| 摘要 |
Carbon monoxide and hydrogen are reacted with an olefin in the presence of a cobalt or iron catalyst in a hydroformylation reaction zone at elevated temperature and pressure to obtain a product comprising an aldehyde, unreacted carbon monoxide and hydrogen, and at least one metal carbonyl; the unreacted synthesis gas (i.e. hydrogen and carbon monoxide) carrying at least one metal carbonyl is subsequently recovered from the reaction product and is recycled to the hydroformylation zone, being demetalled during the recycling process by passing it along with heated fresh synthesis gas to a demetalling chamber, the amount and temperature of the fresh synthesis gas being adjusted so that the temperature of the mixture of fresh synthesis gas and recovered synthesis gas is higher than the decomposition temperature of the metal carbonyl present with the highest decomposition temperature; any metal carbonyl present is thereby decomposed, free metal being deposited in the demetalling chamber, and the mixture of fresh synthesis gas and recovered synthesis gas, free of metal carbonyl and free metal, is passed to the hydroformylation zone. In addition to the carbonyl formed from the catalyst it is possible to have present in the product from the hydroformylation zone the carbonyls of iron, nickel, chromium and molybdenum, which may be present in the walls of the reactor. When cobalt is employed as the catalyst it is preferred to have the demetalling chamber divided into two zones, one being a decobalting zone and the other being a zone in which the other metal carbonyls are decomposed. In an example an olefine, such as heptene, is reacted with a mixture of carbon monoxide and hydrogen in the presence of a cobalt salt of a fatty acid, e.g. naphthenic acid; the reaction product is cooled and the unreacted carbon monoxide and hydrogen, containing cobalt carbonyl with or without other metal carbonyls is passed with fresh synthesis gas to a demetalling chamber; after demetalling, as described above, the synthesis gas is recycled to the hydroformylation zone. |
