[Chemical Knowledge]：The nature and use of liquid ammonia, upstream and downstream raw materials, storage methods, the nature of liquid ammonia and the harm to the human body.

Liquid Ammonia Properties

Ammonia is a colorless and transparent liquid liquefied by ammonia gas at low temperature or high pressure, and its chemical formula is NH3. Its boiling point is -33.34°C and it has a strong pungent odor. Liquid ammonia has a high latent heat of vaporization, can effectively absorb heat, and its liquid density is 682kg/m³. Due to its high hydrogen content, liquid ammonia is often used as a hydrogen source or reducing agent. Liquid ammonia is volatile in air and forms ammonium hydroxide solution with water, so special attention should be paid to its volatility and corrosiveness.

Liquid ammonia use

Liquid ammonia is widely used in chemical, agricultural and energy fields. In the field of chemical industry, liquid ammonia is the key raw material for the synthesis of nitrogen fertilizers (such as urea and ammonium nitrate), and it is also the basic raw material for the production of nitric acid, aniline and other chemical products. In agriculture, liquid ammonia is used as a direct fertilizer to supplement soil nitrogen and increase crop yields. On the energy side, liquid ammonia is being investigated as an efficient hydrogen storage medium for fuel cells and energy storage. Liquid ammonia is also used as a refrigerant in refrigeration systems, especially in industrial cooling equipment.

Liquid ammonia upstream feedstock

The main upstream feedstocks for liquid ammonia are nitrogen and hydrogen. Nitrogen is mainly obtained from the air separation, through the air separation device. Hydrogen is mainly produced by steam reforming or partial oxidation of fossil fuels such as natural gas and petroleum gas. In recent years, the development of water electrolysis and biomass conversion technology also provides a new way for the production of hydrogen. Catalysts, such as iron-based catalysts, are also used in the production of liquid ammonia, which play an important role in improving the efficiency of ammonia synthesis.

Liquid ammonia downstream products

There are many kinds of downstream products of liquid ammonia, mainly concentrated in the fields of fertilizer, chemical industry and refrigeration. Fertilizer products include urea, ammonium nitrate, ammonium phosphate, etc., which play an important role in agricultural production. Chemical products such as nitric acid, aniline, etc. are the basic raw materials for a variety of chemical materials and pharmaceutical products. Liquid ammonia is also used as an industrial refrigerant and is widely used in food processing, cold storage and refrigerated transportation.

Liquid ammonia storage method

The storage of liquid ammonia requires special facilities and strict safety management. Generally, liquid ammonia is stored in low-temperature or high-pressure storage tanks, which are usually made of corrosion-resistant materials and equipped with safety valves, explosion-proof devices and other facilities. The low-temperature storage method is usually kept below -33°C, and the low-temperature environment is maintained by the cooling system; the high-pressure storage method increases the pressure to liquefy the ammonia, and the common storage pressure is 8-10 bar. In the process of storage, it is necessary to regularly check the tightness of the equipment to prevent the leakage of liquid ammonia from causing harm to the environment and human body.

Liquid ammonia transportation method

The transportation of liquid ammonia also requires strict safety measures. Common modes of transportation include road tankers, railway tankers and special liquid ammonia ships. The transport container shall be corrosion-resistant and explosion-proof and equipped with a pressure relief device and a temperature control system. Safety protection measures during transportation are also very important, such as equipped with protective clothing, gas detectors and emergency treatment equipment, etc., to deal with possible leaks and accidents.

Liquid Ammonia Safety Management

Liquid ammonia has high requirements for safety management due to its volatile, strong corrosive and toxic properties. The leakage of liquid ammonia will cause serious harm to the environment and human health, so in the process of production, storage and transportation, the safety operation procedures must be strictly observed. Factories and warehouses should be equipped with complete ventilation systems and leak detection devices, and detailed emergency plans should be developed. Staff should be professionally trained and wear appropriate protective equipment. Safety isolation area shall be set up around the liquid ammonia facilities to prevent contact with outside personnel.

Environmental impact

Ammonia poses certain risks in the environment. When liquid ammonia leaks into the atmosphere, it will quickly volatilize and diffuse, forming irritating and corrosive gases, causing harm to animals, plants and human health. After liquid ammonia enters the water body, it will react with water to generate ammonium hydroxide, change the pH value of the water body, and affect the aquatic ecosystem. Therefore, the production and use of liquid ammonia must take effective environmental protection measures to prevent its pollution to the environment. Wastewater treatment and gas purification equipment are essential configurations in liquid ammonia plants to reduce the environmental impact of emissions.

Liquid ammonia industry trends

With the global emphasis on green energy and environmental protection, liquid ammonia as a hydrogen energy carrier and zero-carbon fuel has broad application prospects. In the future, liquid ammonia is expected to play an important role in hydrogen fuel cells and clean energy transportation. Technological advances will further improve the production efficiency and safety of liquid ammonia and reduce its impact on the environment. Policy support and the growth of market demand will promote the development of liquid ammonia industry to a more environmentally friendly, efficient and intelligent direction.

Conclusion

As an important chemical raw material and energy carrier, liquid ammonia has broad application prospects. Its unique physical and chemical properties make it play a key role in many fields. Due to its high environmental and safety requirements, the production, storage and transportation of liquid ammonia require strict management and advanced technical support. With the advancement of technology and changes in market demand, the liquid ammonia industry will usher in new development opportunities and contribute to green energy and sustainable development.