Vaporization, work

Figure 3.14 shows a typical batch distillation column Fresh feed is charged into the still pot and heated until it begins to boil. The vapor works its way up the column and is condensed in the condenser. The condensate liquid runs into... 

The C4 stream is fed to the middle of a fractionator, and a high boiling point solvent is fed at the top. The solvent, as it works its way down, strips out the butadiene as the C4 vapor works its way up the column. The solvent and butadiene come out the bottom and can easily be split in a second column. Two popular high boiling point solvents are N-methylpyrrolidone (NMP) and Dimethylformamide (DMF). The chapter on benzene has more details on the extractive distillation process. 

There are six vapor working fluids listed on the menu of CyclePad. The fluids are ammonia, methane, refrigerants 12, 22, and 134a, and water. Water has the characteristics of items 4, 5, 7, and 8 above and it remains a top choice for industrial central vapor power plants. Hence, steam power engineering remains the most important area of applied thermodynamics. 

Avoid breathing cyclohexane, hexane, adipoyl chloride, or sebacoyl chloride vapors. Work carefully to avoid skin contact with any of the liquid reagents wear chemically resistant rubber gloves. Do not ingest reagents. Avoid eye contact wear chemical safety goggles. Cyclohexane, hexane, acetone, and alcohol are flammable keep away from heat and open flames. Follow precautions on the containers. The nylon rope should not be handled with bare hands until after it has been washed thoroughly with alcohol and dried. 

Carbon and sulfur are reacted (Reaction 4.1) in the absence of air in oval or cylindrical vessels called retorts. The vessels are approximately 3 ft in diameter and 10 ft in height [117] and are constructed from chrome alloy steel or cast iron. Usually, 1-4 retorts are installed in a furnace [118]. The furnace is heated by coal, gas or oil. Coal is intermittently added from the top of the retort while vaporized sulfur is continuously fed in from the bottom. Carbon disulfide is formed while the sulfur vapor works its way through the hot coal (800—1000 C) to the top of the retort. The reacted gases exit the top of the retort through a duct. Nonreactive ash and coal dust are periodically removed as they make their way to the bottom while fresh coal is added. Deposits are also removed from the inside walls of the retort, usually on a monthly or bimonthly basis. Because of the corrosive sulfur vapor, the retorts must be replaced every 1—2 years. 

Condensate - The liquid resulting when water vapor contacts a cool surface also the liquid resulting when a vaporized working fluid (such as a refrigerant) is cooled or depressurized. 

Most calorimeters that measure a latent heat of vaporization work under isobaric conditions. The measurement of a latent heat of v orization requires monitoring heat input into calorimeter and the amount of liquid evaporated during measurement time. " ... 

We have shown that TPS, RETPS, and ESR scattering are important mechanisms in the production of stimulated radiation in Na vapor. Work is in progress to calculate and measure accurately the angular dependence of the emission and to compute the laser-induced light shifts of a three-level system in which both excited states are strongly coupled to the laser field. 

Equation (10b) is used in this work whenever the vapor mixture does not contain one or more carboxylic acids. 

The heat capacity of an ideal vapor is a monotonic function of temperature in this work it is expressed by the empirical relation... 

The problem with this approach is obvious. It involves a considerable amount of work to generate a measure of the quality of the sequence, the total vapor load, which is only a guideline. There are many other factors to be considered. Indeed, as we shall see later, when variables such as reactor conversion are optimized, the sequence might well need readdressing. 

At first we tried to explain the phenomenon on the base of the existence of the difference between the saturated vapor pressures above two menisci in dead-end capillary [12]. It results in the evaporation of a liquid from the meniscus of smaller curvature ( classical capillary imbibition) and the condensation of its vapor upon the meniscus of larger curvature originally existed due to capillary condensation. We worked out the mathematical description of both gas-vapor diffusion and evaporation-condensation processes in cone s channel. Solving the system of differential equations for evaporation-condensation processes, we ve derived the formula for the dependence of top s (or inner) liquid column growth on time. But the calculated curves for the kinetics of inner column s length are 1-2 orders of magnitude smaller than the experimental ones [12]. 

Equation XVII-70 bears a strong resemblance to the Langmuir equation (see Ref. 4)—to the point that it is doubtful whether the two could always be distinguished experimentally. An equivalent form obtained by Volmer [53] worked well for data on the adsorption of various organic vapors on mercury [54] (see Problem XVII-40). 

The metal is widely used in laboratory work for making thermometers, barometers, diffusion pumps, and many other instruments. It is used in making mercury-vapor lamps and advertising... 

In professional laboratories fume hoods are big metal boxes resting on counter tops and are connected by ducts to blower motors on the roof of the facility. The blower motor is constantly sucking the air from the hoods to the outside so that chemists will not be exposed to the vapors of chemicals they are working with inside the hood. The same precautions are taken by non-dead underground chemists. 

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