Mole fraction feed hydrogen

The feed to the CSTR consisted of a mixture of thiophene, hydrogen, and hydrogen sulfide. The mole fractions of butene (C4Hg), butane (C4H10), and hydrogen sulfide in the reactor effluent were measured. The mole fractions of hydrogen and thiophene were not measured. 

The hydrogen feed contains methane as an impurity at a mole fraction of... 

The liquid stream can readily be separated into relatively pure components by distillation, the benzene taken off as product, diphenyl as an unwanted byproduct and the toluene recycled. It is possible to recycle the diphenyl to improve selectivity, but it will be assumed that is not done here. The hydrogen feed contains methane as an impurity at a mole fraction of 0.05. The production rate of benzene required is 265 kmol-lr1. Assume initially that a phase split can separate the reactor effluent into a vapor stream containing only hydrogen and methane, and a liquid containing only benzene, toluene and diphenyl, and that it can be separated to produce essentially pure products. For a conversion in the reactor of 0.75,... 

Integration of this equation results in a first order reaction expression in terms of the hydrogen-free mole fraction of MCP ( m) and the corresponding equilibrium value (Ye), rg the molar density of reactor gases, M the molecular weight of MCP, p the partial pressure of CH, P the total pressure, and W the weight of feed per hour per weight of catalyst ... 

Other chromium catalysts for ethylene polymerization employ chromo-cene [246] and bis(triphenylsilyl) chromate [247] deposited on silica-alumina. The catalyst support is essential for high activity at moderate ethylene pressures (200—600 p.s.i.). The former catalyst is activated further by organo-aluminium compounds. Polymerization rates are proportional to ethylene pressure and molecular weight is lowered by raising the temperature or with hydrogen (0.1—0.5 mole fraction) in the monomer feed wide molecular weight distributions were observed. 

Figure 9.11 depicts the profiles of the feed-side mole fractions of CO and C02 along the length of the countercurrent membrane reactor. The modeling results showed that this membrane reactor could convert CO via the WGS reaction and then decrease CO concentration from 1% to 9.82ppm along with the removal of almost all the C02 from the hydrogen product. In the membrane reactor, the removal of C02 enhanced the WGS reaction. 

A condenser operates with a feed vapor consisting of ammonia(l)-water vapor(2)-hydrogen(3) at a pressure of 340 kPa. At one point in the condenser the mole fractions in the bulk vapor are y n, = 0.30, y2o = 0.40, and y3o = 0.30. The liquid on the condensing surface at this point is at 93.3°C and contains 10 mol% ammonia and 90 mol% water, with negligible hydrogen. The composition of the vapor-gas mixture at the liquid surface, assumed to be in equilibrium with the liquid surface of the stated composition, is y g = 0.455, y2g = 0.195, and y33 = 0.35. Employ the exact matrix solution of the Maxwell-Stefan equations to estimate the rate of condensation of water relative to that of ammonia. 

Example 12-1 Wakao et al. studied the conversion of ortho hydrogen to para hydrogen in a fixed-bed tubular-flow reactor (0.50 in. ID) at isothermal conditions of — 196°C (liquid nitrogen temperature). The feed contained a mole fraction P-H2 of fc, = 0.250., The equilibrium value at — 196°C is = 0.5026. The catalyst is Ni on AI2O3 and has a surface area of 155 m /g. The mole fraction p-Hj in the exit stream from the reactor was measured for different flow rates and pressures and for three sizes of catalyst granular particles of equivalent spherical diameter, 0.127 mm, granular particles 0.505 mm, and nominal f x -in. cylindrical pellets. The flow rate, pressure, and composition measurements are given in Table 12-1. 

Design studies for a commercial plant by Geppert and associates [Gl] indicate that optimum conditions are feed composition f = 0.042 mole fraction UF5 in hydrogen, pressure ratio pjp = 2.1, and a cut 0 = 3, at which a — 1 = 0.0148, still four times that in gaseous diffusion, and somewhat higher than what would be predicted for centrifugal equilibrium at the speed attainable from expansion through this pressure ratio. The cut of 3 necessitates use of a three-up, one-down cascade, as shown in Sec. 14.2 of Chap. 12. 

An additional important bit of process information, from Grant et al. [G2], is For the UCOR process, the cut is typically 0.045 to 0.055. Figure 14.29 is a flow sheet for one stage of the UCOR process on which the preceding information has been represented, with a particular cut of 8 = 0.050. This cut requires use of a 19-up, 1-down cascade. The only important process variable not stated in published information is the UF content of the mixture with hydrogen fed to the stage. As will be shown in the next section, a UF feed composition of 0.032 mole fraction is consistent with the reported process information. 

Figure 4 shows the variation with temperature of the equilibrium mole fractions for a few feed gas compositions. The curves in Sections A and B represent the equilibrium state for mixtures initially composed of 3.4% hydrogen sulfide and 5.9% carbon monoxide in the absence and presence of 15% water vapor, respectively. Helium made up the balance in each gas mixture. Species present at less than the micromolar fraction level were ignored. To conduct the same computer program on each gas mixture, an extremely low concentration of water vapor (4.5 X 10"5% ) was assumed in cases A and C of Figure 4. Sections C and D in this figure illustrate the effect of 7% water vapor for a sulfur dioxide-carbon monoxide mixture at the low concentration level. As expected, both hydrogen sulfide and hydrogen were present with the water vapor, and the concentrations of hydrogen sulfide and carbonyl sulfide increased with temperature up to 700 °C.

H,S and H,S/CH Transport Data. Hydrogen sulfide fluxes were mea-sured at sunblent conditions (84.0 kPa, 298 K) for both Na and EDA lEMs for feed mole fractions up to 0.05 H2S. Figure 3 Is a plot of steady-state H S flux versus the log-mean mole fraction driving force for both membranes. Each point Is the average of at least five steady-state flux values. Ninety-five percent confidence Intervals were less than 2K of the mean for the EDA lEM values and less than 3.5J for the Na lEM values. 

A 0.50 m. long column is used to remove methane (M) from hydrogen using Calgon Carbon PCB activated carbom The feed gas is 0.002 mole fraction methane. Superficial velocity is 0.0465 m/s during the feed step. The high pressure is 3.0 atm while the low pressure is 0.5 atm. A standard 2-column Skarstrom cycle is used. The symmetric cycle is ... 

The hydrogen in the anode feed of reformate-based systems is typically diluted with CO2 and (in case of POX or ATR) nitrogen. As a consequence, the hydrogen mole fraction at the anode inlet is rarely higher than 0.3 (vs. 75 percent in the case of a direct hydrogen system). This decreases the ideal potential of the cells and increases the concentration-related losses. 

A condenser operates with a feed vapor of ammonia, water, and hydrogen (3.36 atm). At a given point in the unit the respective mole fractions are 0.3, 0.4, and 0.3. The liquid on the condenser is at 37.8°C (0.10 ammonia, 0.90 water). Estimate the rate of condensation of water relative to ammonia. 

Figure 4. The results of a step-up in feed hydrogen mole fraction (A) snow overshoots and much longer transients than the reverse step-down experiment (B) for Catalyst I...

The hydrogen feed contains methane as an impurity at a mole fraction of 0.05. The production rate of benzene required is 265 kmol h . ... 

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