A study on coke deposition and coking inhibitors during AGO pyrolysis in pulsed micro-reactor system

Abstract

A study on coke deposition and coking inhibitors during atmospheric gas oil (AGO) pyrolysis was made in an improved pulsed micro-reactor system. The system is noted for its simple structure, easy alteration of operating parameters, small volumes of feedstock used for pyrolysis, high accuracy of coke formation measurement and short operating cycle. It is particularly suitable for identifying coking inhibitors over a wide range of conditions. The effect of the reactor surface pretreatment on coke deposition was made following surface pretreatments of H 2 reduction, air oxidation and H 2S passivation. On a reactor surface of steady reduced state, the inhibiting effect of various organic compounds to coke deposition was investigated. It was found that sulfur is a key element in coking inhibitors and that the molecular structure of S-containing molecules greatly affects the inhibiting effect. Also, the effect of coking inhibitors on product distribution of AGO pyrolysis was investigated. A mechanism of coke formation and its inhibition is presented.