New PLOT Column Technology Stabilises Flow and Improves Analysis of Light Hydrocarbons, Solvents and Permanent Gases

PLOT columns are widely used in petroleum and other industries because their retention and selectivity characteristics allow gases and volatiles to be separated with high resolution at above ambient temperatures. However, the utility of PLOT columns, particularly of the porous polymer columns, is significantly limited by the mechanical instability of the particle layers. One of the biggest challenges with conventional PLOT columns is that vibrations or any change in gas velocity, pressure, or surface stress can result in a release of particles - or even complete segments - from the adsorption layer. This creates restrictions in the column, which result in highly variable flow behaviours over time and between columns. In practice, conventional PLOT columns of the same dimensions can differ in flow by a factor of 4-6, when operated at the same nominal pressure. This makes them extremely difficult to use reliably in applications where consistent flow and predictable retention times are important, such as when flow or valve switching is utilised.