540-84-1 Usage
Description
Isooctane is a flammable liquid isomer of octane. It is best known for defining the octane
number to rate the antiknock quality of gasoline, which is related to engine performance.Since 1930, many chemical processes, such as alkylation
and polymerization, have been developed to increase the production of branched compounds
in refi nery operations. High octane numbers in gasoline are those associated with the alkenes
(olefins) and aromatics, especially akyl benzene compounds. For example, 2-pentene has a
RON of 154. Benzene itself has a RON of 98, but 1,3,5-trimethylbenzene has a RON of 170.
The highest octane numbers in gasoline are associated with cyclic alkenes, but these account
for only a minute fraction of gasoline.
Chemical Properties
Different sources of media describe the Chemical Properties of 540-84-1 differently. You can refer to the following data:
1. 2,2,4-Trimethylpentane (isooctane), C8H18, is a colorless
liquid naturally found in crude petroleum and in small
amounts in natural gas. It is released to the
environment by the petroleum industries, by automotive
exhausts and emissions, and from hazardous-waste sites,
landfills, and emissions from wood combustion.
2. colourless liquid
3. Octane is a colorless liquid with a gasoline-like
odor. The odor threshold is 4 ppm and 48 ppm (New
Jersey Fact Sheet).
Physical properties
Colorless, flammable liquid with a gasoline-like odor. An odor threshold concentration of 670
ppbv was reported by Nagata and Takeuchi (1990).
Uses
Different sources of media describe the Uses of 540-84-1 differently. You can refer to the following data:
1. 2,2,4-Trimethylpentane is used as a mobile phase in High Performance Liquid Chromatography and Liquid Chromatography coupled with Mass Spectrometry.
2. Isooctane is a petroleum product, producedby the refining of petroleum. It is used as thestandard in determining the octane numbersof fuels (its antiknock octane number is 100)and as a solvent in chemical analysis.
3. In determining octane numbers of fuels; in spectrophotometric analysis; as solvent and thinner.
Definition
ChEBI: An alkane that consists of pentane bearing two methyl substituents at position 2 and a single methyl substituent at position 4.
Production Methods
Isooctane is produced from the fractional distillation of
petroleum fractions and naphthas. It is also produced from
the alkylation of 2-methylpropene with isobutane.
General Description
A clear colorless liquid with a petroleum-like odor. Flash point 10°F. Less dense than water and insoluble in water. Vapors are heavier than air.
Air & Water Reactions
Highly flammable. Insoluble in water.
Reactivity Profile
Saturated aliphatic hydrocarbons, such as 2,2,4-Trimethylpentane, may be incompatible with strong oxidizing agents like nitric acid. Charring of the hydrocarbon may occur followed by ignition of unreacted hydrocarbon and other nearby combustibles. In other settings, aliphatic saturated hydrocarbons are mostly unreactive. They are not affected by aqueous solutions of acids, alkalis, most oxidizing agents, and most reducing agents.
Hazard
Intermediate, azeotropic distillation entrainer.
Health Hazard
Different sources of media describe the Health Hazard of 540-84-1 differently. You can refer to the following data:
1. Inhalation or contact with material may irritate or burn skin and eyes. Fire may produce irritating, corrosive and/or toxic gases. Vapors may cause dizziness or suffocation. Runoff from fire control or dilution water may cause pollution.
2. The acute toxicity of isooctane is very lowand is similar to n-octane. Exposure tohigh concentrations may produce irritationof respiratory tract. Exposure to 30,000 ppmfor an hour may be lethal to mice. There isno report of any other adverse effects fromexposure to isooctane.
Fire Hazard
Highly flammable liquid; flash point (closed
cup) －12.2°C (10°F); autoignition temperature
418°C (784°F) (NFPA 1997); fireextinguishing
agent: dry chemical, foam, or
CO2; use a water spray to keep fire-exposed
containers cool. Isooctane forms explosive
mixtures with air within the range 1–4.6%
by volume of air.
Flammability and Explosibility
Flammable
Safety Profile
Mutation data reported.
High concentrations can cause narcosis. A
very dangerous fire hazard when exposed to
heat, flame, oxidmers. Can react vigorously
with reducing materials. Explosive in the
form of vapor when exposed to heat or
flame. To fight fire, use CO2, dry chemical.
When heated to decomposition it emits
acrid smoke and irritating fumes. See also
ALKANES.
Potential Exposure
Octane is used as a solvent; as a
fuel; as an intermediate in organic synthesis; and in
azeotropicdistillations.
Carcinogenicity
Male and female rats were initiated
with 170 ppm N-ethyl-N-hydroxyethylnitrosamine for
2 weeks and subsequently exposed to isooctane for 61
weeks. An increase in atypical cell foci (a preneoplastic
lesion) was observed in male but not female rats promoted
with the high dose.
Source
Schauer et al. (1999) reported 2,2,4-trimethylpentane in a diesel-powered medium-duty
truck exhaust at an emission rate of 1,240 μg/km.
A constituent in gasoline. Harley et al. (2000) analyzed the headspace vapors of three grades of
unleaded gasoline where ethanol was added to replace methyl tert-butyl ether. The gasoline vapor
concentrations of 2,2,4-trimethylpentane in the headspace were 2.7 wt % for regular grade, 2.8 wt
% for mid-grade, and 3.3 wt % for premium grade.
California Phase II reformulated gasoline contained 2,2,4-trimethylpentane at a concentration of
34.6 g/kg. Gas-phase tailpipe emission rates from gasoline-powered automobiles with and without
catalytic converters were 8.20 and 1,080 mg/km, respectively (Schauer et al., 2002).
Environmental fate
Surface Water. Mackay and Wolkoff (1973) estimated an evaporation half-life of 4.1 sec from a
surface water body that is 25 °C and 1 m deep.
Photolytic. The following rate constants were reported for the reaction of 2,2,4-trimethylpentane
and OH radicals in the atmosphere: 2.3 x 10-12 cm3/molecule?sec at 300 K (Hendry and
Kenley, 1979); 2.83 x 10-12 cm3/molecule?sec at 298 K (Greiner, 1970); 3.73 x 10-12
cm3/molecule?sec at 298–305 K (Darnall et al., 1978); 3.7 x 10-12 cm3/molecule?sec (Atkinson et
al., 1979); 3.90 x 10-12 cm3/molecule?sec at 298 K (Atkinson, 1985). Based on a photooxidation
rate constant of 3.68 x 10-12 cm3/molecule?sec for the reaction of 2,2,4-trimethylpentane and OH
radicals in summer sunlight, the lifetime is 16 h (Altshuller, 1991).
Products identified from the reaction of 2,2,4-trimethylpentane with OH radicals in the presence
of nitric oxide included acetone, 2-methypropanal, 4-hydroxy-4-methyl-2-pentanone, and hydroxy
nitrates (Tuazon et al., 2002).
Chemical/Physical. Complete combustion in air produces carbon dioxide and water vapor.
2,2,4-Trimethylpentane will not hydrolyze in water.
Shipping
UN1262 Octanes, Hazard Class: 3; Labels:
3-Flammable liquid.
Purification Methods
Distil isooctane from sodium, pass it through a column of silica gel or activated alumina (to remove traces of olefins), and again distilled from sodium. Extract repeatedly with conc H2SO4, then agitate it with aqueous KMnO4, wash it with water, dry (CaSO4) and distil it. Purify it also by azeotropic distillation with EtOH, which is subsequently washed out with water, and the trimethylpentane is dried and fractionally distilled. [Forziati et al. J Res Nat Bur Stand 36 126 1946.] [Beilstein 1 IV 439.]
Incompatibilities
Reacts with strong oxidizers, causing fire
and explosion hazard. Attacks some forms of plastics, rubber
and coatings.
Waste Disposal
Dissolve or mix the material
with a combustible solvent and burn in a chemical incinerator
equipped with an after burner and scrubber. All federal,
state, and local environmental regulations must be observed.
Check Digit Verification of cas no
The CAS Registry Mumber 540-84-1 includes 6 digits separated into 3 groups by hyphens. The first part of the number,starting from the left, has 3 digits, 5,4 and 0 respectively; the second part has 2 digits, 8 and 4 respectively.
Calculate Digit Verification of CAS Registry Number 540-84:
(5*5)+(4*4)+(3*0)+(2*8)+(1*4)=61
61 % 10 = 1
So 540-84-1 is a valid CAS Registry Number.
InChI:InChI=1/C8H18/c1-7(2)6-8(3,4)5/h7H,6H2,1-5H3
540-84-1Relevant articles and documents
Isobutane/2-Butene Alkylation on Ultrastable Y Zeolites: Influence of Zeolite Unite Cell Size
Corma, A.,Martinez, A.,Martinez, C.
, p. 185 - 192 (1994)
The alkylation reaction of isobutane with trans-2-butene has been carried out on a series of steam-dealuminated Y zeolites with unit cell sizes ranging from 2.450 to 2.426 nm.A fixed-bed reactor connected to an automatized multiloop sampling system allowed us to make differential product analysis from very short (1 min or less) to longer times on stream.A maximum in the initial 2-butene conversion was found on samples with unit cell sizes between 2.435 and 2.450 nm.However, the TMP/DMH ratio, i.e., the alkylation-to-oligomerization ratio, continuously increased withzeolite unit cell size.The concentration of reactants in the pores, the strength distribution of Broensted acid sites, and the extent of hydrogen transfer reactions, which in turn depend on the framework Si/Al ratio of a given zeolite, were seen to affect activity and product distribution of the catalysts.Finally, the influence of these factors on the aging characteristics of the samples was also discussed.
Hybrid Catalysts Based on Sulfated Zirconium Dioxide and H-beta Zeolite for Alkylation of Isobutane with Isobutylene
Yuferova,Devyatkov, S. Yu.,Fedorov,Semikin,Sladkovskii,Kuzichkin
, p. 1605 - 1613 (2017)
Physicochemical properties of new hybrid catalysts based on sulfated zirconium oxide supported by zeolite of the Beta structural type were investigated. The acid-base characteristics of the catalysts were determined by the amount of the supported component, the maximum concentration of Br?nsted acid centers (277 Μmol/g) was achieved upon deposition of 1.7 wt.% sulfated zirconium oxide. The texture characteristics of the final catalyst were determined by the starting support. Tests of the catalysts in the reaction of isobutane alkylation with isobutylene demonstrated their advantage in selectivity and stability over the classical bulk sulfated zirconium oxide. The variation of the surface acidity is correlated with the amount of the deposited sulfated zirconium dioxide and has an extremum point at around 4 wt.%. Hybrid catalysts based on H-Beta zeolite with supported sulfated zirconium dioxide are more stable and exhibited a higher selectivity with respect to C8 hydrocarbons and trimethylpentanes, compared with bulk sulfated zirconium dioxide.
MxOy/SO42--/dealuminated zeolite β (M=Ti, Fe) as novel catalysts for alkylation of isobutane with 1-butene
Sun, Mingxing,Sun, Jianwei,Li, Quanzhi
, p. 519 - 520 (1998)
A new kind of MxOy/SO42--/H-form dealuminated β (DHβ) catalysts prepared here were applied to alkylation of isobutane with 1-butene. The group of MxCy/SO42-/DHβ (M = Ti, Fe) catalysts has a lower rate of deactivation and higher selectivity of this alkylation than other group of Hβ and DHβ. It is proposed that the strong acid sites corresponding to the active sites for this alkylation can be formed by the interaction among DHβ, MxOy, and SO42-.
Ionic liquid-catalyzed alkylation of isobutane with 2-butene
Yoo, Kyesang,Namboodiri, Vasudevan V.,Varma, Rajender S.,Smirniotis, Panagiotis G.
, p. 511 - 519 (2004)
A detailed study of the alkylation of isobutane with 2-butene in ionic liquid media has been conducted using 1-alkyl-3-methylimidazolium halides-aluminum chloride encompassing various alkyl groups (butyl-, hexyl-, and octyl-) and halides (Cl, Br, and I) on its cations and anions, respectively. The emphasis has been to delineate the role of both cations and anions in this reaction. The ionic liquids bearing a larger alkyl group on their cation ([C8mim]) displayed relatively higher activity than a smaller one ([C6 or C4mim]) with the same anionic composition, due to the high solubility of reactants in the former. Among the ionic liquids with different halide groups, bromides ([C8mim]Br-AlCl3) showed outstanding activity, because of the higher inherent acidity relative to others. From the 27Al NMR study, a major peak at ～99.5 ppm corresponding to [AlCl3Br]- (～99.5 ppm) was observed. Moreover, the anion showed a strong acidity based on FT-IR characterization; the largest peak related to acidity (1570 cm-1) was detected. Under various composition conditions, catalytic activity and amount of TMPs increased with concentration of anion. This is mainly attributed to a higher amount of strong acid ions [Al2Cl6Br]- which can react with hydrogen atoms at the 2-position of an imidazolium ion to form Bronsted acid. However, the ionic liquid with strong acidity (X=0.58) deactivated rapidly due to a higher sensitivity to moisture, causing decomposition. Under various reaction temperature conditions, optimum catalytic activity was observed at 80°C. The result is also attributed to the effect of anion composition. The strong acidic anion increased with temperature. However, at higher reaction temperatures (120°C), the ionic liquid showed a lower activity and TMP selectivity, since the solubility and Bronsted acid sites were reduced by decomposition of imidazolium ions. The selected ionic liquid sample ([C8mim]Br-AlCl3) was compared with one of the standard commercial catalysts, sulfuric acid. Under optimum experimental conditions, it was observed that both catalysts showed comparable catalytic behavior. However, ionic liquid showed higher activity, and lower TMP selectivity due to a more acidic nature and a lower amount of Bronsted acid sites, respectively.
A Polymer-Supported Organotin Hydride and Its Multipurpose Application in Radical Organic Synthesis
Gerlach, Martin,Joerdens, Frank,Kuhn, Heiko,Neumann, Wilhelm P.,Peterseim, Markus
, p. 5971 - 5972 (1991)
The multipurpose application of a polystyrene-supported, regenerable organotin hydride for radical organic syntheses is demonstrated using 10 examples taken from dehalogenation of bulky or multifunctional halides, dehydroxylation of secondary alcohols, and deamination of secondary or tertiary amines.
HYDROTHERMAL PRODUCTION OF ALKANES
-
Paragraph 0022; 0035-0036, (2021/04/17)
Synthesizing an alkane includes heating a mixture including an alkene and water at or above the water vapor saturation pressure in the presence of a catalyst and one or both of hydrogen and a reductant, thereby hydrogenating the alkene to yield an alkane and water, and separating the alkane from the water to yield the alkane. The reductant includes a first metal and the catalyst includes a second metal.
PROCESS OF MAKING OLEFINS OR ALKYLATE BY REACTION OF METHANOL AND/OR DME OR BY REACTION OF METHANOL AND/OR DME AND BUTANE
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Page/Page column 15; 25; 26; 31; 32, (2017/05/10)
Methods of simultaneously converting butanes and methanol to olefins over Ti-containing zeolite catalysts are described. The exothermicity of the alcohols to olefins reaction is matched by endothermicity of dehydrogenation reaction of butane(s) to light olefins resulting in a thermo- neutral process. The Ti-containing zeolites provide excellent selectivity to light olefins as well as exceptionally high hydrothermal stability. The coupled reaction may advantageously be conducted in a staged reactor with methanol/DME conversion zones alternating with zones for butane(s) dehydrogenation. The resulting light olefins can then be reacted with iso-butane to produce high-octane alkylate. The net result is a highly efficient and low cost method for converting methanol and butanes to alkylate.
