Vapor pressure ethylene

Fig. 1. Vapor pressures of glycols at various temperatures. A, ethylene glycol B, diethylene glycol C, triethylene glycol and D, tetraethylene glycol.

Liquid Sorption. If a moist gas is passed through sprays of a liquid sorbent, such as lithium chloride or an ethylene glycol solution, moisture is removed from the air at a rate depending on the vapor pressure difference. This is a function of the absorbent concentration and is maintained at the required level by a regeneration cycle. The regeneration process is continuous and is achieved by allowing a percentage of the chemical into the exhaust-heated air. 

Figure 11-26. Vapor pressure curve for ethylene refrigerant. (Used by permission Starling, K. E. Fluid Thermodynamic Properties for Light Petroleum Systems, 1973. Gulf Publishing Co., Houston, Texas. All rights reserved.)...

Calculate the vapor pressure of water over each of the following ethylene glycol (C2H602) solutions at 22°C (vp pure water = 19.83 mm Hg). Ethylene glycol can be assumed to be nonvolatile. 

C12-0064. Ethylene glycol, an automobile coolant, has the chemical formula HOCH2 CH2 OH. Calculate the vapor pressure of water above a coolant solution containing 65.0 g of ethylene glycol dissolved in 0.500 L of water (density = 1.00 g/mL), at 100 °C, the boiling point of pure water. 

Ethylene glycol is not as active in depression of the freezing point as methanol, but it has a very low vapor pressure evaporation loss in a coolant system is due more to the evaporation of water than to the evaporazation of ethylene glycol. Furthermore, the flammability problem is literally eliminated. 1 1 mixtures of ethylene glycol and water do not exhibit a flash point at all. 

Vapor Cloud Explosions. Lenoir and Davenport (Ref. 16) have summarized some major VCEs worldwide from 1921 to 1991. The materials involved in these incidents suggest that certain hydrocarbons—such as ethane, ethylene, propane, and butane—demonstrate greater potential for VCEs. Several factors may contribute to these statistics. These materials are prevalent in industry and are often handled in large quantities, increasing the potential for an incident. Certain inherent properties of the materials also contribute to their potential for explosion. These include flammability, reactivity, vapor pressure, and vapor density (with respect to air). 

Coupling Medium. Distilled water has proven to be more effective than tap water as the conducting liquid as evidenced by greater cavitation in the reaction flasks (and faster reaction rates). Moreover, distilled water leads to significantly less corrosion of the bath walls. Other low vapor pressure liquids such as ethylene glycol can be used. 

SI water= ethylene glycol water where APwater = vapor pressure lowering of water, H20... 

Adsorption of ethylene at 90 K on oxide coated thermionic emission cathodes was measured (Wooten Brown, JACS 65 113, 1943). The volume adsorbed is in V ml measured at 1 Torr and 25 C. The vapor pressure is Ps = 30.6(10-3) Torr. 

Fig. 5.6 Vapor pressure differences between equivalent isotopic isomers of dideuteroethylene. The three mercury levels shown (left to right) measure the vapor pressures of ordinary ethylene C2D4, /ram-ethylene-1,2dj, and ei.v-cthylene- l dj. The vapor pressure of gem-ethylene-1,ld2 is very similar to the cis-isotopomer and is not shown in this photograph (Bigeleisen, J., Science 147, 463 (1965))...

The amount of ethylene is limited because it is necessary to restrict the amount of unsaturated components so as to avoid the formation of deposits caused by the polymerization of the olefin(s). In addition, ethylene [boiling point —104°C (—155°F)] is more volatile than ethane [boiling point —88°C (—127°F)], and therefore a product with a substantial proportion of ethylene will have a higher vapor pressure and volatility than one that is predominantly ethane. Butadiene is also undesirable because it may also produce polymeric products that form deposits and cause blockage of lines. 

Aromatic fuel The prior results were obtained using propane (not very sooty) and ethylene (considerably more sooty) as fuels. The results were extended to a very sooty aromatic fuel by choosing benzene, as it had a sufficient vapor pressure to be entrained into the fuel flow. 

Therefore, the maximum storage pressure (2760 to 32,060 kPag, or 400 to 3200 psig) usually exceeds the vapor pressure of all commonly stored hydrocarbon liquids. Higher-vapor-pressure products such as ethylene or ethane cannot be stored in relatively shallow caverns. 

Ethylene Cyanohydrin or /3-Hydroxypropio-nitrile, HO.CH8.CH2.CN mw 71.08, N 19.71% poisonous straw-colored Uq, sp gr 1.0404 at 25°/4, fr p -46°, bp 227-28°(dec), vapor pressure 20mm at 117 miscible with w, acet, ethanol, chlf, methyl-ethyl ketone si sol in eth insol in benz, CC14 naphtha. It can be prepd by interaction of ethylene oxide with... 

The use of thermal and catalytic cracking processes for the production of high-octane motor gasolines is accompanied by the production of quantities of light hydrocarbons such as ethylene, propylene, butene, and isobutane. These materials are satisfactory gasoline components octane-wise, but their vapor pressures are so high that only a portion of butanes can actually be blended into gasoline. Alkylation is one of several processes available for the utilization of these excess hydrocarbons. 

Blockages of valves and pipes can also occur by gas hydrates. Such adducts can be formed by a number of gases with water. In Fig. 7.1-5 the pressure-temperature diagram of the system propane/water with an excess of propane is presented. The line, (g), shows the vapour-pressure curve of propane. Propane hydrate can be formed at temperatures below 5.3°C. At pressures below the vapor pressure of propane a phase of propane hydrate exists in equilibrium with propane gas (Fig. 7.1-5, area b). At higher pressures above the vapor pressure of propane and low temperatures a propane hydrate- and a liquid propane phase were found (area d). In order to exclude formation of gas hydrates these areas should be avoided handling wet propane and other compounds like ethylene, carbon dioxide [14], etc. 

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