Propellants isobutane

Other Isobutane-Based Chemicals. Isobutane can be directly dehydrogenated to isobutylene by a modification of the Houdry process. This can then be converted to MTBE. The estimated use is over 1 billion lb of isobutane. Because of their inertness and higher vapor pressures, high-purity propane and butanes have become the important substitutes for fluorocarbons as aerosol propellants. Isobutane can also be used as a solvent in polymer processing, and as a blowing agent for foamed polystyrene. 

Aerosol hairsprays contain concentrates representing 85% of the total product. The concentrates will be diluted with 15% A-46 Propellant (isobutane and propane) to obtain an acceptable pressure, and the spray character will be adjusted with the appropriate valve system. These hairsprays contain 80% VOC (Table 7-6) and meet the requirements outside of California today. The hairspray of Table 7-7 meets the 55% VOC standard for California. 

Hydroca.rbons. Hydrocarbonsn such as propane, butane, and isobutane, which find use as propellants, are assigned numbers based upon their vapor pressure in psia at 21°C. For example, as shown in Table 2, aerosol-grade propane is known as A-108, / -butane as A-17. Blends of hydrocarbons, eg, A-46, and blends of hydrocarbons and hydrochlorocarbons orHCFCs are also used. The chief problem associated with hydrocarbon propellants is their flammabihty. 

In 1987 nonmotor fuel uses of butanes represented ca 16% of the total consumption. Liquid petroleum gas (LPG) is a mixture of butane and propane, typically in a ratio of 60 40 butane—propane however, the butane content can vary from 100 to 50% and less (see Liquefied petroleum gas). LPG is consumed as fuel in engines and in home, commercial, and industrial appHcations. Increasing amounts of LPG and butanes are used as feedstocks for substitute natural gas (SNG) plants (see Fuels, synthetic). / -Butane, propane, and isobutane are used alone or in mixture as hydrocarbon propellents in aerosols (qv). 

Isobutane is used in cigarette lighters and camp stoves as a fuel. It is easily liquefied under pressure, and the liquid becomes a gas immediately when the pressure is released. It is also used as a propellant in hairsprays and spray breath fresheners. 

Hydrocarbons have also been considered as potential propellants for pharmaceutical aerosols. To date concerns regarding flammability seem to have precluded significant developments with propane, isobutane, butane, and mixtures of these alkanes [28]. 

Simple hydrocarbons can also be used as CFC substitutes. Hydrocarbons such as propane, 2-methylpropane (common name isobutane), and butane are efficient aerosol propellants. These hydrocarbons are stable and inexpensive, but they are extremely flammable. 

Propane, butane, and isobutane are hydrocarbons (HC). They are used as aerosol propellants alone, in combination with each other, and in combination with a hydrofluoroalkane (HFA) propellant. They are used primarily in topical pharmaceutical aerosols (particularly aqueous foam and some spray products). 

Depending upon the application, the concentration of hydrocarbon propellant range is 5-95% w/w. Eoam aerosols generally use about 4-5% w/w of a hydrocarbon propellant consisting of isobutane (84.1%) and propane (15.9%), or isobutane alone. Spray-type aerosols utilize propellant concentrations of 50% w/w and higher. ... 

Various blends of hydrocarbon propellants that have a range of physical properties suitable for different applications are commercially available, e.g., CAP30 (Calor Gas Ltd.) is a mixture of 11% propane, 29% isobutane, and 60% butane. A-46 (Aeropres) is a commonly used mixture for aerosol foams and consists of about 85% isobutane and 15% propane. The number following the letter denotes the approximate vapor pressure of the blend or mixture. 

Dimethyl ether has been increasingly used as a propellant in aerosol formulations to replace chloro-fluorocarbons, which are found to destroy the ozone layer of the atmosphere. Dimethyl ether is nontoxic and easily degrades in the troposphere. Although about 90% of the major current U.S. aerosol industry uses hydrocarbon-based propellants (mostly isobutane and propane), DME could become a more widely used propellant in the coming years. Several aerosol-based... 

A 31 (hydrocarbon) Caswell No. 503A 1,1-Dimethyl-ethane EINECS 200-857-2 ERA Pesticide Chemical Code 097101 HSDB 608 Isobutane 2-Methylpropane Propane, 2-methyl- R 600a Trimethylmethane, Hydro-carbon gas used as a fuel and an Aerosol propellant. Colorless gas mp = -138.3° bp = -11,7° d 0.5510 insoluble in H2O, soluble in organic solvents, Air Prods Chems Phillips 66. 

Fragrances Pine Needles SYN802277U (Polak Frutal Works) Isobutane Propellant... 

Recall that butane is used in lighters and in torches. Isobutane is used as both an environmentally-safe refrigerant and a propellant in products such as shaving gel, as shown in Figure 21.9. In addition to these applications, both butane and isobutane are used as raw materials for many chemical processes. 

Figure 21.9 Butane is a fuel used in lighters. Isobutane is used as a propellant in products such as shaving gel. 

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