Temperature gas composition

Run I Reactor pressure Reactor temperature Gas composition (mole percent) butene-1 ds-butene-2 rrans-butene-2 53.33 kPa 25 °C 3.0 21.9 75.1... 

Factors affecting the selection of operating conditions are stack size, heat transfer rate, voltage level, load requirement, and cost. The performance curve is defined by cell pressure, temperature, gas composition, and utilization. Typical MCFCs will generally operate in the range of 100 to... 

Gasifier Types and Characteristics The three main types of gasifier reactors, moving bed, fluidized bed, and entrained bed, as shown in Fig. 24-4, are all in commercial use. The moving bed is sometimes referred to as a fixed bed, because the coal bed is kept at a constant height. These gasifiers can differ in many ways size, type of coal fed, feed and product flow rates, residence time, and reaction temperature. Gas compositions from the gasifiers discussed below are listed in Table 24-10. 

These will influence the local conditions of temperature, gas composition and fractional conversion applicable to any particular particle. The ultimate aim, which is diflicult to achieve because of the complexity of the problem, is to estimate the overall conversion which will be obtained for any particular set of operating conditions. 

Fig. 13.3. Cooldown path added to Fig. 13.2. It is a horizontal line at the lsl catalyst bed intercept % S02 oxidized level - between the 1st catalyst bed intercept temperature and the specified 2nd catalyst bed gas input temperature. Gas composition and % S02 oxidized don t change in the gas cooling equipment.

Whereas extraction with an organic solvent is not desirable from an environmental point of view, supercritical CO2 represents an environmentally benign and clean alternative as demonstrated/461 If the process is run continuously, as depicted in Figure 4.5, it can even compete with the industrial cobalt-based process/47,61,621 Careful tuning is, however, required and the effects of different ionic liquids, temperature, gas composition and substrate flow rate are all important. 

Axial Profile of Temperature, Gas Composition, Carbon on Catalyst of a Commercial... 

As pointed out by Qin and Wolf (74), the window in which oscillations occur at UHV conditions does not seem to be accessible at atmospheric conditions with supported metal catalysts. It is not evident that oscillations can be explained via a consideration of the changing surface structures, which cannot be measured. For the supported catalysts there are gradients of gas-phase temperature, solid temperature, gas composition, and surface composition so that a successful simulation via the solution of the coupled... 

Before closing this section we should mention several relatively recent papers that provide additional details relevant to the overview given above. The effects of evaporation, back-reaction, diffusion, and dust enrichment on isotopic fractionation in forsterite have been discussed in great detail by Tsuchiyama et al. (1999) and Nagahara and Ozawa (2000) and extended to multicomponent systems in Ozawa and Nagahara (2001). Richter et al. (2002) combined theoretical and experimental approaches to study elemental and isotopic fractionation effects due to evaporation from CMAS liquids and included consideration of the effects of temperature, gas composition, and diffusion in both the residue and in the surrounding gas. 

It was not in Mittasch s character to be satisfied with this conspicuous achievement. Parallel to extensive studies on the influence of pressure, temperature, gas composition, catalyst poisons and other factors on the synthesis reaction, he worked toward new types of multi-component catalysts for a great number of other catalytic gas reactions. With his associates Ch. Beck, C. Muller, and Ch. Schneider, he thus discovered efficient catalysts for the water gas reaction, for hydrogenations in the gas phase (among which the synthesis of alcohols and hydrocarbons from carbon monoxide and hydrogen is particularly noteworthy), for the production of nitric acid via the oxidation of ammonia, and for many more industrial processes which are the backbone of large segments of our present chemical industry. 

The measurements on the research facility were carried out at stationary or quasi stationary conditions. The measurements of air flows, gas temperatures, gas composition, and heat output were analysed continously and monitored online. The gas composition was analyzed in the flue gas after the boiler exit with industrial gas analyzers. For the analysis of the hot gas in the reduction zone a suction pyrometer combined with a probe for detection was used. With this probe also short fluctuations could be monitored with extremely short delay. Besides, a hot gas sampling line with different analyzers for measuring the gas in the reburn zone was installed. Table 2 gives on overview over the gas analysis equipment. 

Effects of Sulfur- Deactivation of SCR catalysts by sulfur compounds can occur by several mechanisms, and the effects can be strongly dependent on temperature, gas composition, and the composition of the catalyst and its support. The most commonly encountered sulfur problems arise from the SO2 in combustion gases and/or SO3, which may come primarily from oxidation of part of the SO2 by the SCR catalyst. 

Furthermore, Chapters 12 and 13 of this book are devoted to advanced diagnostic techniques that have almost superseded traditional intrusive techniques (water-cooled probes inserted into the combustion chamber for measuring local temperature, gas composition, etc.). Also flameless oxidation is better studied by nonin-trusive techniques as the insertion of probes disturbs the local conditions and may cause the onset of a local flame front. Fluorescence (like LIF techniques) as described in other chapters, or even simpler, a UV picture of the reaction zone are very suitable to describe flameless oxidation... 

Catalytic combustion of SO2, toluene and 1,2-dichloroethane were conducted at atmospheric pressure in a tubular flow reactor with an inner diameter of 18 mm. Catalyst extrudates or monoliths were packed into the reactor with glass wool plugs at each end. The reactor was placed in a furnace equipped with a temperature control to maintain a constant reactor temperature, and two thermocouples to measure the inlet and outlet reactor temperatures. Gas compositions and flow rates were set by mass flow controllers. The following reaction conditions were used to test the cataljTic activity of the 0.2 wt. % Pt supported samples ... 

The key question about the values of AS and AH and, if possible, about their dependence on the temperature may be eventually solved by carrying out quite systematic series of experiments with several experimental conditions, e.g., experiment period, starting temperature, gas composition and velocity, column diameter, etc., varied over a wide range for one and the same adsorbate-adsorbent pair (Steffen and Bachmann 1978b Chuburkov et al. 1993). Provided that AS and AH are temperature-independent, dependence of In cm) T... 

Furthermore, by varying other experimental conditions such as current load, temperature, gas composition, and as recently shown by Andreaus et al. [2002] hydrogen humidification and membrane thickness, measured cell impedance can be split into anode impedance, cathode impedance and electrolyte resistance, without using reference electrodes. These results were used to derive appropriate equivalent circuits for the analysis of impedance spectra measured on fuel cells operating with H2/O2, H2/air and H2 + lOOppm CO/O2. The variation of the experimental conditions is also a useful method to confirm the accuracy of the equivalent circuit. 

An understanding of protective oxidation of metal is enhanced by knowledge of the mechanisms of solid-state diffijsion. For a particular metal, the reaction mechanism will in general be a function of pretreatment and surface preparation, temperature, gas composition and pressure, and elapsed time of reaction. When the large variations in properties of different metals and alloys and their oxides are also considered, it is not surprising that a large theoretical base is needed to describe the oxidation behavior of metals. Thermodjmamics and kinetics are two basic factors associated with the formation and subsequent protection by these oxide layers at high temperatures. 

Table 1. The total hydrogen content, n H), and the line shape parameters for the broad and the narrow components of the NMR line for eight plasma-deposited a-Si H samples prepared under different conditions as listed in column 1 (RF power density, substrate temperature, gas composition and deposition electrode). For the first four deposited on room-temperature substrates, the broad line is a Pake doublet due to SIH2. For the second four, deposited on heated substrates, the broad line is a Gaussian.

Explosive decompression repeated cycling of set conditions on a test rig of the type described by Cox. Temperature, gas compositions and pressure cycles would be further defined (Section 5.1 this chapter). 

The iteration scheme is shown in Figure 6.4. First, initial data, such as initial temperature, gas composition, pressure etc., are applied to the whole computational domain. Then, the electrochemical model is solved to calculate the local current density at a given operating potential, followed by solving of the chemical model to calculate the reaction rates and reaction heat. Based... 

Experiments and simulations provide access to very different types of information when it comes to gaining new insight that may eventually lead to the design of improved materials. Experimentally, one can directly measure phenomenological effect of varying temperature, gas composition, applied voltage, or other conditions but the atomic level details are often out of reach. In simulations, the scenario is quite the opposite, here information about... 

Eor non-isothermal calculations, the heat balance is necessary to determine the temperature for a given heat loss. Hence, the results from such an equilibrium calculation are the temperature, gas composition, and the amount of gas produced from a given quantity of coal and gasifying agent. 

A similar approach was taken for the furnace testing. The temparature of the furnace was calibrated prior to the actual testing of the woven Ml Hi-Nic-S/BN/SiC specimens. The ftimace was calibrated to maintain a specimen temperature of 1235 5°C, which is equal to the surface temperature in the direct flame impingement area of specimen in the AFIT/AFRL burner rig. R-type thermocouple, the same type used during the calibration of the temperature in the burner rig test, was used to calibrate for the targeted surface temperature. Gas composition inside the furnace was assumed to be that of laboaratory air, i.e. 79 vol % of N2 and 21 vol % of O2, as the furnace was open to the air in the laboratory. The relative humidity in the room at the time of testing was 55 5%, which translates approximately to less than 2 vol % of HjO. 

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