Thermal Runaway Reactions

Some research for the controlled assessment for Thermal Runaway Reactions.

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THERMAL RUNAWAY REACTIONS
What is a thermal runaway reaction?
Thermal runaway refers to a situation where an increase in temperature changes the
conditions in a way that causes a further increase in temperature, often leading to a
destructive result. It is a kind of uncontrolled positive feedback.
In other words, the term "thermal runaway" is used whenever a process is accelerated
by increased temperature, in turn releasing energy that further increases temperature. In
chemistry (and chemical engineering), this risk is associated with strongly exothermic
reactions that are accelerated by temperature rise. In electrical engineering, thermal
runaway is typically associated with increased current flow and power dissipation,
although exothermic chemical reactions can also occur under some conditions. Thermal
runaway can occur in civil engineering, notably when the heat released by large
amounts of curing concrete is not controlled. In astrophysics, runaway nuclear fusion
reactions in stars can lead to nova and several types of supernova explosions, and also
occur as a less dramatic event in the normal evolution of solar mass stars, the "helium
flash".
What causes a thermal runaway reaction?
Thermal runaway occurs when the reaction rate increases due to an increase in
temperature, causing a further increase in temperature and hence a further increase in
the reaction rate. Thermal runaway may result from unwanted exothermic side
reaction(s) that begin at higher temperatures, following an initial accidental overheating
of the reaction mixture. Thermal runaway is most often caused by failure of the reactor
vessel's cooling system. Failure of the mixer can result in localized heating, which
initiates thermal runaway. Similarly, in flow reactors, localized insufficient mixing causes
hotspots to form, wherein thermal runaway conditions occur, which caused violent
blowouts of reactor contents and catalysts. Incorrect equipment component installation
is also a common cause. Many chemical production facilities are designed with
highvolume emergency venting, a measure to limit the extent of injury and property
damage.
How industry controls the risks of thermal runaway reactions?

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