Engineering Headway Vol. 40

Abstract: Environmental protection within service, production, and business enterprises is increasingly subject to Vietnam's stringent regulatory demands. This study develops a comprehensive framework of guidelines and indicators to evaluate environmental protection performance within these enterprises. These indicators were formulated through a meticulous synthesis of relevant legal documents and refer to previous research findings. Subsequently, the indicators were refined using the SMART method and consultations with subject-matter experts. The proposed framework encompasses 23 indicators derived from the DPSIR model. Additionally, the Environmental Protection Performance Index (EPPI) was developed using integrated linear, multicriteria analysis and the analytic hierarchy process weighting. The study conducted a pilot application in 2024 with nine companies in Thu Dau Mot City, revealing that their environmental protection activities ranged from average to commendable, with scores of 25.8 to 76.8. The study elucidates the EPPI's ability to assess compliance levels and to conveniently compare enterprise rankings across different spatial and temporal dimensions. In this study, nine enterprises were observed for their environmental protection performance. Furthermore, the implications of the EPPI for environmental management are profound, as it has the potential to incentivise enterprises to continually enhance their environmental management practices, fostering a more promising and optimistic outlook for future advancements.

Abstract: In this study, biodiesel was produced through the catalytic conversion of waste cooking oil into fatty acid methyl esters using methanol and calcium oxide derived from calcined eggshells as a heterogeneous catalyst. Different factors affecting reaction performance, including feedstock addition method, the molar ratio of methanol to waste cooking oil, catalyst loading, reaction time, and reaction temperature, were systematically studied. The results showed a biodiesel yield of 90% under optimal conditions: a feedstock addition time of 2 hours, a methanol-to-waste cooking oil weight ratio of 10:1, a catalyst loading of 7% based on the weight of the oil feedstock, a reaction time of 5 hours, and a reaction temperature of 60 °C. The CaO catalyst was successfully reused three times, with only a minor loss of activity. Complete conversion of waste cooking oil to biodiesel was confirmed by TLC, using a solvent system with a 15:1 volume ratio of petroleum ether to ethyl acetate. Column chromatography with the same solvent system was used for further purification. FT-IR analysis confirmed the successful transesterification, as evidenced by spectral changes associated with the formation of methyl esters. GC-MS identified various fatty acid methyl esters, providing insights into the composition and confirming product quality. Additionally, in laboratory-scale tests, selected fuel properties, including density, viscosity, flash point, copper chip corrosion, and water content, were measured. The results indicate that biodiesel has characteristics similar to those of conventional diesel and commercial biodiesel, supporting its potential as a renewable energy resource.