Chemical technology helps steel companies to “make gas into gold”

At present, the steel industry has overcapacity, the benefits have fallen sharply, and the number of loss-making enterprises has increased substantially. The prices of raw materials for steel production such as iron ore and electric power have been rising. According to this expert, the use of advanced chemical technology to efficiently optimize the comprehensive utilization of the “three gas” of coke oven gas, blast furnace gas and converter gas in the steel production, and further improve the calorific value and group of by-product gas resources. The utilization value of the points, "gas into gold", will be a way for steel companies to adjust the structure and achieve new growth points.

It is understood that three different gases of coke oven gas, blast furnace gas and converter gas will be produced in the steel production process, and the blast furnace gas yield is as high as 2000 cubic meters per ton of iron. Coke oven gas contains a high amount of H2 (about 55% hydrogen), converter gas contains a high amount of CO (about 60% carbon monoxide), and H2 and CO are valuable gas resources, which are the main products of chemical products such as methanol. raw material. For a long time, the use of these three kinds of gases by steel companies has been used as fuel for power generation or direct ignition and release, which not only causes great waste of resources, but also pollutes the environment. With the increasing energy shortages and increasing environmental requirements, the effective use of these gases is becoming more urgent and important.

Yin Ruizhen, an academician of the Chinese Academy of Engineering, pointed out that steel production is actually an iron-coal chemical process and its deep processing. The calorific value of three kinds of gas, such as coke oven gas, blast furnace gas and converter gas, accounts for 74.6 of the total secondary energy of the steel mill. %. Yin Ruizhen emphasized that if steel companies do not see the function of by-product gas energy conversion, their vision is limited to product manufacturing functions, and the energy cost problem in steelmaking costs will not be solved.

According to reports, in fact, Sichuan Dagang Group began research and development of methanol-based technology using coke oven gas and converter gas as raw materials in 2006. Through the re-distribution of various gas sources, coke oven gas and converter gas were developed. New technology for the synthesis of methanol from raw materials. The use of coke oven gas plus converter gas to produce methanol, the cost of energy per ton of steel used for power generation is reduced by 18.51 yuan, which has improved energy utilization, and also achieved CO2 emission reduction. Up to 140,000 tons. Dagang Group also made full use of blast furnace gas to maximize the cost of using high-quality coke oven gas, reducing methanol production costs and increasing methanol production.

After the optimization and utilization of “three gas”, Dagang Group realized the coordinated and efficient development of steel and coal coking industry. In addition, Dagang also carried out waste heat recovery from the coke oven flue gas, which can produce 7 tons of saturated steam of 0.8 MPa per hour, which not only recovers waste heat, but also creates new benefits for the enterprise and eliminates white smoke from the chimney. The phenomenon has improved the surrounding environment.

Jin Gan, president of the China Coking Industry Association, said that Dagang Group's comprehensive optimization of the use of coke oven gas has enabled the green transformation of the steel and coal coking industry, opening a new path for steel companies to add new economic growth points. He emphasized that steel and coking joint enterprises have the advantages of technological process and industrial chain length. If they can further replace the low calorific value gas such as blast furnace gas or the complementary utilization of the comprehensive utilization components of converter gas, optimize the energy structure and resources. There will be more, and the potential for appreciation is even greater.

Some insiders said that the use of steel "three gas" as raw material for the development of C1 chemical industry has the lowest cost and the strongest competitiveness, using its components to produce methanol, hydrogen, production of LNG (liquefied natural gas) and dimethyl ether, etc., the production process has been More mature, steel companies can choose high-value-added product routes according to local conditions, and can fully maintain a good profit level.

The technological innovation of producing methanol with “three gas” as raw materials will fundamentally change the product structure of iron and steel enterprises. Iron and steel enterprises are expected to embark on the road of C1 chemical development, thus promoting industrial transformation and upgrading. At the same time, the low-cost advantages of steel “three gas” raw materials also bring competition for the development of traditional coal chemical industry and new coal chemical industry.