A Fixed Point on the Pressure Scale: Carbon Dioxide Vapor Pressure at 273.16 K

The vapor pressure of carbon dioxide in equilibrium with mixtures of solutions of potassium carbonate and potassium bicarbonate

The adsorption kinetics and equilibria of pure carbon dioxide (CO2), ethylene (C2H4), and ethane (C2H6) on 4A(CECA) commercial zeolite have been measured over the temperature range T = (293.15 to 353.15) K using a glass-vacuum volumetric device. The adsorption rates of the gases were measured automatically via a custom acquisitions data card that was capable of registering pressure and time (t) data five times per second in the first period for t = (0 to 180) s, simultaneously. All of the gases showed a decreasing adsorption affinity and isosteric heat of adsorption in the order CO2 > C2H4 > C2H6. Unlike CO2, an activated diffusion for C2H4 and C2H6 for low t was observed. The adsorption activation energy for ethane Ea = (14.6 ± 0.2) kJ·mol−1 was found to be slightly higher than that for ethylene Ea = (13.8 ± 1) kJ·mol−1. The dual Langmuir model described the CO2 adsorption isotherms, whereas those for C2H4 and C2H6 were fitted with the Sips equation at (293.15 and 323.15) K. The three gases were reversibly adsorbed, and the adsorption selectivity for gas binary mixtures decreased in the sequence CO2/C2H6 > C2H4/C2H6 > CO2/C2H4. The obtained results indicate that 4A(CECA) zeolite could be a good candidate for separating these binary gas mixtures at 293.15 K.

Experimental water content measurements of carbon dioxide in equilibrium with hydrates at (223.15 to 263.15) K and (1.0 to 10.0) MPa

In Parts 1–5 of this paper1 charts were given which showed the vapour pressures of ammonia and carbon dioxide over aqueous solutions at 20° and 40°. Measurements of the vapour pressure of ammonia have now been made at 90° in order to provide data for calculating the efficiency of ammonia stills.

Mathematical simulation of pulmonary O 2 and CO 2 exchange.

Adsorption of carbon dioxide near its critical point on DeGussa IV activated carbon is investigated in this study. A volumetric method was used to measure the adsorption/desorption isotherms at 284, 300, 305, 310, and 314 K over a large pressure range. At subcritical temperatures, adsorption isotherms display a discontinuity at the vapor pressure of carbon dioxide, and desorption hysteresis is observed. However, there is no desorption hysteresis if adsorption is terminated before vapor−liquid transition occurs. At supercritical temperatures, adsorption isotherms display a plateau, and the excess decreases beyond the critical pressure. No hysteresis occurs during the desorption process. The adsorption isotherms can be represented very well by the simplified local density model.

Phase equilibria in the binary system carbon disulfide-carbon dioxide

A dynamic method for determining the vapor pressure of carbon dioxide at 0 C

Carbon dioxide equilibrium between product and gas phase of modified atmosphere packaging systems: Exemplified by semihard cheese

On the phase behaviour of the (carbon dioxide + water) systems at low temperatures: Experimental and modelling

The effect of carbon dioxide equilibrium on pH in dilute lakes

The effects of pH, carbon dioxide vapor pressure, pCO(2), and temperature on E1 and E3 deleted recombinant adenovirus vector (rAV) production with HEK293S cells have been studied in the ranges of pH = 6.7-7.7, pCO(2) = 0.05-0.20 atm, and T = 32-39 degrees C, respectively. The experiments were performed in four 500-mL bioreactors in parallel, which make possible the reduction of inter-run variability. Cell concentration and viability, relative oxygen uptake rate (OUR), fluorescence, and viral titer were measured. It was found that, although pH and pCO(2) did not affect significantly cell viability in the range studied, they had an important effect on virus titer. pCO(2) allowed the maximum production of rAV at 0.05 atm, and pH showed a very sharp optimum at 7.2. Temperature had an effect on both cell metabolism and virus titer. Low temperature prolonged cell viability and high OUR. Most of all, a 3-fold increase in virus yield was found at 35 degrees C compared to that at 37 degrees C, while 32 degrees C was not as beneficial (1.5-fold increase). This finding could have an important impact on large-scale production. This phenomenon was modeled using a simple 3-parameter synthesis-decay model. This model shows how the optimum gain in virus production at 35 degrees C is due to a balance between the production and decay processes at that temperature.

Modeling gas hydrate-containing phase equilibria for carbon dioxide-rich mixtures using an equation of state

Indirect methods for characterization of carbon dioxide levels in fermentation broth

SUMMARYWater and carbon dioxide vapor pressures were determined at 25 °C for freeze‐dried whole egg powders containing various levels of sucrose and of corn syrup solids added before drying. The manometric method used permitted determinations of vapor pressures over a range of moisture levels with a single sample.At moisture levels commonly encountered in commercial whole egg solids (2–6%), addition of both types of carbohydrate consistently increased equilibrium water vapor pressures over the dried products. Equilibrium values for carbon dioxide partial pressures were not obtained but the amounts found made it necessary to apply appropriate corrections in the determinations of water vapor pressure.The results are discussed in relation to Mail‐lard‐type browning reactions and oxidative flavor deterioration in dried whole egg.