A method for separating a homogeneous catalyst from a solution includes forming a host-guest compound between a first isomer of the catalyst and inclusion compound in the solution and isolating the host-guest compound from the solution. The catalyst may be released from the inclusion compound by converting the first isomer of the catalyst to a second isomer of the catalyst.

Disclosed herein are methods to rejuvenate a deactivated hydroformylation catalyst solution wherein the solution comprises rhodium, polydentate phosphine ligands, and polydentate phosphine ligand degradation products. In one embodiment, such methods comprise adding a peroxide to the deactivated hydroformylation catalyst solution.

Disclosed herein are methods to rejuvenate a deactivated hydroformylation catalyst solution wherein the solution comprises rhodium, polydentate phosphine ligands, and polydentate phosphine ligand degradation products. In one embodiment, such methods comprise adding a peroxide to the deactivated hydroformylation catalyst solution.

The present disclosure relates to the recovery of an alkoxide catalyst used in a process depolymerizing a polyester to form a diacid or diester and a diol. The present disclosure also relates to the recovery of an alkoxide catalyst used in a process depolymerizing polyethylene terephthalate to form dimethyl terephthalate and mono ethylene glycol.

The present disclosure relates to the recovery of an alkoxide catalyst used in a process depolymerizing a polyester to form a diacid or diester and a diol. The present disclosure also relates to the recovery of an alkoxide catalyst used in a process depolymerizing polyethylene terephthalate to form dimethyl terephthalate and mono ethylene glycol.

Residual hydrogenation catalyst produced from reduction of nitrile rubber is recovered by a chelation step using a chelating agent and a series of extraction using semi-coagulation with polar solvents and an optional washing steps for the separation of catalyst-chelating agent complex from hydrogenated nitrile rubber solution. The chelating agent is selected from xanthate, dithiocarbamate, and trithiocarbonate compounds.

Residual hydrogenation catalyst produced from reduction of nitrile rubber is recovered by a chelation step using a chelating agent and a series of extraction using semi-coagulation with polar solvents and an optional washing steps for the separation of catalyst-chelating agent complex from hydrogenated nitrile rubber solution. The chelating agent is selected from xanthate, dithiocarbamate, and trithiocarbonate compounds.

Realized is a method for restoring the activity of a catalyst for producing a carbonate ester by a simple technique with no use of a complicated step such as calcining or the like to allow the catalyst to be reusable, and a method for producing a carbonate ester at a high yield by use of the catalyst thus regenerated. The above-described problem has been solved by a method for regenerating a catalyst containing CeO.sub.2, the catalyst being usable for a carbonate ester generation reaction of generating a carbonate ester from carbon dioxide and an alcohol, the method comprising (a) a separation step of separating the catalyst as a crude catalyst from a reaction solution of carbon dioxide and the alcohol; and (b) a catalyst processing step of washing the crude catalyst with a washing alcohol to provide a purified catalyst.

Realized is a method for restoring the activity of a catalyst for producing a carbonate ester by a simple technique with no use of a complicated step such as calcining or the like to allow the catalyst to be reusable, and a method for producing a carbonate ester at a high yield by use of the catalyst thus regenerated. The above-described problem has been solved by a method for regenerating a catalyst containing CeO.sub.2, the catalyst being usable for a carbonate ester generation reaction of generating a carbonate ester from carbon dioxide and an alcohol, the method comprising (a) a separation step of separating the catalyst as a crude catalyst from a reaction solution of carbon dioxide and the alcohol; and (b) a catalyst processing step of washing the crude catalyst with a washing alcohol to provide a purified catalyst.

A method of equipment decontamination may include: introducing a cleaning stream comprising hydrogen and a solvent comprising a fatty acid methyl ester and an oxygenated solvent into the equipment; and introducing a stream comprising nitrogen into the equipment, wherein the equipment comprises deposits and other contaminants.