CO2, inside

The concept requires that for reversible reactions equilibrium be attained in the center of the catalyst. A numerical simulation of the set of continuity equations for CH4 and CO2 inside a ring-shaped catalyst particle used in an industrial reformer confirmed the presumption that equilibrium is indeed attained within a very thin layer close to the surface. 

Example 2.12 In order to reduce the CO content in the waste gas from a furnace, the exhaust gas is passed over the porous CuO particles (pellets) of a catalytic reactor in the exhaust pipe. The CO (substance A) is oxidised with O2 to CO2 inside and at the surface of the pellets, according to the reaction... 

Figure 10. Overall isotopic fractionation (essentially the difference between CO2 and biomass) as a function of pjp, the ratio of partial pressures of CO2 inside and outside C-fixing cells. The scde on the right-hand axis is inverted and shows ( lomass for plants using CO2 with S = -8%o. The solid tines represent C3 plants and maize, a representative C4 plant, with the point indicating its typical value of p/p (Marino and McElroy 1991). The horizontal dashed line shows that fip is independent of p /p when L, the leakiness coefficient for bundle-sheath cells in a C4 plant, is 0.38 (see Eqns. 13-19 and accompanying discussion). The dotted line represent a (hypothetical) plant with gas-tight bundle-sheath cells and indicates that the biomass of such a plant could be emiched in relative to CO2 forpjp > 0.45.

Soft Drinks The partial pressure of CO2 inside a bottle of soft drink is 4.0 atm at 25°C. The solubihty of CO2 is 0.12 mol/L. When the bottle is opened, the partial pressure drops to 3.0 x 10 atm. What is the solubility of CO2 in the open drink Express your answer in grams per liter. 

Pop Rocks is a carbonated candy like soda is a carbonated beverage. The fizzing that goes on in your mouth is due to carbon dioxide (CO2) bubbles escaping from the candy. To make this unique treat, the ingredients are heated, exposed to high pressures of carbon dioxide, and then cooled to trap the CO2 inside the candy. 

Fermentation of 750. mL of grape juice (density = 1.0 g/cm ) is allowed to take place in a hottle with a total volume of 825 mL until 12% hy volume is ethanol (C2H5OH). Assuming that the CO2 is insoluble in H2O (actually a wrong assumption), what would be the pressure of CO2 inside the wine bottle at 25°C (The density of ethanol is 0.79 g/cm. )... 

The absorption coefficient a(a>) assumes nonnegligible values only within the small spectral ranges Aco of absorption lines (a few gigahertz around the center frequencies coo). On the other hand, the scattering cross section, which is proportional to ct)" for Rayleigh scattering, does not vary appreciably over these small ranges Aco. Therefore, measurements of the laser beam attenuation at the two different frequencies coi and co2 inside and just outside an absorption profile yields the ratio... 

The gas flow rates have been controlled with Brooks MFCs. For CO2 injection, a piston with adjustable volume has been used that allows fast injection of a measured amount of CO2 via a nozzle (d= 0.004 m) into the bed. Glass beads (dpartide = 400-600 pm, density = 2525 kg/m ) are fluidized by dried N2, (M if= 0.206 m/s). CO2 is fiUed in a piston at a certain prepressure via a three-way valve (V2 in Fig. 4.56). For fast bubble injection, CO2 inside the piston is then compressed by air at high pressure (6 bar) for fast bubble injection. CO2 at high pressure is subsequently released into the column through a solenoid valve (Vs) opened in 0.01 s. The amount ofC02 injected is determined by different pressure before and after injection and the volume of CO2 filled to the piston. The injection velocity depends on the amount of tracer gas and the injection time. 

Fig. 4.60A plots the standard deviation of concentration in time which indicate that the very low standard deviation of concentration is obtained for the initial period, where CO2 is suddenly injected into the column, and the bubble is detached from the distributor (without gas exchange with the emulsion phase). Afterward, N2 from the emulsion phase dilutes the bubble, leading to an increased standard deviation, until the end of the evolution. The standard deviation approaches the plateau at i = 0.11 s, when about 50% of CO2 inside the bubble is replenished by N2. For time longer than i= 0.11 s, the concentration decreases slowly, due to the diffusion contribution. Fig. 4.60 shows that the concentration inside the bubble during the phase exchange is nonuniform. This means that, once the concentration in the emulsion phase can be detected, a more detailed model should be used to elucidate the gas exchange between bubble and emulsion. For the scope of this chapter, a simplified method is used. 

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