Separation of CO from blast furnace gas is an international problem, which is mainly due to the blast furnace gas also contains a large number of N2 and CO2. Because of the close boiling point of N2 and CO, the traditional cryogenic rectification process cannot be used to separate CO from blast furnace gas. The adsorption of CO and N2 is low, and the adsorption of CO2 is easy to poisoning and deactivation, so the conventional pressure swing adsorption method cannot be used for CO separation of blast furnace gas.
PIONEER, on the basis of its mature and leading PSA technology, according to the characteristics of blast furnace gas, developed the process of the formation of a unique CO separation technology of blast furnace gas, by which blast furnace gas can be used from the low cost of mass separation CO. The enriched CO gas can be used for the following three purposes:
CO is a kind of important raw material with chemical synthesis which can be purified to 99% from the blast furnace for the production of ethylene glycol, acetic acid, dimethyl carbonate, polycarbonate, TDI, DMF and other chemical products, thus significantly enhancing the added value of the gas. To obtain CO by the use of blast furnace gas has a large cost advantage. With the rapid development in the non-steel industry, it has attracted attention by many domestic and overseas famous iron and steel enterprises.
1. To produce high value-added chemical products
2. To be premium fuel
The carbon monoxide purified up to 70% from blast furnace, whose heat value is up to 8200kj/nm3, can replace the coal and natural gas for metallurgy, such as the combustion section in iron making links.
3. To be reducing gas of blast furnace injection
The research shows that, to increase concentration of CO from the blast furnace gas and converter gas to above 45%, by the use of separation technology, and then to inject into the blast furnace will significantly improve the carbon monoxide and hydrogen content of the furnace, and indirect reduction acceleration of the sinter in the furnace shell, which helps improve the production and heat efficiency.
Economic Benefit Analysis
PIONEER makes the following calculation according to the present coal-chemistry industry situation. To produce 1m3 CO with high purity by separation and purifying of CO from coal gas cost ￥2.00 at the current price of coal, but it only cost less than ￥1.00 to produce 1m3 CO with high purity by separation and purifying of CO from BFG with PIONEER’s technology. This means Pioneer can save 50% of the CO producing cost than coal gas making.
This technology has been implemented by Hengyang Steel Group. The project design of BFG handling capacity of 67000 Nm3/h, to17500 Nm3 preparation of CO product gas, purity of 70%. CO-enriched will be used as an alternate to natural gas and weighs 30% of total gas consumption at full capacity. It created significant economic benefits to the enterprise, and the elimination of the BFG emission, and a significant reduction in carbon emissions.