Chemical Industry

（1） Oxygen

1. Fertilizer

During the production of synthetic ammonia, oxygen is mainly used for the oxidation of feed gas to strengthen the process and increase the fertilizer output.

2. Gasification and liquefaction of coal

Coal gasification industry is a large user of oxygen. Oxygen is used as the gasification agent of pulverized coal. In the process of coal gasification, if pulverized coal is used for gasification, 500~900m3 oxygen is consumed per ton of synthetic ammonia; Oxygen is used as oxidant to convert solid coal into combustible gas mixture; In the process of coal liquefaction, oxygen is used as the medium to convert coal from hydrogen poor solid hydrocarbon to hydrogen rich liquid hydrocarbon, and the oxygen consumption is large. The oxygen required to produce 1 ton of coal synthetic fuel is at least 0. 3 tons of oxygen/1 ton of coal, or 1 ton of oxygen/1 ton of coal. Therefore, 10~20 sets of 58400~73000m3/h oxygen generators installed in parallel are required for the synthetic fuel unit with a capacity of 100000 barrels/day.

3. Petroleum

Oxygen is used as the gasification agent of pulverized coal or heavy oil, and the high-temperature cracking of heavy oil can not be separated from oxygen. Consumption index of various transformation schemes for medium-sized ammonia plants using heavy oil as raw material and coal as raw material (equivalent to about 10t/h of ammonia output), in which oxygen consumption is: coal water slurry pressurized gasification (conventional furnace) is 9264m3/h; Water pulverized coal pressurized gasification (two zone double temperature furnace type) is 7333 m3/h; The pressurized gasification of dry powder is 7179m3/h; Continuous gasification of smokeless lump coal under atmospheric pressure and oxygen enrichment, Shenhua Coal Liquefaction Demonstration Project in China will be the first in the world to adopt direct coal liquefaction technology to achieve large-scale oil synthesis; Gasification with heavy oil will consume 250~700m3 per ton of synthetic ammonia; Gasification with residue oil, with a consumption of 850~940m3 per ton of synthetic ammonia;

4. Chemical products

Oxygen is used to manufacture medicine, dyes, explosives and other chemical products. In addition, it is also used to strengthen production, such as the production of yellow phosphorus by oxygen blowing and the gasification of inferior coal by oxygen injection.

（2） Nitrogen

Nitrogen is mainly used as protective gas, replacement gas and washing gas in chemical plants to ensure safe production. For polypropylene production, pure nitrogen (99.99%) shall be used as protective gas and replacement gas. High purity nitrogen is a crucial gas for chemical fiber production. For example, Liaoyang Petrochemical Fiber General Plant has three sets of 3000m3/h high purity nitrogen units. The synthetic leather factory should also be protected by high-purity nitrogen. For example, Yantai Synthetic Leather Factory has a set of 1000m3/h high-purity nitrogen device. Forest chemical plants also need to use nitrogen as the process protection gas in the production process of sensitive coating, rosin, resin, etc. It can be said that chemical plants are large users of nitrogen, and nitrogen is the "security gas" of chemical plants. It is promising to develop chemical nitrogen, and nitrogen is also an important raw material for synthetic fibers (acrylic fiber, nylon) and synthetic rubber.

1. Fertilizer

Nitrogen is the main raw material of nitrogen fertilizer industry, such as ammonium nitrate with 36% nitrogen, ammonium sulfate with 21% nitrogen and urea with 46% nitrogen. 7%。 Nitrogen is also used to replace the air or gas in pipes and containers before the nitrogen fertilizer plant starts production or after the system is overhauled to ensure safe operation. Lime nitrogen is a chemical nitrogen fertilizer, and 300~500m3 of nitrogen is consumed for 1 ton of lime nitrogen; Nitrogen is mainly used for ammonia synthesis. Ammonia is the main raw material of chemical fertilizer industry and basic organic chemical industry.

2. Coal chemical industry

In a small ammonia plant made from water gas, the ratio of nitrogen and hydrogen after nitrogen addition is stable, the operation is stable, and the power consumption of ammonia can be reduced; In addition, refined nitrogen (99.99%) is used to protect the catalyst; Clean the refined hydrogen nitrogen mixture with pure liquid nitrogen, so that the inert gas (methane and hydrogen) is very small, and the content of carbon monoxide and oxygen does not exceed 20PPm. The nitrogen consumption of nitrogen washing is about 750 m3/t ammonia. Oxygen is used as the gasification agent of pulverized coal or heavy oil, and nitrogen is used as the feed gas and as the safety protection gas of the device (99.99% pure nitrogen is required for coal contact protection).

3. Petroleum

As enhanced oil production gas; As the "oil displacement gas", nitrogen is required to be oil-free and anhydrous dry nitrogen with purity of 99. More than 99%, injection pressure 20~60 MPa.

（3） Carbon dioxide

1. Organic chemical industry

Carbon dioxide can be used in organic chemical synthesis to produce a variety of commonly used chemical products, such as urea, salicylic acid, etc; Carbon dioxide as a monomer raw material, under the action of bimetallic coordination PBM catalyst, is activated to a high degree, and copolymerizes with epoxide to generate aliphatic polycarbonate (PPC). After post-treatment, carbon dioxide resin material is obtained; Carbon dioxide can be used as foaming agent in plastic industry.

2. Petroleum

In the petroleum mining industry, one ton of CO2 liquid injected into the oil well can increase the crude oil production by 3-5 tons.

3. Fertilizer

Urea fertilizer is composed of CO2 and ammonia; It can be used as the gas fertilizer for plant greenhouses and the fertilizer for aquatic tanks. Carbon dioxide is the best gas fertilizer. If carbon dioxide gas is sprayed twice a week, after 4-5 times of spraying, vegetables will increase by 90%, rice by 70%, soybeans by 60%, and sorghum by even 200%.

（4） Hydrogen

1. Petrochemical industry

1) Synthetic ammonia, methanol, etc

Hydrogen containing gases with different components are used as feed gas and hydrogenation gas for synthetic ammonia, methanol and petroleum refining. For a 1000t/d ammonia plant, 336 cubic meters of hydrogen are required for each ton of ammonia produced. The main cost of large-scale production of synthetic ammonia depends on hydrogen. For a 2500t/d methanol plant, 560 cubic meters of hydrogen are required for each ton of methanol produced; Hydrogen is also the feed gas for organic hydrogenation.

2) Synthetic organic compounds

Hydrogen reacts with carbon monoxide to synthesize a variety of organic compounds, such as the synthesis of ethylene glycol, the synthesis of polymethylene, and the homologation of alcohols.

2. Petroleum

1) Refining crude oil

Crude oil shall be refined by hydrodesulfurization and hydrocracking, and hydrodesulfurization agent shall be used in petroleum refining. The hydrogen consumption in the petroleum industry is second only to that of synthetic ammonia. Hydrogen is mainly used for naphtha hydrodesulfurization, crude diesel hydrodesulfurization, fuel oil hydrodesulfurization, improving the flameless height of aircraft fuel and hydrocracking. In the petrochemical industry, hydrogen is mainly used for C3 fraction hydrogenation, gasoline hydrogenation C6-C8 fraction hydrodealkylation and cyclohexane production.

2) Impurity removal

Hydrogenation of catalytic reforming feedstock is to remove sulfide, nitride, lead, arsenic and other impurities from naphtha.

3. Other

Another important use of hydrogen is the hydrogenation of fats in margarine, cooking oil, shampoo, lubricants, household cleaners and other products.

（5） Acetylene

Acetylene gas is one of the important raw materials for organic synthesis. If it is added with hydrogen chloride, hydrocyanic acid and acetic acid, it can be used as raw materials for polymer production; It is used to manufacture acetaldehyde, acetic acid, benzene, synthetic rubber, synthetic fiber, etc. It is also one of the monomers of three synthetic materials (rubber, plastic, fiber); Acetylene is decomposed into carbon and hydrogen at high temperature, from which acetylene carbon black can be prepared. Under certain conditions, acetylene polymerizes to produce aromatic hydrocarbons such as benzene, toluene, xylene, naphthalene, anthracene, styrene, indene, etc.

Note: valuable products can be produced by substitution reaction and addition reaction. For example, acetylene is directly hydrated to produce acetaldehyde; Acetylene reacts with hydrogen chloride to produce vinyl chloride; Acetylene reacts with acetic acid to produce vinyl acetate; Acetylene reacts with hydrogen cyanide to produce acrylonitrile; Acetylene reacts with ammonia to form methylpyridine and 2-methyl-5-ethylpyridine; Acetylene reacts with toluene to produce xylenylethylene, and then the catalyst is cracked to produce three isomers of methylstyrene: acetylene is condensed with one molecule of formaldehyde to propargyl alcohol, and with two molecules of formaldehyde to butynediol; Methylethynyl alcohol can be prepared by addition reaction of acetylene and acetone, and then isoprene can be formed by reaction; Acetylene reacts with carbon monoxide and other compounds (such as water, alcohol, mercaptan) to produce acrylic acid and its derivatives.

（6） Fluorine gas

1. Manufacturing fluoride

1) Preparation of hydrofluoric acid and sodium fluoride

Using the reaction of fluorine and water, fluorine can be used to prepare hydrofluoric acid (HF: 2H2O+2F2==4HF+O2). Hydrofluoric acid plays an important role in the purification of aluminum and uranium, the removal of oxides on the silicon surface in the etching of glass, the semiconductor industry, the synthesis of a variety of fluorine containing organic compounds, etc. Fluorine can also be used to prepare sodium fluoride, which can be used as wood preservative, agricultural insecticide, brewing bactericide, pharmaceutical preservative, welding flux Alkaline zincate zinc plating additive, etc.

2) Prepare fluorinating agent for different purposes

Using the nature that simple fluorine can react with almost all simple substances, a variety of fluorinating agents with different uses can be made. For example, chlorine trifluoride, chlorine pentafluoride, bromine trifluoride, iodine pentafluoride, cobalt trifluoride, antimony pentafluoride, silver difluoride, boron trifluoride, arsenic trifluoride, large arsenic fluoride, etc. These fluorinating agents are milder than simple fluorine and can be used for the preparation of many organic and inorganic fluorides that need to control the degree of fluoride.

2. Manufacture of fluoroplastics

Fluorine containing plastics can be prepared by the reaction of fluorine gas and plastics. Fluorine containing plastics have the characteristics of high temperature resistance, oil resistance, high vacuum resistance, acid and alkali resistance, and resistance to a variety of chemicals. They have been used in modern aviation, missiles, rockets, aerospace, ships, atomic energy and other cutting-edge technologies, as well as automobile, shipbuilding, chemistry, petroleum, telecommunications, instruments, machinery and other industrial fields.

3. Production of sulfur hexafluoride gas

Sulfur hexafluoride is obtained by reacting simple fluorine with simple sulfur. Sulfur hexafluoride has good heat resistance, chemical stability and very high electrical insulation, and is widely used as arc extinguishing medium on high-voltage electrical appliances and electronic equipment.

4. Preparation of organic fluoride

Perfluorinated oil or perfluorinated grease, which is made by thoroughly fluorizing hydrocarbons with fluorine, is a key material in nuclear fuel production. Many fluorine-containing organics can be prepared by controlling the reaction with nitrogen diluted fluorine gas, such as hexafluoroethane, octafluoropropane and other pharmaceutical and pesticide intermediates, refrigerants, fluoroplastics, plasma etchants, etc.

5. Production of nitrogen trifluoride

Fluorine gas reacts with nitrogen containing compounds such as NH3, NH4F, xHF, (NH4) 3AIF6 under certain conditions to generate trifluoride. Nitrogen trifluoride has special physical and chemical properties, which makes it can be used as rocket propellant, etching agent and cleaning agent in semiconductor chip manufacturing process.