Download Butane

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<div>Butane (/ˈbjuːteɪn/) or n-butane is an alkane with the formula C4H10. Butane is a highly flammable, colorless, easily liquefied gas that quickly vaporizes at room temperature and pressure. The name butane comes from the root but- (from butyric acid, named after the Greek word for butter) and the suffix -ane. It was discovered in crude petroleum in 1864 by Edmund Ronalds, who was the first to describe its properties,[6][7] and commercialized by Walter O. Snelling in early 1910s.</div><div></div><div></div><div>The first synthesis of butane was accidentally achieved by British chemist Edward Frankland in 1849 from ethyl iodide and zinc, but he had not realized that the ethyl radical dimerized and misidentified the substance.[8]</div><div></div><div></div><div></div><div></div><div></div><div>download butane</div><div></div><div>Download Zip: https://t.co/Z6URUItZWA </div><div></div><div></div><div>The proper discoverer of the butane called it "hydride of butyl",[9] but already in the 1860s more names were used: "butyl hydride",[10] "hydride of tetryl"[11] and "tetryl hydride",[12] "diethyl" or "ethyl ethylide"[13] and others. August Wilhelm von Hofmann in his 1866 systemic nomenclature proposed the name "quartane",[2] and the modern name was introduced to English from German around 1874.[14]</div><div></div><div></div><div>Butane did not have much practical use until the 1910s, when W. Snelling identified butane and propane as components in gasoline and found that, if they were cooled, they could be stored in a volume-reduced liquified state in pressurized containers.</div><div></div><div></div><div>The density of butane is highly dependent on temperature and pressure in the reservoir.[15] For example, the density of liquid propane is 571.81 kg/m3 (for pressures up to 2MPa and temperature 270.2 C), while the density of liquid butane is 625.50.7 kg/m3 (for pressures up to 2MPa and temperature -130.2 C).</div><div></div><div></div><div>n-Butane, like all hydrocarbons, undergoes free radical chlorination providing both 1-chloro- and 2-chlorobutanes, as well as more highly chlorinated derivatives. The relative rates of the chlorination is partially explained by the differing bond dissociation energies, 425 and 411 kJ/mol for the two types of C-H bonds.</div><div></div><div></div><div>Normal butane can be used for gasoline blending, as a fuel gas, fragrance extraction solvent, either alone or in a mixture with propane, and as a feedstock for the manufacture of ethylene and butadiene, a key ingredient of synthetic rubber. Isobutane is primarily used by refineries to enhance (increase) the octane number of motor gasoline.[17][18][19][20]</div><div></div><div></div><div>For gasoline blending, n-butane is the main component used to manipulate the Reid vapor pressure (RVP). Since winter fuels require much higher vapor pressure for engines to start, refineries raise the RVP by blending more butane into the fuel.[21] n-Butane has a relatively high research octane number (RON) and motor octane number (MON), which are 93 and 92 respectively.[22]</div><div></div><div></div><div>Pure forms of butane, especially isobutane, are used as refrigerants and have largely replaced the ozone-layer-depleting halomethanes in refrigerators, freezers, and air conditioning systems. The operating pressure for butane is lower than for the halomethanes such as Freon-12 (R-12), so R-12 systems such as those in automotive air conditioning systems, when converted to pure butane, will function poorly. A mixture of isobutane and propane is used instead to give cooling system performance comparable to use of R-12.[24]</div><div></div><div></div><div>Butane is also used as lighter fuel for common lighters or butane torches and is sold bottled as a fuel for cooking, barbecues and camping stoves. In the 20th century the Braun company of Germany made a cordless hair styling device product that used butane as its heat source to produce steam.[25]</div><div></div><div></div><div></div><div></div><div></div><div></div><div>As fuel, it is often mixed with small amounts of mercaptans to give the unburned gas an offensive smell easily detected by the human nose. In this way, butane leaks can easily be identified. While hydrogen sulfide and mercaptans are toxic, they are present in levels so low that suffocation and fire hazard by the butane becomes a concern far before toxicity.[26][27] Most commercially available butane also contains some contaminant oil, which can be removed by filtration and will otherwise leave a deposit at the point of ignition and may eventually block the uniform flow of gas.[28]</div><div></div><div></div><div>The butane used as a solvent for fragrance extraction does not contain these contaminants[29] and butane gas can cause gas explosions in poorly ventilated areas if leaks go unnoticed and are ignited by spark or flame.[5] Purified butane is used as a solvent in the industrial extraction of cannabis oils.</div><div></div><div></div><div>Commercial production of extracts in medicinal and recreational states generally does not carry the same risk of fire as it utilizes a closed-loop system that recycles the solvent (whereas the process described above is considered an open system as the butane escapes). Within a closed-loop system, a machine recovers and recycles the butane; it is not released into an area in which it may be inadvertently ignited.5 The closed-loop system of extraction is utilized by retail manufacturers of BHO concentrates and is clearly the safer of the two methods.41 Both forms of extraction methods may yield a host of BHO concentrates (crumble, wax, shatter, etc.), each varying in their use and perceived quality.42</div><div></div><div></div><div>Butane is a colorless gas with a faint disagreeable odor, although it isconsidered to be odorless by some. It is poorly soluble in water. Thelower explosive limit is 1.9%. Butane is produced from natural gas. Itsmain uses are in the production of chemicals like ethylene and1,3-butadiene, as a refrigerant, as an aerosol propellant, as aconstituent in liquefied petroleum gas, and as the main component of gaslighter refills. Because it is easily accessible, butane is often usedin inhalant abuse.</div><div></div><div></div><div>The toxicity of butane is low. Huge exposure concentrations can beassumed in butane abuse. The predominant effects observed in abuse casesare central nervous system (CNS) and cardiac effects. Case studies alsoreveal that serious brain damage and underdeveloped organs can occur infetuses in case of high single exposures during the week 27 or 30 ofpregnancy. Quantitative data for setting AEGL values are sparse.Quantitative human data include an old study with human volunteersfocused on the warning properties of butane.</div><div></div><div></div><div>Mortality from butane in mice and rats is preceded by CNS effects. Somedata are available on cardiac effects in dogs, but they are insufficientfor setting AEGL values. Data on CNS effects are available for mice andguinea pigs. Butane was negative in the bacterial reverse-mutation assay(Ames test). Carcinogenicity studies and studies on reproductivetoxicity are lacking.</div><div></div><div></div><div>The AEGL-1 values for butane are based on observations in a study withvolunteers on the warning properties of short exposures to butane (Patty and Yant 1929). It wasconcluded that 10,000 ppm (10-min exposure) was a boundary fordrowsiness. An intraspecies uncertainty factor of 1 is consideredadequate because the concentration-response curve for CNS-effectsappears to be very steep; thus, interindividual variability will berelatively small. Also, no noticeable irritation was reported atconcentrations up to 100,000 ppm (probably for a few min), and a largeruncertainty factor of 3 would lead to unrealistically low AEGL-1 values.Available data suggest a relatively high value for n (Stoughton and Lamson 1936),so time extrapolation was performed using n = 3. Data on butane (Gill et al. 1991) andpropane (Stewart et al.1977) indicate that steady-state plasma concentrations forbutane will be reached within 30 min. By analogy to other CNS-depressingsubstances, the effects of butane are assumed to be solely concentrationdependent. Therefore, time extrapolation was performed from 10 min to30-and 60-min exposures, where the steady-state concentration wascalculated. The calculated values for AEGL-1 are presented in Table 1-1. The values areconsidered protective of the irregular breathing observed in guinea pigsexposed to butane at 21,000-28,000 ppm for up to 2 h (Nuckolls 1933). Thecalculated 10-min AEGL-1 value is greater than 50% of the lowerexplosive limit for butane, and the other AEGL-1 values are greater thanthan 10% of the lower explosive limit.</div><div></div><div></div><div>The AEGL-3 values for butane are based on an acute exposure study withrats and mice (Shugaev1969). Mice and rats were exposed to butane for 2 and 4 h,respectively. The reported data allowed the calculation ofLC01s (lethal concentrations, 1% lethality). The 2-hLC01 for mice was 160,000 ppm and the 4-h LC01for rats was 172,000 ppm. The 2-h LC01 for mice was chosen asstarting point for AEGL-3 derivation, because mice appear to be the moresusceptible species and 160,000 ppm was the lowest concentration tested.A total uncertainty factor of 3 is considered sufficient to account fortoxicokinetic and toxicodynamic differences between individuals andinterspecies differences for the following reasons. The effects areattributed to butane itself and no relevant differences in kinetics areassumed. The data are from a species with a relatively highsusceptibility to butane. The concentration-response curve appears to bevery steep indicating that a large uncertainty factor is unnecessary.Further, a larger factor would lead to unrealistically low values thatwould be similar to the AEGL-2 values. Time scaling was conductedsimilar to that performed for AEGL-2 values. The AEGL-3 values for 30min and for 1, 4 and 8 h of exposure were set equal to that for the 2-hAEGL value. The AEGL-3 values for the 10-min exposure were derived bytime scaling according to the dose-response regression equationCn t = k, using n = 3. The calculated 10-minvalue of 77,000 ppm is supported by the data from Patty and Yant (1929). They reported thatexposure to slowly increasing concentrations of butane up to 50,000 ppm(total exposure duration at least 10 min) and a short exposure (durationnot specified) to 100,000 ppm on the same day did not result in seriouscomplaints (Patty and Yant1929). All of the AEGL-3 values are greater than the lowerexplosive limit for butane.</div><div></div><div></div><div>Butane is produced from raw natural gas and from petroleum streamsobtained by catalytic cracking, catalytic reforming, and other refiningprocesses. Butane is used in the production of ethylene and1,3-butadiene, in the synthesis of a number of chemicals, as arefrigerant and an aerosol propellant, in the blending of gasoline ormotor fuel, as a constituent in liquefied petroleum gas, and as anextraction solvent in deasphalting processes (Low et al. 1987). Butane used in gas lighterrefills consists of butane with small amounts of isobutane andpropane.</div><div></div><div> 7c6cff6d22</div>