Chemistry - Pressure and steam - an interesting aspect of ethene
Pressure and steam - an interesting aspect of ethene production!
According to Le Chatelier's principle, the _yield _of ethylene (also known
as ethene) will be increased if lower pressures are used, i.e. the system
will try to compensate for the lowered pressure by the position of
equilibrium moving to the side with more particles.
Lower than atmospheric pressure may be used. However, working at pressures
below atmospheric can be hazardous, and if air is drawn into the cracker
the hydrocarbon mixture may become explosive at the high temperatures used.
The _double bonds_ in ethene are _very reactive._ To maintain low pressure
in the equilibrium system and at the same time a safe pressure in the
cracking vessel, _steam _is used. Since steam is not part of the actual
equilibrium, it has _no effect on the behaviour of the equilibrium system._
To all intents and purposes, the steam is acting as an inert gas and while
it contributes to the_ total pressure_ in the cracking vessel, it does not
have any impact on the position of equilibrium.
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