CATALYTIC BURNING PROCESS

摘要

PURPOSE:To improve ignitability in low temp. and prevent deterioration by heat at the same time by using catalysts and forming cross sectional area of flow paths at a catalyst vessel in such a manner that catalyst having superior low temp. activity but inferior heat resistance at the upper stream part and catalyst having superior heat resistance but low temp. activity at the down stream part and the former cross sectional area of flow path is determined to be smaller than the latter one. CONSTITUTION:Catalyst forming a catalyst layer 21A of the upper stream part is made by adding catalyst such as platinum or palladium, etc. to gamma-alumina catalyst carrier and has superior low temp. activity and on the other hand, catalyst forming a catalyst layer 21B is made by adding catalyst such as platinum to catalyst carrier such as alumina, zirconium and silicon carbide, etc. and has superior heat resistance. At the start time operation, preheated temp. of fuel gas by a preheater 14 is set up to be higher than ignition temp. of catalyst forming catalyst layer 21A and then burning reaction takes place only in the catalyst layer 21A of the upper stream part and by its burning heat, temp. of the catalyst layer 21B of the down stream part becomes higher than its ignition temp. When the flow rate is increased consecutively, fire extinction takes place at the catalyst layer 21A of the upper stream part and burning starts at the catalyst layer 21B of down stream part because gas flow velocity in the catalyst layer 21A of the upper stream part is larger than that in the catalyst layer 21B of the down stream.