【Ten Years of Rapid Development in Chemical Processing Equipment】Successful development of the integrated flue gas desulfurization and denitration process using the dual-ammonia method from 1732 to 2017

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This post was last edited by Desert Fish on 2024-5-13 at 20:46. 2 0 2 4 Happy May Day – safety first! Let’s give praise and support to the achievements in China’s chemical engineering technology and equipment. **********************[A Decade of Progress in Chemical Engineering Equipment] An ongoing update and summary thread; feel free to join the discussion: https://bbs.hcbbs.com/thread-3576046-1-1.html (Source: Haichuan Chemical Industry Forum) ***************** On May 2, 2017, the online monitoring data from China’s first integrated desulfurization and denitrification system built by Shandong Tiejiong Metallurgical Technology Co., Ltd. using the “dual-ammonia method” showed that the levels of sulfur dioxide, nitrogen oxides, and dust in the flue gas from the coke ovens were 5 milligrams, 350 milligrams, and 18 milligrams per cubic meter respectively, which are far below the **standard** values of 50 milligrams, 500 milligrams, and 30 milligrams per cubic meter. This marks that, after half a year of trial operation, this integrated desulfurization and denitrification system using the \"dual-ammonia method\" has demonstrated clear advantages in terms of investment, cost, and efficiency. This also indicates that the engineering application of the new integrated flue gas desulfurization and denitrification process developed by Tietong Metallurgy has been successful in its initial stages; the company has currently filed a **patent application for this technology. In recent years, Shandong TieXiong Metallurgical Technology Co., Ltd., relying on its provincial-level technology R&D center, has actively promoted the integration of industry, academia, and research. Focusing on the key issues, challenges, and critical problems in the technological development of the coking industry, it has carried out technological innovation and research projects in collaboration with Tsinghua University and Wuhan University of Science and Technology, and has successfully developed a new integrated process for desulfurization and denitrification of flue gases from coke ovens. The first unit was completed and put into trial operation in November 2016. Wang Hehong, director of the Technology R&D Center at Shandong Tiejiong Metallurgy Technology Co., Ltd., explained that in this process, within the integrated desulfurization and denitrification tower, free ammonia present in concentrated ammonia water reacts with sulfur dioxide in the flue gas to produce sulfuric acid ； At the same time, due to the action of ozone, free ammonia in ammonia water reacts with nitrogen oxides in flue gas to form *ao acid an. Due to the unique role of ammonia in this process, as well as the characteristics of the products produced, this process is referred to as the \"dual-ammonia method\" for integrated desulfurization and denitrification. It is understood that currently, the desulfurization and denitrification processes for coke oven flue gas in China largely follow the methods used in power plants in the past. Since coke oven flue gas differs from that in power plants, the oily substances present in it can cause catalyst poisoning and shorten their service life. A catalyst is an intermediate that accelerates the rate of chemical reactions; its performance directly affects the efficiency and outcomes of these reactions. Chemical processes that utilize catalysts are influenced by factors such as the operating conditions of the catalyst, its rate of degradation, the cost of raw materials, its reduction and regeneration, and post-treatment procedures. “The \"diammonia method\" for desulfurization and denitrification uses ozone as a strong oxidant; the amount of ozone added is adjusted according to the parameters of the flue gas after desulfurization and denitrification, thereby enabling direct and linear control over the efficiency of these processes. The control over these parameters is precise, and the process is not affected by catalysts. This approach not only reduces operating costs but also avoids secondary pollution resulting from the later treatment of catalysts. The greatest advantage of this process is its ability to integrate perfectly with the coking process. The raw materials for desulfurization and denitration are residual ammonia water and concentrated ammonia water, both of which are by-products of coking wastewater treatment, and are inexpensive and readily available. The desulfurization and denitrification products are sulfuric acid AN and *AO acid AN, which can be directly fed into the ammonium sulfate production process. No solid, liquid, or gaseous waste is generated; this not only prevents secondary pollution but also increases the yield and nitrogen content of the ammonium sulfate product. This process integration simplifies the desulfurization and denitrification of coke oven flue gas, while also avoiding the problems associated with high operating costs. The desulfurization and denitrification equipment installed by Tiejiong Metallurgical Construction costs over 20 million yuan in total. Compared with other process routes, it reduces the investment by about half, and its operational energy consumption and raw material usage are also significantly lower. Wang Hehong explained that the \"diammonia method\" process enables the integration of desulfurization and denitrification, that is, these two processes are carried out within a single tower, which reduces the investment required for building the facility as well as its operating costs. It is expected to become the mainstream technology for purifying flue gases from coke ovens in China.