Biodiesel production from Elaeagnus angustifolia.L seed as a novel waste feedstock using potassium hydroxide catalyst

Recent advances in transesterification for sustainable biodiesel production, challenges, and prospects: a comprehensive review

Biodiesel, a renewable and sustainable alternative to fossil fuels, has garnered significant attention as a potential solution to the growing energy crisis and environmental concerns. The review commences with a thorough examination of feedstock selection and preparation, emphasizing the critical role of feedstock quality in ensuring optimal biodiesel production efficiency and quality. Next, it delves into the advancements in biodiesel applications, highlighting its versatility and potential to reduce greenhouse gas emissions and dependence on fossil fuels. The heart of the review focuses on transesterification, the key process in biodiesel production. It provides an in-depth analysis of various catalysts, including homogeneous, heterogeneous, enzyme-based, and nanomaterial catalysts, exploring their distinct characteristics and behavior during transesterification. The review also sheds light on the transesterification reaction mechanism and kinetics, emphasizing the importance of kinetic modeling in process optimization. Recent developments in biodiesel production, including feedstock selection, process optimization, and sustainability, are discussed, along with the challenges related to engine performance, emissions, and compatibility that hinder wider biodiesel adoption. The review concludes by emphasizing the need for ongoing research, development, and collaboration among academia, industry, and policymakers to address the challenges and pursue further research in biodiesel production. It outlines specific recommendations for future research, paving the way for the widespread adoption of biodiesel as a renewable energy source and fostering a cleaner and more sustainable future.

Graphene-based catalysts for biodiesel production: Characteristics and performance

Biodiesel is a promising alternative to reduce the dependency on fossil fuels. However, biodiesel's cost is still higher than its petroleum counterpart, hence its production process must be modified to make it economically viable. Microalgae are an alternative feedstock to replace agricultural crops for biodiesel production, and offer several advantages such as fast growth, use of non-arable land, growth in saline and wastewater, and high lipid yield. Unfortunately, biodiesel production from microalgae is very energy-intensive and costly, mainly due to the high energy consumption required for dewatering and drying. Therefore, utilizing wet microalgal biomass instead of dry biomass can be a promising solution to reduce the biodiesel production cost Furthermore, the use of heterogeneous catalysts offers high efficiency, recoverability, and reusability, and is therefore very promising from the economic and environmental perspectives. The unique characteristics of graphene-based nano-catalysts, such as their high surface area, two-dimensional structure, and functional groups, make them suitable candidates for biodiesel production. In this review, the use of graphene-based catalysts for biodiesel production is analyzed in depth, and their efficiency compared to other heterogeneous catalysts is scrutinized. Moreover, their recoverability, reusability, and economic feasibility are critically discussed, and their potential to produce biodiesel from wet microalgae is explored as a sustainable and cost-effective approach.

Optimization of Biodiesel Production Parameters from Cucurbita maxima Waste Oil Using Microwave Assisted via Box-Behnken Design Approach

The production of biodiesel from vegetables or fruits waste oils has high potential as renewable energy. The Cucurbita maxima wastes are massive source of oils, which are believed to indicate the possible sources of renewable energy whose biodiesel can be produced. Hence, the study explores the potential of the Cucurbita maxima wastes, for the production of biodiesel. In this study, the Soxhlet extraction method was used to extract Cucurbita maxima waste oil using an organic solvent. Through Box-Behnken design (BBD), the effects of methanol to oil molar ratio (6–10), catalyst concentration (2–6%), and reaction time (45–75 min) on the transesterification efficiency of methyl esters were investigated. The oil contents of Cucurbita maxima waste was found to be $44.6\pm 0.21$ %. This oil was characterized, and after obtaining the pure characterized oil, biodiesel was produced using microwave assisted by the transesterification process. The optimum conversion efficiency of the Cucurbita maxima waste oil to fatty acid methyl ether was 97.76%, at the optimal parameters, methanol to oil ratio (8.4 : 1), catalyst concentration (3.14%), and reaction time (57.12 min). The results revealed that all parameters have a significant effect on the yield of biodiesel ( $p<0.0001$ ). The physicochemical properties reveal that the Cucurbita maxima waste oil could be applied as a potential source of material for methyl ester production. The fatty acid profile of the oil indicated that it was mainly composed of unsaturated fatty acid, which ensures good flow properties of the fuel. The results of these studies showed the prospective of Cucurbita maxima wastes as a new potential feedstock for biodiesel production.

Optimization of biodiesel production parameters from Prosopis julifera seed using definitive screening design

The concept of waste to valuable products is a hot topic with more explorations going on worldwide to minimize the environmental pollution and wastage of food-based feedstocks. In this work, biodiesel was produced from Prosopis julifera seed oil using ethanol as solvent and magnesium nanocatalyst and the process was optimized by employing an advanced statistical optimization method; definitive screening design. The maximum biodiesel yield from Prosopis julifera seed was found to be 32.5%. Acid esterification and transesterification were applied to minimize the acidity. Acidity of the P. julifera oil was initially reduced to 1.52 mg KOH/g using acid catalyst H₂SO₄, and then to 0.88mg KOH/g by transesterification process using magnesium oxide.

Optimum biodiesel conversion efficiency of 94.83% was achieved under 10:1 ethanol-to-oil ratio, 5% magnesium oxide concentration, 80 min reaction time, 45 °C reaction temperature and 1000 rpm agitation rate. The transesterification reaction was found to be highly affected by the ethanol-to-oil ratio and catalyst concentration. The results showed that the catalytic activity of the magnesium oxide was sufficient for the production of biodiesel from P. julifera seed oil.

The fuel properties were evaluated according to ASTM standards. FTIR analysis confirmed the existence of functional groups with respect to the fingerprint region of P. julifera ethyl esters. The Definitive screening design method can be suggested as an alternative method for the optimization of process parameters within limited materials and number of experiments. The findings suggest that this method of production of biodiesel from P. julifera seed oil shall open up new possibilities for a novel natural biofuel.

Synthesis and catalytic properties of calcium oxide obtained from organic ash over a titanium nanocatalyst for biodiesel production from dairy scum

The fatty acid methyl ester (FAME) production from dairy effluent scum as a sustainable energy source using CaO obtained from organic ash over titanium dioxide nanoparticles (TNPs) as the transesterification nano-catalyst has been studied. The physical and chemical properties of the synthesized catalysts were characterized, and the effect of different experimental factors on the biodiesel yield was studied. It was revealed that the CaO-TiO₂ nano-catalyst displayed bifunctional properties, has both basic and acid phases, and leads to various effects on the catalyst activity in the transesterification process. These bifunctional properties are critical for achieving simultaneous transesterification of dairy scum oil feedstock. According to the reaction results, the catalyst without and with a low ratio of TNPs showed a low catalytic activity. In contrast, the 3Ca-3Ti nano-catalyst had the highest catalytic activity and a strong potential for reusability, producing a maximum biodiesel yield of 97.2% for a 3 wt% catalyst, 1:20 oil to methanol molar ratio for the dairy scum, and a reaction temperature of 70 °C for a period of 120 min under a 300 kPa pressure. The physical properties of the produced biodiesel are within the EN14214 standards.

Biodiesel Production from Waste Oils: A South African Outlook

The viability of large-scale biodiesel production ultimately boils down to its cost of commercialisation despite other very important factors such as the negative environmental and health effects caused by the direct combustion of fossil diesel. How much each country’s economy will be influenced by the production of biodiesel will be determined by the commitment of various stakeholders to the much-needed transition from petroleum-based resources to renewable resources. Biodiesel production is largely determined by the cost of the feedstock (>70%) and this review focuses on the use of waste oil resources as biodiesel feedstock with a special focus on waste cooking oil (WCO). Generating value from waste oil provides an alternative waste management route as well as a positive environmental and economic contribution. The transesterification process for biodiesel production, its catalysis and some important technical and economic aspects are covered in this communication with a special focus on the South African framework. An overview of the current research and its implications going forward is discussed.

Heterogeneously catalyzed biodiesel production from Azadiricha Indica oil: Predictive modelling with uncertainty quantification, experimental optimization and techno-economic analysis

This study presents predictive modelling with uncertainty analysis, optimization and techno-economic feasibility of Bio-catalyzed Biodiesel Production from Azidirica Indica Oil (BCBPAIO). Central Composite Design (CCD) predictive model and optimum conditions for BCBPAIO were developed in Design Expert software. The model uncertainty analysis was performed using Monte Carlo simulation. The BCBPAIO simulation and economic analysis were conducted in ASPEN Batch Process Developer V10. The correlation coefficient (R²) and adjusted R² value of the CCD model were 0.9922 and 0.9780 respectively. CCD model certainty gave 73.51% with 100,000 trials; the oil transesterification optimum conditions gave 87.04% conversion with 3.62 wt% of catalysts; and methanol to oil molar ratio of 8:1 at 59 °C for 4 h. The annual production cost, total capital investment, payback time and internal rate of returns are $ 3537105, $ 5243784, 2.67 and 43% respectively. This study shows that the production is profitably feasible.