Conventional methods for determining Wax Appearance Point (WAP) and wax content in crude oils—such as differential scanning calorimetry (DSC), rheology, and modified acetone precipitation (SY/T 7550–2000)—offer established reliability but face challenges with complexity, sensitivity, and operational ease. This study introduces Back Scattered Light (BSL) analysis method as alternative that is rapid, non-invasive and leverages wax particles’ unique scattering properties. Using BSL, WAPs were accurately measured for six crude oil samples (YM, YD, SHB, XJN, YQ, GD) at temperatures between 16°C and 48°C. The method was validated using samples YD and YM whose results were compared with the coventional methods. The BSL method showed great accuracy, achieving a 1–5 % error margin for WAP. Unlike classical methods, BSL ably identified the two WAPs in YM (47°C and 36.33°C), corresponding to distinct paraffin and microcrystalline wax types that were confirmed with optical microscopy. Wax content estimations of 20.29 % (YD) and 35.12 % (YM) were consistent with DSC and SY/T 7550–2000 within a 5 % margin. Experiments with commercial wax in heptane showed BSL’s sensitivity to both macro- and microcrystalline wax types. The BSL method’s reduced sample requirements, shorter testing times, and ease of operation make it a compelling alternative to traditional approaches, with significant potential for enhancing sustainable wax management in crude oil processing.
The cuticular wax of Korla pear stored under different relative humidity (0 ± 1 ℃, 50–55%, 70–75% and 90–95%) was examined in terms of total wax content, chemical composition and crystal morphology. The cuticular wax was composed of alkanes, olefins, fatty acids, alcohols, aldehydes, esters and terpenoids. High humidity maintained the content of total wax, alkanes and aldehydes at sufficient levels, especially C 29 alkane and C 18 aldehyde, which could positively regulate the quality of the pear fruits. Cuticular wax contributes to the capacity of preserving water, maintaining cell wall and delaying senescence. Scanning electron microscopy showed that wax crystals appeared as numerous platelets with irregular ovate crystals, high humidity delayed the transformation of wax structure. Taken together, high humidity delayed the ripening and aging by effectively maintaining wax, which was essential for postharvest storage and provide a reference for the production of synthetic wax for Korla pear fruits.
In this paper, the effect of the ethylene vinyl acetate (EVA) copolymer, commonly used in improving rheological behavior of waxy oil, is introduced to investigate its effect on the formation of cyclopentane hydrate in a water-in-waxy oil emulsion system. The wax content studied shows a negative effect on the formation of hydrate by elongating its induction time. Besides, the EVA copolymer is found to elongate the induction time of cyclopentane hydrate through the cocrystallization effect with wax molecules adjacent to the oil–water interface.
危险品化学品经营许可证（带存储）