Biodiesel production from waste cooking oil using copper doped zinc oxide nanocomposite as heterogeneous catalyst

Exploring the Impact of Al2O3 Additives in Gasoline on HCCI-DI Engine Performance: An Experimental, Neural Network, and Regression Analysis Approach

This study delves into the influence of incorporating alumina (Al2O3) nanoparticles with waste cooking oil (WCO) biofuels in a gasoline engine that employs premixed fuel. During the suction phase, gasoline blends with atmospheric air homogeneously at the location of the inlet manifold. The biodiesel, enhanced with Al2O3 nanoparticles and derived from WCO, is subsequently directly infused into the combustion chamber at 23° before the top dead center. The results highlight that when gasoline operates in the homogeneous charge compression ignition with direct injection (HCCI-DI) mode, there is a notable enhancement in thermal efficiency by 4.23% in comparison to standard diesel combustion. Incorporating the Al2O3 nanoparticles with the WCO biodiesel contributes to an extra rise of 6.76% in thermal efficiency. Additionally, HCCI-DI combustion paves the way for a reduction in nitrogen oxides and smoke emissions, whereas biodiesel laced with Al2O3 nanoparticles notably reduces hydrocarbon and carbon monoxide discharges. Predictive tools such as artificial neural networks and regression modeling were employed to forecast engine performance variables.

A comprehensive review on nanocatalysts and nanobiocatalysts for biodiesel production in Indonesia, Malaysia, Brazil and USA

Biodiesel is an alternative to fossil-derived diesel with similar properties and several environmental benefits. Biodiesel production using conventional catalysts such as homogeneous, heterogeneous, or enzymatic catalysts faces a problem regarding catalysts deactivation after repeated reaction cycles. Heterogeneous nanocatalysts and nanobiocatalysts (enzymes) have shown better advantages due to higher activity, recyclability, larger surface area, and improved active sites. Despite a large number of studies on this subject, there are still challenges regarding its stability, recyclability, and scale-up processes for biodiesel production. Therefore, the purpose of this study is to review current modifications and role of nanocatalysts and nanobiocatalysts and also to observe effect of various parameters on biodiesel production. Nanocatalysts and nanobiocatalysts demonstrate long-term stability due to strong Brønsted-Lewis acidity, larger active spots and better accessibility leading to enhancethe biodiesel production. Incorporation of metal supporting positively contributes to shorten the reaction time and enhance the longer reusability. Furthermore, proper operating parameters play a vital role to optimize the biodiesel productivity in the commercial scale process due to higher conversion, yield and selectivity with the lower process cost. This article also analyses the relationship between different types of feedstocks towards the quality and quantity of biodiesel production. Crude palm oil is convinced as the most prospective and promising feedstock due to massive production, low cost, and easily available. It also evaluates key factors and technologies for biodiesel production in Indonesia, Malaysia, Brazil, and the USA as the biggest biodiesel production supply.

Lignocellulosic Biorefinery Technologies: A Perception into Recent Advances in Biomass Fractionation, Biorefineries, Economic Hurdles and Market Outlook

Lignocellulosic biomasses (LCB) are sustainable and abundantly available feedstocks for the production of biofuel and biochemicals via suitable bioconversion processing. The main aim of this review is to focus on strategies needed for the progression of viable lignocellulosic biomass-based biorefineries (integrated approaches) to generate biofuels and biochemicals. Processing biomass in a sustainable manner is a major challenge that demands the accomplishment of basic requirements relating to cost effectiveness and environmental sustainability. The challenges associated with biomass availability and the bioconversion process have been explained in detail in this review. Limitations associated with biomass structural composition can obstruct the feasibility of biofuel production, especially in mono-process approaches. In such cases, biorefinery approaches and integrated systems certainly lead to improved biofuel conversion. This review paper provides a summary of mono and integrated approaches, their limitations and advantages in LCB bioconversion to biofuel and biochemicals.

Utilization of Nanotechnology and Nanomaterials in Biodiesel Production and Property Enhancement

In today’s world, the applications of nanotechnology and nanomaterials are attracting interest in a wide variety of study domains because of their appealing qualities. The use of nanotechnology and nanomaterials in biodiesel processing and manufacturing is a focus of research globally. For accelerating the progress and development of biodiesel production, more focus is being given to the application of advanced nanotechnology for maximum yield in low cost. Hence, this paper will discuss the utilization of numerous nanomaterials/nanocatalysts for biodiesel synthesis from multiple feedstocks. This study will also focus on nanomaterials’ applications in algae cultivation and lipid extraction. Furthermore, the current study will comprehensively overview the nanoadditives blended biodiesel in diesel engines and the significant challenges and future opportunities. Moreover, this paper will also focus on human and environmental safety concerns of nanotechnology-based large-scale biodiesel production. Hence, this review will provide perception for future manufacturers, researchers, and academicians into the extent of research in nanotechnology and nanomaterials assisted biodiesel production and its efficiency enhancement.

Biodiesel Production Using Wild Apricot (Prunus aitchisonii) Seed Oil via Heterogeneous Catalysts

We confined the formation and characterization of heterogenous nano-catalysts and then used them to produce biodiesel from the novel non-edible seed oil of Prunus aitchisonii. P. aitchisonii seeds' oil content was extracted at about 52.4 ± 3% with 0.77% FFA. Three different heterogenous nano-catalysts-calcined (CPC), KPC, and KOH-activated P. aitchisonii cake Titanium Dioxide (TiO2)-were synthesized using calcination and precipitation methods. The mentioned catalysts were characterized through XRD, SEM, and EDX to inspect their crystallin dimension, shape, and arrangement. Titanium dioxide has morphological dimensions so that the average particle size ranges from 49-60 nm. The result shows that the crystal structure of TiO2 is tetragonal (Anatase). The surface morphology of CPC illustrated that the roughness of the surface was increased after calcination, many macropores and hollow cavities appeared, and the external structure became very porous. These changes in morphology may increase the catalytic efficiency of CPC than non-calcined Prunus aitchisonii oil cake. The fuel belonging to PAOB stood according to the series suggested by ASTM criteria. All the characterization reports that P. aitchisonii is a novel and efficient potential source of biodiesel as a green energy source.

Heterogeneous nanocatalyst for biodiesel fuel production: bench scale from waste oil sources

Biodiesel is a promising clean energy supply that can be made from sustainable and low-grade fuels using a variety of methods. Transesterification is one of the processes that can occur in the manifestation of an effective catalyst. The catalyst may be homogeneous or heterogeneous in nature. This article reviews on the formation of biodiesel from various sources of waste oils using heterogeneous nanocatalysts. The manufacture of biodiesel using homogeneous and heterogeneous catalysis had been extensively studied, and new heterogeneous catalysts are constantly being examined. In general, homogeneous catalysts are effective at remodeling biodiesel with low free fatty acid (FFA) and single-origin feedstock having water. Heterogeneous catalysts, instead have higher interest, a wider scope of selectivity, better FFA, and better water adaptability. These properties are regulated by the number and intensity of active basic or acid sites. In order to achieve a viable alternative to conventional homogeneous catalysts for biodiesel processing, heterogeneous catalysts made from waste and biocatalysts are needed. Nanocatalysts have recently attracted interest due to their high catalytic performance under favorable operating conditions. This review evaluates the usage of heterogeneous nanocatalysts for the production of biodiesel from different sources of waste oil and the factors effecting the process of biodiesel production.

Ionic Liquid Co-Catalyst Assisted Biodiesel Production From Waste Cooking Oil Using Heterogeneous Nanocatalyst: Optimization and Characterization

In the present work, the biodiesel was produced from waste cooking oil (WCO) using heterogeneous zinc doped iron nanocatalyst and tetrabutylammonium iodide (TBAI) as co-catalyst. The heterogeneous zinc doped iron nanocatalyst was synthesized and characterized. The functional group in the heterogeneous nanocatalyst was confirmed using FTIR analysis, the crystalline nature was studied by XRD analysis, and the size and structure of the nanocatalyst were analyzed by SEM. The optimization of transesterification parameters like oil to methanol molar ratio, zinc doped iron concentration, TBAI concentration, temperature, and time were carried out for the maximum conversion of biodiesel from WCO. At 50 min the maximum biodiesel conversion of 90% was achieved at 55°C with 12% catalyst, 30% co-catalyst, and 1:11 WCO to methanol ratio. The presence of functional groups and the methyl ester composition of the biodiesel from WCO were confirmed by FTIR and GC-MS analysis. The use of zinc doped iron nanocatalyst with TBAI showed good catalytic activity to produce biodiesel from WCO.

Dietary exposure of zinc oxide nanoparticles (ZnO-NPs) from canned seafood by single particle ICP-MS: Balancing of risks and benefits for human health

The present study aims to give information regarding the quantification of ZnO-NPs in canned seafood, which may be intentionally or unintentionally added, and to provide a first esteem of dietary exposure. Samples were subjected to an alkaline digestion and assessment of ZnO-NPs was performed by the single particle ICP-MS technique. ZnO-NPs were found with concentrations range from 0.003 to 0.010 mg/kg and a size mean range from 61.3 and 78.6 nm. It was not observed a clear bioaccumulation trend according to trophic level and size of seafood species, although the mollusk species has slightly higher concentrations and larger size. The number of ZnO-NPs/g does not differ significantly among food samples, observing an average range of 5.51 × 10⁶ - 9.97 × 10⁶. Dissolved Zn determined with spICP-MS revealed comparable concentration to total Zn determined with ICP-MS in standard mode, confirming the efficiency of alkaline digestion on the extraction of the Zn. The same accumulation trend found for ZnO-NPs was observed more clearly for dissolved Zn. The ZnO-NPs intake derived from a meal does not differ significantly among seafood products and it ranges from 0.010 to 0.031 µg/kg b.w. in adult, and from 0.022 to 0.067 µg/kg b.w. in child. Conversely, the intake of dissolved Zn is significantly higher if it is assumed a meal of mollusks versus the fish products, with values of 109.3 µg/kg b.w. for adult and 240.1 µg/kg b.w. for child. Our findings revealed that ZnO-NPs have the potential to bioaccumulate in marine organisms, and seafood could be an important uptake route of ZnO-NPs. These results could be a first important step to understand the ZnO-NPs human dietary exposure, but the characterization and quantification of ZnO-NPs is necessary for a large number of food items.

Conversion of waste seed oil of Citrus aurantium into methyl ester via green and recyclable nanoparticles of zirconium oxide in the context of circular bioeconomy approach

In the current scenario of energy crises and depleting fossil fuels, there is need of sustainable and cheaper interventions with green technology to address these obstinate glitches. Biodiesel produced from waste, non-edible seed oils is a cleaner, green and alternate source of fuel for diesel engines which can possibly add to circular bioeconomy. In this study, Citrus aurantium a novel, nonedible and waste seed oil (38% w/w) producing feedstock was subjected to biodiesel synthesis using recyclable zirconium oxide nano particles synthesized with Alternanthera pungens aqueous leave extract. Maximum yield of 94% was obtained through optimized reaction parameters of methanol to oil molar ratio 6:1, reaction time 120 min, temperature 87.5 °C and catalyst loading of 0.5 wt% using Response Surface Methodology. Green nano particles of zirconium oxide were characterized via Scanning Electron Microscopy (SEM), X-Ray Diffraction (XRD) and Energy diffraction X-Ray (EDX) while; physiochemical characterization of synthesized biodiesel was carried through Fourier-transform infrared spectroscopy (FTIR), Gas Chromatography/Mass spectroscopy (GC/MS), and Nuclear magnetic resonance (NMR ¹H and ¹³C). Fuel properties of methyl ester met international standards of ASTM D-6571, EN 14214 and China GB/T 20828-2007. It was concluded that biodiesel production from Citrus aurantium waste and non-edible seed oil can be efficiently employed for generation of renewable energy which would further provide assistance in transformation of linear economy to circular bioeconomy.

NaOH-Catalyzed Methanolysis Optimization of Biodiesel Synthesis from Desert Date Seed Kernel Oil

Biodiesel synthesis from non-edible vegetable oil via catalytic transesterification is one of the effective ways to replace petroleum-based fuels in the area of renewable energy development and is beneficial to environmental security. Therefore, this research investigates the optimization of process parameters (temperature, methanol to oil ratio, and NaOH catalyst dose) for the conversion of biodiesel from non-edible desert date (Balanites Aegyptiaca) seed kernel oil using the Box-Behnken experimental design of response surface methodology statistical analysis. Accordingly, the optimum values of reaction conditions, namely, a temperature of 60.5 °C, methanol to oil ratio of 6.7:1, and catalyst dose of 0.79 %wt, yielded 93.16% biodiesel. Fourier transform infrared spectroscopy analysis confirmed the cracking of a single glycerol backbone from the triglycerides and the substitution by methoxyl in the presence of a NaOH catalyst. The physicochemical properties of the biodiesel were investigated and compared with standards in terms of its density, viscosity, higher heating value, acid value, saponification value, cetane number, cloud point, pour point, and flash point, and the values are within the recommended standard limits of American Standard for Testing Material (ASTM D6751) and European Committee for Standardization (EN14214). Thus, the results revealed that homogeneous base catalysis of non-edible oil under optimum reaction conditions provides high yield of biodiesel.

Heterogeneous ZnO-containing catalysts for efficient biodiesel production

Biodiesel is one of the main biofuels used to replace fossil resources, and is mainly produced from esterification and transesterification of fatty acids and oils catalyzed by acids, bases or enzymes. Among the existing catalysts, metal oxides and their derivatives play an important role because of their high catalytic activity and low cost. ZnO is a metal oxide and its related nanomaterials are easy to prepare, which gives ZnO superior reactivity and extensive applications. Suitably modified ZnO nanomaterials typically have high specific surface areas, suitable pore sizes, and enhanced catalytic performance in the production of biodiesel. The present review introduces the application progress of ZnO catalysts in biodiesel preparation. The current shortcomings and future challenges of the basic heterogeneous catalytic systems for biodiesel production are also discussed.

Nanoferrites heterogeneous catalysts for biodiesel production from soybean and canola oil: a review

Fossil fuel depletion and pollution are calling for alternative, renewable energies such as biofuels. Actual challenges include the design of efficient processes and catalysts to convert various feedstocks into biofuels. Here, we review nanoferrites heterogeneous catalysts to produce biodiesel from soybean and canola oil. For that, transesterification is the main synthesis route and offers simplicity, cost-effectiveness, better process control, and high conversion yield. Catalysis with nanoferrites and composites allow to obtain yields higher than 95% conversion with less than 5.0 wt.% of catalyst loading at 80 °C in 1-2 h. More than 90% conversion yields can be achieved with a moderate alcohol/oil molar ratio, i.e., between 12:1 to 16:1. Catalyst recovery is easy due to the magnetic properties of nanoferrite, which can be effectively reused up to 4 times with less than 10% loss of catalytic efficiency.

Implication, visualization, and characterization through scanning electron microscopy as a tool to identify nonedible oil seeds

Second-generation biofuels prove to be a distinctive and renewable source of sustainable energy and cleaner environment. The current study focuses on the exploration and identification of four nonedible sources, that is, Brassica oleracea L., Carthamus oxyacantha M.Bieb., Carthamus tinctorius L., and Beaumontia grandiflora Wall., utilizing light microscopy (LM) and scanning electron microscopy (SEM) for studying the detailed micromorphological features of these seeds. LM revealed that size ranges from 3 to 20 mm. furthermore, a great variety of color is observed from pitch black to greenish gray and yellowish white to off white. Seeds ultrastructure study with the help of SEM revealed a great variety in shape, size, color, sculpturing and periclinal wall shape, and so on. Followed by the production of fatty acid methyl esters from a novel source, that is, seeds oil of Brassica oleracea L. (seed oil content 42.20%, FFA content 0.329 mg KOH/g) using triple metal impregnated montmorillonite clay catalyst (Cu-Mg-Zn-Mmt). Catalyst was characterized using SEM-EDX, FT-IR. Maximum yield of Brassica oleracea L. biodiesel (87%) was obtained at the conditions; 1:9 of oil to methanol ratio, 0.5 g of catalyst, 5 hr reaction time, and 90°C of temperature. Synthesized biodiesel was characterized by FT-IR, GC-MS, and NMR. Fuel properties of the Brassica oleracea L. FAMES were determined and found in accordance with ASTM standards.

Multilayered Nano-Entrapment of Lipase through Organic-Inorganic Hybrid Formation and the Application in Cost-Effective Biodiesel Production

Significant components of cost-effective medium for Magnusiomyces capitatus A4C extracellular lipase (ECL) production were optimized via a five-level factorial design. A simplistic, economical, and green approach was adopted for biomimetic mineralization to prepare multilayered nano-entrapped ECL, which were then applied as biocatalysts for the production of fatty acid methyl ester (FAME). The optimal ECL (0.8 mg protein/mL) and CuSO₄∙5H₂O (1.2 mM) showed the highest capacity for enzyme loading. The ECL-CuSO₄-hybrid showed an 89.7% conversion of triacylglycerides into FAME via transesterification and a 98.7% conversion of oleic acid into FAME via esterification at 72 h. The ECL-CuSO₄-hybrid gave 65% and 78.7% FAME production after 5 successive reuses via transesterification and esterification reactions, respectively. Therefore, these ECL-inorganic hybrid biocatalysts have high economical potential to be used for the production of biodiesel as the future petrodiesel replacement.

Transesterification of waste edible oils to biodiesel using calcium oxide@magnesium oxide nanocatalyst

In the present research, application of waste edible oil (WEO) as a suitable and abundant source for biodiesel production using CaO@MgO nanocatalyst derived from waste chicken eggshells was studied. To this end, FT-IR, XRD, SEM, EDX, Map, and TEM analyses were performed to investigate characteristics of the CaO@MgO nanocatalyst. Also, the physical properties of the biodiesel such as flash point, kinematic viscosity, density, distillation point, cloud point, pour point, cetane number, oxidation stability, and acid number were determined according to the international standards. In addition, FT-IR and HNMR analyses were used to determine the biodiesel characteristics. Moreover, the produced catalyst was successively reused for up to 6 cycles and the results showed that the catalytic activity of the catalyst produced was sufficient for biodiesel production from WEO for up to three cycles, beyond which its catalytic activity decreased. The present work further considered the effects of different parameters on biodiesel production using central composite design to determine optimal conditions. According to the results, the highest biodiesel conversion yield (98.37%) was achieved in a reaction time of 7.08 h, reaction temperature of 69.37 °C, methanol-to-oil ratio of 16.7:1, and catalyst concentration of 4.571 wt% which shows the highest biodiesel conversion yield ever achieved from waste edible oil.

Production of green diesel from catalytic deoxygenation of chicken fat oil over a series binary metal oxide-supported MWCNTs

Deoxygenation processes that exploit milder reaction conditions under H₂-free atmospheres appear environmentally and economically effective for the production of green diesel.

Efficient deoxygenation of waste cooking oil over Co3O4–La2O3-doped activated carbon for the production of diesel-like fuel

Untreated waste cooking oil (WCO) with significant levels of water and fatty acids (FFAs) was deoxygenated over Co₃O₄–La₂O₃/AC_nano catalysts under an inert flow of N₂ in a micro-batch closed system for the production of green diesel.

The Effect of Various Components of Triglycerides and Conversion Factor on Energy Consumption in Biodiesel Production

Major components of triglycerides in palm oil are palmitic acid, oleic acid, and linoleic acid, in which the presence of these components effects the final purity of a biodiesel. Since reaction process and type of catalyst influence the composition of the free fatty acid (FFA) ASPEN HYSYS was used to simulate a biodiesel production process. Furthermore, higher yield of biodiesel was desired to increase its efficiency as fuel application. Palm oil was taken as the raw material at different components of FFA wt% by using sulphated zirconium (SZ) as the catalyst. Three simulations of biodiesel production processes were performed using ASPEN HYSYS based on 99 % of conversion factor to determine the energy consumption and the results were compared. The conversion factor for each component and the mixture of all of the components was discussed. Results showed that triolein with 0.12 wt% of oleic acid produced 99.75 % of biodiesel, while tripalmitin with 0.5 wt% of palmitic acid is the most abundant FFA in palm oil producing 99.67 % of biodiesel. The total energy consumption in the three processes were different because, different types of feedstocks and unit operations arrangements have been used.

Process enhancement of supercritical methanol biodiesel production by packing beds

Continuous fixed bed reactors filled by three kinds of packing which were glass bead, glass spring and Dixon rings were investigated. The effect of temperature, pressure, the molar ratio of methanol to oil, flow rate, the size and shape of the packing were researched. The highest yield 90.84% of FAME was obtained by filling Dixon rings as packing with the condition of the temperature was 350°C, the pressure was 22MPa, the molar ratio of methanol to oil was 42:1. In addition, the reusability of Dixon rings was perfect. Numerical simulation was researched to provide theoretical basis for experimental results, besides the kinetics and thermodynamics behavior were investigated to explore the reaction mechanism.

Continuous flow through a microwave oven for the large-scale production of biodiesel from waste cooking oil

This report presents a method for producing large quantities of biodiesel from waste cooking oil (WCO). Preliminary studies on optimization of the WCO transesterification process in a continuous-flow microwave reactor are carried out using commercial SrO as a catalyst. The SrO catalyst can be separated and reused for five reaction cycles without loss in activity. Challenges like mass flow and pressure drop constraints need to be surmounted. SrO nanoparticles deposited on millimeter-sized (3-6mm) silica beads (41wt% SrO/SiO₂) are prepared and evaluated as a substitute for the SrO catalyst. A WCO conversion value to biodiesel as high as 99.2wt% was achieved with the reactor packed with 15g of 41wt% SrO/SiO₂ catalyst in 8.2min with 820mL of feed. Excellent performance of the fixed-bed catalyst without loss in activity for a lifetime of 24.6min converting a feed of 2.46L to FAME was observed.

Synthesis of fatty acid methyl ester from the transesterification of high- and low-acid-content crude palm oil (Elaeis guineensis) and karanj oil (Pongamia pinnata) over a calcium-lanthanum-aluminum mixed-oxides catalyst

The synthesis of fatty acid methyl ester (FAME) from the high- and low-acid-content feedstock of crude palm oil (CPO) and karanj oil (KO) was conducted over CaO-La2O3-Al2O3 mixed-oxide catalyst. Various reaction parameters were investigated using a batch reactor to identify the best reaction condition that results in the highest FAME yield for each type of oil. The transesterification of CPO resulted in a 97.81% FAME yield with the process conditions of 170°C reaction temperature, 15:1 DMC-to-CPO molar ratio, 180min reaction time, and 10wt.% catalyst loading. The transesterification of KO resulted in a 96.77% FAME yield with the conditions of 150°C reaction temperature, 9:1 DMC-to-KO molar ratio, 180min reaction time, and 5wt.% catalyst loading. The properties of both products met the ASTM D6751 and EN 14214 standard requirements. The above results showed that the CaO-La2O3-Al2O3 mixed-oxide catalyst was suitable for high- and low-acid-content vegetable oil.

Biodiesel production from soybean oil by quaternized polysulfone alkali-catalyzed membrane

A series of alkalized polysulfones (APSF) were synthesized by several chemical reactions (chloromethylation, quaternization and alkalization). Among these reactions, chloromethylation and quaternization are two key reactions and have been studied in detail regarding the optimization of both chloromethylation and quaternization. FTIR and (1)H NMR spectrum confirmed the successful preparation of chloromethylated polysulfone. The best IEC of APSF was obtained for 1.68meqg(-1) under reaction time of 10h and reaction temperature of 45°C. The APSF membrane as a heterogeneous catalyst for the transesterification of soybean oil with methanol was prepared through the method of solvent evaporation phase inversion. The effects of co-solvent types, mass ratios of soybean oil/co-solvent, water content and free fatty acids (FFAs) content in soybean oil on the conversions using the APSF membrane during transesterification were studied. The reusability of the APSF membrane and the kinetics of the reaction catalyzed by the APSF membrane were also investigated.

Process optimization and kinetics of biodiesel production from neem oil using copper doped zinc oxide heterogeneous nanocatalyst

Heterogeneous nanocatalyst has become the choice of researchers for better transesterification of vegetable oils to biodiesel. In the present study, transesterification reaction was optimized and kinetics was studied for biodiesel production from neem oil using CZO nanocatalyst. The highly porous and non-uniform surface of the CZO nanocatalyst was confirmed by AFM analysis, which leads to the aggregation of CZO nanoparticles in the form of multi layered nanostructures. The 97.18% biodiesel yield was obtained in 60min reaction time at 55°C using 10% (w/w) CZO nanocatalyst and 1:10 (v:v) oil:methanol ratio. Biodiesel yield of 73.95% was obtained using recycled nanocatalyst in sixth cycle. The obtained biodiesel was confirmed using GC-MS and (1)H NMR analysis. Reaction kinetic models were tested on biodiesel production, first order kinetic model was found fit with experimental data (R(2)=0.9452). The activation energy of 233.88kJ/mol was required for transesterification of neem oil into biodiesel using CZO nanocatalyst.