Feasibility of biodiesel production from waste cooking oil: lab-scale to pilot-scale analysis

Investigation of the use of aluminum oxide nanoparticle-enhanced waste cooking oil blends in compression ignition engines

The sustainable utilization of waste cooking oil (WCO) as an alternative to fossil fuels has gained considerable attention due to its potential for delivering substantial environmental and economic benefits. This research attempts to explore the impact of incorporating aluminum oxide nanoparticles (AONP) into WCO on the emissions, combustion characteristics, and overall performance of a single-cylinder compression ignition (CI) engine. Comparative analyses were conducted against conventional commercial diesel fuel and pure WCO, as well as varying blends of WCO with AONP at 25 ppm, 50 ppm, and 75 ppm concentrations. The experimental results demonstrate a notable enhancement in brake thermal efficiency (BTE), with a 13.2% increase observed in the WCO + 75 AONP fuel blend compared to neat WCO. Engines fueled by WCO nanoparticle blends showed significant augmentation in-cylinder pressure and heat release rates. Furthermore, these blends exhibited a substantial reduction in carbon monoxide (CO), hydrocarbons (HC), and soot emissions by 44%, 31%, and 48%, respectively, while nitrogen oxide (NO) emissions increased by 7% compared to neat WCO. Among the assessed fuel mixtures, the WCO + 75 AONP blend demonstrated higher engine performance. This study underscores the potential of aluminum oxide nanoparticle-enhanced WCO blends as viable and environmentally responsible options for sustainable energy solutions. However, challenges such as production costs and long-term fuel stability must be addressed to establish nano-fuels as financially viable alternatives.

Biodiesel production and exploring properties of Datura stramonium L. oil with its optimization using combined approaches-Taguchi, grey relational analysis, and response surface methodology

Biodiesel production through the synthesis of Datura stramonium L. oil is studied to explore the most efficient approaches to suggest an alternate feedstock for biodiesel production. The main objective of this work is to optimize the process variables of biodiesel synthesis by using some statistical approach (Taguchi method, grey relational analysis (GRA), and response surface methodology (RSM) analyzing three parameters, i.e., alcohol-to-oil molar ratio, catalyst (NaOH) concentration, and process temperature for achieving maximum biodiesel derived from Datura stramonium L. oil. The transesterification process is applied by using an ultrasonic-assisted technique. Grey relational analysis (GRA) was successfully applied with the Taguchi method resulting in the optimum combination of A2B1C1. Based on the findings, the best operating conditions for transesterifying are attained with the RSM approach consisting of a 5.697:1 molar ratio (level 2), 0.3 (wt.%) NaOH concentration (level 1), and 70 °C process temperature (level 1). With a value of 87.02%, these ideal operating conditions produce the maximum yield as compared to grey relational analysis (GRA) yields 83.99%. The obtained results have been verified through the characterization of oil and biodiesel as well. Also, the fuel qualities of DSL biodiesel were identified and assessed. DSL oil was found 137.6 degrees of unsaturation during fatty acid profile analysis. DSL biodiesel was found the best kinematic viscosity (4.2 mm2/s) and acid value (0.49) when compared to Karanja and palm biodiesel. D. stramonium L. was recognized as a suitable species for biodiesel feedstock according to the findings.

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.

An ICP-MS study on metal content in biodiesel and bioglycerol produced from heated and unheated canola oils

This study addresses the challenges of biodiesel production costs and waste oil disposal by investigating the use of low-cost waste oil as a feedstock. The impact of heating temperature on biodiesel yield and trace metal levels is examined using response surface methodology (RSM). Optimal conditions for high biodiesel yields (95-98%) from canola oil are determined with a methanol/oil ratio of 12:1, 1 wt% catalyst, and 60-min reaction time. For crude bioglycerol, the optimal conditions involve a methanol/oil ratio of 4.25:1, 2.93 wt% catalyst, and 119.15-min reaction time. Elemental analysis reveals the presence of high-concentration metals like Cu and Zn and low-concentration ones such as Pb, As, Se, and Zr in both oil feedstocks and their respective biodiesel and bioglycerol products. The study demonstrates that thermal stress on canola oil significantly impacts biodiesel and bioglycerol yields and trace metal levels during the transesterification process. The findings contribute to enhancing cost-effectiveness and environmental sustainability in biodiesel production.

Valorization of hazardous waste cooking oil for the production of eco-friendly biodiesel using a low-cost bifunctional catalyst

Biodiesel is considered the prospective substitute for non-renewable fossil fuel-derived sources of energy. However, the high costs of feedstocks and catalysts inhibit its large-scale industrial implementation. From this perspective, the utilization of waste as the source for both catalyst synthesis and feedstock for biodiesel is a rare attempt. Waste rice husk was explored as a precursor to prepare rice husk char (RHC). Sulfonated RHC was employed as a bifunctional catalyst for the simultaneous esterification and transesterification of highly acidic waste cooking oil (WCO) to produce biodiesel. The sulfonation process coupled with ultrasonic irradiation proved to be an efficient technique to induce high acid density in the sulfonated catalyst. The prepared catalyst possessed a sulfonic density and total acid density of 4.18 and 7.58 mmol/g, respectively, and a surface area of 144 m²/g. A parametric optimization was conducted for the conversion of WCO into biodiesel using the response surface methodology. An optimal biodiesel yield of 96% was obtained under the conditions of methanol to oil ratio (13:1), reaction time (50 min), catalyst loading (3.5 wt%), and ultrasonic amplitude (56%). The prepared catalyst showed higher stability up to five cycles with biodiesel yield greater than 80%.

Biodiesel and Bioplastic Production from Waste-Cooking-Oil Transesterification: An Environmentally Friendly Approach

Alternative sources of fuel have been a concern in the last few decades. The growth of urbanization and industrialization will lead to the exhaustion of fossil fuels, attracting studies on alternative routes. The main aim of this study was to produce biodiesel from waste cooking oil (WCO) by methyl transesterification using sodium hydroxide as a catalyst. For this, the physicochemical parameters of biodiesel were studied in triplicate (density, acidity, saponification, viscosity, corrosiveness to copper, visual appearance, and cloud point). An analysis by thin layer chromatography and infrared spectrometry was also performed. The increase in yield (83.3%) was directly proportional to the increase in the catalyst (0.22 g of NaOH). The infrared absorption spectra of WCO and biodiesel showed the presence of common and singular bands of each material. Furthermore, a simple and low-cost mechanism was proposed for purifying glycerol. The spectra of glycerol versus purified glycerin showed that the glycerin produced was pure, being used in the formulation of bioplastic. The product was checked for biodegradation and photodegradation, with incredible soil-degradation times of 180 days and photodegradation of only 60 days. In this way, biodiesel production from WCO showed environmentally friendly proposals and applicability. As the next steps, it is necessary to test the biodiesel produced in combustion engines and improve the bioplastic production, including a spectroscopic characterization and extensive biodegradation testing.

Micelle effect on the conversion of micropore to mesoporous molecular sieves and biodiesel synthesis

Tetrabutylammonium bromide (TBAB) is used as a template for the preparation of AlPO4 and AlSiO4 materials by the hydrothermal method. TBAB is acting as individual template molecules due to this...

Brazilian açaí berry seeds: an abundant waste applied in the synthesis of carbon-based acid catalysts for transesterification of low free fatty acid waste cooking oil

Residues of açaí seeds (Euterpe oleracea Mart.) were a novel source for the synthesis of the acid heterogeneous catalyst applied in the conversion of low free fatty acid waste cooking oil (WCO) to biodiesel. Yield of activated carbon (AC) and catalyst (CAT), as well as density of SO₃H groups and total acidity, was analyzed in an entirely random designed experiment using multiple linear regression, one-way ANOVA, and Tukey's post hoc test. Time, temperature, dosage of KOH, and ratio of H₂SO₄/AC were the predictor variables with 3 levels each, at a significance level of α = .05. A significant yield variation portion of AC was explained by the experimental factors (R² = .891, F (3, 23) = 62.9, p < .0001), as did the yield of CAT (R² = .960, F (3, 23) = 185.7, p < .0001), density of SO₃H (R² = .969, F (3, 23) = 242.2, p < .0001), and total acidity (R² = .973, F (3, 23) = 280.6, p < .0001). Levels of time (p = .001) and KOH dosage (p = .006) were significant to the yield of AC, and temperature levels were not influent on density of SO₃H (p = .731) or total acidity (p = .762). CAT showed a S_BET of 249 m² g^-1, V_pore of 0.104 cm³ g^-1, low crystallinity, high thermal stability, and a mesoporous amorphous structure. Optimized catalytic tests resulted in 89% conversion of WCO and 11 cycles of reuse, better than pure H₂SO₄ or pure KOH (p < .0001) and also better than many biomass-derived catalysts reported in the literature.

Experimental investigation of biodiesel production from Madhuca longifolia seed through in situ transesterification and its kinetics and thermodynamic studies

The present investigation aims to develop simultaneous extraction and conversion of inedible Madhuca longifolia seed oil into biodiesel by one-step acid-catalyzed in situ transesterification/reactive extraction process. Six different types of pretreatment were used to assess maximum yield of biodiesel. The maximum yield of 96% biodiesel was acquired with ultrasonic pretreatment at 1% moisture content, 0.61 mm seed grain size, 55 °C temperature, 400 rpm stirring speed, 15 wt% catalyst (H₂SO₄) concentration, and with 1:35 seed oil to methanol ratio in a time period of 180 min. This reaction kinetics precedes first order also the finest value of rate constant and activation energy were calculated as 0.003 min^-1 and 14.840 kJ mol^-1. The thermodynamic energy properties ΔG, ΔH, and ΔS are computed as 96457.172 J/mol, 12121.812 J/mol K, and - 257.12 J/mol K correspondingly. The enumerated outcome illustrates a heat absorb non-spontaneous/endergonic and endothermal reaction. The result of proposed work unveils ultrasonic pretreatment escalates the biodiesel efficiency and reactive extraction exemplifies the clean, cost-effective single-step approach for production of biodiesel from non-edible sources.