In-situ coke removal

In a catalytic partial oxidation process wherein a hydrocarbon fuel and an oxidant are fed into a reactor and contacted with a catalyst under catalytic partial oxidation conditions sufficient to produce hydrogen and carbon monoxide;

• the improvement comprising:
• (i) employing a catalyst consisting essentially of a partial oxidation catalyst capable of converting a hydrocarbon into hydrogen and carbon monoxide;
• (ii) varying the feed of hydrocarbon fuel, or the feed of oxidant, or both feeds to produce a fuel-rich feed ratio of hydrocarbon fuel to oxidant to the reactor;
• and maintaining the fuel-rich feed ratio at a temperature between 850° C. and 1,050° C. for a fuel-rich cycle-time sufficient to produce hydrogen and carbon monoxide, and further wherein the fuel-rich cycle time is greater than 15 seconds but less than a time that would produce a temperature greater than 1,050° C. when the hydrocarbon fuel is shut off;
• (iii) varying the feed of hydrocarbon fuel, or the feed of oxidant, or both feeds to produce a fuel-lean feed ratio of hydrocarbon fuel to oxidant to the reactor;
• and maintaining the fuel-lean feed ratio at a temperature greater than 850° C. and less than 1,050° C. for a fuel-lean cycle-time greater than 100 milliseconds and less than 800 milliseconds so as to remove coke deposits and to maintain a substantially constant yield of partially-oxidized reaction product;
• and
• (iv) reiterating process steps (i) to (iii) throughout the process;
• and further wherein the aforementioned process steps are conducted in the absence of co-fed water or steam.