High efficiency processes for olefins, alkynes, and hydrogen co-production from light hydrocarbons such as methane

A method of making alkenes and alkynes, the method comprising:

• performing pyrolysis of a light hydrocarbon in the presence of oxygen in a reaction zone at a temperature and pressure suitable to produce an alkyne and carbon monoxide;
• catalytically hydrogenating the alkyne in a hydrogenation zone to produce an alkene;
• directing the carbon monoxide to a CO shift device;
• converting at least a portion of the carbon monoxide to hydrogen in the CO shift device to produce a stream including the hydrogen;
• and
• directing the stream including the hydrogen into the reaction zone.

A method of making alkenes and alkynes, the method comprising:

• performing pyrolysis of a light hydrocarbon in the presence of oxygen in a reaction zone at a temperature and pressure suitable to produce an alkyne and carbon dioxide;
• catalytically hydrogenating the alkyne in a hydrogenation zone to produce an alkene;
• converting at least a portion of the carbon dioxide to methane in a carbon dioxide conversion and methanation zone;
• and
• directing a stream including the methane from the carbon dioxide conversion and methanation zone into the reaction zone.