The impact of processing conditions on PGSS micronisation of Fischer-Tropsch waxes

Micronisation of two Fischer-Tropsch waxes with differing melting temperatures (Wax 1 <Wax 2) via the particles from gas saturated solutions process (PGSS) was successfully performed. The impact of pressure, temperature, wax loading and nozzle type on particle size, morphology and bulk density was investigated. Increased wax loading increased particle size and reduced sensitivity to changes in pressure and temperature. Nozzle diameter did not impact particle size greatly, but nozzle shape did. Bimodal particle size distributions were observed at low pressure and low temperatures. Wax 2 formed spherical, non-porous particles at low pressure and high temperature due to delayed solidification. Micronisation reduced lamellar size but had little effect on crystal structure. Wax 2 showed greater crystal stability over time than Wax 1. The results demonstrate that PGSS process parameters, particularly temperature and nozzle shape, influence wax particle characteristics, providing critical insights for optimising micronisation strategies in industrial applications. • PGSS micronisation of two Fischer-Tropsch waxes. • Investigating the impact of pressure, temperature, wax loading and nozzle diameter. • Interpret particle size, particle shape and bulk density results. • Bimodal size distributions measured at low pressure and high wax loading. • Monitoring impact of processing conditions on particle crystal structure.