Monitoring wax crystallisation in diesel using differential scanning calorimetry (DSC) and microcalorimetry

Abstract The crystallisation of wax on cooling a diesel was monitored by DSC with cooling rates of 5–0.2 ° C min and by a microcalorimeter with the lower rates of 0.1–0.01 ° C min . The melting of crystallised wax was also monitored by DSC to assess the thermodynamic reversibility of the process. The results show that crystallisation temperatures from DSC at a cooling rate of 1 ° C min are close to those from microcalorimetry at 0.01 ° C min (a realistic cooling rate for diesel in a vehicle). A comparison of crystallisation and melting data shows that equilibrium crystallisation conditions are not achieved even at the lowest cooling rate used here.