Study of SiO2 coat preparation and its anti-coking behaviour

摘要

A SiO2 coat was prepared on an HP40 steel surface via atmospheric-pressure chemical vapour deposition (APCVD). The composition and surface appearance of the coat were then investigated with the aid of energy dispersive spectrometry and scanning electron microscopy, and its anti-coking ability was analysed by virtue of anti-coking mechanism and an anti-coking test. A 5 mu m-thick SiO2 coat was prepared through APCVD at 800 degrees C, with tetraethyl orthosilicate as the source material and air as the carrier and diluent gas. The prepared SiO2 coat can effectively prevent catalyst coking (with an anti-coking rate above 70%) under pyrolysis conditions and can improve the anti-coking ability of HP40 steel.