.