Abstract: Oxidative recovery methods that use oxygen or air for recovery of homogeneous metal catalysts, such as cobalt catalysts, used in for example hydroformylation processes, can be hazardous. Explosive or flammable gas mixtures may be generated inside the process equipment, which can deflagrate upon any ignition source such as a static electricity discharge. The use of a flammable diluent has been found to be a very effective way of optimizing the recovery method, by bringing the resulting gas mixtures above their upper flammability limit. The offgas produced is then also easier to dispose of as a fuel, as compared to when a non-flammable diluent is used.

Abstract: Oxidative recovery methods that use oxygen or air for recovery of homogeneous metal catalysts, such as cobalt catalysts, used in for example hydroformylation processes, can be hazardous. Explosive or flammable gas mixtures may be generated inside the process equipment, which can deflagrate upon any ignition source such as a static electricity discharge. The use of a flammable diluent has been found to be a very effective way of optimizing the recovery method, by bringing the resulting gas mixtures above their upper flammability limit. The offgas produced is then also easier to dispose of as a fuel, as compared to when a non-flammable diluent is used.

Abstract: The Cobalt Flash Process is modified by replacing formic acid with acetic acid as process acid. Efficiency using acetic acid as process acid is achieved by two improvements which may be added separately and independently: (1) separation of acetic acid and water from the condensate distilled off in the cobalt salt concentration stage; and (2) removal of formic acid from the system by reaction with the product alcohol in the preformer.

Abstract: The Oxo Process that recycles its cobalt primarily as cobalt salt is improved by concentration of the cobalt salt solution from the demetalling section and the addition of a separation step for organic acid and water. This allows for a higher reuse of acid in the process and thus a lower amount of acid in the waste water. Injecting a higher concentration of cobalt salt solution to the reaction section also reduces the requirement for cobalt source.