Potassium hydroxide solutions vapor pressure

Katan, T. Campa, A.B. "Vapor Pressure of Ammonia in Aqueous Potassium Hydroxide Solutions," J. Chem. Eng. Data, 1963,... 

Caustic Potash Solution — (I) Chemical Designations — Synonyms Potassium Hydroxide Solution Lye Otemical Formula KOH—H O (ii) Observable Characteristics — Physical State (as normally shipped) Liquid Cobr Colorless Odor None (iii) Physical and Chemical Properties — Physical State at 15 X and 1 atm. Liquid Molecular Weight Not pertinent Boiling Point at 1 atm. >266, > 130, >403 Freezing Point Not pertinent Critical Temperature Not pertinent Critical Pressure Not pertinent Specific Gravity 1.45 - 1.50 at 20° C (liquid) Vapor (Gas) Density Not pertinent Ratio of Specific Heats of Vapor (Gas) Not pertinent Latent Heat... 

Grayish-white metal hody-centered cubic crystalline structure density 19.3 g/cm3 melts at 3,422°C vaporizes at 5,555°C vapor pressure 1 torr at 3,990°C electrical resistivity 5.5 microhm-cm at 20°C modulus of elasticity about 50 to 57 x lO psi (single crystal) Poisson s ratio 0.17 magnetic sus-ceptibilty +59 x 10-6 thermal neutron absorption cross section 19.2 + 1.0 barns (2,200m/sec) velocity of sound, about 13,000 ft/sec insoluble in water practically insoluble in most acids and alkabes dissolves slowly in hot concentrated nitric acid dissolves in saturated aqueous solution of sodium chlorate and basic solution of potassium ferricyanide also solubibzed by fusion with sodium hydroxide or sodium carbonate in the presence of potassium nitrate followed by treatment with water... 

All areas containing fluorine under pressure should be inspected for leaks at suitable intervals, and any leaks discovered should be repaired at once after fluorine has been removed from the system. Ammonia vapor expelled from a squeeze bottle of ammonium hydroxide at suspected points of leakage may be used to detect leaks. Filter paper impregnated with potassium iodide solution... 

A schematic flow diagram of the unit is shown in Figure 3-33. A solution of 48 wt% potassium hydroxide is added to the contaminated diethanolamine before it enters the top of a packed tower where it is contacted with superheated steam rising from the reboiler. Essentially all of the amine and water is vaporized, and the product is withdrawn at a point below the packed section into a condenser, which is held at a slightly lower pressure than that prevailing in the reboiler. A steam jet is used to maintain the required pressure. The salts drop into the reboiler and melt at 420 to 440°F, and any residual diethanolamine is flashed off. The temperature of the diethanolamine-water vapor withdrawn is 300 to 375°F. The temperatures in the column and reboiler are sufficient to vaporize practically all the amine without decomposition. Heat is supplied by circulating oil at 600°F through the reboiler tubes. Recovery of 90% of reusable diethanolamine is claimed. 

The AFC and PAFC are both liquid electrolyte solutions. The AFC, however, is based on an alkaline electrol3de solution of potassium hydroxide (KOH) in water. Other alkaline solutions can be used, notably sodium hydroxide (NaOH), but KOH is an inexpensive, easily handled solution that is used in other areas such as agriculture, so a distribution network already exists. The KOH solution molarity is typically between 30 and 80%, depending on the operating temperature. A higher molarity reduces the vapor pressure of the solution, and thus high-temperature systems require a high electrolyte concentration. 

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