Patent GB-650485-A (GB)
Title: Process for the conversion of liquid hydrocarbons into aromatic hydrocarbons and gaseous products
Filed: 1948-04-12
Abstract: Non-aromatic hydrocarbon mixtures having a boiling-range within 50-400 DEG  C., particularly petroleum distillates boiling between 90 DEG  and 300 DEG  C., are converted into aromatic hydrocarbons and olefin-containing gases by passing the vaporized feed through a reactor filled with substantially non-absorptive pieces of non-metallic, refractory material, at a temperature between 600 DEG and 800 DEG  C., a pressure between atmospheric and 5 atm. (gauge), and a space velocity between 0.05 and 0.6, preferably between 0.2 and 0.6, litres of liquid-feed per hour per litre-volume of the reactor. "Substantially non-absorptive pieces" are defined as those which absorb not more than 50 mgm., and preferably not more than 10 mgm., of water per c.c. of material under certain conditions which are set forth in the Specification.  The material must be refractory at 1000 DEG  C., and it must be able to withstand a large number of oxidation treatments for the burning-off of carbon.  Suitable materials are hard porcelain, stone-ware, and non-absorptive bodies formed of quartz, fused silica, and carborundum.  When the process is applied to a paraffinic or naphthenic distillate boiling below 300 DEG  C., about equal weights of liquid and gaseous products are obtained.  The liquid product contains benzene, toluene, xylenes, and other aromatic hydrocarbons, including polycyclic compounds.  The gaseous product contains ethylene, propylene, butenes and butadiene in addition to methane and ethane.  The feed-mixture may also be a product of the cracking or reforming of a mineral oil, or it may be a Fischer-Tropsch synthetic mixture.  The reactor preferably consists of a cracking section having a relatively large "surface to volume" ratio, followed by a thermo-neutral, aromatization section having a relatively small "surface to volume" ratio.  In an example, the reactor was made of 18/8 Ni-Cr stainless steel and consisted of a tube 20 feet long and 3 inches in diameter followed by a 4 feet, 6 inch tube of 9 inch diameter.  Both tubes were packed with lumps ( 1/2 inch X 3/4 inch) of porcelain obtained from broken-up, high-tension insulators, in such a way that about 50 per cent free space was left.  A kerosene of Middle East origin (B.R. 175-265 DEG C.) was vaporized at about 500 DEG  C. and passed through the reactor at a gauge pressure of 25 lbs./square inch and a space velocity of 0.42.  The average temperature in both sections of the reactor was 685 DEG  C.  About 47 per cent of the kerosene was converted into a liquid product containing over 90 per cent of aromatic compounds; and a substantial proportion of this liquid boiled below 200 DEG  C. Specifications 255,159, [Class 32], 363,051, [Group III], 552,216, 559,297, 574,973, 575,383, 575,766, 575,770 and 575,771 are referred to.ALSO:Non-aromatic hydrocarbon mixtures having a boiling-range within 50-400 DEG  C., particularly petroleum distillates boiling between 90 DEG  and 300 DEG  C., are converted into aromatic hydrocarbons and olefin-containing gases by passing the vaporized feed through a reactor filled with substantially non-absorptive pieces of non-metallic, refractory material, at a temperature between 600 DEG  and 800 DEG  C., a pressure between atmospheric and 5 atm. (gauge), and a space velocity between 0.05 and 0.6, preferably between 0.2 and 0.6, litres of liquid-feed per hour per litre-volume of the reactor.  "Substantially non-absorptive pieces" are defined as those which absorb not more than 50 mgm. and preferably not more than 10 mgm., of water per c.c. of material under certain conditions which are set forth in the Specification.  The material must be refractory at 1000 DEG  C., and it must be able to withstand a large number of oxidation treatments for the burning-off of carbon.  Suitable materials are hard porcelain, stoneware, and non-absorptive bodies formed of quartz, fused silica, and carborundum.  When the process is applied to a paraffinic or naphthenic distillate boiling below 300 DEG  C., about equal weights of liquid and gaseous products are obtained.  The feed-mixture may also be a product of the cracking or reforming of a mineral oil, or it may be a Fischer-Tropsch synthetic mixture.  In an example, the reactor was made of 18/8 Ni-Cr stainless steel and consisted of a tube 20 feet long and 3 inches in diameter followed by a 4 foot, 6 inches tube of 9 inch diameter.  Both tubes were packed with lumps ( 1/2 inch X 3/4 inch) of porcelain obtained from broken-up, high-tension insulators, in p  such a way that about 50 per cent free space was left.  A kerosene of Middle East origin (B.R. 175-265 DEG  C.) was vaporized at about 500 DEG  C. and passed through the reactor at a gauge pressure of 25 lbs./square inch and a space velocity of 0.42.  The average temperature in both sections of the reactor was 685 DEG  C.  About 47 per cent of the kerosene was converted into a liquid product containing over 90 per cent of aromatic compounds; and a substantial proportion of this liquid boiled below 200 DEG  C. Specifications 255,159, [Class 32], 363,051, 552,216, [Group IV], 559,297, 574,973, [Group IV], 575,383, 575,766, [Group IV], 575,770 and 575,771, [Group IV], are referred to.