Phase gas-solid

Solid phase concentration of adsorbate i, mols i / g solid Gas phase density, mols/m3... 

Pyrolysis processes were discussed in previous sections. Suffice it to say that if the heating rate is fast, a solid particle is heated to high temperatures in a short period of time, and then the gas-gas phase and solid-gas phase gasification reactions take place simultaneously. 

By drawing a horizontal line across the figure at p = we see how the line cuts the solid-gas phase boundary at —78.2°C. Below this temperature, the stable form of CO2 is solid dry ice, and C02(g) is the stable form above it. Liquid CO2 is never the stable form at in fact, Figure 5.5 shows that CCfyi) will not form at pressures below 5.1 x In other words, liquid CO2 is never seen naturally on Earth which explains why dry ice sublimes rather than melts under s.t.p. conditions. 

A preparative solid- gas phase synthesis of acetyl hypofluorite (1, R = Me) has been described it is based on the reaction of dilute fluorine (with air or nitrogen) with a solid complex of potassium acetate with acetic acid and can be also modified7 -9 for the preparation of acetyl... 

Since the electrolyte is a condensed phase, adsorption at electrodes, unlike at the solid—gas phase interface, is a process of replacement of specifically adsorbed solvent molecules or ions at the interface. 

Torr and 38.6°C. (a) Sketch the approximate phase diagram and label the solid, liquid, and gaseous phases and the solid-liquid, liquid-gas, and solid-gas phase boundaries, (b) Sketch an approximate cooling curve for a sample at constant pressure, beginning at 500 Torr and 25°C and ending at 200°C. 

FIGURE 18.6 Supercritical region of a hypothetical compound. The solid lines represent phase boundaries between solid-liquid, liquid-gas, and solid-gas phases. Supercritical region is the region indicated by the dotted line. 

The results obtained (see Tables 2 and 3 and Fig. 1) show that they are closer to the ones obtained with coal as feed than to the ones obtained with coal-limestone feed. Moreover, not only the total PAH emissions are similar to the ones in absence of Ca, but also the PAH solid/gas phase distribution coincide because none PAH was detected in the cyclone and condenser traps, solid emissions. Therefore, all the PAH were emitted on gas phase, as it happens at SC runs. 

New technologies for methanol synthesis are presently being developed. These new systems, which have been tested in bench or demonstration units, use either low temperature liquid-gas phase or solid-gas phase methanol reaction techniques. However, the suitability for cormvercialization of these new technologies is uncertain due to either questionable economical advantages or insufficient development therefore, this paper will address the conventional methanol synthesis loop. 

Calculation procedures for adsorption and ion exchange differ only in detail from liquid-liquid extraction since an ion-exchange resin or adsorbent is analogous to the solvent in extraction. All coordinate systems used to represent solvent-solute or liquid-vapor equilibria may be used to display three-component solid-liquid, or solid-gas phase equilibria states. For the case of gas adsorption, equilibria are usually a function of pressure and temperature, and so isobaric and isothermal displays such as Fig. 3.21, which represents the propane-propylene-silica gel system, are convenient. 

Both [Ni(TTL)]a, and [Co2(CO)2(TTL)]a react with oxidizing agents such as iodine either in solution-suspension or in solid-gas phases, according to Equations 11 and 12, respectively (5). A suspension of the... 

Radiant heat transfer between surfaces of the solid (gas phase). 

Wlieii the tungsten filament inside tlie bulb is heated to a higli temperature (about 3000°C), tlie tiuigsten sublimes (solid —> gas phase transition) and then it condenses on the inside walls of the bulb. Tlie inert, pressurized Ar gas retards sublimation and oxidation of the tungsten filament. 

Due to slow kinetics, the conventional heterogeneous catalysis of the dehydrogenation of decalin in the solid-gas phase is performed at temperatures of more than 400 °C, which might result in the formation of by-products or carbonaceous deposit on the catalyst in addition to thermal energy loss. In a recent study, an attempt was made to apply the so-called liquid-film concept to hydrogen evolution from decalin with carbon-supported platinum-based catalysts under reactive distillation conditions in order to obtain high electric power suflficient for PEMFC vehicle operations in the temperature range 200-300°C [236]. 

Polymerizations catalyzed by transition metal oxides on support were described variously as employing solid/liquid suspensions, fixed beds, and solid/gas-phase operations. It appears, however, that the industrial practices are mainly confined to use of solid/liquid suspension processes. The polymerization is carried out at the surface of the catalyst suspended in a hydrocarbon diluent. 

Solid-Liquid and Solid-Gas Phase-Transfer Catalysis.163... 

Preparative centrifugal separations are often classified according to the phases of the media and the material to be purified, e.g., gas-gas, liquid-liquid, or liquid-solid. Gas-phase separations are very important in certain applications, e.g., uranium-isotope enrichment, but are highly specialized and not widely used. Liquid-liquid or even liquid-liquid-solid separations, on the other hand, are much more common. However, the majority of preparative separations involve the sedimentation of solid particles in a liquid medium. 

Use of microelectrodes under steady state conditions, where radial rather than linear diffusion is dominant, minimizes the influence of uncompensated resistance and enables studies to be routinely undertaken in toluene, conducting pol57ners, solids, gas phase, critical fluids, as well as without deliberately added supporting electrolyte. ... 

In addition to the investigations described, other kinetic experiments have been carried out with the help of solid-electrolyte galvanic cells. The investigations include phase-boundary reactions at the solid-gas phase boundary (including measurements of evaportion and condensation rates) and phase-boundary reactions at the solid-solid phase boundary. These investigations will not be discussed here. 

PCMs ° are the materials possessing the ability to absorb, store and release latent heat through undergoing one of the four types of phase transformations (solid-solid, solid-liquid, liquid-gas and solid-gas phase transformations) in a nearly isothermal process within a certain range of environmental temperature. During this process, the latent heat can be stored or released from PCMs going from one physical state (e.g., solid) to another (e.g., liquid) or vice versa. 

Figure 9.1 Phase diagram for a typical pure substance showing the hquid-gas, solid-hquid, and solid-gas phase coexistence boundaries. Point A where these three coexistence lines meet is the triple point. Point B at which the hquid-gas coexistence line terminates is the critical point.

The plot of pressure vs. temperature for a solid-gas phase change reflects the large effect of tanperature on vapor pressure thus, it resembles the Uquid-gas curve in rising steeply with higher temperatures. 

The Clapeyron equation also works for liquid-gas and solid-gas phase transitions, but as we will see shortly, some approximations can be made that allow us to use other equations with minimal error. 

Solid-gas phase interfaces are therefore described by other means, such as by the FreundHch, Langmuir and BET isotherm. Heat of adsorption during the physical adsorption is of the same order as heat of condensation. Adsorption heat during chemisorption is of the same order as the reaction heat. ... 

An aerosol-assisted chemical vapor deposition (AACVD) can also be implemented in the intermediate thermal range between processes B and D, provided that suitable solvents and precursors are used (process C according to the classification made by Vigui6 and Spitz). In proper conditions, the solvent vaporizes first, then the precursor vaporizes (or sublimes) and the vapor reaches the substrate to undergo a heterogeneous solid-gas phase decomposition. Thus, whether or not an aerosol-assisted deposition process may be classified as chemical vapor deposition depends on two factors ... 

Solid-gas phase transition (heat of sublimation of dry ice) absorbent type... Lithium bromide-water, water-ammonium etc. adsorbent type... Zeolite-water vapor, silica gel-water vapor etc. 

Figure 1.8 shows schematically a more complete view of the three-dimensional graph of Figure 1.7, including the solid-liquid and solid-gas phase transitions. There... 

In principle, the phase behaviour models discussed above apply for solid-gas phase systems, too (33, 38). Trae equilibrium behaviour is less easily... 

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