Gas molarity

Figure 9.25. Transient effect of applied positive current (1=5 mA) on the rate of consumption of hydrogen (rH2) and oxygen (r0) gas molar flow rate fm=13x 0"s mol/s.35 Reproduced by permission of The Electrochemical Society, Inc.

Fig. 1. Relationship between catalyst temperature and reaction time in methane partial oxidation catalyzed by Ni/Si02 (temperature of the gas phase (a) 1019 K, (b) 899 K, (c) 809 K, (d) 625 K). The reaction was carried out in a fixed-bed reactor (a quartz tube of 2 mm inside diameter) at atmospheric pressure. Before reaction, the feed gas was allowed to flow through the catalyst undergoing heating of the reactor from room temperature to 1073 K at a rate of 25 K min-1 to ignite the reaction, and then the reactant gas temperature was decreased to the selected value. Reaction conditions pressure, 1 atm catalyst mass, 0.04 g feed gas molar ratio, CH4/O2 = 2/1 GHSV, 90,000 mL (g catalyst)-1 h-1) (25).

Fig. 5. Methane conversion and oxygen flux during partial oxidation of methane in a ceramic membrane reactor. Reaction conditions pressure, 1 atm temperature, 1173 K, feed gas molar ratio, CH Ar = 80/20 feed flow rate, 20 mL min-1 (NTP) catalyst mass, 1.5 g membrane surface area, 8.4 cm2 (57).

Fig. 9. C02 conversions in the C02 reforming of CH4 catalyzed by Pt/Zr02 ( ), Pt/Ti02 ( ), and Pt/y-Al203 (A). Each catalyst contained 0.5 wt% Pt. Before reaction, the catalyst was reduced in flowing H2 at 1125 K for 1 h. Reaction conditions temperature, 875 K feed gas molar ratios, C02/CH4/Ar/N2 = 4.2/4.2/7.5/1.0 GHSV, 32,000 mL (g catalyst)-1 h-1 (188).

Fig. 12. Conversions of CH4 and CO2 and selectivities for formation of CO and H2 as a function of time on stream for C02 reforming of CH4 catalyzed by 17 wt% Ni/La203. Before reaction, the catalyst was reduced in flowing H2 at 773 K for at least 5 h and then at 1023 K for 2 h. Reaction conditions pressure, 1 atm temperature, 1023 K feed gas molar ratio, CH4 /C02 = 1 /1 GHSV is unknown (228).

Feed gas (molar C3H6 composition ratios) O2 H2O Major products Reference... 

The molar heat ratio (y) is defined as the ratio of molar heat at constant pressure and molar heat at constant volume. For a monoatomic gas, molar heat ratio is given by,... 

Based on Avogadro s law, one mole of a gas occupies the same volume as one mole of another gas at the same temperature and pressure. The molar volume of a gas is the space that is occupied by one mole of the gas. Molar volume is measured in units of L/mol. You can find the molar volume of a gas by dividing its volume by the number of moles that are present (- ). Look at the Sample Problem below to find out how to calculate molar volume. Then complete the following Thought Lab to find the molar volumes of carbon dioxide gas, oxygen gas, and methane gas at STP. 

S, O and N molar balances are now used to relate Fig. 10.1 s feed gas composition to oxidized gas molar quantities. The balances are all based on 1 kg-mole of feed gas. 

D 3.0 moles of hydrogen gas (molar mass is 2) will have a mass of 6.0 grams. 

The variation in gas molar flow rate caused by absorption and reaction is negligible When the gas phase reactant is diluted with an inert (as in this case), this is a reasonable assumption ... 

Fig. 7. Methane conversion, CO selectivity, and oxygen flux through the ceramic membrane during the partial oxidation of methane in a ceramic membrane reactOT (see Fig. 6). Reaction conditions temperature, 1148 K catalyst, 3(X) mg of LiLaNi0 7-Al2Q3 air flow rale, 3(X) mL min (NTP) feed gas molar ratio, CH4/He = 1/1 feed flow rate, 42.8 mLmin (NTP) (72).

Fig. 10. Carbon deposition on nickel-containing catalysts at 973 K as determined by TGA. Before reaction, the catalysts were reduced at 1073 K for 3 h. Reaction conditions temperature, 973 K feed gas molar ratio, CO2/CH4 = 1/1 GHSV, 144,000 mL (g catalyst) h (214).

---