【Major Industrial Equipment in the Chemical Industry】237 – An innovative approach: ion liquid technology for the separation and recovery of ammonia-containing gases
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Red May for chemical industry workers! Reply reward! ---------------------------------------------- The past decade has been a period of rapid development for China’s chemical industry, marked by the emergence of many new processes, products, and equipment. There has also been significant progress in China’s chemical processing equipment, which has contributed to the swift advancement of the petrochemical sector. Here, we have compiled some of the achievements and breakthroughs made by Chinese equipment manufacturers in terms of larger-scale production and increased use of domestic equipment. We invite everyone to share their insights and discuss these topics together; let’s cheer for Made in China and support the development of chemical processing equipment! ===================== On May 10, the China Petroleum and Chemical Industry Federation organized an appraisal meeting for scientific and technological achievements on \"Green new technologies for the absorption and recycling of industrial ammonia using ionic liquid methods\", held both online and offline. The appraisal committee, headed by He Mingyuan, an academician of the Chinese Academy of Sciences, concluded that this technology is highly innovative, advanced, mature, and reliable; it possesses independent intellectual property rights and is at the international leading level ； It offers significant economic and environmental benefits, is in line with **energy-saving and environmental protection industry policies; it enables the treatment and recycling of ammonia-containing gases in related industries, thus holding broad application prospects. This achievement was jointly accomplished by the Institute of Process Engineering, Chinese Academy of Sciences, the Chemical Division of Jinduicheng Molybdenum Co., Ltd., and other organizations. Academician Zhang Suojiang, director of the Institute of Process Engineering at the Chinese Academy of Sciences, told reporters that as a new type of medium composed of cations and anions, ionic liquids possess characteristics such as designable structure, hydrogen bond-electrostatic coupling, and adjustable acidity and basicity, which endow them with a higher capacity to dissolve ammonia molecules and greater selectivity in their absorption. Ionic liquids also possess extremely high cohesive energy and very low vapor pressure; they are non-volatile, and during desorption and regeneration, they do not cause secondary pollution due to volatilization like organic solvents. Therefore, ionic liquids have inherent advantages for the absorption and separation of gases.
“Based on this, we have innovatively developed a new green technology for the purification and recovery of ammonia-containing gases using non-aqueous ionic liquid systems. We have invented functional composite ionic liquid absorbents with high ammonia absorption capacity and good cyclic stability, thereby overcoming the challenges posed by the high viscosity of ionic liquids, which leads to low absorption rates and high costs, thus hindering their use on a large industrial scale. ”Zhang Suojiang explained. Based on the properties of ionic liquids, a packed tower with internal components to enhance absorption and equipment for the efficient and rapid desorption of ionic liquid films were designed and developed. A new process for the absorption, purification, and regeneration of ionic liquids was created, enabling continuous online purification without the need for shutdowns; this has resulted in a set of new technologies for the separation, recovery, and utilization of ammonia-containing gases using ionic liquid methods. Compared with the water washing process of imported units, the new technology offers advantages such as lower energy consumption, direct recovery of ammonia, compliant exhaust emissions, and no generation of ammonia-nitrogen wastewater. Through joint efforts, this technology was successfully applied at the chemical subsidiary of Jinmo Co., Ltd. located in Weinan, Shaanxi, resulting in the construction of the world’s first industrial demonstration plant for ammonia recovery from molybdenum chemical process exhaust gases, with a processing capacity of 130 million Nm3 per year. Since January 2019, this device has been operating steadily for 40 months in a row; its overall cost is more than 36% lower than that of the existing washing method, and it enables the recycling of ammonia resources. Online monitoring by environmental protection authorities showed that the ammonia-containing exhaust emissions met the required standards, resolving the environmental challenges faced during the company’s production process and serving as a model for the large-scale use of ionic liquids in the field of industrial gas separation.
It is reported that ammonia, as one of the important basic chemical products, is widely used in industries such as chemicals, metallurgy, pharmaceuticals, and electronics. For example, large amounts of industrial ammonia-containing gases are generated during the production of synthetic ammonia, urea, ammonium molybdate, molybdenum oxide, melamine, and other products. At the same time, ammonia is an alkaline gaseous pollutant; it reacts with SOX and NOX in the atmosphere to form secondary particles such as ammonium sulfate and **-like PM2.5 particles, which are one of the main causes of fog and haze. **The 13th Five-Year Plan for Ecological and Environmental Protection specifically introduces restrictions on the total emissions of ammonia nitrogen pollutants, resulting in stricter standards for ammonia emissions. Although existing methods such as washing, and absorption using sulfuric acid or phosphoric acid aqueous solutions can achieve the required purification levels for ammonia-containing exhaust gases, the resulting dilute ammonia water, ammonium sulfate, or ammonium phosphate have low utility value and can cause secondary pollution, posing a significant challenge to the green development of this industry. It is urgent to develop transformative technologies for the efficient and energy-saving purification, separation, and recovery of ammonia-containing exhaust gases; this is also an urgent need for the green upgrading of the industry. At present, the total amount of ammonia-containing exhaust gases in China’s industry is quite large, at around 3 million tons per year, and this applies to multiple industries; there is therefore great potential for recycling these gases. Efficient separation and recovery of ammonia from industrial ammonia-containing gases is a key method for effectively controlling ammonia pollution and reducing the formation of secondary aerosol particles. At the same time, the comprehensive recovery and utilization of ammonia resources not only brings significant economic benefits but also reduces the demand for synthetic ammonia, thereby indirectly lowering carbon emissions. This technology provides an advanced and reliable solution for the purification and recycling of ammonia-containing gases in industry, which will greatly accelerate the industrialization of ionic liquids and enhance China’s influence in the global fields of ionic liquids and green chemistry.
Like **There is an increased focus on environmental protection, and new processes and technologies are also being continuously applied