High-Purity Acetylene Product Description

Acetylene, also known as carbide gas, is a slightly toxic, flammable gas that is colorless at standard temperature and pressure and possesses mild anesthetic properties while inhibiting cellular oxidation. Industrially, acetylene is produced through the hydrolysis of calcium carbide, a mineral rich in calcium carbonate. Its explosive limits in air range from 2.5% to 80%. Pure acetylene is odorless; however, since the calcium carbide feedstock used to produce acetylene contains trace amounts of calcium sulfides and phosphides, industrial acetylene inevitably contains impurities such as phosphine and hydrogen sulfide, giving it a pungent, garlic-like odor. Under atmospheric pressure, acetylene cannot be liquefied; it is sparingly soluble in water but readily dissolves in organic solvents like petroleum ether, ethanol, and benzene, with extremely high solubility in acetone. Consequently, industrial acetylene is acetylene dissolved in acetone, also referred to as dissolved acetylene. It is primarily used for metal welding and cutting, organic synthesis, atomic absorption spectroscopy, standard gases, calibration gases, synthetic rubber production, and illumination.

Applications of High-Purity Acetylene

Acetylene combined with oxygen produces an oxyacetylene flame with a temperature as high as 3,200°C, commonly used for cutting metals such as shipbuilding and steel structures.

High‑purity acetylene is used in instruments such as atomic absorption spectrometers.

Acetylene is used to synthesize pharmaceuticals and chemical intermediates such as vinylacetylene or divinylacetylene.

Used for the production of standard gases such as transformer oil analysis standard gases.

At high temperatures between 400 and 500°C, acetylene can undergo cyclic trimerization to form benzene; when using nickel cyanide Ni(CN)₂ as a catalyst, cyclooctatetraene can be produced at 50°C and 1.2–2 MPa.

The “acetylene bomb,” which uses acetylene gas as the damaging agent, is employed to destroy tanks or other armored vehicles.

Precautions for High-Purity Acetylene

Acetylene is typically dissolved in solvents such as acetone and porous materials, then stored in steel cylinders. The cylinders should be kept in a cool, well‑ventilated, dry location, with a storage temperature not exceeding 40°C. Ideally, they should be stored separately outdoors in a designated, isolated area. Keep them away from ignition sources and heat sources, protect them from direct sunlight, and ensure they are segregated from oxygen, compressed air, oxidizing agents, fluorine, chlorine, bromine, copper, silver, mercury, copper salts, mercury salts, silver salts, organic peroxides, explosives, toxic substances, and radioactive materials.

When moving acetylene cylinders, use a dedicated cylinder dolly and handle them with care. During transportation, be sure to securely fasten the safety cap on the cylinder to prevent damage to the cylinder accessories and avoid potential hazards.

Use with a dedicated acetylene regulator such as the YQE-213 after pressure reduction, and always use it in conjunction with an acetylene flashback arrestor to strictly prevent backfire.

The neck of the acetylene cylinder is marked with the cylinder inspection date. Expired cylinders must be entrusted to acetylene distributors such as Puyuan Gas or other authorized dealers to undergo inspection at a qualified pressure vessel inspection agency; the use of expired cylinders is strictly prohibited.

Acetylene pipeline equipment and pipelines must be grounded and strictly sealed. Before use, acetylene gas pipelines should undergo nitrogen pressure testing and soap solution leak detection to ensure that the acetylene pipeline is free from leaks.

Industrial acetylene often contains gases such as phosphine and hydrogen sulfide, so it is frequently accompanied by the toxic effects of these substances; therefore, workplaces should be well‑ventilated.

Physicochemical Properties of High-Purity Acetylene

Molecular weight: 26.038

Triple point: (128 kPa): -80.55°C

Boiling point (170 kPa): -75.0℃

Liquid density (-80.75℃): 610 kg/m³

Gas density (273.15 K, 101.325 kPa): 1.1747 kg/m³

Relative density (air = 1, 0°C, 101.325 kPa): 0.908

Specific volume (15.6°C, 101.325 kPa): 0.9008 m³/kg

Gas–liquid volume ratio (15°C, 100 kPa): 556 L/L

Critical temperature: 3532°C

Critical pressure: 6190 kPa

Critical density: 230.4 kg/m³

Compression ratio:

Heat of fusion (-80.75°C, 128 kPa): 96.4 kJ/kg

Heat of vaporization (-83.80℃, 101.325 kPa): 801.36 kJ/kg

Specific heat capacity (0°C, 101.33 kPa): Cp = 1636.62 J/(kg·K) Cv = 1308.79 J/(kg·K)

Specific heat ratio (26.8°C, 101.325 kPa): Cp/Cv = 1.234

Acetylene vapor pressure (-20°C): 1510 kPa (0°C): 2665 kPa (20°C): 4367 kPa

Viscosity (101.33 kPa, 20°C): 0.0103 mPa·s

Thermal conductivity (101.325 kPa, 200 K): 0.01181 W/(m·K)

Refractive index (20°C, 101.325 kPa, 5876 Å, gas): n = 1.000598

Flammability range of acetylene in air (20°C, 101.325 kPa): 2.2%–85%.

Minimum ignition temperature of acetylene in air (101.325 kPa): 305°C

Flame temperature during stoichiometric combustion in air: 2950°C

Maximum flame velocity during stoichiometric combustion in air: 1.46 m/s

Flammability range in oxygen (20°C, 101.325 kPa): 2.8%–93%

Minimum autoignition temperature in oxygen (101.325 kPa): 296°C

Flame temperature during stoichiometric combustion in oxygen: 3070°C

Maximum flame velocity during stoichiometric combustion in oxygen: 7.60 m/s

Heat of combustion under stoichiometric conditions in oxygen: 58,492 J/m³ (upper limit) / 56,442 J/m³ (lower limit)

The concentration at which the maximum explosion pressure is generated in air: 14.5%

Maximum explosion pressure: 10.3 kg/cm³

Minimum ignition energy: 0.019 mJ

Toxicity Level: 1

Flammability Level: 4

Explosivity Level: 3

Acetylene is a colorless, flammable gas with anesthetic properties under standard temperature and pressure. It is odorless in its pure form, but when impurities are present, it develops a pungent, unpleasant garlic-like odor. Lighter than air, acetylene can form explosive mixtures with air and is highly susceptible to combustion and explosion. It is slightly soluble in water; at 25°C and 101.325 kPa, its solubility in water is 0.94 cm³/cm³. It is soluble in alcohol, acetone, benzene, diethyl ether, and other solvents.

Specifications and Technical Parameters