GB647155A - Improvements in or relating to a process of synthesizing hydrocarbons - Google Patents

Abstract

<PICT:0647155/IV (b)/1> <PICT:0647155/IV (b)/2> <PICT:0647155/IV (b)/3> Hydrocarbons and oxygenated compounds are synthesized by introducing a gas mixture comprising carbon monoxide and hydrogen into the base of a reaction zone containing finely-divided synthesis catalyst and passing the gas upwardly at a low velocity to maintain the catalyst in suspended dense phase liquid-like condition, unreacted gases and reaction products being separated from catalyst, and unreacted gases and normally gaseous products removed from heavier products. With a catalyst bulk density of 10-40 lbs./c.ft., a gas velocity of about 0.1-10 generally 0.5-1.5 ft./sec. is used. A catalyst particle size of about 100-400 mesh or smaller is suitable. Gaseous hydrocarbons, e.g. natural gas, may be desulphurized and passed with carbon dioxide and steam over a Group 8 metal oxide, especially oxides of Ni, Fe, and Mn in proportions by weight of 1 : 1 : 0.5, to give a 2 : 1 hydrogen to carbon monoxide mixture. The heat necessary may be obtained by burning part of the initial hydrocarbon gas mixed with part of the recycled gases. The synthesis temperature is controlled by cooling catalyst or synthesis gas outside the reaction zone. The reactor 45, Fig. 1, may be funnel-shaped at top and bottom, a pipe 49 extending into an enlarged settling chamber 50. Primary cyclone separators 52 pick up through inlets 53, gases from which the bulk of the catalyst has settled, the removed catalyst being returned through dip legs 54, and the gases passing to secondary separators 56. The settled catalyst is maintained fluent and freed from deposited hydrocarbons by injecting hot stripping gas through lines 58 or a perforated annular pipe 59, and is fed to the lower part of the reactor through cooling tubes 60 having cooling jackets 68. To disperse the returned catalyst in the up-flowing gas and aerate that in the cooling tubes, conical-shaped ported members 61 are fed with inert gas through lines 64. In a modification, Fig. 3, the reactor is surrounded by an annular chamber containing tubes 60 and extended to surround the base, the catalyst being suspended by gas introduced by line 44 and its rate of flow controlled by a valve 61a. In a further modification, Fig. 4, the catalyst from settling zone 50 may be discharged through standpipe 67 surrounded by cooling jacket 68 and returned through valve 69 to the inlet gas stream from pipe 44 or may be recycled through pipe 71 to heat exchanger 72 and returned by any of lines 77 in an inert gas from line 75. Gases separated from the products may be fed to a second synthesis stage. Gasoline or naphtha products may be reformed and heavy products cracked. Gases may be polymerized or alkylated. Specification 558,879 is referred to.ALSO:<PICT:0647155/III/1> <PICT:0647155/III/2> <PICT:0647155/III/3> Hydrocarbons and oxygenated compounds are synthesized by introducing a gas mixture comprising carbon monoxide and hydrogen into the base of a reaction zone containing finely-divided synthesis catalyst and passing the gas upwardly at a low velocity to maintain the catalyst in suspended dense phase liquid-like condition, unreacted gases and reaction products being separated from catalyst, and unreacted gases and normally gaseous products removed from heavier products. With a catalyst bulk density of 10-40 lbs./c. ft., a gas velocity of about .1-10, generally .5-1.5 ft./sec. is used. A catalyst particle size of about 100-400 mesh or smaller is suitable. Gaseous hydrocarbons, e.g. natural gas, may be desulphurized and passed with carbon dioxide and steam over a Group 8 metal oxide, especially oxides of Ni, Fe, and Mn in proportions by weight of 1 : 1; 0.5, to give a 2 : 1 hydrogen to carbon monoxide mixture. The heat necessary may be obtained by burning part of the initial hydrocarbon gas mixed with part of the recycled gases. The synthesis temperature is controlled by cooling catalyst or synthesis gas outside the reaction zone. The reactor 45, Fig. 1, may be funnel-shaped at top and bottom, a pipe 49 extending into an enlarged settling chamber 50. Primary cyclone separators 52 pick up through inlets 53, gases from which the bulk of the catalyst has settled, the removed catalyst being returned through dip legs 54, and the gases passing to secondary separators 56. The settled catalyst is maintained fluent and freed from deposited hydrocarbons by injecting hot stripping gas through lines 58 or a perforated annular pipe 59, and is fed to the lower part of the reactor through cooling tubes 60 having cooling jackets 68. To disperse the returned catalyst in the upflowing gas and aerate that in the cooling tubes, conical-shaped ported members 61 are fed with inert gas through lines 64. In a modification, Fig. 3, the reactor is surrounded by an annular chamber containing tubes 60 and extended to surround the base, the catalyst being suspended by gas introduced by line 44 and its rate of flow controlled by a valve 61a. In a further modification, Fig. 4, the catalyst from settling zone 50 may be discharged through standpipe 67 surrounded by cooling jacket 68 and returned through valve 69 to the inlet gas stream from pipe 44 or may be recycled through pipe 71 to heat exchanger 72 and returned by any of lines 77 in an inert gas from line 75. Gases separated from the products may be fed to a second synthesis stage. Gasoline or naphtha products may be reformed and heavy products cracked. Gases may be polymerized or alkylated. Specification 558,879 is referred to.