DOI: https://doi.org/10.55373/mjchem.v27i5.145

Keywords: Hylocereus undatus foliage; oil content; mixing time; mixing temperature

Abstract

Poor control of the emulsification mechanism may result in increased operational costs, particularly due to complications within the pipeline system in the oil and gas industry. The development of stable water-in-crude oil emulsion is highly undesirable yet unavoidable in petroleum processing. To mitigate this, the chemical surfactant is commonly used to break the emulsion. However, excessive use of chemical surfactants poses serious environmental concerns, especially to aquatic ecosystems. The discovery of Hylocereus undatus (H. undatus) foliage as a biosurfactant offers a promising alternative, owing to its lower toxicity, biodegradability, and eco-friendly attributes. Emulsion stability is influenced by several factors, including surface tension, viscosity, oil content, mixing time, and temperature. This study investigates the effects of oil content (at varying oil-to-water ratios), mixing time, and temperature on the performance of H. undatus foliage as a biosurfactant. The stability of the water-in-oil emulsion was evaluated using a tensiometer, rheometer, FTIR spectroscopy, and creaming index measurements. Results revealed that emulsions with a 5:5 oil-to-water ratio demonstrated the highest stability, with the greatest average viscosity (4.217 mPa.s), the lowest creaming index (0%), and the greatest phase separation behaviour at 88.24%. Furthermore, an optimal mixing time of 10 mins produced the most stable emulsion. FTIR analysis further confirmed this, indicating that the emulsion’s high stability was associated with a lower O-H stretching wavenumber as well as having the lowest creaming index value (0%). Similarly, samples processed at an optimal temperature of 50 °C displayed the lowest surface tension (27.6 mN/m) and a reduced creaming index (less than 5%), indicating a highly stable emulsion system. In conclusion, these findings support the adoption of sustainable industrial practices by replacing synthetic surfactants with natural, biodegradable alternatives derived from H. undatus foliage, aligning with SDG 12: Responsible Consumption and Production.