Method of on-line coating of a film on the inner walls of the reaction tubes in a hydrocarbon pyrolysis reactor

摘要

A method of on-line coating a coat film on the inner wall of a reaction tube in a hydrocarbon pyrolysis reactor for preventing the formation and the deposit of coke on the inner walls. This method comprises the steps of vapor depositing a mixed solution of a metal alkoxide and a chromic compound on the inner walls concurrently with introducing a carrier at a flow rate of 1-5000 kg/hr/coil at a temperature of 600-900° C. under a pressure of 0-3 kg/cm2 to form a buffer layer on the inner walls; and vapor depositing a metal alkoxide as a barrier on the buffer layer; and vapor depositing an alkali metal/alkaline earth metal compound alone or mixed with metal alkoxide as a decoking layer on the barrier. A decoking layer may further be provided on the diffusion barrier.