Carbon-dioxide hydration

Carbon atom, 4. See also Atomic orbitals Carbon dioxide hydration, 197-199. See also Carbonic anhydrase Carbonic anhydrase, 197-199,200 Carbonium ion transition state, 154, 159 Carboxypeptidase A, 204-205 Catalysis, general acid, 153,164,169 in carboxypeptidase A, 204-205 free energy surfaces for, 160, 161 in lysozyme, 154... 

Englezos, P. and S. Hull, Phase Equilibrium Data on Carbon Dioxide Hydrate in the Presence of Electrolytes, Water Soluble Polymers and Montmorillonite , CanJ. Chem. Eng, 72, 887-893 (1994). 

M S. Zhurko, F.V. (2006a). Formation and decomposition of ethane, propane, and carbon dioxide hydrates in silica gel mesopores under high pressure. J. Phys. Chem. B, 110 (39), 19717-19725. 

Moudrakovski, I.L. McLaurin, G.E. Ratcliffe, C.I. Ripmeester, J.A. (2004). Methane and Carbon Dioxide Hydrate Formation in Water Droplets Spatially Resolved Measurements from Magnetic Resonance Microimaging. J. Phys. Chem. B, 108, 17591-17595. 

Servio, P. Englezos, P. (2003a). Morphology of methane and carbon dioxide hydrates formed from water droplets. AlChEJ., 49 (1), 269-276. 

Vlahakis, J.G., Chen, H.-S., Suwandi, M.S., Barduhn, A.J., The growth rate of ice crystals properties of carbon dioxide hydrate, a review properties of 51 gas hydrates, Syracuse U. Research and Development report 830, prepared for U S. Department of the Interior, November (1972). 

Yoon, J.-H. Kawamura, T. Yamamoto, Y. Komai, T. (2004). Transformation of Methane Hydrate to Carbon Dioxide Hydrate In Situ Raman Spectroscopic Observations. J. Phys. Chem. A, 108, 5057-5059. 

The carbonato complexes of lanthanides and actinides are of importance with regard to the metal ion speciation in the environment. These are, however, not linked with the enzyme models for carbon dioxide hydration and hence are not dealt with in further detail. 

Hara et al., 2005). THP, cyclobutanone, and cyclohexane also showed pressure reductions for carbon dioxide hydrate formation (Mooijer-van den Heuvel et al., 2001). THP, cyclobutanone, cyclohexane, and methylcyclohexane all reduced not only the pressure for propane hydrate formation, but also shifted the H-Lw-Lc3H8 line to lower temperature (Mooijer-van den Heuvel et al., 2002). 

Long and Sloan (1996) performed a series of measurements to investigate the site of nucleation for natural gas and carbon dioxide hydrate initiation in a sapphire tube. 

A number of other researchers have also confirmed that nucleation and subsequent growth typically occurs at the water-hydrocarbon interface for methane hydrate (Huo et al., 2001 0stergaard et al., 2001 Taylor, 2006) and carbon dioxide hydrate (Kimuro et al., 1993 Fujioka et al., 1994 Hirai et al., 1995 Mori, 1998). 

Servio and Englezos (2003a) examined the effect of pressure driving force on the morphology of methane and carbon dioxide hydrates grown from water droplets... 

In situ neutron diffraction studies have provided insight into the mechanism of surface conversion of ice particles to carbon dioxide hydrate particles (Henning et al., 2000). The experiments were performed at 230-276 K and around 6.2 MPa. It was proposed from these measurements that after the initial period of fast... 

Coexistence of si and sll carbon dioxide hydrate has been detected from x-ray diffraction measurements during hydrate growth (Staykova and Kuhs, 2003). Similarly, metastable sll hydrate phases were detected using NMR spectroscopy during si xenon hydrate formation (Moudrakovski et al., 2001a) and during si methane/ethane hydrate formation (Bowler et al., 2005 Takeya et al., 2003). 

Rehder et al. (2004) measured the dissociation rates of methane and carbon dioxide hydrates in seawater during a seafloor experiment. The seafloor conditions provided constant temperature and pressure conditions, and enabled heat transfer limitations to be largely eliminated. Hydrate dissociation was caused by differences in concentration of the guest molecule in the hydrate surface and in the bulk solution. In this case, a solubility-controlled boundary layer model (mass transfer limited) was able to predict the dissociation data. The results showed that carbon dioxide hydrate dissociated much more rapidly than methane hydrate due to the higher solubility in water of carbon dioxide compared to methane. 

Anomalous self-preservation stabilizes methane hydrate and carbon dioxide hydrate particles at atmospheric pressure at 242-271 K for up to 2-3 weeks. This phenomenon can have implications for natural gas storage. 

Simple Carbon Dioxide Hydrate with Inhibitors... 

Figure 6.49 Acid, base, and salt inhibition of simple carbon dioxide hydrates.

Methane + carbon dioxide hydrates with methanol 90.09% CH4 Data Robinson and Ng (1983) 69.75% CH4 Data Robinson and Ng (1986)... 

Figure 6.56 Methanol inhibition of methane + carbon dioxide hydrates.

Larson, S.D., Phase Studies of the Two-Component Carbon Dioxide-Water System, Involving the Carbon Dioxide Hydrate, University of Illinois, Urbana, IL (1955). 

Khalifah, R. G. The carbon dioxide hydration activity of carbonic anhydrase. I. Stop-flow kinetic studies on the native human isoenzymes B and C. J. Biol. Chem. 246, 2561-2573(1971). 

C02-6H20 -91 to 10 45 bars (pressure) C02-6H20 (carbon dioxide hydrate) Marion et al. 2006 Sloan 1998... 

There is an abundance of experimental gas partial pressures for gas hydrate equilibria across a broad range of temperatures (Fig. 3.10 Sloan 1998). The lower temperature limit in our model database for these systems is 180 K (Fig. 3.10) because this is the lower limit of our model s ability to estimate aw (Fig. 3.1, Eq. 3.11), which is needed to calculate the solubility product of gas hydrates (Eq. 3.36). In our model, the upper temperature limit for methane hydrate is at 298 K (25 °C), which is the upper temperature limit for FREZCHEM the upper temperature limit for carbon dioxide hydrate is at 283K (10 °C), which is the temperature where liquid C02(l) becomes the thermodynamically stable phase. 

Fig. 3.10. Experimental data for methane and carbon dioxide hydrate equilibria. Reprinted from Marion et al. (2006) with permission...

Dholabhai PD, Kalogerakis N, Bishnoi PR (1993) Equilibrium conditions for carbon dioxide hydrate formation in aqueous electroyte solutions. J Chem Eng Data 38 650-654... 

Englezos P, Hall S (1994) Phase equilibrium data on carbon dioxide hydrate in the presence of electrolytes, water soluble polymers and montmorillonite. Can J Chem Eng 72 887-893... 

Larson SD (1955) Phase studies of the two-component carbon dioxide-water system involving the carbon dioxide hydrate. PhD dissertation, University of Illinois... 

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