Decoking process
AssigneeNOVA Chemicals (International) S.A.
InventorsMichael Koselek, Leslie Benum, Vasily Simanzhenkov, Hany Farag
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Abstract
In chemical processes for cracking hydrocarbons, reactors are subject to coking. This results in carburization of the metal substrate for the reactor leading to a reduced reactor life. If the reactor is subject to a decoke process, followed by a steam scour and nitriding there is a reduced tendency to carburization of the metal substrate improving the reactor life.
Claims12
In the decoking of a reactor for the conversion of a chemicals feedstock at a temperature greater than 700° C., the final step comprising treating a scoured reactor surface which contacts the hydrocarbons with a mixture comprising steam and nitrogen in a weight ratio from 4:1 to 1:1 in an amount from 500 to 3000 kg/hr 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.
Dependencies are inferred from the claim text.