Vinyl chloride cylinders

Bulk polymerisation processes have been known for many years but until the mid-1960s the only commercial process was one operated by Pechiney-St Gobain in France. This process was a one-stage process and according to one patent example vinyl chloride was polymerised with 0.8%% of its own weight of benzoyl peroxide in a rotating cylinder containing steel balls for 17 hours at 58°C. 

Most of the byproduct HCl is used captively, primarily in oxyhydrochlorination processes for making vinyl chloride and chlorinated solvents or for Mg processing (p, 110), The scale of the industry is enormous for example, 5,2 million tonnes of HCl per annum in the US alone (1993), HCl gas for industrial use can be transmitted without difficult over moderate distances in mild-steel piping or in tank cars or trailers. It is also available in cylinders of varying size down to laboratory scale lecture bottles containing 225 g. Aqueous hydrochloric acid consumption (1993) was 1,57 Mt (100% basis). Price for anhydrous HCl is 330/tonne and for 31,4% aqueous acid 73/tonne (1993) depending on plant location and amount required. 

Vinyl chloride may be stored in ordinary steel cylinders, tank cars, and storage tanks. The monomer must be stored under pressure to maintain a liquid state. Vessels are loaded or unloaded by use of inert gas pressure or most commonly by using pumps. 

CAS-No [75-01-4] chloroethylene ethylene monochloride monochloroethene VC vinyl chloride monomer VINYL CHLORIDE (cylinder) H2C = CHCI... 

Before distilling checkfor peroxides if found, render harmless. Depending on the degree ofexposure.regularmedicalcheckups are advisable. Turn leaking cylinder so that leak is on top to prevent liquid vinyl chloride escaping. ... 

Store and use cylinders of vinyl chloride in well-ventilated areas away from heat and all sources of ignition such as flames and sparks. Do not use vinyl chloride around sparking motors or other equipment that is not explosion-proof equipment. Do not store reserve cylinder stocks of vinyl chloride with cylinders containing oxygen, chlorine, or other highly oxidizing or combustible materials [4]. 

Vinyl chloride is shipped as a liquefied compressed gas in cylinders, single-unit tank cars and TMU (ton multi-unit) tank cars, and in tank trucks and TMU tanks on trucks. For all these types of containers, it is required that all parts of valves and pressure relief devices in contact with the contents of the container must be of a metal or other material (suitably treated if nec-... 

Under present regulations, cylinders of all types authorized for vinyl chloride service must be requalified by hydrostatic test every 5 years with the exception of specification 3E (for which periodic hydrostatic retest is not required). 

Authorized pressure relief devices for vinyl chloride cylinders include Type CG-2 fusible plugs which have a nominal yield temperature of 165°F (73.9°C) and IVpe CG-7 pressure relief valves. See CGA S-1.1, Pressure Relief Device Standards—Part 1—Cylinders for Compressed Gases, for specific requirements. [6]... 

The standard valve outlet connection in the United States and Canada for vinyl chloride cylinders is Connection CGA 510. The limited standard connection is Connection CGA 290. [7]... 

With suitable safety precautions, a 12-oz. (see Note a) beverage bottle (internal capacity approximately 375 ml) is fitted with a rubber stopper equipped with both a gas inlet tube that can be closed off with a suitable valve and an exhaust tube that leads to a drying tube. The gas inlet tube should extend approximately half-way into the bottle. This equipment is tared. The stopper and its tubes are removed, and 170 gm of doubly deionized and deaerated water is placed in the bottle followed by 0.2 gm of the suspending agent [vinyl acetate-maleic anhydride copolymer or poly(vinyl alcohol) such as Elvanol 50-42] and 0.2 gm of the initiator (lauroyl peroxide, benzoyl peroxide, or AIBN). The rubber stopper with its inlet and outlet tubes is attached to the bottle, the valve is closed, and the assembly is again tared. Then it is thoroughly cooled in a Dry Ice-acetone bath. While the bottle is in this bath, the gas inlet tube is attached to a cylinder of uninhibited vinyl chloride, and the valve on the gas inlet tube is opened. Then the cylinder valve is opened slowly, and vinyl chloride is passed into the bottle. 

From time to time, the valves are closed, the gas inlet tube is disconnected from the cylinder, and the weight of the bottle is checked. Slightly more than 100 gm of vinyl chloride is condensed into the bottle. The cylinder valve is closed, the cylinder is disconnected (see Note b), and the bottle is allowed to warm to room temperature in a suitable fume hood while standing upright on the pan of a beam balance. Condensate is periodically removed from the bottle and pan. When enough vinyl chloride has boiled away to leave exactly 100 gm of monomer in the bottle, the rubber stopper is removed and the bottle is rapidly sealed with an appropriate crown cap. If other bottles have to be prepared, the capped bottles are stored in a Dry Ice-acetone bath until all bottles have been prepared. 

The vessel is cooled in a Dry Ice-acetone bath. The air is displaced with oxygen-free nitrogen, and approximately 500 gm of uninhibited vinyl chloride is condensed from a cylinder into the reactor. The autoclave is closed and warmed to room temperature. With agitation, the reaction mixture is maintained between 40"" and 50°C for approximately 20 hr. The polymerization is essentially complete when a notable drop in internal pressure takes place. 

Vinyl chloride monomer and 1,3-butadiene in pressurized cylinders. 

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