Micro process engineering

Micro process engineering is the science of conducting chemical or physical processes (<a href="/facts/Unit_operation/7TAe9XH0">unit operations</a>) inside small volumina,
typically inside channels with diameters of less than 1 mm
(microchannels) or other structures with sub-millimeter dimensions. 
These processes are usually carried out in continuous flow mode, as opposed to <a href="/facts/Batch_production/cXFjDSl1">batch production</a>, allowing a throughput high enough to make micro process engineering a tool for chemical production. Micro process engineering is therefore not to be confused with <a href="/facts/Microchemistry/sDWyX7WF">microchemistry</a>, which deals with very small overall quantities of matter.
The subfield of micro process engineering that deals with chemical
reactions, carried out in microstructured reactors or
"<a href="/facts/Microreactor/uokqUU9j">microreactors</a>", is also known as microreaction technology.
The unique advantages of microstructured reactors or microreactors are <a href="/facts/Enhanced_heat_transfer/21DeTyVu">enhanced heat transfer</a> due to the large surface <a href="/facts/Area-to-volume_ratio/lEl1rKLh">area-to-volume ratio</a>, and enhanced <a href="/facts/Mass_transfer/GrHKD4h2">mass transfer</a>. For example, the length scale of <a href="/facts/Diffusion/KbAxroBa">diffusion</a> processes is comparable to that of microchannels or even shorter, and efficient mixing of <a href="/facts/Reactant/c3GLInCu">reactants</a> can be achieved during very short times (typically milliseconds). The good heat transfer properties allow a precise temperature control of reactions. For example, highly 
<a href="/facts/Exothermic_reaction/w5IjYYfL">exothermic reactions</a> can be conducted almost <a href="/facts/Isothermal/6mkdESuS">isothermally</a> when the microstructured reactor contains a second set of microchannels ("cooling passage"), fluidically separated from the reaction channels ("reaction
passage"), through which a flow of cold fluid with sufficiently high
<a href="/facts/Heat_capacity/I63nzSyp">heat capacity</a> is maintained. It is also possible to change the temperature of microstructured reactors very rapidly to intentionally achieve a non-isothermal behaviour.

Micro process engineering open-in-new

Micro process engineering