Gas and vapour phase

Numerous determinations [181a,218,464,1275,1998,2032a] of the standard enthalpy of formation of phosgene have been reported, and the most important of these are summarized in Table 6.1 [464]. 

Based on the mean of the most recently determined calorimetric [464] and equilibrium [1275] values, the value of A/fJ jgg(g) is -219.6 0.6 kj mol [464]. From a recent 

MNDO calculation [514], the value of -221.3 kJ mol has been predicted, in good 

The entropy of phosgene in the ideal gas state has been obtained by combining the 

The enthalpy and entropy values of superheated phosgene vapour have been calculated 

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Equation 9" can be calculated using the data available in Figure 2. The average gas pressure in the reactor during steady state operation was 1.6 kPa. The rate of pressure built up in the closed reactor was determined to be approximately 150 kPa h. As a result, the average residence time of the gas and vapour phase in the reactor was found to be about 40 s. 

Heat required for the pyrolysis of wood is slightly endothermic and was determined to be 733 kJ kg of organic wood converted. The standard heat of reaction at 323 K and 1.6 kPa was found to be approximately 92 kJ kg" of air-dry wood. The thermal efficiency of the process is high at 82%. The mean residence time of the gas and vapour phase product in the reactor was empirically found to be about 40 s. Heat is mainly transferred by radiation in the type of reactor used. 

The flow direction for adsorption in a vertical fixed bed is determined not only by the potential for lifting or fluidizing the bed but also by whether the feed is a gas or a liquid. For gas and vapour phase applications velocities which cause crushing of an adsorbent tend to be much higher than those required to lift a bed and therefore it is convenient to arrange to have the highest flowrate in the downwards direction through a vertical bed. 

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