Chlorinated ethylenes

Gaseous vent streams from the different unit operations may contain traces (or more) of HCl, CO, methane, ethylene, chlorine, and vinyl chloride. These can sometimes be treated chemically, or a specific chemical value can be recovered by scmbbing, sorption, or other method when economically justified. Eor objectionable components in the vent streams, however, the common treatment method is either incineration or catalytic combustion, followed by removal of HCl from the effluent gas. 

Removal of metal chlorides from the bottoms of the Hquid-phase ethylene chlorination process has been studied (43). A detailed summary of production methods, emissions, emission controls, costs, and impacts of the control measures has been made (44). Residues from this process can also be recovered by evaporation, decomposition at high temperatures, and distillation (45). A review of the by-products produced in the different manufacturing processes has also been performed (46). Several processes have been developed to limit ethylene losses in the inerts purge from an oxychlorination reactor (47,48). 

Fig. 63. Molecular arrangement in (a, c) plane of a mixed ethylene-chlorine binary crystal illustrating (a) radical pair formation, (b) single chain growth and (c) chain growth in the vicinity of product line. Molecules labelled 1-4 are ethylene (C2H4), chlorine, chloroethyl radical (C2H4CI) and anti 1,2-dichloroethane (C2H4CI2), respectively.

A chloroethane compoundion plant was detonated because of the pressure of ethane/ethylene/chlorine mixture at 80°C and under 10 bar. 

For example, the industrial synthesis of vinyl chloride involves a mixture of ethylene, chlorine and oxygen. This is carried out in such a way that hydrogen chloride which forms during the reaction keeps the ethylene/oxygen mixture outside the LEL - UEL range. 

Write out and balance the overall equation for the manufacture of vinyl chloride from ethylene, chlorine and oxygen. 

Fig. 4.3a. The change in the energy of LU, ezv and in the total energy, E, of ethylene-chlorine cation system...

Fig. 4.3 b. The changes in the LU partial population of pt orbital at -carbon ethylene-chlorine cation system... 

Figure 9—2 shows the plant with its three reactors. The pyrolysis furnace is in the middle. At the top of the figure, the basic feeds, to the plant are shown—ethylene, chlorine, and oxygen. Ethylene and chlorine alone are sufficient to make EDC via the route on the left. The operation, call it Reaction One like Figure 9-1 does, takes place in the vapor phase in a reactor with a fixed catalyst bed of ferric (iron) chloride at only 100—125°F. A cleanup column fractionates out the small amount of by-products that get formed, leaving an EDC stream of 96—98% purity. 

PSPP has been commercialized for the production of oxygen and for the recovery and recycle of ethylene and a small amount of chlorocarbons (the adsorbed stream) to an ethylene-chlorination process while purging nitrogen (the less-adsorbed component) from the process ... 

More modern processes use the oxychlorination concept (Fig. 1) in which the vinyl chloride is produced from ethylene, chlorine, and oxygen. 

Acute symptoms of injury from various pollutants in different horticultural and agronomic groups are visible on the affected plant. Symptom expressions produced include chlorosis, necrosis, abscission of plant parts, and effects on pigment systems. Major pollutants which produce these injuries include sulfur dioxide, peroxyacetyl nitrate (PAN), fluorides, chlorides, nitrogen dioxide, ozone, and particulate matter minor pollutants are ethylene, chlorine, ammonia, and hydrogen chloride. Symptoms of acute injury are often used to identify pollutant source and to estimate agricultural damage. 

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