Description
Also known as Naptha. Naptha is a general term applied to refined, partly refined, or unrefined petroleum products and liquid products of natural gas, not less than 10% of which distill below 175°C (347 °F) and not less than 95% of which distill below 240 °C (464°C)when subjected to distillation in accordance with the Standard Method of Test for Distillation of Gasoline, Naphtha,Kerosene,and Similar Petroleum Products(ASTMD86). Used as a source, by various cracking processes, of gasoline, special naphthas, petroleum chemicals, especially ethylene. Cracking for ethylene also produces propylene, butadiene, pyrolysis gasoline,and fuel oil, source of synthetic natural gas.
Physical properties
Petroleum ether is a colorless transparent liquid, slightly odor, low polarity. Petroleum ether is a mixture of various small molecule ethers after petroleum cracking. According to the boiling point, it can be divided into 30-60℃ and 60-90℃.It is insoluble in water and can be miscible with acetone, ether, ethyl acetate, benzene, chloroform and higher alcohols above methanol. It can dissolve synthetic resins such as coumarone resin and triglyceride rosinate. Partially dissolves rosin, pitch, frankincense and aromatic resins. Does not dissolve shellac and alkaloids. Except for castor oil, most liquid fats are soluble, and solid fats are slightly soluble. The fatty acid is soluble, but the hydroxy acid is hard to dissolve, so petroleum ether can be used to separate the hydroxy acid mixed in the fatty acid. Raw rubber and vulcanized rubber swell significantly in petroleum ether. Chlorinated rubber, nitrocellulose, cellulose acetate, benzyl cellulose, etc. are insoluble in petroleum ether.
Synthesis
Industrial petroleum ether contains impurities such as unsaturated hydrocarbons, aromatic hydrocarbons, sulfides, acidic substances and non-volatile substances. When refining, it is washed with concentrated sulfuric acid (98%~99%) until the color disappears, and then washed with alkali and water in sequence. The dehydrating agent is dried and then rectified. After washing with concentrated sulfuric acid, the petroleum ether can be washed with a saturated solution of potassium permanganate dissolved in 10% sulfuric acid until the purple color in the water layer no longer disappears. Then it is washed with water, the dehydrating agent is dried and distilled. Anhydrous sodium sulfate, phosphorus pentoxide, sodium metal and calcium chloride are used as dehydrating agents.Using mineral spirits as raw material, wash with concentrated sulfuric acid, 20% sulfuric acid solution containing 0.1 mol/L potassium permanganate, 10% to 15% alkali solution and distilled water to remove the aromatic hydrocarbon compounds and olefins respectively. Compound, free acid brought in by pickling and free alkali brought in by alkali. Then carry out rectification, remove a small amount of head liquid, collect the distillate according to the required boiling range, and obtain the petroleum ether product.
Mechanism of Toxicity
The acute toxicity from overexposure to petroleum ether is manifested primarily in central nervous system (CNS) effects. The mechanism of toxicity is unknown; however, the general anoxia observed is most likely due to oxygen deprivation. The mechanism of toxicity from long-term overexposure to petroleum ether is dependent on the chemical makeup of the distillate. For example, if peripheral neuropathy is observed, it is most likely due to a high concentration of n-hexane in the petroleum ether. n-Hexane is known to cause axonal damage in peripheral nerves.
Definition
PETROLEUM ETHER is a complex combination of hydrocarbons obtained from the distillation of crude oil or natural gasoline. It consists predominantly of saturated hydrocarbons having carbon numbers predominantly in the range of C5 through C10 and boiling in the range of approximately 35.degree.C to 160.degree.C (95.degree.F to 320.degree.F).
Flammability and Explosibility
Extremely flammable
Agricultural Uses
Naphtha is used as a raw material for producing hydrogen required for the manufacture of nitrogen fertilizers. It is also one of the favored feedstocks for ammonia production. In addition to being a source of hydrogen, naphtha is a good solvent used for degreasing, extraction in plants, drycleaning, etc.
