Chlorofluorocarbons production

It appears that the ultimate replacements for the high volume chlorofluorocarbon products are to be more highly fluorinated organic chemicals, thus requiring significantly higher volumes of HF in thek manufacture. 

Approximately 50% of the demand for tetrachloroethylene is in the dry-cleaning industry where about 80% of all dry cleaners use it as their primary cleaning agent. Use as a feedstock for chlorofluorocarbon production accounts for 30% of current demand. Metal cleaning and miscellaneous appHcations represent 12 and 8% of demand, respectively. The miscellaneous appHcations include such varied uses as transformer insulating fluid, chemical maskant formulations, and as a process solvent for desulfurizing coal. 

Beclomethasone dipropionate and budesonide Modulite formulations have been compared with equivalent chlorofluorocarbon products in small groups of healthy volunteers and asthmatic patients (18) there was no significant difference in morning serum cortisol or urinary cortisol excretion, suggesting that the systemic availability of the inhaled corticosteroids with different propellants is similar. Moreover, plasma profiles of beclomethasone dipropionate and B17MP were similar after inhalation of beclomethasone dipropionate Modulite and beclomethasone dipropionate-chlorofluorocarbon, suggesting that pulmonary delivery to the lung is comparable with the two propellants (18). 

There have been three randomized, double-blind studies in adult asthmatics of the efficacy and safety of a beclomethasone dipropionate-hydrofluoroalkane 134a formulation, equivalent in dose per actuation to the currently marketed beclomethasone dipropionate chlorofluorocarbon products (19-21). Daily doses of beclomethasone dipropionate hydrofluoroalkane 134a 1000 pg over 12 weeks given by metered-dose inhaler (19) or a spacer jet device (20) were equivalent in terms of safety and efficacy compared with beclomethasone dipropionate chlorofluorocarbon 1000 pg. The same was true for doses of 400 pg (21). 

Kalcevic, V. McGahan, J.F. Process for Treating Spent Catalyst Including Antimony Halides from Chlorofluorocarbon Production US Patent 4,751,063, Jun. 14, 1988. 

The decomposition of the chlorofluorocarbon products a highly reactive chlorine atom (free radical). This reacts with ozone ... 

Chlorofluorocarbons (CFCs). Prior to 1978 most aerosol products contained chlorofluorocarbon propeUants. Since that time, the use of chlorinated fluorocarbons for aerosols has been seriously curtailed. These compounds have been impHcated in the depeletion of the ozone (qv) layer and are considered to be greenhouse gases (see Airpollution Atmospheric modeling). 

Production of hydrogen fluoride from reaction of Cap2 with sulfuric acid is the largest user of fluorspar and accounts for approximately 60—65% of total U.S. consumption. The principal uses of hydrogen fluoride are ia the manufacture of aluminum fluoride and synthetic cryoHte for the Hall aluminum process and fluoropolymers and chlorofluorocarbons that are used as refrigerants, solvents, aerosols (qv), and ia plastics. Because of the concern that chlorofluorocarbons cause upper atmosphere ozone depletion, these compounds are being replaced by hydrochlorofluorocarbons and hydrofluorocarbons. 

North American HF production capacity has declined since the early 1980s and several smaller producers, such as Harshaw and Essex, have closed plants. Production is expected to continue to decline in the short term because of chlorofluorocarbon (CPC) cutbacks, but is expected to rebound later in the 1990s as replacement hydrochlorofluorocarbons are introduced to the marketplace. 

Cmde HCl recovered from production of chlorofluorocarbons by hydrofluorination of chlorocarbons contains unique impurities which can be removed by processes described in References 53—62. CICN—CI2 mixtures generated by reaction of hydrogen cyanide and CI2 during the synthesis of (CICN) can be removed from the by-product HCl, by fractional distillation and recycling (see Cyanides) (59). 

Ninety-six percent of the EDC produced in the United States is converted to vinyl chloride for the production of poly(vinyl chloride) (PVC) (1) (see Vinyl polymers). Chloroform and carbon tetrachloride are used as chemical intermediates in the manufacture of chlorofluorocarbons (CECs). Methjiene chloride, 1,1,1-trichloroethane, trichloroethylene, and tetrachloroethylene have wide and varied use as solvents. Methyl chloride is used almost exclusively for the manufacture of silicone. Vinylidene chloride is chiefly used to produce poly (vinylidene chloride) copolymers used in household food wraps (see Vinylidene chloride and poly(vinylidene chloride). Chloroben2enes are important chemical intermediates with end use appHcations including disinfectants, thermoplastics, and room deodorants. 

Recently several patents have been issued (16—18) describing the use of 1,2-dichloroethylene for use in blends of chlorofluorocarbons for solvent vapor cleaning. This art is primarily driven by the need to replace part of the chlorofluorocarbons because of the restriction on their production under the Montreal Protocol of 1987. Test data from the manufacturer show that the cleaning abiUty of these blends exceeds that of the pure chlorofluorocarbons or their azeotropic blends (19). 

Trichloroethylene is being evaluated by the industry as a precursor in the production of hydrochlorofluorocarbons (HCEC), the replacement products for the chlorofluorocarbons impHcated in the depletion of the stratospheric ozone. At this time it is too early to project any estimates or probabihties for potential volume changes as a result of this opportunity (23). 

World capacity and demand for tetrachloroethylene were approximately 1100 and 845 thousand metric tons ia 1974, respectively. Although demand iacreased iato the mid-1980s, siace then demand for tetrachloroethylene has decreased significantly as a result of the phaseout of chlorofluorocarbons, the use of more efficient dry-cleaning equipment, and iacreased reclamation of waste solvent. World capacity and demand as of 1988 are provided ia Table 2 Several United States manufacturers have shut down faciUties ia the last fifteen years. Current manufacturers and their capacities are Hsted ia Table 3. United States production and sales history is shown ia Table 4. 

A leader in the refrigerants industry, we manufacture and supply customers with economical chlorofluorocarbon (CFC) replacements and non-ozone depleting hydrofluorocarbon (HFC) refrigerants for automotive, home, commercial and transportation uses. In the Americas and Asia, you can find these products under the Genetron name and in Europe and the Middle East under Honeywell Refrigerants. 

The Montreal Protocol of July 1987 resulted in an international treaty in which the industrialized nations agreed to halt the production of most ozone-destroying chlorofluorocarbons by the year 2000. This deadline was hastily changed to 1996, in February 1992, after a U.S. National Aeronautics and Space Administration (NASA) satellite and high-altitude sampling aircraft found levels of chlorine monoxide over North America that were 5i % greater than that measured over Antarctica. 

The products are available as tablets, capsules, liquids (in the form of solutions, suspensions, emulsions, gels, or injectables), creams (usually oil-in-water emulsions), ointments (usually water-in-oil emulsions), and aerosols, which contain inhalable products or products suitable for external use. Propellants used in aerosols include chlorofluorocarbons (CFCs), which are being phased out. Recently, butane has been used as a propellant in externally applied products. The major manufactured groups include ... 

The introduction of the chlorofluorocarbon (CFC) fluids in the early 1930s marked the incepuon of the halofluorocarbon industry. Both in terms of tonnage produced and product value, the CFCs have dominated the organofluorocarbon industry and have provided the feedstocks for the development of other fluorocarbon products such as poly(tetrafluoroethylene). 

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