The low-temperature oxidation heat production of coal seriously endangers the life and safety of miners and causes huge property losses to enterprises, while the characteristics of low-temperature oxidation heat production of coal are still unclear, mainly affected by the ambiguity of the existing analysis methods. For the existing instruments in the measured low-temperature oxidation heat flow change curve does not appear inflection point [1], resulting in the curve integral baseline is not fuzzy, in the use of the baseline for the calculation of raw materials to solve the change in the amount of heat there is a certain deviation, especially coal, biomass, etc. at lower temperatures in the oxidation of exothermic cannot be shown to produce heat of the integrity of the calorimetric peaks [2].

  To address the challenge of incomplete exothermic peaks during low-temperature oxidation, we propose a measurement method based on a microcalorimetric analyser with a stable phase change material baseline. The method can not only accurately determine the low-temperature oxidation heat production characteristics of the feedstock; but also achieve the exothermic peak integrity of the feedstock within the set temperature variation range by the stable phase change material baseline, thus providing accurate data for the subsequent study of the low-temperature oxidation characteristics of the feedstock.
In this study, stable phase change materials were used as the reference baseline for the measurement of trace heat in coal samples (Fig. 1). Firstly, the heat flow curves under conventional measurements were measured and analysed for 4 coal samples with different degrees of metamorphism; Then, the organic phase change materials with stable heat flow curves were selected to measure the heat flow curves for three different temperature intervals of organic phase change paraffin waxes (40℃, 80℃, 120℃), and recently the heat flow curves of coals with different degrees of metamorphism were measured using different phase change materials as baselines.