## 1 Introduction  
Energy is the dominant sector that stimulates the economy (in terms of growth, progressive development, societal status, and national security) of all countries [1; 2]. Energy fulfills the basic need (food, light), necessary health care systems (vaccines, intensive care, and controlled temperature-monitoring medical equipment), educational aids (computer, television, Internet-based information transfer such as email, world-wide-web, virtual meetings, and so on), and serves as fuel for productive activities in industry, transport, agriculture, manufacturing, mining, and so on [3; 4; 5], to meet the rapid growth in population. Corresponding British Petroleum statistics on the world's energy supplies (BP2020) indicate that fossil fuels (raw oil, coal, and natural gas \(\sim\)33.1%, 27%, and 24.2%) showed maximum contributions, followed by nuclear, hydro, and other renewable sources by 4.3%, 6.4%, and 5%, respectively [6]. High consumption of fossil fuels to meet strict energy demand has led to climate change that could result in global warming [7; 8]. To meet energy demand and meet stricter pollution standards, researchers around the world have been drawn to identify alternate sources of sustainable and environmentally friendly fuels, such as biodiesel, ethanol, and butanol [9; 10]. Biodiesel and ethyl alcohol are produced using raw materials that are generally considered renewable, mainly from plant and animal feedstocks [11]. The performance of biodiesel and ethyl alcohol in internal combustion engines has led to better engine performance and better emission characteristics [12; 13]; therefore, efficient methods for the production of biodiesel from various resources or raw materials are of practical or relevant relevance. The production of biodiesel can be achieved via pyrolysis, dilution, microemulsion, and transesterification (alkali-catalyzed, supercritical, chemistry, lipase, etc.) processes [14; 15; 16; 17; 18]. Transesterification is the most dominant method of biodiesel production, in which it undergoes a reaction (using the catalytic hardening reaction and yield, while a non-catalytic reaction ensures a lower yield with potential high temperature and pressure requirement) of fatty acid or oil with alcohol esters and glycerol as a result [18]. Biodiesel production is performed by the transesterification of triglycerides (containing \(\sim\)10% of the incorporated oxygen fraction) that allows for the efficient combustion of fuel [19]. Many investigations have been conducted for biodiesel production utilizing various feedstocks such as Palm [20], Mahua-sunflower [21], rapesed [22], morning oleifera [23], Karania [24], Garcinia Gummi-Gutta [25], waste fish oil, bitter almond oil, and waste cooking oil [13]. The biodiesel conversion of plant oils (Moringa oleifera and palm oils) and animal fats in the presence of homogeneous or heterogeneous catalysts (calcium hydroxide, NaOH, KOH) are performed with the assistance of the transesterification process [15; 20; 23]. The following observations are made from the analysis of the literature review that: (a) transesterification has proven to be an efficient technique for the synthesis of biodiesel using various raw materials; (b) raw materials are region-specific, which prevents demand from meeting global requirements for biodiesel production; (c) transesterification parameters need to be optimized that influence the yield of biodiesel from raw materials. Attempts are needed to select locally available and economical raw materials and to optimize transesterification parameters that could result in low-cost biodiesel. NS oil has proven to be a potential raw material for biodiesel synthesis due to its better fuel properties [26]. NS can be cultivated in abundance in hilly, non-arable, marginal areas of India and thus treated as a viable alternative to fossil fuel [27].