In this work, naturally available moringa oleifera leaves (also known as horseradish trees or drumstick trees) are chosen as a heterogeneous catalyst in the transesterification for biodiesel production from palm oil. The dry moringa oleifera leaves are calcinated at 700 °C for 3 hours to improve their adsorbing property. The calcinated catalyst characterization analysis from XRD and EDX highlights the presence of calcium, potassium, and other elements. Response surface method (RSM) optimization and artificial neural network (ANN) modeling were carried out to elucidate the interaction effect of significant process variables on biodiesel yield. The results show that a maximum biodiesel yield of 92.82% was achieved at optimum conditions of catalyst usage (9 wt.%), molar ratio, methanol to triglyceride (7:1), temperature (50 °C) and reaction time (120 min). The catalyst usage (wt.%) was identified as a significant process variable, followed by the molar ratio. Furthermore, the biodiesel’s significant fuel properties in terms of thermal, physical, chemical, and elemental match the established standards of ASTM. Finally, when the catalyst was reused for five cycles, more than 50% of the biodiesel yield was achieved.

This article presents an overview of the technology status and market trends of LPG-fueled vehicles through the literature approach to re-evaluate their future. In the review, it is discovered that LPG vehicles are globally increasing, though with a concentration in some countries. Of the 25 countries included in the World LPG Association (WLPGA) annual report 2018, Turkey, Poland, India, Ukraine, and Mexico are the countries with the best LPG vehicle trends in average of 23%. Meanwhile, Australia, Japan, South Korea, United Kingdom, the Netherlands, France, and Germany with a long history of implementing LPG as an alternative fuel has experienced a decline in the 2013-2017 period by 17%. This was allegedly due to the penetration of diesel-fueled vehicles over the last ten years. Moreover, developed countries experiencing decline have succeeded in developing electric-based vehicles such as Hybrid Electric Vehicle (HEV), Plug-in hybrid electric vehicle (PHEV), Battery Electric Vehicles (BEV), and Fuel Cell Electric Vehicles (FCEV) due to stringent demands for emission standards.

In this study, waste and discarded cooking oils (WCO) of palm, sunflower, rice bran and groundnut oils are collected from local restaurants. The high viscous WCO was converted into waste cooking oil biodiesel (WCOBD) by a single-stage transesterification process. During the transesterification process, the important parameters which show a significant change in biodiesel yield are studied using the optimization tool of response surface methodology (RSM). Results reported that 91.30% biodiesel yield was achieved within L18 experiments and NaOH catalyst was identified as the most influential parameter on WCOBD yield. Artificial Intelligence (AI) based modeling was also carried out to predict biodiesel yield. From AI modeling, a predicted yield of 92.88% was achieved, which is 1.70% higher than the RSM method. These results reveal the prediction capabilities and accuracy of the chosen modeling and optimization methods. In addition, the significant fuel properties are measured and observed within the scope of ASTM standards (ASTMD6751) and fatty acid profiles from chromatography reveal the presence of high unsaturated fatty acids in WCOBD. Therefore, utilizing the waste cooking oils for biodiesel production can mitigate the global challenges of environmental and energy paucity.

Derived from Coir coconut waste, coir fiber offers an environmentally friendly response to ecological challenges in various industries. Its application aligns with achieving Sustainable Development Goals (SDGs), such as eliminating extreme poverty, ensuring food security, and promoting decent employment and economic expansion. It also fosters environmentally friendly consumption and production, mitigates global warming, and conserves biodiversity. The study involves a comprehensive review of current literature, examining the methodologies including extraction techniques, surface modifications, and manufacturing processes like hand layup, casting, compression molding, hot pressing, and injection molding. The analysis identifies key improvements in mechanical, thermal, and physical properties of coir fiber composites, particularly enhanced tensile strength, thermal stability, and reduced water absorption due to chemical treatments. This confirms previous findings and contributes toward enhancing our understanding that coir fiber is extensively utilized in multiple industries, including housing, construction, transportation, biomedical, wrapping, electrical power, communication technology, biofuel, and bioenergy due to their natural abundance, affordability, ease of shaping, superior durability, and eco-friendly characteristics. Another crucial practical implication is that coir fiber and its composites offer numerous advantages that have significant consequences for the development of coir fiber in various fields.