Chemical reaction engineering

Chemical reaction engineering designs and analyses reactors by combining chemical kinetics with mass balance, energy balance and transport. A desired molecular reaction must be achieved in a vessel where mixing, temperature and residence time affect conversion.

For a steady well-mixed flow reactor with constant volume $V$, volumetric flow $Q$ and a first-order consumption rate $kC$, the species balance is $0=Q{C}_{\mathrm{in}}-QC-kVC$. Hence $C/C_{\mathrm{in}}=1/(1+kV/Q)$. This derivation assumes uniform concentration, equal inlet/outlet volumetric flow and constant rate coefficient. An ideal plug flow reactor instead gives $C_{\mathrm{out}}/C_{\mathrm{in}}=e^{-kV/Q}$. Different flow histories can thus yield different conversion at the same mean residence time.