Inert additives

Another example of pressure control by variable heat transfer coefficient is a vacuum condenser. The vacuum system pulls the inerts out through a vent. The control valve between the condenser and vacuum system varies the amount of inerts leaving the condenser. If the pressure gets too high, the control valve opens to pull out more inerts and produce a smaller tube area blanketed by inerts. Since relatively stagnant inerts have poorer heat transfer than condensing vapors, additional inerts... 

Clearly, the exponents offered further support for the assumed solvent conditions at 0.1 M NaCl and 1.5 M NaCl. Together with the results from the inert salt dependent experiments shown in Fig. 6, we were able to establish changes of size and shape of the NaPA chains which were induced by regular electrostatic screening effects. Now an important prerequisite has been met in order to successfully isolate and assess specific effects of multi-valent cations on these polyelctrolyte features in the presence of an additional inert salt. This will be discussed in Sect. 3.2. 

As an example of intrinsic safety features, consider the HYLIFE design. The HYLIFE reactor room has no external walls or roof it is surrounded by other rooms and covered with a crane loft. The reactor room contains an inert gas (no air). The entire Li inventory can be drained in minutes in case of an air leak into the room such a leak would require hours before lithium combustion is possible. There are no water or steam components in the reactor room, and all concrete is steel lined. The lithium loop is everywhere sub-atmospheric pressure (1 Pa to 80 kPa or 10 to 620 Torr) hence, small leaks will be inward. Large leaks will fall on a sloped floor that drains to tall narrow tanks containing hollow graphite spheres that would float above spilled lithium. Additional inert gas injection capability will be available in these areas. 

The advantages of simplicity and low cost more than outweigh the disadvantages of hydrogen consumption and production of additional inerts in the makeup gas to the synthesis loop. 

Interesting additional inert gas effects have been observed by Biron and Nalbandjan [17]. Using silica vessels they confirmed the above behaviour but in experiments under conditions analogous to those used by Semenova, already discussed, they found the critical explosion pressures to be unaffected by argon addition. Their results are given in Table 4. The conditions used by Semenova correspond with extremely low chain breaking efficiency at the vessel wall, and under these conditions the rates... 

Experiments were carried out in a laboratory fixed-bed catalytic reactor, consisting of a stainless steel tubing of 400 mm length and 9 mm internal diameter. The reactor was loaded with 0.30 g of catalyst, mixed with 1 g of inert glass as dilutant. The catalyst was placed in the middle section of the reactor, and the upper part was filled with additional inert material. The reactor was placed inside an electric furnace, the temperature being controlled by a PID controller (Honeywell) connected to a thermocouple situated inside the reactor, in the zone charged with catalyst. The system was provided with 5 additional thermocouples that measured the reactor wall temperature at different positions. 

It was assumed that the yield of OCM products could be enhanced by increasing the efficiency of CH3 recombination, which competes with reaction (35). Since the recombination of methyl radicals is a three-body process (see Section III.D), its efficiency can be increased by increasing total pressure, or by introducing an additional inert surface, which can play a role of third body. Indeed, it was demonstrated that the increase of inert gas (He or Ar) pressure at constant pressures of methane and oxygen leads to a substantial increase of OCM selectivity and yield (Sinev et al., 1996). Moreover, the addition of a 10-fold amount of various solid materials possessing a very low activity under the same conditions (quartz, fused MgO, Mg phosphate) to a relatively efficient OCM catalyst (Nd/MgO) led to a drastic increase (up to twofold) in the yield of OCM products (Sinev et al., 1997a, b). 

Gradient sublimation To ensure a high material yield in combination with a high selectivity, sublimation over an extended temperature gradient ( 500 K/m) is the preferred method if the sublimation temperature of the host material is known. Inside a glass tube separation across the temperature gradient takes place and, in most cases, the purified fraction occurs spatially well-separated from the contaminants. The efficiency can be improved in terms of yield and stability in the presence of an additional inert carrier gas, e.g. Ar or N2, which at low pressure (10 Torr) reduces the molecular mean free path and equilibrates temperature fluctuations across the glass tube. 

Vapors of two different monomers (A and B) together with a hot inert gas are fed to a mixer (such as a jet mixer, a simple short tube, or a combination of both) and then to the reactor inlet. Additional inert gas can be introduced as needed. The reactor effluent stream consisting of some polymer, possible oligomers, and by-product acid, is conducted through a quench chamber where the stream is cooled by a flow of relatively cold inert gas. The cooled stream is then led through a separator such as combination of a cyclone separator and filters to remove solid material. The filtered stream is then passed through a water scrubber to remove hydrogen halide and vented to the atmosphere or recycled. 

Tetraethyl pyrophosphate Thallium (I) sulfate Thiophenol Triazophos Tributyltin acetate Trimethylcyclohexanol Turpentine Zinc hexafluorosilicate pesticide additive, inert PEG-75 soy glycerides pesticide aid... 

The application of oxy-combustion to a coal-fired steam cycle is illustrated in Fig. 10.6. Since combustion of coal in pure oxygen produces flame temperatures much higher than combustion in air, a portion of the C02-rich flue gas is typically recirculated back to the burner to limit the peak temperature in the combustion chamber. Different arrangements can be adopted Fig. 10.6 recycles a portion of the dry exhaust from the flue gas desulfurizer (FGD) back to the stream that transports the pulverized coal to the burner. A wet recycle stream, drawn just downstream of the electrostatic precipitator, provides additional inert gas to keep the furnace temperature close to that found in air fired boilers. 

Inert Feed Material to Control Exothermic Reactions. In some cases, it may be necessary to add additional inert feed streams to the process in order to control the reactions taking place. Common exanples of this are partial oxidation reactions of hydrocarbons. For exanple, consider the partial oxidation of propylene to give acrylic acid, an inportant chemical in the production of acrylic polymers. The feeds consist of nearly pure propylene, air, and steam The basic reactions that take place are as follows ... 

Additives Inert or reactive inorganic materials added to concrete to achieve specific properties. 

More than three dozen elements have been shown to be reversible to their ions in molten solvents of one sort or another. Although this total encompasses a variety of solvents, it is generally true that a satisfactory metal-metal ion electrode couple in one solvent will also be reversible in other melts, provided, of course, that the metal or its ion do not react irreversibly with other components of the melt. Included in these electrode systems are not only halogen-halide electrodes (on carbon), but also the more unusual 02/0 , CO2 + 02/C03, and NO2 4- 02/N03 couples using Pt, C, etc. as the electrode material. In addition, inert conductors such as Pt, C, and Ta usually function very well as oxidation-reduction electrodes sensitive to two oxidation states of a given metal in the melt. 

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