Oxygenate separation using a metal salt

A method comprising:

• converting a lower alkane to an alkene in an oxidative dehydrogenation (ODH) reactor and producing from the ODH reactor an ODH outlet stream comprising the alkene, unconverted lower alkane, an oxygenate, and a carbon-based oxide;
• introducing the ODH outlet stream and a caustic outlet stream having a metal salt to a quench tower and converting the oxygenate in the quench tower to a derivative salt formed from the oxygenate and the metal salt, wherein the derivative salt comprises at least one of an acetate, an acrylate, or a malonate;
• removing from the quench tower a quench outlet stream comprising the alkene, the unconverted lower alkane, and the carbon-based oxide;
• introducing the quench outlet stream to a caustic wash tower;
• contacting the carbon-based oxide from the quench outlet stream with a caustic agent in the caustic wash tower to form the metal salt;
• and
• removing from the caustic wash tower the caustic outlet stream that is introduced to the quench tower.

A method comprising:

• converting a lower alkane to an alkene in an oxidative dehydrogenation (ODH) reactor and producing from the ODH reactor an ODH outlet stream comprising the alkene, unconverted lower alkane, an oxygenate, and a carbon-based oxide;
• quenching the ODH outlet stream in a quench tower with a quenching agent comprising a caustic outlet stream having a metal salt, thereby converting the oxygenate to a derivative salt formed from the oxygenate and the metal salt;
• removing from the quench tower a quench outlet stream comprising the alkene, the unconverted lower alkane, and the carbon-based oxide;
• and
• contacting the quench outlet stream with a caustic agent in a caustic wash tower, thereby forming the metal salt from the caustic agent and the carbon-based oxide from the quench outlet stream, wherein the caustic outlet stream having the metal salt is provided from the caustic wash tower to the quench tower.