Patent GB-774285-A (GB)
Title: Process for the treatment of catalysts
IPC: C07C1/04
Filed: 1953-11-13
Abstract: In the synthesis of hydrocarbons or oxygencontaining organic compounds by the hydrogenation of an oxide of carbon, e.g. carbon monoxide, in the presence of a catalyst suspended in a liquid medium, the catalyst is reactivated, or its active life extended, by lowering the catalyst concentration in the suspension during the course of the synthesis.  The volume of the suspension may be increased by adding additional liquid medium or by allowing liquid synthesis products to accumulate; alternatively, part of the suspension may be withdrawn and replaced by liquid not containing catalyst.  The content of elementary carbon which forms in the suspension during the synthesis may be maintained at or below 6 per cent by weight.  Dilution may reduce the catalyst concentration to 5-70 per cent of the initial concentration.  The process may be combined with other methods of reactivation, such as hydrogenation, oxidation or extraction; when part of the suspension is withdrawn from the synthesis zone, it may be separated into a portion poorer in carbon and a portion richer in carbon by centrifuging, settling, or by magnetic means in the case of iron, cobalt, or nickel catalyst; the catalyst poorer in carbon is suspended in the liquid medium and again used for synthesis.  In an example, unsupported iron catalyst is suspended in synthesis hydrocarbons and carbon monoxide and hydrogen are reacted at 255-270 DEG  C. and 10 atmospheres gauge pressure; when the conversion rate drops, half the suspension is removed and replaced by fresh synthesis hydrocarbons.ALSO:In the synthesis of hydrocarbons or oxygen-containing organic compounds by the hydrogenation of an oxide of carbon, e.g. carbon monoxide, in the presence of a catalyst suspended in a liquid medium, the catalyst is reactivated, or its active life extended, by lowering the catalyst concentration in the suspension during the course of the synthesis.  The volume of the suspension may be increased by adding additional liquid medium or by allowing liquid synthesis products to accumulate; alternatively, part of the suspension may be withdrawn and replaced by liquid not containing catalyst.  The content of elementary carbon which forms in the suspension during the synthesis may be maintained at or below 6 per cent by weight.  Dilution may reduce the catalyst concentration to 5-70 per cent of the initial concentration.  The process may be combined with other methods of reactivation, such as hydrogenation, oxidation, or extraction; when part of the suspension is withdrawn from the synthesis zone, it may be separated into a portion poorer in carbon and a portion richer in carbon by centrifuging, settling, or by magnetic means in the case of iron, cobalt, or nickel catalyst; the catalyst poorer in carbon is suspended in the liquid medium and again used for synthesis. In an example, unsupported iron catalyst is suspended in synthesis hydrocarbons and carbon monoxide and hydrogen and reacted at 255 DEG -270 DEG C. and 10 atmospheres gauge pressure; when the conversion rate drops, half the suspension is removed and replaced by fresh synthesis hydrocarbons