Patent GB-707987-A (GB)
Title: Process for the catalytic hydrogenation of carbon monoxide in the presence of a liquid
IPC: C07C1/04
Filed: 1950-10-27
Abstract: The hydrogenation of carbon monoxide to hydrocarbons and oxygenated compounds is effected by passing the synthesis gas through a hydrogenation catalyst of particle size .002-1 mm. suspended in a hydrocarbon oil, the suspension containing 50-500 g. of catalyst base metal per litre, the flow rate of fresh synthesis gas expressed in normal litres/hour/litre of suspension being 10-30 times the percentage content by weight of catalyst base metal in the suspension, at a pressure within the range 3-150 atmospheres and adapted to said flow rate so that the latter, measured at that pressure, is within the range 5-100 litres/hour/litre of suspension, whereby the mixture of gas and suspension attains a constant volume about 40-100 per cent greater than that of the suspension itself. The two phases form a substantially homogeneous and stable mixture under these conditions, the gas bubbles being of substantially equal size and conversion of CO being nearly 100 per cent.  Temperatures may be 10-70 DEG  C. higher than usual, e.g. 200-360 DEG  C.  The catalyst may be a Group 8 metal, e.g. Fe, Ni, Co or Ru, especially iron obtained from iron compounds, e.g. hammer scales, ferric oxide residues, and iron ores, which may be reduced by the synthesis gas while suspended in the oil.  Activators such as alkali metal, copper, thoria or magnesia may be added.  Reduction is preferably effective with CO-containing gas at 10-50 DEG  C. above the synthesis temperature, pressures of 1-10 atmospheres and a gas flow of more than 100 cm./hour/cm. of suspension.  Reduction in the dry is effected at about atmospheric pressure with gas flow down to about 50 cm./cm. of catalyst.  The catalyst is dispersed in the oil which may be a fraction of the synthesis product boiling at 250-360 DEG  C. Surface tension modifiers may be added, e.g. alkali or aluminium soaps, pyridine or esters such as phosphoric esters. The dispersion is contained in a reactor having a gas inlet at the base and a distributer such as a porous filter.  An exit duct is fitted in the cover and a withdrawal duct in the side. Temperature may be raised gradually and, when it attains 10-50 DEG  C. above the initial figure, i.e. the catalyst activation temperature, additional catalyst may be fed from the gas entry side.  Activated or regenerated catalyst may alternatively be added.  Alkali compounds may also be added sufficient to compensate for alkali metal loss or to increase the content if higher boiling products are desired.  With a synthesis gas rich in hydrogen, and iron catalysts, a relatively high rate of flow is used and the gases recycled, advantageously with fresh gas in a ratio of exit gas: fresh feed = 2-5 times the ratio H2 : CO in the fresh feed.  Alternatively, the exit gas is passed through successive stages of a multistage synthesis.  C3-C8 olefines, largely isoolefins, or solid hydrocarbons may be obtained by varying the conditions.  In examples (1) a suspension containing 10 kg. iron activated with Cu and K2CO3, of particle size 0.05 mm., in 90 kg. 300-320 DEG  C. fraction of synthesis oil is activated with a 3CO : 2H2 mixture passed at 10-15 normal cm. per hour at 280 DEG  C. and 12 atmospheres gauge, conditions then being altered to 258 DEG  C., 25 atmospheres gauge and throughput 25 normal cm. per hour; (2) a precipitated ferric oxide catalyst is used in an oil suspension containing 20 per cent iron, synthesis being effected at 250 DEG  C. and 20 atmospheres with a gas-feed rate of 300 normal cm./hour/cm. suspension, exit gas after removal of products being in part recycled with fresh feed.  Catalyst is later removed gradually and replaced by fresh or regenerated catalyst with higher alkali content, the oil medium also being renewed; (3) a 10 per cent iron catalyst in oil suspension is used at 255 DEG  C., 10-15 atmospheres, and 220 cm. gas/hour/cm., exit gas being recycled and catalyst gradually replaced, the yield of high boiling hydrocarbons being increased if desired by feeding hydrocarbons boiling below 320 DEG  C. to the reactor; (4) a treated bauxite residue is suspended in oil to give 50 g. iron/litre, 140 cm. gas being passed/hour/cm. medium at 255-310 DEG  C. and 15 atmospheres; (5) a catalyst obtained by decomposing ferric nitrate is ground in oil and made up to 20-22 per cent iron suspension, sodium stearate equal to 2 per cent of the iron being present, synthesis being effected with a gas feed of 400 cm./hour/cm. suspended at 20 atmospheres and 260 rising to 295 DEG  C.ALSO:The hydrogenation of carbon monoxide to hydrocarbons and oxygenated compounds is effective by passing the synthesis gas through a hydrogenation catalyst of particle size .002-1mm. suspended in a hydrocarbon oil, the suspension containing 50-500 g of catalyst base metal per 1., the flow rate of fresh synthesis gas expressed in normal litres/hr./litre of suspension being 10-30 times the percentage content by weight of catalyst base metal in the suspension, at a pressure within the range 3-150 atm. and adapted to said flow rate so that the latter, measured at that pressure, is within the range 5-100 1./hr./litre of suspension, whereby the mixture of gas and suspension attains a constant volume about 40-100 per cent. greater than that of the suspension itself.  The two phases form a substantially homogeneous and stable mixture under these conditions, the gas bubbles being of substantially equal size, and conversion of CO being nearly 100 per cent.  Temperatures may be 10-70 DEG C. higher than normal, e.g. 200-360 DEG C.  The catalyst may be a Group 8 metal, e.g. Fe, Ni, Co or Ru, especially iron obtained from iron compounds, e.g. hammer scales, ferric oxide residues and iron ores, which may be reduced by the synthesis gas while suspended in the oil.  Activators such as alkali metal, copper, thoria or magnesia may be added. Reduction is preferably effected with CO-containing gas at 10-50 DEG C. above the synthesis temperature, pressures of 1-10 atm., and a gas flow of more than 100 c.m./hr./c.m. of suspension. Reduction in the dry is effected at about atmospheric pressure with gas flow down to about 50 c.m./c.m. of catalyst.  The catalyst is dispersed in the oil which may be a fraction of the synthesis product boiling at 250-360 DEG C.  Surface tension modifiers may be added, e.g. alkali or aluminium soaps, pyridine or esters such as phosphoric esters.  The dispersion is contained in a reactor having a gas inlet at the base and a distributer such as a porous filter.  An exit duct is fitted in the cover and a withdrawal duct in the side.  Temperature may be raised gradually and, when it attains 10-50 DEG C. above the initial figure, i.e. the catalyst activation temperature, additional catalyst may be fed from the gas entry side.  Activated or regenerated catalyst may alternatively be added.  Alkali compounds may also be added sufficient to compensate for alkali metal loss or to increase the content if higher boiling products are desired.  With a synthesis gas rich in hydrogen, and iron catalysts, a relatively high rate of flow is used and the gases recycled, advantageously with fresh gas in a ratio of exit gas : fresh feed = 2-5 times the ratio H2 : CO in the fresh feed.  Alternatively, the exit gas is passed through successive stages of a multi-stage synthesis. C3-C8 olefins, largely iso-olefins, or solid hydrocarbons may be obtained by varying the conditions.  In Examples: (1) a suspension containing 10 kg. iron activated with Cu and K2CO3, of particle size .05 mm. in 90kg. 300-320 DEG C. fraction of synthesis oil is activated with a 3CO : 2H2 mixture passed at 10-15 normal c.m. per hr. at 280 DEG C. and 12 atm. gauge, conditions then being altered to 258 DEG C., 25 atm. gauge and throughput 25 normal c.m per hr.: (2) a precipitated ferric oxide catalyst is used in an oil suspension containing 20 per cent. iron, synthesis being effected at 250 DEG C. at 20 atm. with a gas feed rate of 300 normal c.m./hr./c.m. suspension, exit gas after removal of products being in part recycled with fresh feed.  Catalyst is later removed gradually and replaced by fresh or regenerated catalyst with higher alkali content, the oil medium also being renewed: (3) a 10 per cent. iron catalyst in oil suspension is used at 255 DEG C., 10-15 atm. and 220 c.m. gas/hr./c.m., exit gas being recycled and catalyst gradually replaced, the yield of high boiling hydrocarbons being increased if desired by feeding hydrocarbons boiling below 320 DEG C. to the reactor: (4) a treated residue is suspended in oil to give 50 g. iron/l., 140 c.m. gas being passed/hr./c.m. medium at 255-310 DEG C. and 15 atm.: (5) a catalyst obtained by decomposing ferric nitrate is ground in oil and made up to 20-22 per cent. iron suspension, sodium stearate equal to 2 per cent. of the iron being present, synthesis being effected with a gas feed of 400 c.m./hr./c.m. suspension at 20 atm. and 260 rising up to 295 DEG C.