Methane and nitrogen

When cyanoacetylene (5), which is produced when an electric discharge is passed through a mixture of methane and nitrogen, is dissolved in a phosphate buffer a stable enol-phosphate (6) is formed. Pyrophosphate is produced when neutral aqueous solutions of (6) and orthophosphate are heated, and the phosphorylation of UMP has been achieved. However, from a study of the rate of phosphorylation and a consideration of environmental factors, especially the likely phosphate concentration in oceans, it is suggested that (6) is not an important intermediate in prebiotic phosphorylation. The conversion of the 3 -phosphate of 0 2 -cyclocytidine (7) into 2, 3 -cyclic CMP under mild conditions in aqueous solution has... 

Several laboratories, including that of F. Raulin in Paris (Coll et al., 1998) and of J. Ferris in the USA (Clarke and Ferris, 1997) have carried out experiments on simulated Titan atmospheres these indicate that methane and nitrogen can exist side by side (Table 3.1). 

Seo, Y.-T. Kang, S.-P. Lee, H. (2001). Experimental determination and thermodynamic modeling of methane and nitrogen hydrates in the presence of THF, propylene oxide, 1,4-dioxane and acetone. Fluid Phase Equilibria, 189, 99-110. 

CO2 Separation Using a Thermally Optimised Membrane. This project aims to manufacture a high-temperature polymer membrane with better separation capabilities than current polymer membranes. The project focuses on the separation of CO2, methane, and nitrogen gases in the range of 100 to 400°C. 

The prebiotic synthesis of pyrimidines is based on cyanoacetylene, which is obtained in good yields by sparking mixtures of methane and nitrogen and by the... 

A simple numerical soln is developed. General theory developed is check by expts with expln flame of 03 andO. for which complete and reliable kinetic data are available. General theory is applied to mixts of Methane and Nitrogen air, helium air, and argon air. 

Each quadruple point occurs at the intersection of four three-phase lines (Figure 1.2). The lower quadruple point is marked by the transition of Lw to I, so that with decreasing temperature, Qi denotes where hydrate formation ceases from vapor and liquid water, and where hydrate formation occurs from vapor and ice. Early researchers took Q2 (approximately the point of intersection of line Lw-H-V with the vapor pressure of the hydrate guest) to represent an upper temperature limit for hydrate formation from that component. Since the vapor pressure at the critical temperature can be too low to allow such an intersection, some natural gas components such as methane and nitrogen have no upper quadruple point, Q2, and... 

About the same time as the initial measurements of sH with methane and adamantane in the Colorado School of Mines (CSM) laboratory by Lederhos et al. (1992), Becke et al. (1992) surmised that they measured the sH equilibrium for methane + methylcyclohexane. Structure H phase equilibria data were reported for binary systems with methane as the help gas (Mehta and Sloan, 1993, 1994, 1996 Thomas and Behar, 1994), with methane and nitrogen as the help gas (Danesh et al., 1994), and binary systems with salt (Hutz and Englezos, 1995). 

Tohidi et al. (2001) also suggested that the stability of simple methane and nitrogen hydrates could be increased by using sH large guest formers. They suggested that the C6 Cio fraction of real petroleum fluids are potential sH hydrate formers, though no evidence exists so far that real reservoir fluids are more likely to form structure H. 

I 7) Miesowicz, H. Gas chromatographic determination of argon, methane and nitrogen in the circulating gas of ammonia production. Chem. Anal. 12, 903 (1967). — Anal. Abstr. 15, 5937(1968). 

Under proper conditions of temperature and pressure, water molecules can form ice-like structures in which there are cavities. If small molecules such as methane and nitrogen are present, they can be held in the cavities and there serve to stabilize the crystalline structure. The resulting crystalline structures are called clathrates.20,21 Although each crystalline form has a unique composition, there are no chemical bonds per se. Thermodynamically the structures are solid solutions. Although several... 

Thus the lifetime of a constituent with a first order removal process is equal to the inverse of the first order rate constant for its removal. Taking an example from atmospheric chemistry, the major removal mechanism for many trace gases is reaction with hydroxyl radical, OH. Considering two substances with very different rate constants for this reaction, methane and nitrogen dioxide... 

Carbon monoxide, normally present in small amounts, less than 1 per cent Methane and nitrogen from traces to a few per cent... 

For a first approximation to the solution, we will assume that essentially all the methanol condenses, with only trace amounts appearing in the recycle line. We will also assume that most of the water condenses and that very small amounts of carbon monoxide, carbon dioxide, hydrogen, methane, and nitrogen dissolve in the condensate. To account for methanol and water vapor in the recycle gases and the solubility of the gases in the crade methanol, we would have to include phase equilibrium relationships in the analysis. As stated earlier, several condensable byproducts, high and low-boiling compounds in the cmde methanol, are present in small amounts, as shown in Table 3.5.1. We will not consider these compounds in the synthesis-loop analysis. 

Zirconia sensors have been used primarily in the exhaust system of automobiles to control the air-to-fuel ratio for meeting the federal requirements on such noxious gases as carbon monoxide, methane and nitrogen oxides. The applicability of zirconia sensors for this particular application is based on the assumption that, under thermodynamic equilibrium, the partial pressure of oxygen in the exhaust gas depends primarily on the air-to-fuel ratio. To compensate for the fact that in reality equilibrium is not reached, catalytic platinum electrics are incorporated in the zirconia sensor design [Stevens, 1986]. In the zirconia sensor, the outside of the zirconia tube is exposed to the exhaust gas while the inside is exposed to the ambient air as a reference atmosphere. 

Mosier A., Schimel D., Valentine D., Bronson K., and Parton W. (1991) Methane and nitrogen oxide fluxes in native, fertilized, and cultivated grasslands. Nature 350, 330-332. 

Figure 10 Axial (left) and radial (right) temperature profiles of the packed-commercial>pellet bed during steam reforming of methane and nitrogen flow conditions at gaseous-inlet hourly space velocities of 8400 hr" [X/R = distance from centerline/inside radius of reactor]. (From Ref. 10.)...

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