Figure 1

A picture of one of the two four-unit low pressure reactor systems in the Center is shown in Figure 1.

Figure 2

In each of these four unit systems the reactors are monitored individually by a single computer with reservoir and reactor pressure and reaction temperature recorded over the course of the reaction. In addition, the room temperature near the reservoirs is also monitored and this value, along with the calibrated reservoir volume, is used to calculate the moles of gas consumed in the reaction. The computer screen (Figure 2) shows the progress of each reaction by depicting the pressure drop in each reservoir along with the reaction temperature, the moles of gas consumed and the elapsed time of the reaction.

Figure 3

The reactors used with these low pressure systems are the threaded pressure reactor bottles available from Ace Glass (A in Figure 3) which are connected to the manifold through Teflon heads. The fittings on these heads provide for a thermocouple (B) to measure the internal reaction temperature, the ability to purge the reactor prior to the introduction of the reaction gas through the manifold connection (C) and a septum port (D) through which the substrate can be introduced into the reactor after pretreatment of the catalyst or samples of the reaction mixture can be taken. Agitation of the reaction mixture is accomplished by a magnetic stirrer with the stir-bar (E) suspended above the bottom of the reactor on a freely rotating shaft. This arrangement prevents the stir-bar from crushing the catalyst particles during the reaction. The reactor is heated using the heating mantle (F). Temperature control of the reaction is maintained using a coarse adjustment based on the internal mantle temperature and fine adjustments based on the internal reactor temperature. Temperature control of ±1°C is routinely attained.