This study examined the potential of nanocatalyst CuO-CeO 2 and Fe 2 O 3 for efficient conversion of Sterculia foetida seed Oil into biodiesel. S. foetida contains 40% oil content and low free fatty acid value (0.18 mg KOH/g). The synthesized nanocatalyst was characterized using X-Ray Diffraction (XRD), Fourier Transform Infrared Spectroscopy (FT-IR), and Scanning Electron Microscopy (SEM) techniques. The maximum conversion was achieved (92% yield) using CuO-CeO 2 at 0.25% catalyst loading. The optimized reaction was carried out by experimental variables included molar ratio (1:9), temperature (70 • C), reaction time (3 h) and stirring rate (600 rpm) using reflux transesterification method. The XRD results showed the size of crystals with order 54.4 nm for CuO-CeO 2 and 31.3 nm for Fe 2 O 3. The SEM images of CuO-CeO 2 showed spherical structure having an average particle size of 32.3 nm. SEM images of Fe 2 O 3 showed the size ranges from 46.27 to 28.76 nm having regular morphology, including spherical shape. The FT-IR analysis of this nanocatalyst also reinforced the results of this study. Gas Chromatography Mass Spectroscopy (GC-MS) and Fourier Transform Infrared Spectroscopy (FT-IR) confirmed the efficient conversion of S. foetida seed oil into biodiesel using prepared nanocatalysts. The prepared nanocatalysts are cheaper, readily available and can be used for industrial scale biofuel production assembly, making it economically feasible and more cost effective.

The current study focuses on the synthesis of Cerium oxide (CeO2) nanocatalyst via Tragacanth Gum (TG) using the wet impregnation method and its application for sustainable biodiesel production from a novel, non-edible Descurainia sophia (L.) Webb ex Prantl seed oil. The D. sophia seed oil has higher oil content (36 wt%) and free fatty acid (FFA) value (0.6 mg KOH/g). Innovative analytical methods, such as X-ray diffraction (XRD), scanning electron microscopy (SEM), energy dispersive X-ray (EDX), transmission electron microscopy (TEM), thermogravimetric analysis (TGA), and Fourier transform infrared spectroscopy, were used to characterize the newly synthesized, environmentally friendly, and recyclable CeO2-TG phytonanocatalyst (FT-IR). The results show that the CeO2-TG phytonanocatalyst was 22 nm in diameter with a spherical shape outer morphology, while the inner structure was hexagonal. Due to low FFA content, the D. sophia seed oil was pretreated and transesterified via a single step. Using varying parameters, the optimized process variables were determined via Response Surface Methodology (RSM). The optimum process values were 8:1 methanol to oil molar ratio, 0.3 wt% catalyst concentration, 90 °C temperature, and reaction time of 210 min with 98% biodiesel yield. The recently created phytonanocatalyst was reliable and effective, with three times reusability in the transesterification reaction. Thin layer chromatography (TLC), FT-IR, gas chromatography–mass spectroscopy (GCMS), and Nuclear magnetic resonance (NMR) analyses were used to characterize the synthesized biodiesel. Physico-chemical properties of D. sophia biodiesel, i.e., Kinematic viscosity (4.23 mm2/s), density (0.800 kg/m3), pour point (−7 °C), cloud point (−12 °C), and flash point (73.5 °C) agree well with international biodiesel standards (ASTM-6751, 951), (EU-14214), and China (GB/T 20828) standards. The results show that the synthesized nanocatalyst demonstrated remarkable stability, indicating a bright future for industrial biodiesel production from low-cost feedstock.

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.

Biodiesel is a promising, bio‐based, renewable, nontoxic, environment friendly, and alternative fuel for petroleum derived fuels which helps to reduce dependency on conventional fossil fuels. In this study, six novel, nonedible seed oil producing feedstock were explored for their potential for sustainable production of biodiesel. It is very important to correctly identify oil yielding plant species. Scanning electron microscopy (SEM) was used as reliable tool for authentic identification of oil yielding seeds. Macromorphological characters of seeds were studied with light microscopy (LM). Outcomes of LM of seeds exposed distinctive variation in seed size from 16.3 to 3.2 mm in length and 12.4 to 0.9 mm in width, shape varied from oval to triangular, and color from black to light brown. Oil content of nonedible seed ranged from 25 to 30% (w/w). Free fatty acid content of seed oil varied from 0.32 to 2.5 mg KOH/g. Moreover, ultra structural study of seeds via SEM showed variation in surface sculpturing, cell arrangement, cell shape, periclinal wall shape, margins, protuberances, and anticlinal wall shape. Surface sculpturing varied from rugged, reticulate, varrucose, papillate, and striate. Periclinal wall arrangements confirmed variation from rough, wavy, raised, depressed, smooth, and elevated whereas, anticlinal walls pattern showed variation from profuse undulating, smooth, raised, grooved, deep, curved, and depressed. It was concluded that SEM could be a latent and advanced technique in unveiling hidden micromorphological characters of nonedible oil yielding seeds which delivers valuable information to researchers and indigenous people for precise and authentic identification and recognition.

In the current study, a novel green nano-catalyst from Tragacanth gum (TG) was synthesized and used for sustainable biodiesel production from Brassica juncea (L.) Czern. seed oil. Brassica juncea (L.) Czern contains 30% oil on dry basis and free fatty acid content of 0.43 mg KOH/g. Physiochemical characterization of a newly synthesized nano-catalyst was performed by X-ray Diffraction (XRD), Scanning Electron Microscopy (SEM), Energy Dispersive X-ray (EDX), Transmission Electron Microscopy (TEM), and Fourier Transform Infrared Spectroscopy (FT-IR) analysis. The XRD results showed an average crystalline size of 39.29 nm. TEM analysis showed the cluster form of NiSO4 nanoparticles with a size range from 30–50.5 nm. SEM analysis of the catalyst showed semispherical and ovoid shapes with surface agglomeration. The synthesized catalyst was recovered and re-used in four repeated transesterification cycles. Maximum biodiesel yield (93%) was accomplished at 6:1 methanol to oil molar ratio, catalyst concentration of 0.3 wt%, at 90 °C for 120 min at 600 rpm using Response Surface Methodology (RSM) coupled with central composite design (CCD). Brassica juncea (L.) Czern. biodiesel was characterized by Thin Layer Chromatography (TLC), FT-IR, Nuclear Magnetic Resonance (NMR) (1H, 13C), and Gas Chromatography-Mass Spectroscopy (GCMS) analytical techniques. The major fatty acid methyl esters were 16-Octadecenoic acid and 9-Octadecenoic acid methyl ester. The fuel properties, i.e., flash point (97 °C), density (825 kg/m3 at 40 °C), kinematic viscosity (4.66 mm2/s), pour point (–10 °C), cloud point (–14 °C), sulfur content (66 wt.%), and total acid number (182 mg KOH/g) were according to the International biodiesel standards. The reaction kinetic parameters were determined, and all the reactions followed Pseudo first-order kinetics. It was concluded that non-edible Brassica juncea (L.) Czern. seed oil is one of the sustainable candidates for the future biofuel industry using a cleaner, reusable, and highly active Ni-modified TG nano-catalyst.