By contrast, in the system propionic acid d) - methyl isobutyl ketone (2), (fi and are very much different when y 1, Propionic acid has a strong tendency to dimerize with itself and only a weak tendency to dimerize with ketone also,the ketone has only a weak tendency to dimerize with itself. At acid-rich compositions, therefore, many acid molecules have dimerized but most ketone molecules are monomers. Acid-acid dimerization lowers the fugacity of acid and thus is well below unity. Because of acid-acid dimerization, the true mole fraction of ketone is signi-  [c.35]

Because the precision assigned to the upper and lower extrapolated points is relatively poor, it is possible to obtain a maximum or minimum in the curve, even when fitting all real and extrapolated data from 200 to 600°C. Extrema can occur anywhere, but generally they occur very close to either the lower or the upper end. A check of the sign of the slope at 200°C and 600°C easily indicated the presence of an extremum. When an extremum occurred, a new fit was established to avoid it.  [c.142]


In the first class, azeotropic distillation, the extraneous mass-separating agent is relatively volatile and is known as an entrainer. This entrainer forms either a low-boiling binary azeotrope with one of the keys or, more often, a ternary azeotrope containing both keys. The latter kind of operation is feasible only if condensation of the overhead vapor results in two liquid phases, one of which contains the bulk of one of the key components and the other contains the bulk of the entrainer. A t3q)ical scheme is shown in Fig. 3.10. The mixture (A -I- B) is fed to the column, and relatively pure A is taken from the column bottoms. A ternary azeotrope distilled overhead is condensed and separated into two liquid layers in the decanter. One layer contains a mixture of A -I- entrainer which is returned as reflux. The other layer contains relatively pure B. If the B layer contains a significant amount of entrainer, then this layer may need to be fed to an additional column to separate and recycle the entrainer and produce pure B.  [c.81]

Now let us take a closer look at the two most commonly used heat engines (steam and gas turbines) to see whether they achieve this efficiency in practice. To make a quantitative assessment of any combined heat and power scheme, the grand composite curve should be used and the heat engine exhaust treated like any other utility.  [c.194]

Now scan a range of values of Ar ,in and calculate the targets for energy, number of units, and network area and combine these into a total cost. The results are given in Table 7.4.  [c.235]

For a chemical to affect health, a substance must come into contact with an exposed body surface. The three ways in which this happens are by inhalation, skin contact, and ingestion, the latter being rare.  [c.259]

Various heat pumping schemes have been proposed as methods for saving energy in distillation. Of these schemes, use of the column overhead vapor as the heat pumping fluid is usually the most economically attractive. This is the vapor recompression scheme shown in outline in Fig. 14.6.  [c.346]

Carnot s cycle A hypothetical scheme for an ideal heat machine. Shows that the maximum efficiency for the conversion of heat into work depends only on the two temperatures between which the heat engine works, and not at all on the nature of the substance employed.  [c.84]

The dihydrochloride is a white crystalline powder, m.p. about 225 C (decomp.). Used as an antiseptic and skin sterilizing agent, and as a bacteriostat in some pharmaceutical formulations.  [c.92]

COMMON /ALL/ NN LLt KK, IPRTt 1ST COMMON /STAT/ C0V(5 5), RH0<5,5), SIGMA(5> COMMON /DATA/ X<50t >t XM(50,5>t EVX(50f5)  [c.238]


Figure 14.6 Heat pumping in distillation. A vapor re-compreasion scheme. (From Smith and Linnhoff, Trans. IChemE, ChERD, 66 195, 1988 reproduced by permission of the Institution of Chemical Engineers.) Figure 14.6 Heat pumping in distillation. A vapor re-compreasion scheme. (From Smith and Linnhoff, Trans. IChemE, ChERD, 66 195, 1988 reproduced by permission of the Institution of Chemical Engineers.)
CH2Br COOH. White crystalline solid, m.p. 50"C, b.p. 208 C. Soluble in water and alcohol. Prepared by the action of dry bromine on dry ethanoic acid in presence of small amounts of red phosphorus. Produces sores upon the skin used in chemical syntheses. See Reformatski reaction.  [c.68]

Crystalline solid m.p. 35-36 "C, b.p. 154--156 C, prepared by oxidizing A,A -dicycIo-hexylthiourea with HgO in carbon disulphide solution, also obtained from cyclohexylamine and phosgene at elevated temperatures. Used as a mild dehydrating agent, especially in the synthesis of p>eptides from amino-acids. Potent skin irritant.  [c.135]

Nacconate 100 A lachrymatory liquid b.p. 25l°C. Manufactured from phosgene and 2,4-diaminotoJuene. Used for preparing polyurethane foams and other elastomers by reaction with polyhydroxy compounds. Produces skin irritation and causes allergic eczema and bronchial asthma.  [c.139]

See pages that mention the term SACM : [c.67]    [c.149]    [c.236]    [c.238]    [c.238]    [c.238]    [c.241]    [c.246]    [c.246]    [c.246]    [c.246]    [c.246]    [c.246]    [c.263]    [c.280]    [c.286]    [c.8]    [c.198]    [c.198]    [c.207]    [c.346]    [c.348]    [c.404]    [c.50]    [c.53]    [c.64]    [c.75]    [c.106]    [c.128]    [c.129]    [c.134]    [c.137]    [c.139]    [c.141]    [c.141]   
Computational chemistry (2001) -- [ c.168 , c.368 ]