Desiccants table

Table 7.12 Capacities and relative cost of desiccants Table 7.13 Desiccants suitable for producing very dry and pure solvents under batch distillation conditions ...

Example. 40/23/50 indicates conditioning for 40hr at 23°C at 50 percent RH. 48/50 -I- Des indicates conditioning for 48 hr at 50°C followed by desiccation. Table 11-1 summarizes conditioning procedures. 

The products of the reaction are filtered, washed with alcohol first and then with diethyl ether, and dried over P2O5 in a vacuum desiccator. Table 3.7 lists infrared spectral data of these complexes. 

Bipyridiniums. The bipyridinium herbicides (Table 2), paraquat and diquat, ate nonselective contact herbicides and crop desiccants. Diquat is also used as a general aquatic herbicide (2,296). Bipyridinium herbicides are organic cations and are retained ia the soil complex via cation exchange. They are strongly sorbed to most soils and are not readily desorbed (332). Both paraquat and diquat are not readily leached (293). 

The purity of oxygen from chlorate candles before and after gas filtration is indicated in Table 2. A particulate filter is always used. Filter chemicals are HopcaUte, which oxidizes CO to CO2 molecular sieves (qv), which remove chlorine compounds and basic materials, eg, soda lime, which removes CO2 and chlorine compounds. Other than H2O and N2, impurity levels of <1 ppm can be attained. Moisture can be reduced by using a desiccant (see Desiccants). Gas purity is a function of candle packaging as well as composition. A hotter burning unit, eg, one in which steel wool is the binder, generates more impurities. 

Table 2. Performance of Chemical Desiccants in Drying Air at Room Temperature...

Often, in drying inorganic salts, the final material that is required is a hydrate. In such cases, the purified substance is left in a desiccator to equilibrate above an aqueous solution having a suitable water-vapour pressure. A convenient range of solutions used in this way is given in Table 17. 

This instrument was laid in a vacuum desiccator with the fiber vertical. A flashlight bulb was set up outside the desiccator, and the position of the spot of light reflected by the meter mirror was observed on a piece of tissue paper pasted to the desiccator wall. The experimental results given in Table I were obtained. 

Loading was accomplished by exposing the activated zeolites to benzene-de vapors. The extent of vapor adsorption was determined by the increase in weight of the zeolite. The samples were found to be extremely hydroscopic and thus kept in a vacuum desiccator until their use. After two or three temperature runs the samples began to adsorb water vapor. Therefore, only the data obtained for the first two variable temperature cycles are presented here. The samples studied are listed in Table I. 

Diquat and paraquat are quaternary ammonium compounds largely used as contact herbicides and crop desiccants. When systemic absorption occurs, paraquat and diquat are rapidly distributed into the body. Paraquat primarily accumulates in the lungs and kidneys, while the highest diquat concentrations have been found in the gastrointestinal tract, liver, and kidneys (WHO, 1984). Urine is the principal route of excretion for both diquat and paraquat, which are primarily eliminated as unmodified compounds. Occupationally exposed workers can be monitored by measuring paraquat and diquat concentrations in urine samples (Table 6). Blood concentrations are useful to monitor acute poisoning cases. 

After the six-month field test, the Prototype Unit was disassembled and the component parts were individually swabbed with sterilized cotton wools (4 cm2). Each samples were stored in 1 ml sterilized distilled water and 50 pi of samples were transferred to TSA and MEA plates. The TSA plates were incubated at 37 °C for 24 h and bacterial colonies were counted. The number of fungal colonies was determined from the MEA plates after incubating at 30 °C for 5 days. The results of the test are shown in Table 12.9-7. The results show that bacteria and fungi thrived near the air intake where they deposited on the grills, panel and around the intake slots. However once the microorganisms are drawn through the catalyst-coated desiccant wheel, the number of viable... 

Thus, transition metal cations in the lower valence state may also act as Lewis bases. Factors that affect the reactions promoted by Lewis acidity are listed in Table I. Lewis acid sites reversibly adsorb water (6s 9, 42), which may thus strongly compete with organic compounds that have weaker Lewis base properties, such as aromatic hydrocarbons. Lewis acidity depends on the degree of hydration and is strongest under desiccating conditions. Examples of reactions that are promoted by Lewis acidity are summarized in Table II. Other examples have been reviewed by Solomon and Howthorne (37). 

When optically active allylic alcohol 6a and propargylic alcohol 6p were reacted with amides 2c and 2f, only racemic products 7ac, 7af, and 7pf were obtained (Scheme 2). The results suggested a mechanism through the formation of a carbe-nium intermediate. The observed racemization can also be ascribed to the reversibility of the present reaction. The result shown in Scheme 3 indicated that the reaction is reversible under the reaction conditions. When 7af was treated with 5 mol% of Bi(OTf)3 and KPF6 and 1 equiv of carbamate 2c, a mixture of 7af (28%) and 7ac (68%) was recovered after 1 h. The result suggested that Bi(OTf)3/KPF6 cleaved the C-N bond in 7af derived from sulfonamide 2f, and that 7ac is thermodynamically more stable than 7af. We assume that the desiccant (Drierite) had a beneficial effect on the reactions of substrates shown in Tables 10-12 because of the observed reversibility of the present reaction. In this reaction, the possibility... 

Catalyst batch B was separated into three parts B w ox was activated and tested immediately after preparation, Biowox+imo was activated immediately after preparation but activity tests were performed one month later, and Bimo+bw-ox was activated and tested one month after preparation. During the waiting period, catalysts were stored in foil wrapped containers under air in a desiccator. The data for catalysts Aiowox and Biowox in Figure 3 and Table 1 show that both the CO oxidation rates and Eapp values were highly reproducible between batches, provided that the catalysts are activated and tested soon after preparation. Catalyst Blow ox+imo was a factor of two less active than the freshly prepared and activated Biow-ox catalyst Bimo+iow ox showed similar decreases in activity. 

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