Patent GB-478841-A (GB)
Title: A process for the manufacture of hydrocarbon mixtures containing a high percentage of alkenes of high molecular weight
IPC: C10G9/00
Filed: 1936-10-19
Abstract: A process for the manufacture of alkene-containing hydrocarbon mixtures which may be used to prepare salts of sulphuric acid esters &c. suitable as wetting-agents by evaporating hydrocarbon material, containing a high percentage of paraffin wax, e.g. paraffin filter cakes, in the presence of an inert diluent as completely as possible without cracking, and heating the evaporated material, after removal of constituents which under the prevailing conditions of temperature are not in the vapour phase, to cracking temperature, wherein in order to produce hydrocarbon mixtures containing alkenes having 10 or more carbon atoms in the molecule, the evaporated material is heated rapidly and for a very short period to cracking temperature, the time required for bringing the evaporated material to cracking temperature and the cracking time not exceeding 5 seconds.  The evaporation and cracking is carried out under 2--5 atmos. pressure, the hydrocarbon partial pressure not exceeding 0,6 of the total pressure.  Cracking temperatures of 500--600 DEG  C. are specified, the evaporation temperatures being 50--150 DEG  C. below the cracking temperatures. Molten crude paraffin cakes are evaporated in a tube furnace at 470 DEG  C. under 4,8 atmos. pressure in the presence of 10 per cent by weight of steam.  The products are passed into a separator where liquids are separated and the vapours are cracked at 545 DEG  C. for 2,9 seconds.  The cracked vapours are cooled by injection of water and products boiling over 300 DEG  C. are recycled.  The fraction boiling between 160 and 300 DEG  C. contains 80 per cent alkenes by volume.ALSO:A process for the manufacture of alkene-containing hydrocarbon mixtures by evaporating hydrocarbon material containing a high percentage of paraffin wax, e.g. paraffin filter cakes, in the presence of an inert diluent as completely as possible without cracking, and heating the evaporated material, after removal of constituents which under the prevailing conditions of temperature, are not in the vapour phase to cracking temperature, wherein in order to produce hydrocarbon mixtures containing alkenes having 10 or more carbon atoms in the molecule, the evaporated material is heated rapidly and for a very short period to cracking temperature, the time required for bringing the evaporated material to cracking temperature and the cracking time not exceeding 5 seconds.  The evaporation and cracking is carried out under 2--5 atmos. pressure, the hydrocarbon partial pressure not exceeding 0,6 of the total pressure.  Cracking temperatures of 500--600 DEG  C., are specified, the evaporation temperature being 50--150 DEG  C. below the cracking temperature. Molten crude paraffin cakes are evaporated in a tube furnace at 470 DEG  C. under 4,8 atmos. pressure in the presence of 10 per cent by weight of steam. The products are passed into a separator where liquids are separated, and the vapours are cracked at 545 DEG  C. for 2,9 seconds.  The cracked vapours are cooled by injection of water and products boiling over 300 DEG  C. are recycled.  The fraction boiling between 160 and 300 DEG  C. contains 80 per cent alkenes by volume and may be used for preparing alcohols, ethers, esters, e.g. alkaline salts of sulphuric acid esters for use as wetting-agents.