Patent ID: 6294078
Filing Date: 2001-09-25
Classification: C10G

Abstract:
A process for controlling the concentration of an antifoulant in a feed stream introduced to a reactor suitable for passivating the inner surfaces of the reactor and the reactor has an inlet and an outlet, comprising:(a) heating the reactor with a furnace;(b) providing a substantially constant flow of feed gas comprising steam;(c) introducing the feed gas to the reactor inlet while the reactor is heated by the furnace such that reactor effluent flows from the reactor outlet and such that a predetermined and substantially constant reactor outlet temperature is produced;(d) introducing the effluent from the reactor to an inlet of a cooler having an outlet such that the effluent flows through the cooler and exits the cooler and such that a cooler outlet temperature is produced which is less than the reactor outlet temperature;(e) designating an initial cooler outlet temperature as T.sub.1 at approximately the commencement of (d) or thereafter during (d) and designating any subsequent cooler outlet temperature as T.sub.2, wherein T.sub.2 -T.sub.1 =.DELTA.T;(f) introducing the antifoulant into the feed gas after T.sub.1 is designated in (e) at a point prior to the introduction of feed gas into the reactor;(g) controlling, during at least a portion of(c), the concentration of the antifoulant in the feed gas so as to maintain .DELTA.T substantially within a range having a lower limit greater than zero, minimum .DELTA.T, and an upper limit, maximum .DELTA.T.