n-Butane

  Butane (CAS NO.106-97-8) is reported in EPA TSCA Inventory.

OSHA PEL: TWA 800 ppm
ACGIH TLV: TWA 800 ppm
DFG MAK: 1000 ppm (2400 mg/m³)
DOT Classification:  2.1; Label: Flammable Gas

n-Butane, also known butane, is a highly flammable, colorless, easily liquefied gas with a faint petroleum-like odor. It is an alkane with four carbon atoms. Butane refers two structural isomers of n-butane and isobutane. It is insoluble in water, soluble in alcohol, ether, chloroform and other hydrocarbons. n-Butane is used primarily as gasoline blending components and less so as liquefied fuel and in the manufacture of chemicals. 

Preparation: Oil field gas, wet natural gas and cracked gas all contain n-butane. So it can be obtained by separation.

1. Separation from oil field gas and wet natural gas: The propane and butane liquefied petroleum gas can be seperated by being pressurized and condensation. After distillation, butane is isolated.

2. Separation from cracked gas: The gas which is obtained from refinery by vacuum distillation at room temperature goes through the following reaction steps: reforming; catalytic cracking; coking; thermal cracking; hydrocracking. The obtained liquid gas can contain a large number of C4 fraction. Then, after reforming, hydrocracking and vacuum distillation, the C4 fraction is mainly butane (n-butane and isobutane). The by-product C4 fraction from ethylene unit also contains butane. After a series of treatment, n-butane (above 90%) can be obtained.

3. Use industrial cymogene (C₄H₁₀ 80% ~ 90%) as raw material and molecular sieve as adsorbent for adsorption purification. The purity of 98% butane can be obtained. Use rectification to remove light components, the product purity can reach 99.99%.

Uses: n-Butane gas is sold bottled as a fuel for cooking and camping. When blended with propane as liquefied petroleum gas, it is largely used for heating homes, cooking and industrial heating. Pure butane gas is used in standard gas, calibration gas, aerosol spray regent, temperature and pressure gauges and ionizing particle counter. n-Butane is also used as fuel for cigarette lighters and portable stoves and as raw material for synthetic rubber and high octane liquid fluids. In addition, it is mainly used as raw material in organic synthesis. For example: after dehydrogenation, butylene and butadiene can be obtained; after isomerization iso-butane can be obtained; after catalytic oxidation, Maleic anhydride, acetic acid, acetaldehyde can be obtained; after halogenate, halogenated butane can be obtained; after nitration, nitrobutane can be obtained.

Safty: n-Butane is a kind of extremely flammable chemical. Therefore, you had better take the following instructions: Keep container in a well-ventilated place; Keep away from sources of ignition - No smoking. Inhalation of n-butane can cause asphyxia, euphoria, drowsiness, cardiac arrhythmia, narcosis, and frostbite, which can result in death from asphyxiation and ventricular fibrillation.

Structure Descriptors:
1. Smiles:C(CC)C
2. InChI:InChI=1/C4H10/c1-3-4-2/h3-4H2,1-2H3

Toxicity: