| CPC C10G 9/16 (2013.01) [C10G 2300/4075 (2013.01)] | 13 Claims |
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1. A process for treating a reactor, the process comprising:
subjecting the reactor to a decoking air burn for a period of time sufficient so that air leaving the reactor has a total carbon oxide content less than 2,000 ppm, wherein the reactor is for the conversion of a chemicals feedstock at a temperature greater than 700° C.;
scouring a reactor surface with steam via a steam scour at a rate of not less than 2500 kg/hour/reactor for a time from 0.5 to 10 hours giving a scoured reactor surface that contacts hydrocarbons in operation, wherein the decoking air burn is performed prior to the scouring, and wherein the reactor surface and the scoured reactor surface are stainless steel having less than 38 weight % of chromium or wherein the reactor surface and the scoured reactor surface are an alloy having less than 20 weight % of chromium, the alloy being a nickel based alloy or a cobalt based alloy; and
treating the scoured reactor surface with a mixture comprising steam and nitrogen in a weight ratio from 20:1 to 30:1 in an amount from 80 to 110 kg/hour per reactor at a temperature from 750° C. to 850° C. for a time not less than 20 minutes, in the absence of added oxygen except for oxygen present in the steam and in the nitrogen, wherein the steam comprises less than 10 parts per billion (ppb) of oxygen and the nitrogen comprises less than 5 parts per million (ppm) of oxygen, wherein treating the scoured reactor surface with the mixture is nitrogenating the scoured reactor surface, wherein the mixture does not comprise an anti-coking agent, wherein the process for treating the reactor does not comprise adding a chemical to reduce coking to the reactor.
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