Recovery of styrene from the C8 fraction of pyrolysis gasoline

a byproduct of steam cracking of naphtha

has been recognized as a very promising approach to meet with increasing demand for styrene

and selective hydrogenation of phenylacetylene is the key reaction during the recovery process. The present study investigated the axial backmixing behaviors of liquid phase in a trickle bed reactor for selective hydrogenation of phenylacetylene. The liquid-phase residence time distribution under various experimental conditions was first measured by using a pulse tracer technique

and then Péclet number and average residence time of liquid phase were determined by the finite element orthogonal collocation method and the Levenberg-Marquardt nonlinear least-squares method. Finally

the effects of operation conditions on axial backmixing of liquid were studied. Liquid backmixing could be reduced by increasing liquid flow rate

gas flow rate

temperature and pressure

but would be exacerbated by increasing particle size.