Liquefied compressed gases with vaporizer

Arsine is shipped as a liquefied compressed gas in steel cylinders under its own vapor pressure of 219.7 psia (1515 kPa, abs). Arsine is slightly soluble in both water and organic solvents. It reacts readily with agents such as potassium permanganate, bromine, and sodium hypochlorite to form arsenic compounds. Arsine is stable at room temperature, but begins to decompose into its elements around 446 F to 464°F (230T to 240°C). 

It is economic to cool the compressed methane for liquefaction by the gas that does not liquefy in the throttling process. In the Claude process, the gas at an intermediate temperature splits into two parts. One of them enters the expander and exhausts as a saturated or slightly superheated vapor, and produces work. The remaining gas is further cooled in the second heat exchanger and throttled to liquefy. The portion that is not liquefied is combined with the output vapor of the expander and recycled into the compressor. 

Example 1 LNG Vaporization and Compression A port facility for unloading liquefied natural gas (LNG) is under consideration. The LNG arrives by ship, stored as saturated liquid at 115 K and 1.325 bar, and is unloaded at the rate of 450 kg s h It is proposed to vaporize the LNG with heat discarded from a heat engine operating between 300 K, the temperature of atmospheric air, and 115 K, the temperature of the vaporizing LNG. The saturated-vapor LNG so produced is compressed adiabatically to 20 bar, using the work produced by the heat engine to supply part of the compression work. Estimate the work to be supplied from an external source. 

Sublimation temperature, °C -64 Melting point, 0 -61 Relative density (water - 1) 1.5 Relativevapordenslty (air -1 5.1 Vapor pressure, mm Hg at 20 C 16,960 Solubility in water none Relative molecular mass 146.1 Gross formula F S COLORLESS COMPRESSED LIQUEFIED QAS Gas is heavier than air and can accumulate close to ground level, causing oxygen deficiency, with risk of unconsciousness. Decomposes when heated above 5CX) C, giving off toxic gases (fluorine and sulfur compounds). In tha presence of moisture above 200°C hydrolysis can take place. ... 

Unless provided with a back-flow prevention system, compressed gas containers must not be connected to process piping where the container may be contaminated by the backflow of other process materials. Certain noncryogenic liquefied gases may be especially susceptible to this type of contamination due to their relatively low vapor pressures at ambient temperatures. In cases where such a possibility may exist, design consideration must include the use of check valves or traps, or both for this purpose. 

Gaseous argon must be handled with all the precautions necessary for safety as with any nonflammable, nontoxic compressed gas. All precautions necessary for the safe handling of any gas liquefied at very low temperatures must be observed with liquid argon. Extensive tissue damage or bums can result from exposure to liquid argon or cold argon vapors. 

Chlorine is a greenish-yellow, nonflammable gas with a distinctive, pungent odor. It is almost 2.5 times as heavy as air. The gas acts as a severe irritant if inhaled. Chlorine liquid has the color of clear amber and is about 1.5 times as heavy as water. It is shipped as a compressed liquefied gas having a vapor pressure of 86.767 psig at 70°F (598.24 kPa at 21.1°C). Chlorine is nonflammable in both gaseous and liquid states. However, like oxygen, it is capable of supporting the... 

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