Patent GB-478668-A (GB)
Title: Improvements in or relating to the manufacture of hydrocarbon gases from coal
IPC: C10G1/06
Filed: 1936-07-23
Abstract: Hydrocarbon gases, e.g. acetylene and lower olefines, e.g ethylene and propylene, are obtained by subjecting coal to extraction with an organic solvent or solvent mixture, hydrogenating the extracted fraction, vaporizing the hydrogenation product and heating the vapours above 600 DEG  C. Solvents specified comprise hydrocarbons, e.g. tetrahydronaphthalene, decahydronaphthalene, phenanthrene, hydrogenated anthracenes and phenanthrenes, benzyl-naphthalenes, diphenyl-benzene and tetra-amylene.  Phenols, e.g. high-boiling fractions of tar acids, p-benzyl-phenol, or 1-[a -hydroxy-benzyl]-naphthalene may also be used or basic compounds, e.g. pyridine, quinoline, quinaldine, acridine, benzyl quinolines, hydrogenated acridines and other hydrogenated heterocyclic bases. Preferably neutral solvents are used in association with a phenol or basic solvent.  The extraction is carried out at 200--400 DEG  C. and at pressures from atmospheric to 200 atmos.  The temperature is preferably raised in stages. Catalysts e.g. stannous hydroxide, tin oxalate, molybdic acid, ammonium molybdate, or nickel are then added to the extract which is hydrogenated under pressures of 20-300 atmos. The oils produced by the hydrogenation are converted into hydrocarbon gases by vaporization and decomposition at 400-1400 DEG  C.  The production of olefines is favoured by heating the oils in a turbulent stream at 700-900 DEG  C. while in the production of acetylene temperatures above 1000 DEG  C. are employed the temperature being preferably raised in stages.  Subatmospheric pressures down to \ba1/10\be-\ba1/20\be atmosphere may be employed.  The products obtained may be fractionally condensed to obtain fractions of low boiling point suitable as motor fuels or may be further converted to reactive gases, e.g. at 600-1400 DEG  C.  The gases may be passed over charcoal or through sulphuric acid to absorb olefines. Powdered bituminous coal is extracted under 50-70 atmos. pressure with a mixture comprising 90 parts decahydronaphthalene and 10 parts pyridine, the temperature being raised slowly from 260-350 DEG  C. The solution is run off and the solvent distilled off by reduction of pressure.  The extract together with a molybdenum catalyst pretreated in air at 500 DEG  C. is hydrogenated at 450-500 DEG  C. and 100 atmos. pressure.  The products are vaporized under a pressure of 100 mm. and passed rapidly through narrow tubes heated to 850 DEG  C. the products being cooled and the olefines separated by absorption in charcoal.ALSO:Hydrocarbon gases, e.g. acetylene and lower olefines e.g ethylene and propylene, are obtained by subjecting coal to extraction with an organic solvent or solvent mixture, hydrogenating the extracted fraction, vaporizing the hydrogenation product and heating the vapours to above 600 DEG  C. Solvents specified comprise hydrocarbons e.g. tetrahydronaphthalene, decahydronaphthalene, phenanthrene, hydrogenated anthracenes and phenanthrenes, benzyl-naphthalenes, diphenyl-benzene and tetraamylene.  Phenols e.g. high-boiling fractions of tar acids, p-benzyl-phenol, or 1-[a -hydroxybenzyl]-naphthalene may also be used or basic compounds e.g. pyridine, quinoline, quinaldine, acridine, benzyl quinolines, hydrogenated acridines and other hydrogenated heterocyclic bases. Preferably neutral solvents are used in association with a phenol or a basic solvent.  The extraction is carried out at 200--400 DEG  C. and at pressures from atmospheric to 200 atmos.  The temperature is preferably raised in stages. Catalysts e.g. stannous hydroxide, tin oxalate, molybdic acid, ammonium molybdate or nickel are then added to the extract which is hydrogenated under pressures of 20--300 atmos.  The oils produced by the hydrogenation are converted into hydrocarbon gases by vaporization and decomposition at 600--1400 DEG C.  The production of olefines is favoured by heating the oils in a turbulent stream at 700--800 DEG  C. while in the production of acetylene temperatures above 1000 DEG  C. are employed, the temperature being preferably raised in stages.  Subatmospheric pressures down to \ba1/10\be...\ba1/20\be atmosphere may be employed. The products obtained may be fractionally condensed to obtain fractions of low boiling point suitable as motor fuels or may be further converted to reactive gases e.g. at 600--1400 DEG  C.  The gases may be passed over charcoal or through sulphuric acid to absorb olefines. Powdered bituminous coal is extracted under 50--70 atmos. pressure with a mixture comprising 90 parts decahydronaphthalene and 10 parts pyridine, the temperature being raised slowly from 260 to 350 DEG  C.  The solution is run off and the solvent distilled off by reduction of pressure.  The extract together with a molybdenum catalyst, pretreated in air at 500 DEG  C. is hydrogenated at 450--500 DEG  C. and 100 atmos. pressure.  The products are vaporized under a pressure of 100 mm. and passed rapidly through narrow tubes heated to 850 DEG  C., the products being cooled and the olefines separated by absorption in charcoal.