Parr hydrogenator reactor bottles

Apparatus for carrying out hydrogenation at several atmospheres can be constructed readily (1,78,93), but there seems little point in this exercise since good commercial equipment is available. The most commonly used commercial low-pressure equipment is the Parr hydrogenator (manufactured by Parr Instrument Co., Moline, Illinois). This equipment (Fig. 1) has withstood the test of time it was first described in 1922 and offered commercially in 1926. It comes in two sizes one for 500-ml reactor bottles and one for 1000-and 2000-ml reactor bottles. Specially made smaller bottles, down to 50 ml, can be used also but require special holders to compensate for differences in bottle heights. Shaker bottles should not be more than half full to ensure good mixing, a consideration in selection of bottle size. 

The most common low pressure reactor is the Parr hydrogenator shown in Fig. 6.5. This system is composed of a reaction bottle that is coimected to a gas reservoir that has a capacity of about four liters. Two versions of the apparatus are commercially available a standard model that takes 250 mL and 500 mL reaction bottles and that can be used to pressures up to about 60 psig and a larger size that uses 1 liter and 2 liter bottles that have about a 40 psig pressure limit. The bottles are coimected to the gas reservoir by a tube inserted through a rubber stopper in the mouth of the bottle. The common black rubber stoppers may contain catalyst poisons that can be extracted into the reaction mixture by some solvents. The use of neoprene stoppers will minimize this problem. 

Special reactor bottles having working volumes of 1 mL to 1000 mL are also available. As depicted in Fig. 6.6, these bottles have threaded Teflon adapters to hold the hydrogen inlet tube so catalyst contamination by the reactor is virtually eliminated. The smaller bottles, which have working volumes between 1 mL and 20 mL, use a spacer to secure them into the shaker assembly (Fig. 6.6a). Those with capacities of 20 mL to 200 mL (Fig. 6.6b) fit directly into the shaker assembly of the smaller Parr apparatus while 500 mL and 1000 mL vessels of this type (Fig. 6.6c) are available for the larger unit. 

Fig. 6.6. Threaded reactor bottles for the Parr Hydrogenator. a) Small scale bottle with threaded Nylon spacer b) bottle for standard reactor and c) bottle for large scale reactor, each with threaded Teflon adapters. (Courtesy Ace Glass, Inc.)...

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See also in sourсe #XX -- [ ]

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