Free gas content

During the last four decades, measurements of weak nuclei (i.e., gas nuclei) in liquids have become especially important in view of their influence on cavitation inception (e.g., ref. 57-59). Understandably, the gas nuclei concentration is closely coupled with the free gas content of the liquid (ref. 58, 60). (A distinction is made commonly in the engineering literature between free gas content and dissolved gas content. The free gas content is that portion of gas which has the normal physical properties of bulk gas. In practical situations, the free gas concentration within the liquid is usually several orders of magnitude lower than the dissolved gas concentration (ref. 58).) Many investigators have developed instruments to detect this free gas content (ref. 58,60) and the freestream gas nuclei concentration associated with it (e.g., ref. 58-60). 

V. 3. The Magnetic Field Effect on Free Gas Content and the Degasiflcation of Water... 

Bromine ttifluoride is commercially available at a minimum purity of 98% (108). Free Br2 is maintained at less than 2%. Other minor impurities are HF and BrF. Free Br2 content estimates are based on color, with material containing less than 0.5% Br2 having a straw color, and ca 2% Br2 an amber-red color. Fluoride content can be obtained by controlled hydrolysis of a sample and standard analysis for fluorine content. Bromine ttifluoride is too high boiling and reactive for gas chromatographic analysis. It is shipped as a Hquid in steel cylinders in quantities of 91 kg or less. The cylinders are fitted with either a valve or plug to faciUtate insertion of a dip tube. Bromine ttifluoride is classified as an oxidizer and poison by DOT. 

Plants producing oleum or Hquid SO typically have one or two additional packed towers irrigated with oleum ahead of the normal SO absorption towers. Partial absorption of SO occurs in these towers, and sulfuric acid is added to maintain desired oleum concentrations. Normally, oleum up to about 35 wt % free SO content can be made in a single tower two towers are used for 40 wt % SO. Liquid SO is produced by heating oleum in a boder to generate SO gas, which is then condensed. Oleums containing SO >40 wt % are usually produced by mixing SO with low concentration oleum. 

The energy of a system can be changed by means of thermal energy or work energy, but a further possibility is to add or subtract moles of various substances to or from the system. The free energy of a pure substance depends upon its chemical nature, its quantity (AG is an extensive property), its state (solid, liquid or gas), and temperature and pressure. Gibbs called the partial molar free heat content (free energy) of the component of a system its chemical potential... 

An interesting and practically valuable result was obtained in [21] for PE + N2 melts, and in [43] for PS + N2 melts. The authors classified upper critical volumetric flow rate and pressure with reference to channel dimensions x Pfrerim y Qf"im-Depending on volume gas content

channel entrance (pressure of 1 stm., experimental temperature), x and y fall, in accordance with Eq. (24), to tp 0.85. At cp 0.80, in a very narrow interval of gas concentrations, x and y fall by several orders. The area of bubble flow is removed entirely. It appears that at this concentration of free gas, a phase reversal takes place as the polymer melt ceases to be a continuous phase (fails to form a continuous cluster , in flow theory terminology). The theoretical value of the critical concentration at which the continuous cluster is formed equals 16 vol. % (cf., for instance, Table 9.1 in [79] and [80]). An important practical conclusion ensues it is impossible to obtain extrudate with over 80 % of cells without special techniques. In other words, technology should be based on a volume con-... 

G° = standard state Gibbs free energy R = gas content T = absolute temperature... 

The water content of a natural gas is a crucial parameter for the formation of gas hydrates, at least in transporting systems. Clearly a water-free gas may not be able to form gas hydrates. Natural gas contains water in the range of 8000 to 10,000 ppm (by volume). Specifications for pipelining restrict the water content to 120 to 160 ppm. The reasons for this limitation are not only the risk of hydrate formation, but also potential corrosion problems. Therefore drying of a wet gas is essential. 

Acid Dew Point For fossil fuels, the acid dew point temperature is that temperature at which the actual mixed acid vapor pressure equals the mixed acid vapor saturation pressure. The mixed acid dew point can be approximated by the sulfuric acid dew point (Fig. 24-56). It can be described as a function of the SO3 and water content of the flue gas (Huijbregts). These concentrations result from the sulfur, hydrogen, and free water content of the fuel the relative humidity of the air and the amount of excess air used. Using the equation of Ver-hoff, where T is degrees K and P is mm Hg (see OUces, A.G.) ... 

The following parameters were then fixedi Glycol contactor inlet temperature Condensate cooler outlet temperature Water content of the gas from the glycol contoctor Maximum free woter content of treated condensate... 

As reported by others, cyclopentadienyl ligands release CpH at low temperature, but decompose to carbon-containing species in the gas phase at high temperature, which lead to deposition of free carbon. The free carbon content could be lowered by using a reactive gas such as H2 (e.g. films with (tBuCp)2V (19) and H2). Moreover, the /-butyl substituent on the Cp ligand in 19 increased the chemical stability of the molecule in the gas... 

Galvanostatic discharge of a fuel cell (MRED method) provided information related to liquid water in a fuel cell in a minimally invasive manner.157 Stumper et al.158 showed that through a combination of this MRED method with a current mapping (segmented fuel cell similar to the one discussed in Stumper et al.135), it was possible to obtain the local membrane water content distribution across the cell area. The test cell was operated with a current collection plate segmented on the cathode along the reactant flow direction. In addition to the pure ohmic resistance, this experimental setup allowed the determination of the free gas volume of the unit cell (between the inlet and outlet valves). Furthermore, the total amount of liquid water presented in the anode or cathode compartment was obtained. 

Figure I 1.7. Variation of viscoelastic scaling factors with gas content for PS-C02 and PDMS-C02 systems. Lower scaling factor values for PS-C02 system, compared with PDMS-C02 system, are due to the closer proximity of the experimental temperatures to Tg of the pure polymer. The top curve displaying results for iso-free volume dilution of high-Mw polystyrene by low-Af polystyrene represents the effect on viscosity of volumetric dilution of high-Mw chains. Viscosity reductions for polymer-gas systems are significantly lower than the iso-free volume dilution curve, indicating that viscosity reduction is primarily due to free volume contributed by dissolved gas.

The raw synthesis gases from partial oxidation of heavy hydrocarbons and coal differ mainly in two aspects from that produced from light hydrocarbons by steam reforming. First, depending on the feedstock composition, the gas may contain a rather high amount of sulfur compounds (mainly H2S with smaller quantities of COS) second, the CO content is much higher, in some cases in excess of 50%. The sulfur compounds (Section 4.3.1.4) can be removed ahead of the shift conversion to give a sulfur-free gas suitable for the classical iron HTS catalyst. In another process variant the sulfur compounds are removed after shift conversion at lower concentration because of dilution by C02. The standard iron catalyst can tolerate only a limited amount of sulfur compounds. With a sulfur concentration in the feed >100 ppm sulfur will be stored as iron sulfide (Eq. 87) ... 

Direct sampling of free soil gas requires that a sampling probe be inserted into the ground to collect a soil gas sample. The deeper the penetration, the more difficult and expensive the procedure becomes, eventually requiring that analysis be conducted on drilling fluids or rock samples recovered from a hole. Deeper holes almost always encounter water, which also influences the collection of free gases, forcing one to analyse the gas content of some type of recycled water or mud system which is used to drill the hole. 

Hydrocarbon concentration values are reported in terms of ppm by volume in the nitrogen headspace or as ppm or ppb by weight, normalised to the weight of sediment. Gases concentrations reported by weight are not truly representative of the actual gas migrating from depth because some of the free gas has been allowed to escape during collection and sample preparation. Furthermore, the sorbed gas is never completely extracted into the headspace, and may not always reflect the true gas content of the soil. 

Gasifier From the various possible types the co-current moving bed gasifier was selected because of its tar free gas production and its simple construction [" ], As feedstock agricultural (forestry waste with a low ash and water content is preferred because of the high caloric value per kg. waste. The gasifier can be divided in four zones (see fig. 1) from top to bottom ... 

Coking produces a blast furnace coke feed substantially free of sulfur. However, the gaseous product, coke oven gas, has a sulfur gas content of 900-1, lOOg/m (at 15°C, 1 atm) [31]. This is mainly hydrogen sulfide, which may be removed either by the vacuum carbonate or Stretford processes. The sulfur gas removal efficiency of the Koppers Company s vacuum carbonate process is about 90%, which produces sulfuric acid, whereas the Stretford process can achieve 99% containment to a sulfur product (Chaps. 3 and 9). The choice of desulfurization process depends on the efficiency required and the sulfur product desired. Condensible hydrocarbons such as benzene (and other aromatics) and phenols have always been recovered by condensation, etc. [34]. 

In this study we performed experiments to investigate the incorporation rate of gas molecules in hydrates and the formation rate of clathrate hydrates from a liquid water phase in absence and in presence of a free gas phase. In case of a present free gas phase we observed the hydrate formation process in an optical cell. We also analysed the gas composition of the gas which was encased in the hydrate after the decomposition of the hydrates (Figure 2, Table 3). Due to the fact that the aim of this study was to investigate the influence of molecular properties of the guest molecules such as dimension (— diffusivity) and water solubility (—> concentration/fugacity) we focused our observation on the content of isomers which do have the same molecular weight but different molecular dimensions (see Table 2) and solubilities. 

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