Determination of the optimizing operating procedure for DSC test of wax-solvent samples with narrow and sharp wax peak and error analysis of data reliability

Abstract

Differential scanning calorimetry (DSC), as a convenient and reliable thermal analysis technique, is widely used to analyze wax precipitation characteristics. This paper studies the optimizing operation conditions in DSC test for wax-solvent mixtures characterized by a narrow and sharp wax peak to promote the test reliability. The influences of cooling rate and isothermal time on the wax precipitation characteristics of wax-solvent samples are investigated through DSC experiments. The shape of heat flow curve, wax precipitation temperature and measured wax content are all affected. According to the stability and repeatability of test results, the optimizing procedure is determined for this kind of oil samples. What is more, this paper analyzes the applicability of the optimizing procedure on a crude oil sample with broad and mild wax peak. Experiment errors in the parallel experiments conducted under the determined procedure are checked, and all of them are in acceptable error ranges. This study may provide a meaningful reference for DSC application and a rethink of the test standard in practical operation for particular waxy mixtures.