GB679194A - Process for the conversion of liquid hydrocarbons into olefin-containing gases and aromatic hydrocarbons - Google Patents

Abstract

Liquid non-aromatic hydrocarbons boiling between 50 DEG and 400 DEG C. are converted into olefine-containing gases and aromatic hydrocarbons, by vaporizing the liquid and passing the vapours, mixed with steam or carbon dioxide, through a reactor comprising a cracking zone packed with a non-metallic refractory material, followed by a non-packed aromatization zone. The temperature in the reactor is maintained between 600 DEG and 850 DEG C., the pressure between atmospheric and 10 atm. (gauge), and the space-velocity between 0.05 and 2.0 litres (liquid hydrocarbon) per hour per litre volume of the reactor. The packing material may be ceramic (e.g. hard porcelain). Petroleum distillates boiling between 90 DEG and 300 DEG C. form suitable starting materials, also the liquid products of the Fischer-Tropsch synthesis. In an example, a kerosene of Middle East origin was emulsified with 0.6 per cent by volume of water, and the mixture was supplied to a vaporizer to produce vapour at 500 DEG C. The vapour was passed through a cracking tube (20 feet long and 3 inches internal diameter) packed with pieces ( 1/2 X 3/4 inches) of broken-up high-tension insulators. The vapour was then passed through a non-packed aromatization tube (4 feet 6 inches long and 9 inches internal diameter). The temperature, pressure, and space-velocity in the reactor were 690 DEG C., 60 p.s.i.g., and 0.93 respectively. The products leaving the aromatization tube were quenched and passed through a heated tar pot to a condenser, and then to a receiver in which the liquids were separated from the gases. The gases contained high percentages of ethylene and propylene; while the liquid products (which comprised 48.6 per cent by weight of the charge) contained high percentages of benzene, toluene, xylene and naphthalene. In another example, kerosene was vaporized (without addition of water); and carbon dioxide (1 per cent) was injected into the vapour, before it was introduced into the reactor. The process may be carried out in the apparatus described in Specification 650,487. Specifications 552,216, 574,973, 575,383, 575,766, 575,771 and 650,485 also are referred to.ALSO:Liquid non-aromatic hydrocarbons boiling between 50 DEG and 400 DEG C are converted into olefine-containing gases and aromatic hydrocarbons by vaporizing the liquid and passing the vapours, mixed with steam or carbon dioxide, through a reactor comprising a cracking zone packed with a non-metallic refractory material, followed by a non-packed aromatization zone. The temperature in the reactor is maintained between 600 DEG and 850 DEG C, the pressure between atmospheric and 10 atm. (gauge), and the space-velocity between 0.05 and 2.0 litres (liquid hydrocarbon) per hour per litre volume of the reactor. The process enables prolonged runs e.g. 400 hours, to be carried out before it becomes necessary to shut down to burn off the carbon deposited in the reactor. The packing material is preferably in the form of lumps, balls, or rings made of hard porcelain, stoneware, quartz, fused silica, or carborundum. Petroleum distillates boiling between 90 DEG and 300 DEG C form suitable starting-materials, also the liquid products of the Fischer-Tropsch synthesis. In an example, a kerosene (B.R. 175 DEG to 265 DEG C) of Middle East origin was emulsified with 0.6 per cent by volume of water, and the mixture was supplied to a vaporizer to produce vapour at 500 DEG C. The vapour was passed through a cracking tube (20 feet long and 3 inches internal diameter) packed with pieces ( 1/2 X 3/4 inches) of broken-up high-tension insulators, the volume of free space being about 50 per cent of the total volume of the cracking tube. The vapour was then passed through a non-packed aromatization tube (4 feet 6 inches long and 9 inches internal diameter). The temperature, pressure, and space-velocity in the reactor were 690 DEG C, 60 p.s.i.g., and 0.93 respectively. The products leaving the aromatization tube were quenched and passed through a heated tar pot to a condenser, and then to a receiver in which the liquids were separated from the gases. The gases (which comprised 50.4 per cent by weight of the charge) contained high percentages of ethylene and propylene, while the liquid products contained high percentages of benzene, toluene, xylene and naphthalene. In another example, kerosene was vaporized (without addition of water); and carbon dioxide (1 per cent) was injected into the vapour, before it was introduced into the reactor. The process may be carried out in the apparatus described in U.S.A. Specification 1,650,487. Specifications 552,216, 574,973, [both in Group IV], 575,383, 575,766, 575,771, [both in Group IV], and 650,485 also are referred to