Читать книгу Biodiesel Production - Группа авторов - Страница 45

Despite extensive research data reported every year and the successful utilization of biodiesel blends in a few countries, the feasibility of utilizing biodiesel globally is still debated since the process is complex, involving costly equipment and high reactant losses, while the feedstock used are not sufficiently available. However, the cultivation and/or utilization of these nonedible and waste feedstock for commercial fuel synthesis provides monetary incentives to farmers, which can bolster economy [53]. The distribution of potential sources of WCO collection also plays an important function in determining the best site for establishing a production plant, since transportation must be minimized. Highly populated areas remain a lucrative choice due to increased number of sources; however, the plant must be strategically placed to avoid local contamination from industrial discharge and emissions. Unfortunately, no extensive studies have been reported so far on this aspect.

Life cycle assessment (LCA) studies provide an insight into the impact of biodiesel synthesis on the market and environment [54]. Lee et al. reported an estimated cost reduction by 10–20% on manufacturing and 42% feedstock cost when using WCO in supercritical systems [55]. A notable point is that waste oil collected from cafes, eateries, and restaurants generally consists of WCO mixed with grease trap waste, which cannot be utilized for fuel synthesis without incurring heavy energy and other purification losses during intensive pretreatment. This also adds to CO₂ emissions (estimated at 92%) during biodiesel synthesis life cycle, with 25% of it generated from transportation of this unusable waste. Anaerobic digester employing methanogens, for example, can be used to solve this [55]. Thus WCO is physically separated before transport and use. Another aspect that can generate more revenue is the processing and sale of glycerol or other products generated from glycerol‐free processes, since they boast widespread use [53]. Carbon footprint remains uninfluenced in a worst‐case scenario when using WCO, since WCO generation can be equated to our dietary activities, and its utilization expectedly resulted in negligible changes for global CO₂ uptake, while nonedible oil usage showed positive impact.