Operating conditions for optimum

At the beginning of Sec. 10.2.b, it was stated that after the solution to the mass balance is used to decide the reactor operating conditions for optimum conversion (or selectivity), then the energy balance is utilized to determine the external conditions required to maintain the desired temperature. Thus, Eq. 10.2.b-l is solved together with the steady-state form of Eq. 10.2.a-5 ... 

It should be noted that although optimum operating conditions for the Aaberg exhaust system might be accurately found under ideal working conditions, the following points should be considered ... 

OPTIMUM OPERATING CONDITIONS FOR DIFFERENT COLUMN TYPES coluan pressure drop 200 bar, viscosity lx 10 V.b/w and diffusion coefficient - 1.0 x 10 w /s... 

Table 3.1 Optimum operating conditions for the hydrodynamic cavitation reactors No. Property Favorable conditions...

For the parallel reactions in equation 10.7.1 one may use this general rule to select the follpw-ing operating conditions as optimum from a selectivity viewpoint when the reactor operates isothermally. 

Scott, R.P.W. and Beesley, T.E., Optimum operating conditions for chiral separations in liquid chromatography. Analyst, 124, 713, 1999. 

Both the COED process and Garrett Flash Pyrolysis have been "proved" in small demonstration plants and subject to tests designed to establish optimum operating conditions for a particular feed coal, both are claimed to be ready for commercial use. 

In choosing the most suitable GC column, the primary criterion employed was the degree of resolution of each analyte from potential interferents that could be achieved under the optimum operating conditions for that column. The compounds considered as potential interferents for each method are given in Table I. Many of these compounds are halocarbons that are likely to coexist with the analytes in the workplace. Others possess physical and chemical properties similar to the analytes. A number of different GC columns and operating conditions were evaluated for each method before optimum results were obtained. 

L 1 and 0.6 jag L, respectively. Due to photolysis, nitrate present in the water at a concentration of 55 mg L 1 was reduced to nitrite generating an additional problem (see section II.D.l). This is because nitrite is thought to be involved in the formation of nitrosamines. Experimental conditions in this plant have been investigated to provide the optimum operating conditions for the removal of herbicides and to minimize the impact of nitrate photolysis. The results obtained in this plant led to concentrations of atrazine and nitrite in the effluent lower than 0.1 and 100 pg L 1, respectively. It must be said, for safe operation of the plant, that an equivalent ozone dose higher than 3 kW energy and a radiant power for the UV lamp between 20 and 35 kW were needed. 

In order to design and dimension stirrers for the homogenization of liquid mixtures - and this is by far the most common task when it comes to stirring - it is vital to know the power characteristic and the mixing time characteristic of the type of stirrer in question. If this information is available for various types of stirrers, it is possible to determine both the best type of stirrer for the given mixing task and the optimum operating conditions for this particular type. 

Optimum operating conditions for LC, as determined by the C terms, are similar to those for GC d and dP should be small and Dp should be large. Also, as noted earlier, LC columns are usually straight, rather than coiled, to prevent the race track effect. Other minor factors in the CM term were discussed earlier. 

Star anise volatile oils can also be isolated by supercritical C02 extraction coupled to a fractional separation technique. Gas chromatography-mass spectrometry analysis of the various fractions obtained in different extraction and fractionation conditions allowed the identification of the best operating conditions for the isolation of essential oil. A good extraction performance was obtained operating at 90 bar and 50°C (for 630min) for both treated materials. Optimum fractionation was achieved in both cases by operating at 90 bar and -10°C in the first separator and at 15 bar and 10°C in the second (Della Porta eta/., 1998). 

The optimum operating conditions under which the desired gas flow rate is attained at the minimum stirrer power (per unit of gas flow) can be found by combining the dimensionless number NA, Ne, and Fr. The appropriate dimensionless group in this case is Ne Fr/NA = P/(qtpgdt), and is likewise a function of Fr H /d,. The optimum operating condition for the tube stirrer is given by Fr d,/H = 1.80 here H — HL — Hx (i.e., liquid height above the stirrer). 

Supercritical fractionation of high molecular weight alkane mixtures with propane or LPG may be used to produce products with lower polydispersity that that of molecular distillation. Operating temperatures just above the cloud point of the mixtures can be used compared to the high temperatures needed in molecular distillation. It was also shown that an optimum reflux ratio exists for every set of operating conditions. For this system it was also found that the operating costs of a supercritical fraction unit is marginally less than that of a molecular distillation unit. 

It is of primary importance to find the optimum operating conditions for GC... 

The optimum operating conditions for GC analysis must be determined prior to the GC-MS analysis. In general, this is accomplished by injecting the sample solution several times while varying such parameters as carrier gas, splitting ratio of carrier gas at the injection port fitted with a split liner, carrier gas flow rate, and oven temperature profile. In addition, the type of capillary column used and the concentration and volume of the sample to be injected also have to be optimized. 

An excellent example of an optimum operation design is the determination of operating conditions for the catalytic oxidation of sulfur dioxide to sulfur trioxide. Suppose that all the variables, such as converter size, gas rate, catalyst activity, and entering-gas concentration, are fixed and the only possible variable is the temperature at which the oxidation occurs. If the temperature is too high, the yield of SO, will be low because the equilibrium between SO, SO, and 0, is shifted in the direction of SO, and 0,. On the other hand, if the temperature is too low, the yield will be poor because the reaction rate between SO, and 0, will be low. Thus, there must be one temperature where he amount of sulfur trioxide formed will be a maximum. This particular temperature would give the... 

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