Diluent gas

Fig. 3. Pressure required for ignition of mixtures of acetylene and a diluent gas (air, oxygen, butane, propane, methane, carbon monoxide, ethylene, oil gas, nitrogen, helium, or hydrogen) at room temperature. Initiation fused resistance wire. Container A, 50 mm dia x 305 mm length (73) B,...

WU low cost, stoichiometric reactions requires significant dry diluent gas mole ratio most every sulfonation and sulfation ... 

Cycle Diluents. Air process technology uses nitrogen as the diluent gas. The amount of nitrogen that enters the process in the air feed caimot be economically diluted (97). 

Numbers in this column indicate oxygen percentage while the letter prefix indicates the diluent gas. For example, the entry "Cl 3" means dilution to an oxygen content of 1 3 percent with carbon dioxide as the diluent gas. The letter prefixes are C = Carbon Dioxide N = Nitrogen A = Argon and H = Helium. 

Numbers in this column indicate oxygen percentage while the letter prefix indicates the diluent gas. For example, the entry "Cl 3" means dilution... 

Diffusion Systems The liquid whose vapor is to be the contaminant of the gas phase is contained in a reservoir maintained at a constant temperature. The liquid is allowed to evaporate and the vapor diffuses slowly through the capillary tube into a flowing gas stream. If the rate of diffusion of the vapor and the flow rate of the diluent gas are known, the vapor concentration in the resultant gas mixture can be calculated. 

Within limits, broad concentration ranges can be prepared by varying the tube dimensions and/or the flow rate of the diluent gas. Diffusion tube systems are preferable to permeation tubes when the latter are no fl Mercially available. 

There has been some controversy about the need for N2 in the formation of HD. Burgess et al. [29] reported that N2 was not required. They used argon as their diluent gas and took the word of the supplier that it was free of N2. Not only is commercial argon seldom free of N2, but it is difficult to remove the last traces of N2, and very little N2 is required to support HD formation. To settle this difference in experimental observations, Li and Burris [30] made it a point to rid their diluent gas of contaminating N2. One can absorb N2 on molecular sieve at liquid N2 temperature the problem is that argon liquefies and freezes before you get down to die temperature of liquid N2. So Li used neon as his inert gas and captured any contaminating N2 on molecular sieve in a liquid N2 bath. When the atmosphere above the nitrogen-ase system was carefully freed of N2 there was no formation of HD. 

Diluent gas Clean air Air Clean air + CO at SO ppm Clean air Clean air Ambient air... 

Elemental composition Cl 54.16%, N 21.40%, O 24.44%. The compound can be identified by its color and other physical properties. Analysis may be done by GC/MS using a diluent gas such as helium. Alternatively, it may be added to an olefinic double bond and the derivatives identified by physical properties, IR, and mass spectra. (See Reactions.)... 

Here v is the linear flow speed, which can be calculated from the cross-sectional area of the flow tube (Ar), the total pressure (P) in the flow tube, the temperature (T), and the molar flow rates (dn / dt) of the reactants and the diluent gas ... 

Microwave heating was also used to induce catalytic oligomerization of methane to afford C2-C4 hydrocarbons.571 Changing the catalysts and the applied power and the use of diluent gas (He) allowed significant alteration of product selectivities. Selectivity to benzene over nickel powder or activated carbon was 24 and 33%, respectively. 

A technique of making known vapor concentrations of reasonably volatile liquids in a diluent gas involves the use of the vapor pressure of the liquid (30). The diluent gas is passed through successive thermostatted bubblers obtaining a mixture determined by the saturation vapor pressure. Thus for ethanol, if the bubblers were maintained at 20°C (ethanol vapor pressure at 20°C... 

A clever means of dynamic generation of standards at the part-per-million level involves permeation through a polymer. In 1966 O Keeffe and Ortman (34) described this technique primarily for air pollution standards. A condensable gas or vapor is sealed as a liquid in a Teflon tube under its saturation vapor pressure as shown in Figure 4.14. After an initial equilibration period the vapor permeates through the tube wall at a constant rate. This rate is determined by weight loss over a period of time. Temperature must be controlled to within .0.1°C to maintain 1% accuracy. In use the tube is thermostatted in a chamber that permits a diluent gas to fully flush the chamber. The concentration is then determined by the same equation used for diffusion tubes. However, since the rate is generally much less in permeation tubes it is usually reported in ng/min. 

If the flow is increased to 2.7 /min the concentration is cut in half. Likewise, at 675 cm Vmin the concentration would be 0.76 ppm. Longer tube length, thinner tube walls, and higher temperature all increase the permeation rate, thus the need to control tube temperature to within 0.1°C. Generally, to prevent the diluent gas from cooling the tube in practice, a low flow is passed across the tube and is then diluted with a higher flow downstream from the tube. The sum of both flows must be used in the calculation. 

Exhaust Gas Recirculation. In one method of NO emission control, exhaust gas is fed back into the inlet manifold and mixed with the fuel and inlet air. The resultant mixture upon combustion in the cylinder results in lower peak combustion temperature and lower NO formation because the reaction of N2 + 0-, — NOx is strongly dependent on the combustion flame temperature (99,109—112). The degree of NO depression is dependent on the amount of exhaust gas recirculation (EGR) as shown in Figure 13. EGR provides a diluent gas having high molecular weight and C02 which absorbs heat. Also, EGR affects the flame speed of the mixture, and thus provides a certain antiknock quality to the combustion process. The impact of EGR on engine parameters has been detailed (113). 

Tertiary gas standards for the provision of traceable measurements to the United Kingdom s vehicle emissions testing programme (the MoT test ). These comprise specific concentrations of mixtures of carbon monoxide, carbon dioxide and propane in a diluent gas of nitrogen. 

Gas standards containing methane in a diluent gas of air or nitrogen, to provide traceable, accurate flammability measurements. 

Parent gas can be divided into two parts the minor component and major component. The major component is also known as background gas or diluent gas. 

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