Gas composition, exit

Let fractional conversion of CO to H2 be C. Then mols of CO reacted = 11.0 x C. From the stoichiometric equation and feed composition, the exit gas composition will be ... 

In this example the outlet exit gas composition has been calculated for an arbitrarily chosen steam CO ratio of 3. In practice the calculation would be repeated for different steam ratios, and inlet temperatures, to optimise the design of the converter system. Two converters in series are normally used, with gas cooling between the stages. For large units a waste-heat boiler could be incorporated between the stages. The first stage conversion is normally around 80 per cent. 

Purification Exit Gas Composition Primary Reforming Secondary Reforming High Temperature CO ShiR Low Temperature CO Shift COj Removal Methanation MUG Ammonia Synthesis Loop... 

This exit gas composition = intercept gas assumption is important because it links catalyst beds in multi-bed S02 oxidation calculations, Chapter 14 onwards. 

Fig. 12.9. Sketch of catalyst bed indicating that exit gas composition and temperature = intercept gas composition and temperature. It assumes that there is no transfer of heat from gas to surroundings, Section 11.3. So once equilibrium is attained, temperature remains constant and the gas remains at its intercept composition. This is discussed further in Section 18.12.

Preliminary comparisons between the calculated exit gas composition and that measured in the IGT experiments have been made. For example, in the case of IGT Run EGO-33, we find very good agreement between the model and the data for CO, CH, H2 and N2 but predict less H2O and more CO2 in the exit gas than is indicated by our interpretation of the experimental measurements. For example, in the nitrogen-free product gas, including steam, a comparison between our evaluation of the data and a one-dimensional simulation of the reactor process gives the composition mass flows in Table II. 

Figure 5. Exit gas composition, (- - Bernstein and Churchill (3) for premixed propane and air.

The close correspondence of the measured wall temperature profiles and exit-gas compositions to those of Bernstein and Churchill (3) for the combustion of premixed propane vapor and air suggests that combustion in a refractory tube is relatively insensitive to the composition and state of the fuel as long as evaporation precedes combustion. 

Stable fiames from atomized fuel droplets and air can be established inside a refractory tube over a range of flow rates, drop sizes, and fuel-to-air ratios. The wall temperature profiles and exit-gas compositions correspond closely to those for premixed fuel gas and air. Very low NO, contents are attainable despite the high flame temperatures. 

The equilibrium relationship is given. The slope of the operating line is also given. To use the McCabe-Thiele analysis, one point on the operating line is needed. The exit gas composition is 1% of H2S (y = 0.01) and the entering water does not contain any H2S (x = 0). Since the points represent passing streams on one end of the cascade, they represent one point on the operating line. 

Figure 2. Exit gas composition from steam cracking of propane in quartz reactor with steel (Sandvik 15RelO) as the foil material after 10 min on stream. Conditions temperature range, 800-870°C feed gas composition, 29 mol% C3Ha, 32% HtO, and 39% N3 and total feed rate, 0.42 L gas/min.

Feed Pretreatment Exit gas composition, mol-% Conversion % Selectivity c2h4, %... 

Figure 5. Exit gas composition from steam cracking of propane. Comparisons between prereduced and preoxidized systems. Conditions as in Figure 4.

Equipment. All of the gasification experiments were conducted with the same apparatus employed in the earlier oxidation work and has been described in detail elsewhere ). The technique involved simultaneous measurements of mass loss (T6A) and exit gas compositions (gas chromatograph) in a vessel which behaved as an ideal back-mix reactor. All experiments were run under isothermal conditions. As before, powdered shale samples (200 mesh) of previously retorted oil shale from the Parachute Creek member in Colorado were suspended from an electrobalance and placed in a furnace. In this way continuous gravimetric readings were available to monitor the consumption of the char. The off-gases were analyzed on a Carle gas chromatograph equipped with a Carbosieve B column. 

Figure 6. Effect of first furnace temperature on the exit gas composition. Inlet gas 0.57% sulfur dioxide, 0.89% carbon monoxide, and 3% water...

Figure 7. Effect of second catalyst temperature on the exit gas composition. a,b = Surinan red mud catalyst. Inlet gas to first catalyst 0.57% sulfur dioxide, 0.89% carbon monoxide, and 7% water vapor in helium. a, b — Berbece bauxite in second catalyst. Inlet gas to first catalyst 0.44% sulfur dioxide, 0.80% carbon monoxide, and 20% water vapor in...

Once the cell had reached run temperature, conductivity across the cell was measured by the current interrupt method. The equilibrium potentials at the cathode and anode were measured with respect to the reference electrode. Baseline exit cathode gas compositions were also measure at this point. Current was then applied to the cell in a step-wise fashion and the cell was allowed to equilibrate after each current step. Once stabilized, potentials with respect to the reference electrode and the exit gas compositions were measured. 

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