Feed Gas Temperature Effect

The effect of feed gas temperature on heatup path is determined by inserting new enthalpy values into Eqn. (11.7). With 660 K feed gas (for example), enthalpy Eqn. (11.7) becomes  

These new enthalpy in values are put into cells D8, E8 and F8 of matrix Table 11.2 as  

A new heatup path is then calculated as described in Section 11.11. The result is a path nearly parallel to the 690 K path 30 K cooler at all % SO2 oxidized values, Fig. 11.6. 

However, they are parallel at every given gas composition (i.e., at every given D). This is because the heat capacities (d//°/d7) of the reactions and products are independent of temperature (Appendix G). 

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Groundwork numerical modeling of the superadiabatic decomposition reactor has been performed, identifying key process parameters. These parameters include fuel gas composition (i.e., H2S-rich and H2S-lean), oxidant composition (air/ enriched air/oxygen), equivalence ratio, superficial gas velocity, feed gas temperature (pre-heating effect), and product gas quenching (to avoid... 

Fig. 12.2 shows the effect of feed gas temperature on intercept temperature and % SO2 oxidized. It indicates that cool feed gas gives ... 

Temperature and Humidity of Rich Gas Cooling and consequent dehumidification of the feed gas to an absorption tower can be very beneficial. A high humidity (or relative saturation with solvent) limits the capacity of the gas phase to take up latent heat and therefore is unfavorable to absorption. Thus, dehumidification of the inlet gas prior to introducing it into the tower is worth considering in the design of gas absorbers with large heat effects. 

In other instances, reaction kinetic data provide an insight into the rate-controlling steps but not the reaction mechanism see, for example, Hougen and Watson s analysis of the kinetics of the hydrogenation of mixed isooctenes (16). Analysis of kinetic data can, however, yield a convenient analytical insight into the relative catalyst activities, and the effects of such factors as catalyst age, temperature, and feed-gas impurities on the catalyst. 

In applications where Nafion is not suitable, at temperatures above 200 °C with feed gas heavily contaminated with CO and sulfur species, a phosphoric acid fuel cell (PAFC)-based concentrator has been effective [15]. Treating the gas shown in Table 1, a H2 product containing 0.2% CO, 0.5%CO2 and only 6 ppm H2S was produced. The anode electrode was formed from a catalyst consisting basically of Pt-alloy mixed with 50% PTFE on a support of Vulcan XC-72 carbon. The cathode was... 

The low-temperature process, as its name implies, operates at a relatively low temperature where the exothermic heat of the direct chlorination reaction is removed by cooling water. The natural circulation is driven by the gas lift effect of the gaseous feeds before solution and the density differences of a cooler leg that has a relatively higher liquid density than the reactor leg. 

The next two major models were those by Fuller and Newman and Nguyen and White,who both examined flow effects along the channel. These models allowed for a more detailed description of water management and the effect of dry gas feeds and temperature gradients. Throughout the next few years, several more 0-D models and 1-D models were generated. Also, some simulations examined... 

Operational Factors Controlling Rate and Selectivity of Carbonylation. In Figures 5 and 6 are shown the effects of reaction temperature and of CO/MeOH feed gas ratio on catalytic performances. Methanol conversion increased monotonically with an increase in the temperature and was 99% at 300 C. The yield of methyl acetate reached a maximum level at 250 C and then decreased. Acetic acid yield increased with increasing temperature and was 95% at 300 C. It should be noted that the yield of DME was 2.7% or less and that its yield was almost zero at 300 C. As already pointed out by the present authors, DME and methyl acetate are converted successively to methyl acetate and acetic acid, respectively (6,2) ... 

Activity Measurements. To test catalytic properties of various samples partial oxidation of methanol to formaldehyde was studied in a flow micro-reactor operating under normal atmospheric pressure (10). For each run about 0.2 g of catalyst sample was used and the activities were measured at 173 C in the absence of any diffusional effects. The feed gas consisted of 72, 2 and by volume of nitrogen, oxygen and methanol vapor respectively. Reaction products were analysed with a 10% Carbowax 20 M column (2m long) maintained at 60 C oven temperature. 

C with a water content of 0.075 kg/kg. Although heat and mass transfer rates were relatively insensitive to the choice of the model, the amount of fog formation was not. The models neglect the effects of condensation within the boundary layer, thus underestimating fog formation by a factor of up to three. The amount of fog formed in flue-gas washing plants increased up to a maximum value with decreasing feed-water temperature over a narrow band of liquid-to-gas ratios. 

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