Fluorine cylinders

Mixtures of 10 and 20% fluorine ia nitrogen or other inert gases are commercially available ia cylinders and tube trailers from Air Products and Chemicals, Inc. Blends can be safely packaged and stored at high, eg, 13.8 MPa (2000 psi), pressure. Filled with a 20% fluorine blend, tube trailers can contain up to 500 kg of fluorine. Such high pressure mixtures permit larger quantities of fluorine to be safely shipped. 

Price. The 1993 U.S. price for fluorine in cylinders was 109/kg for 2.2 kg and 260/kg for 0.7 kg cylinders. The price in large volumes is determined by (/) the price of hydrofluoric acid (2) power costs, ca 4.5 kWh electricity is required for each kilogram of fluorine produced (J) labor costs (4) costs to maintain and rebuild cells and (5) amortization of fixed capital. Fluorine production is highly capital intense. In addition, purification, compression, packaging, and distribution in cylinders increase the cost significantly. 

Specifications. Fluorine, having a dewpoint of 40°C and containing a maximum of 1.0 ppm water, is sold in cylinders according to the following specifications ... 

Bromine ttifluoride is commercially available at a minimum purity of 98% (108). Free Br2 is maintained at less than 2%. Other minor impurities are HF and BrF. Free Br2 content estimates are based on color, with material containing less than 0.5% Br2 having a straw color, and ca 2% Br2 an amber-red color. Fluoride content can be obtained by controlled hydrolysis of a sample and standard analysis for fluorine content. Bromine ttifluoride is too high boiling and reactive for gas chromatographic analysis. It is shipped as a Hquid in steel cylinders in quantities of 91 kg or less. The cylinders are fitted with either a valve or plug to faciUtate insertion of a dip tube. Bromine ttifluoride is classified as an oxidizer and poison by DOT. 

Monel and nickel are the preferred materials of constmction for cylinders and deHvery systems however, copper, brass, steel, and stainless steel can be used at room temperature, providing that these metals are cleaned, dried, and passivated with a fluoride film prior to use. Studies have shown that fluorine passivation of stainless steel and subsequent formation of an iron fluoride layer prior to WF exposure prevents reaction between the WF and the stainless steel surface (23). 

As with CIF3, BrF3 is used to fluorinate U to UFe in the processing and reprocessing of nuclear fuel. It is manufactured commercially on a multitonne pa scale and is available as a liquid in steel cylinders of varying size up to 91 kg capacity. The US price in 1992 was 80perkg. 

Fluorine gas is sold commercially in stainless steel or monel cylinders as compressed gas or as liquid fluorine. 

Fluorine Organic Materials. Experiments were conducted by plunging small pieces of organic materials into lOg of liquid fluorine contained in a small Ni cylinder and surrounded by liquid N in a stainless steel beaker. While neoprene produced only a slight explosion, cotton gave an immediate violent expl with a brilliant white flame... 

Direct fluorination of organic compounds using fluorine is an important methodology when considering safety, environmental and recycling problems. Fluorine can be fed into the reactor from a cylinder for the direct fluorination procedure, but this method has economic and safety disadvantages. Electrochemical generation of fluorine has recently been adopted for fluorination even in the laboratory. It can be operated easily and safely, because operational difficulties have been improved. 

CA UTION Since F2 is a highly oxidizing and toxic gas, experimenters should familiarize themselves with the precautions necessary for the safe handling of F2. The use of diluted F2 in an inert gas (N2 or argon) is considerably safer than pure F2. The apparatus used for the fluorination consisted of a 20% F2/N2 cylinder, a nitrogen cylinder, two flow meters, a Pyrex glass reactor, and valves made of stainless steel or brass. The cylinders, the flow meters, and the valves were connected with stainless steel or copper tubes. 

Special permits are required to ship fluorine. Generally, fluorine is transported as a iionliquelied compressed gas in seamless steel or nickel cylinders. Upon receipt, multijackeled desvars frequently arc used to contain the product. 

A cylinder containing 20% fluorine/80% nitrogen was obtained from Air Products Chemicals, Inc. 

The addition of a gas to a reaction mixture (commonly the hydrogen halides, fluorine, chlorine, phosgene, boron trifluoride, carbon dioxide, ammonia, gaseous unsaturated hydrocarbons, ethylene oxide) requires the provision of safety precautions which may not be immediately apparent. Some of these gases may be generated in situ (e.g. diborane in hydroboration reactions), some may be commercially available in cylinders, and some may be generated by chemical or other means (e.g. carbon dioxide, ozone). An individual description of the convenient sources of these gases will be found under Section 4.2. 

Another feature of the large honeycombs is the nano-phase segregation within the cylinders. The fluorinated segments congregate in the center while the alkyl spacers line the interior of the cylinder walls. This core-shell-in-cylinder... 

The section of H-in. tubing which runs through the insulator acts both as an electrical connection to the anode and as an exit for the fluorine. A piece of 0.0032-in. sheet nickel 3K in- square rolled into a cylinder serves as an electrode, and it is bolted to the center of a disc of copper which covers the bottom of, and is firmly fastened to, the diaphragm. With such a combination, fluorine is liberated on the nickel but not on the copper. A thermometer well of copper tubing is fastened to the cover of the pot. 

MoF6—The direct reaction of molybdenum with fluorine initiated around 100°C. in a copper tube -7 is specific for this highest fluoride. The method is relatively inconvenient in most laboratories because of experimental difficulties and hazards associated with the handling of elemental fluorine. A more recent procedure, which avoids elemental F2, involves the reaction between Mo03 and SF4 in a bomb at 350°C. Sulfur tetrafluoride, although expensive, is commercially available in cylinders. 

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