Toluene volume

When the experiments were performed at the same pressure, temperature, and moisture content but with toluene as modifier and with a static extraction time of 15 or 30 min prior to the dynamic extraction step, then recovery was most affected by moisture content (sum of ranks 88) followed by pressure (sum of ranks 70) and the toluene volume (sum of ranks 68). The fourth variable to influence was the static extraction time (sum of ranks 57). Temperature, volume of collection solvent, and the presence/absence of glass beads were the least important. Figure 6 shows the relative changes in recovery for each compound and for each of the seven variables investigated in Test 2. 

Figure 4.22 Dependence of benzene yields on molar ratio H202 toluene T = 680 °C molar ratio C6H5CH3 112 = 1 4.85 liquid toluene volume rate equals 0.02 h 1 (1 autohydrogenolysis of toluene (without H2) in the presence of H202 2, 3 3 -conjugated hydrogenolysis of toluene per injected and converted toluene, respectively).

Rat feces (CDDs) Grinding of sample with Na2S04 addition 13C12-labeled CDD/CDF mixture Soxhlet extraction with toluene volume reduction clean-up on alumina column, elution with hexane volume reduction clean-up on silica gel, elution with hexane volume reduction clean-up on alumina B Super , elution with hexane solvent evaporation redissolution in benzene HRGC/LRMS (EI/MIM) No data 75-95 (TCDD) >60 (CDD) Abraham et al. 1989a... 

Rat liver and adipose tissue rat fetuses (CDDs) Grinding of sample with Na2S04 addition of [13C]2,3,7,8-TCDD and OCDD Soxhlet extraction with toluene volume reduction addition of hexane clean-up with column chromatography HRGC/LRMS (SIM) No data No data Van den Berg etal. 1987b... 

Air (CDDs) Collection of sample onto glass fiber filter/polyurethane foam cartridge addition of internal standard Soxhlet extraction with toluene volume reduction clean-up and fractionation on Florisil , elutiion with toluene/diethylether, evaporation and redissollution in cyclohexane clean-up on modified silica gel using HPLC and hexane/diethyl ether volume reduction HRGC/LRMS (EI/SIM) HRGC/LRMS (NCI/SIM) 0.1-1 pg/m3 0.2-3 pg/inj (0.01-0.1 pg/m3) 80-122 86-102 Oehme et al. 1986... 

Table 17.7 shows that the yield of PO, the selectivity to PO, and the recovered yield of the catalyst all increase with increase in the TBP/toluene volume ratio reaching a maximum at a ratio of 3 4 and then decrease. It is considered that the water phase is imfavorable for the epoxidation reaction due to the hydrolysis of PO to propylene glycol. When the volume ratio of TBP/toluene reaches 3 4, the polarity of TBP makes the aqueous/oil biphasic mixture a monophasic system, and no aqueous phase dissociates from the oil phase. Thus, the epoxidation reaction is little affected by the water in the added 52% H2O2. 

TBP/toluene (volume ratio) Yield (%) Conversion s (%) Selectivity (%) Recovery yield (wt.%)... 

An estimation of the internal pressure of RT untreated containers after eight hours of toluene exposure can be made based on the toluene volumes lost due to permeation and sorption. The result is a vacuum of 7.7 trnn Hg, where the 1.4 g. of solvent sorbed into the HDPE walls is the dominant factor. This indicates that during the early period of solvent exposure simple sorption of the solvent into the polymer can generate conditions leading to paneling in untreated HDPE containers. 

The ultimate tenacity (Gb) of the fibers prepared shows a pronounced maximum of 2.1 GPa at a toluene volume fraction (0) of 0.6. The drawability and tenacity decrease on either side of the binary solvent composition. 

The phase inversion in such systems can be predicted based on the hold up of dispersed phase and the changes in system properties [13], The authors [12] estimated the phase inversion point, Sauter mean diameter of the droplets in the dispersed phase and mass transfer coefficients for the toluene-HNOj mixtures at various concentrations to characterize the toluene-HNOj dispersion. Their subsequent studies [14] have established the improved catalyst stability in the HNO3 dispersed in toluene medium as compared to toluene dispersed in HNO3 medium. Batch nitration experiments were made under reflux conditions covering a wide range of toluene volume fractions (0.1 to 0.95) to generate the conversion and para selectivity profiles for this volume fraction range (Fig. 2.3). 

Without going into details of the chromatographic method, a SAR separation (asphaltenes having been eliminated) can be performed in a mixed column of silica followed by alumina. The saturated hydrocarbons are eluted by heptane, the aromatics by a 2 1 volume mixture of heptane and toluene, and the resins by a 1 1 1 mixture of dichloromethane, toluene and methanol. 

The water and sediment contents of crude oils is measured according to the standard methods NF M 07-020, ASTM D 96 and D 1796, which determine the volume of water and sediments separated from the crude by centrifuging in the presence of a solvent (toluene) and of a demulsifylng agent Table 8.13 gives the bottom sediment and water content of a few crude oils. 

Experiment 6. Fractional Distillation of a Mixture of Benzene and Toluene. Fractionally distil about 40 ml. of a mixture of equal volumes of benzene and toluene, using the type of fractionating column shown in Fig. ii(b), in which about 18-20 cm. of the column are actually filled with glass sections, but in which the cotton-wool lagging is not used. Distil very slowlyy so that the total distillation occupies about hours. Shield the apparatus very carefully from draughts. Collect the fractions having the b.ps (a) 80-85°, ( ) 85-107°, (c) 107-111°. A sharp separation should be obtained, e.g.y these fractions should have volumes of about 19, 2, and 17 ml. respectively. 

Dichloramine-T. Dilute 80 ml, of freshly prepared 2N sodium hypochlorite soluticMi (preparation, p. 525) with 80 ml. of w ter, and then add with stirring 5 g. of finely powdered toluene-p-sulphonamide, a clear solution being rapidly obtained. Cool in ice-water, and then add about 50 ml. of a mixture of equal volumes of glacial acetic acid and water slowly with stirring until precipitation is complete the dichloro-amide separates at first as a fine emulsion, which rapidly forms brittle colourless crystals. Filter off the latter at the pump, wash well with... 

Prepare a solution of casein as follows. Weigh out 15 g. of casein into a dry 500 ml. conical flask and add about 150 ml. of water. Dissolve 1 5 g. of anhydrous sodium carbonate and i 5 g, of borax in about 20 ml. of hot water and add this solution to the casein. Warm until a solution is obtained, filter if necessary, and make up to a total volume of about 250 ml. with water. Add a few drops of toluene (to prevent putrefaction) and shake the solution. 

It is convenient to divide the petrochemical industry into two general sectors (/) olefins and (2) aromatics and their respective derivatives. Olefins ate straight- or branched-chain unsaturated hydrocarbons, the most important being ethylene (qv), [74-85-1] propjiene (qv) [115-07-17, and butadiene (qv) [106-99-0J. Aromatics are cycHc unsaturated hydrocarbons, the most important being benzene (qv) [71-43-2] toluene (qv) [108-88-3] p- s.y en.e [106-42-3] and (9-xylene [95-47-5] (see Xylenes and ethylbenzene) There are two other large-volume petrochemicals that do not fall easily into either of these two categories ammonia (qv) [7664-41-7] and methanol (qv) [67-56-1]. These two products ate derived primarily from methane [74-82-8] (natural gas) (see Hydrocarbons, c -c ). 

Cyclic Hydrocarbons. The cyclic hydrocarbon intermediates are derived principally from petroleum and natural gas, though small amounts are derived from coal. Most cycHc intermediates are used in the manufacture of more advanced synthetic organic chemicals and finished products such as dyes, medicinal chemicals, elastomers, pesticides, and plastics and resins. Table 6 details the production and sales of cycHc intermediates in 1991. Benzene (qv) is the largest volume aromatic compound used in the chemical industry. It is extracted from catalytic reformates in refineries, and is produced by the dealkylation of toluene (qv) (see also BTX Processing). 

Yield for the process at low catalyst loading is 95%. AJ-Methyl-toluenediamiae, one of the reaction by-products, represents not only a reduction ia yield, but also a highly objectionable impurity ia the manufacture of toluene diisocyanate. Low concentrations of CO (0.3—6% volume) control this side reaction. 

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