Olefins process which combines hydrocarbon cracking with coupling methane

A process to make olefins which combines cracking of a hydrocarbon feedstock with the coupling of methane, said process comprising:

• the coupling in a first zone of a first feed which is essentially methane using an oxygen-affording gas to produce a product containing C.sub.2 hydrocarbons;
• hydrocarbon cracking in a second zone of a second feed which contains predominantly saturated hydrocarbons to form primarily an olefin-containing product;
• effectively transferring heat evolved by said coupling from said first zone to said second zone to provide a majority of the heat required by said cracking without mixing the hot effluent of said coupling into said second zone;
• combining the C.sub.2 + containing portions of the effluents from said first zone and said second zone and individually separating the methane and at least the ethylene and propylene olefinic hydrocarbon components thereof;
• and
• returning unreacted methane contained in the effluent of said first zone together with methane contained in the effluent of said second zone to the feed to said first zone.