Pressure boiling temperature

The constant vapor pressure (boiling temperature) above the two-phase region of certain partially miscible mixtures is usually larger (smaller) than the vapor pressure (boiling temperature) at any other liquid-phase composition in the homogeneous region. In this case, the vapor-phase composition is inside the miscibility gap. Mixtures of this type are called heteroazeotropic mixtures, or simply heteroazeotropes. (Fig. 1, Type II), as opposed to the other types of azeotropes, called homoazeotropes. 

Figure 14.15 Contamination trencis as a function of EUV intensity, hydrocarbon partial pressure, boiling temperature, and molecular weight. ...

Annual Tables of Constants and Numerical Data, 3, Free Energy, Heat Content, Entropy and Activity (J. Gueron and J. P. Mathieu) , Hermann et Cie., Paris, 1937. Annual Tables of Constants and Numerical Data, 6, Vapour Pressure, Boiling Temperatures (W. P. Jorissen and P. C. van Keekem) Gas Laws (W. H. Keesom, J. J. M. Van Santen, and J. Haantjes) , Hermann et Cie., Paris, 1937. 

Example 9.1 A process involves the use of benzene as a liquid under pressure. The temperature can be varied over a range. Compare the fire and explosion hazards of operating with a liquid process inventory of 1000 kmol at 100 and 150°C based on the theoretical combustion energy resulting from catastrophic failure of the equipment. The normal boiling point of benzene is 80°C, the latent heat of vaporization is 31,000 kJ kmol the specific heat capacity is 150 kJkmoh °C , and the heat of combustion is 3.2 x 10 kJkmok. ... 

The results are presented as a distillation curve showing the boiling temperature (corrected to atmospheric pressure) as a function of the distilled volume. 

This is the average boiling temperature at atmospheric pressure (1.013 bar abs). This characteristic is obtained by direct laboratory measurement and is expressed in K or °C. 

Both boron and aluminium chlorides can be prepared by the direct combination of the elements. Boron trichloride can also be prepared by passing chlorine gas over a strongly heated mixture of boron trioxide and carbon. Like boron trifluoride, this is a covalent compound and a gas at ordinary temperature and pressure (boiling point 285 K). It reacts vigorously with water, the mechanism probably involving initial co-ordination of a water molecule (p, 152). and hydrochloric acid is obtained ... 

Commercial grades of sodium aluminate are obtained by digestion of aluminum tnhydroxide in aqueous caustic at atmospheric pressure and near the boiling temperature (7). Digestion of the aluminum hydroxy oxide in aqueous sodium hycboxide [1310-73-2] requbes pressures of up to 1.38 MPa (13.6 atm) and temperatures of about 200°C. Dry sodium aluminate is obtained by evaporation of water. Several processes for the production of sodium aluminate are known that do not reqube the addition of water. In one process, bauxite reacts with molten sodium hycboxide at approximately 400°C (8) in... 

Ethylene oxide is produced in large, multitubular reactors cooled by pressurized boiling Hquids, eg, kerosene and water. Up to 100 metric tons of catalyst may be used in a plant. Typical feed stream contains about 30% ethylene, 7—9% oxygen, 5—7% carbon dioxide the balance is diluent plus 2—5 ppmw of a halogenated moderator. Typical reactor temperatures are in the range 230—300°C. Most producers use newer versions of the Shell cesium-promoted silver on alumina catalyst developed in the mid-1970s. 

The typical phase equiHbrium problem eacouatered ia distiHatioa is to calculate the boiling temperature and the vapor composition ia equiHbrium with a Hquid phase of specified composition at a givea pressure. If the Hquid phase separates, thea the problem is to calculate the boiling temperature and the compositions of the two equiHbrium Hquid phases plus the coexistiag vapor phase at the specified overall Hquid compositioa. Robust and practical numerical methods have been devised for solving this problem (95—97) and have become the recommended techniques (98,99). 

Colorfastness to decatiziag, ISO 10S-E10, iavolves a specimen wrapped around a perforated cylinder and through which steam is passed for 15 min at different pressures or temperatures to represent mild or severe conditions. In colorfastness to steaming, ISO 105-E1 /, a specimen and adjacents are roUed iato a cylinder and placed ia the neck of a flask of boiling water for 30 min. 

Normal Boiling Temperature The normal boiling temperature (point) is the temperature at which the vapor pressure equals exac tly 101,325 Pa (1 atmosphere). Caution shomd be taken in using values from older references, where the temperature may be reported for the prevaihng pressure (0.95-0.97 atm) rather than at 1 atmosphere. If at least two values of vapor pressure very close to 1 atmosphere are available, the normal boihng point can be interpolated or extrapolated on a plot of logP vs. l/T. Tme section on vapor pressure discusses this in more detail. 

Thr = reduced normal boiling temperature = Th/T,-Ty = normal boiling temperature, K Vr = critical pressure, kPa... 

Refrigeration, like dilution, reduces the vapor pressure of the material being stored, reducing the driving force (pressure differential) for a leak to the outside environment. If possible, the hazardous material should be cooled to or below its atmospheric pressure boiling point. At this temperature, the rate of flow of a liquid leak will depend only on liquid head or pressure, with no contribution from vapor pressure. The flow through any hole in the vapor space will be small and will be limited to breathing and diffusion. 

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