[Chemical Knowledge]：Properties, uses, upstream and downstream raw materials, storage methods, characteristics and protective measures of liquid chlorine

Properties of liquid chlorine

liquid chlorine, that is, liquid chlorine, is a colorless or light yellow liquid formed by elemental chlorine at low temperature or high pressure. Liquid chlorine is highly oxidizing and corrosive, and can react with most organic and inorganic substances. Its boiling point is -34.6 ° C., so it is easily gasified at room temperature. Liquid chlorine is denser, heavier than water, and insoluble in water but soluble in organic solvents, such as chloroform and carbon tetrachloride. The strong reactivity of liquid chlorine makes it widely used in the chemical industry.

Uses of liquid chlorine

the use of liquid chlorine is very extensive, mainly concentrated in the following aspects:

1. water treatment liquid chlorine is widely used in the disinfection of tap water and sewage. Its strong oxidation can effectively kill pathogenic bacteria and other microorganisms in the water and ensure the safety of water quality.
2. chemical synthesis liquid chlorine is the basic raw material for the production of a variety of chemical products, such as vinyl chloride (used in PVC production), chlorobenzene, chloroform, chlorine and so on. Chlorination reaction is one of the common reactions in organic synthesis.
3. Pharmaceuticals and Pesticides: Liquid chlorine is used in the pharmaceutical and pesticide industries to synthesize various chlorine-containing compounds, which usually have high biological activities, such as antibiotics and herbicides.
4. Metal Smelting and Processing: Liquid chlorine is used in the preparation of metal chlorides, such as aluminum chloride is used in the production of electrolytic aluminum. In addition, liquid chlorine is also used in the refining process of certain metals to help remove impurities.

Upstream raw material for liquid chlorine

the production of liquid chlorine mainly depends on the following raw materials and processes:

1. chlorine liquid chlorine is obtained by liquefaction of chlorine gas. Chlorine gas is typically produced by electrolysis of sodium chloride solution (I. e., brine). Hydrogen and sodium hydroxide are also produced during the electrolysis process.
2. Salt: As the basic raw material of electrolytic sodium chloride solution, the purity and supply of salt (NaCl) directly affect the production of liquid chlorine.
3. Electric energy: The electrolysis process requires a lot of electricity, and the cost of electricity is an important part of liquid chlorine production. Therefore, the stable supply of electricity and cost control are essential for liquid chlorine production.

Downstream products of liquid chlorine

the downstream products of liquid chlorine are widely used in many industries, including:

1. polyvinyl chloride (PVC): Vinyl chloride monomer is polymerized to produce PVC, which is widely used in building materials, pipes, cable sheathing and other fields.
2. chlorinated organic compounds including chlorobenzene, chloroform, carbon tetrachloride, etc., these compounds have important applications in organic synthesis, solvents, refrigerants, etc.
3. Pesticides and Pharmaceutical Intermediates: Liquid chlorine is used to synthesize a variety of pesticides and pharmaceutical intermediates to meet the needs of the agricultural and pharmaceutical industries.
4. Disinfectant and bleach: Liquid chlorine is widely used as an important disinfectant and bleaching agent in the fields of water treatment and pulp bleaching.

Storage method of liquid chlorine

because liquid chlorine is highly oxidizing, corrosive and toxic, its storage must strictly follow safety regulations:

1. storage tank material liquid chlorine storage tanks are usually made of corrosion-resistant steel, such as stainless steel or special alloy steel, to ensure long-term use is not corroded.
2. Temperature and pressure control: Liquid chlorine must be stored under low temperature or high pressure conditions to prevent its gasification. Low temperature storage is often used to keep the temperature below its boiling point.
3. Sealing and venting: The storage tank needs to be well sealed to prevent leakage of liquid chlorine. At the same time, the storage area should have good ventilation conditions to ensure that the chlorine gas can be diluted and discharged in time in case of leakage.
4. Protective measures: Facilities storing liquid chlorine must be equipped with emergency sprinkler systems, absorption devices and personal protective equipment to deal with possible spills and accidents.
5. Location selection liquid chlorine storage tanks should be kept away from crowded areas and other hazardous chemical storage areas, and obvious safety warning signs should be set up.

Transport of liquid chlorine

the transport of liquid chlorine also requires strict safety measures:

1. special means of transport: The transportation of liquid chlorine must use special tank trucks or pressure vessels, and be equipped with corresponding safety valves and protective equipment.
2. Transportation route: Choose transportation routes that are convenient and avoid densely populated areas, and maintain contact with relevant departments during transportation to ensure timely emergency response.
3. Driver Training: Drivers and escorts transporting liquid chlorine must undergo professional training to master the nature of liquid chlorine and emergency treatment methods.
4. monitoring system: GPS and other monitoring systems should be equipped during transportation to monitor the location and status of vehicles in real time to ensure transportation safety.

Environmental and safety risks of liquid chlorine

the strong oxidizing and corrosive nature of liquid chlorine determines its high environmental and safety risks during use and storage:

1. leakage risk once the liquid chlorine leaks, it quickly gasifies to form toxic gases, posing a serious threat to personnel and the environment. Therefore, liquid chlorine storage and use sites must be equipped with leak detection and treatment equipment.
2. Fire and explosion risk liquid chlorine reacts violently with a variety of organic and reducing substances, which may cause fire and explosion. Therefore, when operating liquid chlorine, the environmental conditions should be strictly controlled to avoid contact with flammable and explosive substances.
3. Corrosion risk: Liquid chlorine is highly corrosive to metals and many non-metallic materials, and long-term contact may cause equipment damage. Therefore, equipment and piping related to liquid chlorine need to be regularly inspected and maintained.

Summary

as an important industrial raw material, liquid chlorine has a wide range of uses and important economic value. There are high safety and environmental risks in the process of production, storage and transportation, which need strict management and regulation. Through scientific and reasonable management measures, it can effectively reduce the harm of liquid chlorine to the environment and human health, and give full play to its important role in industrial production.