Hydrocarbon conversion to ethylene

A tubular, regenerative, reverse-flow thermal reactor for pyrolyzing hydrocarbon, the reactor comprising:

• (a) first and second zones, and a reaction zone located between the first and second zones,
• (b) first and second thermal masses, at least a portion of the first thermal mass being located in the first zone, and at least a portion of the second thermal mass being located in the second zone,
• (c) at least one combustion feed conduit comprising a fuel channel and a separate oxidant channel, the feed conduit being adapted for introducing a combustion feed comprising a fuel and an oxidant into the reactor proximate to the first zone and conveying the combustion feed to the reaction zone, wherein the fuel and oxidant channels are located within the portion of the first thermal mass that is located in the first zone,
• (d) at least one pyrolysis feed conduit for introducing a pyrolysis feed into the reactor proximate to the second zone and conveying pyrolysis feed to the reaction zone, and
• (e) one or more valves for (i) establishing during a first time interval a flow of the combustion feed in a forward direction through the first zone to the reaction zone for combustion and (ii) establishing during a second time interval a flow of the pyrolysis feed in a reverse direction through the second zone to the reaction zone for the pyrolysis, wherein
• the first zone is configured to transfer heat from the first thermal mass to the fuel and to the oxidant during the first time interval and to transfer heat from pyrolysis products to the first thermal mass during the second time interval,
• the reaction zone is configured to combust the combustion feed during the first interval and to expose the pyrolysis feed to a peak pyrolysis temperature in the range of from 850° C. to 1200° C., at a hydrocarbon pressure ≧7 psia (0.48 bara), for a residence time ≦1.0 seconds during the second time interval, and
• the second zone is configured to transfer heat from combustion products to the second thermal mass during the first time interval and to transfer heat from the second thermal mass to the pyrolysis feed during the second time interval.