Hydrogen bromide cylinder

The standard valve outlet connection in the United States and Canada for hydrogen bromide cylinders is Connection CGA 330. [8]... 

Tetra(p-tolylsilyl)methane, hydrogen bromide cylinder. 

Technical 48% and 62% acids are colorless to light yellow Hquids available in dmms, 15,140-L tank trailers, and 37,850-L tank cars. They are classified under DOT regulations as corrosive materials. Anhydrous hydrogen bromide is available in cylinders, under its vapor pressure of approximately 2.4 MPa (350 psi) at 25°C. It is classified as a nonflammable gas. 

During preparation of hydrogen bromide by addition of bromine to a suspension of red phosphorus in water, the latter must be freshly prepared to avoid the possibility of explosion. This is due to formation of peroxides in the suspension on standing and subsequent thermal decomposition [1], In the earlier description of such an explosion, action of bromine on boiling tetralin was preferred to generate hydrogen bromide [2], which is now available in cylinders. 

Hydrogen bromide gas may be produced by combustion of hydrogen in bromine vapor at 37.5°C using a catalyst such as platinized asbestos or platinized silica gel. Unreacted free bromine is removed from the product by passing the gaseous product mixture over hot activated charcoal. Hydrogen bromide formed may be absorbed in water to obtain the acid or may be cooled and liquefied for shipment in cylinders. 

Hydrogen bromide is most conveniently prepared by the action of bromine upon tetrahydronaphthalene (tetralin) if the quantity required does not justify the purchase of a cylinder of the gas. 

It is well known that anhydrous nonoxidizing inorganic acids such as hydrogen chloride and hydrogen bromide do not dissolve metals. These two compounds are stored in steel cylinders without any appreciable corrosion of the metal. The same was true of anhydrous hydrogen fluoride that was stored and delivered in steel cylinders for the past seven decades. 

The less volatile residues should be quite free of bromosilane. However, as a precaution, nitrogen is admitted into the reaction tube, the adapter is removed, and the contents of the tube are poured over pulverized Dry Ice contained in a sink in a hood. Water is then allowed to run over the Dry Ice. The recovered hydrogen bromide can be stored at room temperature after first being condensed at —196° into a 150-ml. stainless-steel cylinder fitted with a stainless-steel needle valve. It is important to... 

EXPLOSION and FIRE CONCERNS noncombustible liquid nonflammable gas NFPA rating (not rated) contact with chemically-active metals (such as potassium (K), sodium (Na), calcium (Ca), powdered aluminum (Al), zinc (Zn) and magnesium (Mg)) will cause fires and explosions contact with flames and/or hot surfaces will emit hydrogen bromide, hydrogen fluoride, free bromine, and small amounts of carbonyl halides product is relatively toxic to humans at levels below fire extinguishing concentration product will not extinguish fires resulting from contact with chemically-active metals use water spray to cool cylinders involved in fires use media suitable for flammable materials in area. 

Hydrogen bromide gas should be handled in the laboratory using the "basic prudent practices" described in Chapter 5.C, supplemented by the procedures described in Chapter 5.H for the handling of compressed gases. Cylinders of hydrogen bromide should be stored in cool, dry locations, separated from alkah metals and other incompatible substances. 

Leaks of HBr gas are evident from the formation of dense white fumes on contact with the atmosphere. Small leaks can be detected by holding an open container of concentrated ammonium hydroxide near the site of the suspected leak dense white fumes confirm a leak is present. In case of the accidental release of hydrogen bromide gas, such as from a leaking cylinder or associated apparatus, evacuate the area and eliminate the source of the leak if this can be done safely. Remove cylinder to a fume hood or remote area if it cannot be shut off. Full respiratory protection and protective clothing may be required to deal with a hydrogen bromide release. 

Disposal In many localities, hydrobromic acid or the residue from a spiU may be disposed of down the drain after appropriate dilution and neutralization. Otherwise, hydrobromic acid and waste material containing this substance should be placed in an appropriate container, clearly labeled, and handled according to your institution s waste disposal guidelines. Excess hydrogen bromide in cylinders should be returned to the... 

Some cylinders have contents that change their chemical characteristic over time (decompose, polymerize, etc.). Examples include 1,3-butadiene, hydrogen bromide and diborane. These changes may eventually result in overpressurization that exceeds the specification of the cylinder. This situation renders the cylinder unsafe for transport. Contents of cylinders that have become contaminated with foreign material may also result in a chemical reaction causing overpressurization or an explosive hazard. These cylinders should be handled with extreme care and only by specially trained and qualified personnel. 

No more hydrogen bromide should be inventoried than can be used in a 6-month period. Cylinders should be moved with valve protector caps in place using carts designed for the purpose. 

Hydrogen bromide is an acid gas and as such can be neutralized with caustic solution. When possible the discharge from a valve leak should be controlled by a flow-limiting valve and piped into a 15 percent solution of sodium hydroxide. Use a trap to prevent reverse flow of the solution to the cylinder valve. 

Hydrogen bromide is shipped as compressed liquefied gas under its own vapor pressure in cylinders. The maximum filling density for hydrogen bromide is 136 percent. 

Hydrogen bromide is a colorless, toxic, and corrosive gas at room temperature and pressure. The liquid is yellowish in color. The gas is heavier than air and fumes with the formation of hydrobromic acid on contact with moist air. It is shipped in cylinders under its own vapor pressure of 320 psig (2206 kPa) at 70°F (21. TC). Hydrogen bro-... 

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