Method for operating a coke oven plant

Abstract

A method for operating a coke oven plant, comprising providing a blast furnace gas stream and a coke oven gas stream treating a part of the blast furnace gas stream in a CO converter unit to obtain a treated blast furnace gas stream, subjecting the treated blast furnace gas stream in a CO-depletion unit to obtain a primary CO-depleted blast furnace gas stream, mixing the primary CO-depleted blast furnace gas stream with a proportion of the blast furnace gas stream in a first mixing unit to obtain a secondary CO-depleted blast furnace gas stream, mixing the secondary CO-depleted blast furnace gas stream with a proportion of the coke oven gas stream in a second mixing unit to obtain a tertiary CO-depleted gas stream, feeding said tertiary CO-depleted gas stream to an underfiring system of a coke oven from the coke oven plant to convert coal to coke thereby producing a coke oven gas and an exhaust gas, where properties of the secondary CO-depleted blast furnace gas stream are determined by a first analyzer downstream the first mixing unit are determined by properties of the tertiary CO-depleted gas stream in a second analyzer downstream the second mixing unit, where the proportion of the blast furnace gas stream and the proportion of the coke oven gas stream are controlled based on said properties determined by said first and second analyzers to adjust at least one of COcontent, CO content, Hcontent, Wobbe Index, stoichiometric combustion air demand and Lower Heating Value in said tertiary CO-depleted gas stream thereby controlling operation of the underfiring system.