Method and device for producing sponge iron by using reducing gas prepared from coke oven gas

Abstract

An invention relates to production of sponge iron by using coke oven gas directly, carried out by: mixing purified blast furnace gas with converter gas and blast-furnace gas and one or two kinds of reduced off-gas as well, feeding into upper reduction zone of reactor of vertical shifting bed to reduce ores containing iron oxide, discharging after cooling down in cooling zone of a reduction furnace. End gas is treated by cooling, removing dust, dewatering and pressuring, separating acid gases and inert gases, and then de-sulfurizing, heating in a heat exchanging section to be fed into methane inverting section, feeding the inverted gas to the upper reduction zone said above. An apparatus concerned with the said process is involved. End gas can be used effectively to produce sponge iron at low cost and eliminate sulfur pollution. Methane inverting catalyst can be used durably.

Description

technical field [0001] The present invention relates to a kind of method (DRI) that utilizes coke oven gas to produce synthetic reducing gas, and utilizes direct reducing gas-based method to produce sponge iron, more specifically, relates to a kind of method of coke oven gas producing reducing gas to produce sponge iron and its equipment. Background technique [0002] Direct reduced iron (DRI), also known as sponge iron, is a kind of metallic iron obtained without blast furnace smelting. The process of producing DRI is called non-blast furnace ironmaking process. The production process of DRI is divided into two types: coal-based and gas-based. Among them, the gas-based method currently accounts for 90% of the output of DRI. The typical processes are the tank method (HYL method) and the shaft furnace method (Midrex method). The shaft furnace method uses a vertical moving bed reduction reactor, which is mainly divided into two parts: Reduction zone, where reducing gas circu...

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Problems solved by technology

However, the organic sulfur in the coke oven gas and the hydrogen sulfide generated when the reducing gas reduces iron ore are not removed. The total sulfur content in these gases is far greater than the maximum sulfur content of 0.1ppm required by the catalyst during natural gas conversion, which will lead to The methane conversion catalyst in the process is rapidly deactivated, which makes the production uneconomical. In the plan for removing carbon dioxide in the tail gas of the reduction reaction, it is only recorded that carbon dioxide can be effectively removed by chemical absorption or physical absorption, and there is no explanation for the removal of carbon dioxide. How to deal with a large amount of hydrogen sulfide in the reduction tail gas while removing carbon dioxide. These hydrogen sulfides are discharged into the atmosphere with carbon dioxide and do not meet environmental protection requirements

[0009] U.S. patents US4270739, US4333761, and US4351513 disclose a direct reduction process using coke oven gas to reduce gas, which removes organic sulfur in COG in the upper part of the reduction zone of the reduction furnace, but does not consider reducing tail gas during the removal conversion process There is a large amount of hydrogen sulfide in the gas, and the actual production can reach 300ppm. These hydrogen sulfides are easy to deactivate the methane conversion catalyst quickly and make the actual operation impossible.

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