Effect of calcination temperature on MnFeCoNiCu/activated carbon catalysts for hydrodeoxygenation of fatty acid methyl esters to bio-jet fuel and green diesel

Sustainable processing of geothermal waste into a functional catalyst for green diesel from hydrocracking castor oil

Activity of NiMo and CoMo catalysts supported on Ti-pillared bentonite for converting waste cooking oil into green diesel

Catalytic hydrodeoxygenation of jatropha oil into green diesel over natural zeolite-supported cobalt catalyst: Insight into Co concentration effect

This work offers a methodical examination of the hydrogenation of taramira oil using gamma alumina-assisted nickel molybdenum catalyst at pressure and temperature of 400°C and 4 MPa respectively. It was observed that the conversion of fatty acids and triglycerides into hydrocarbons is significantly influenced by temperature and pressure. The resulting mixture of gases and other substances is subjected to fractional distillation, wherein it is separated at various boiling points. The chemical composition of the obtained taramira hydrogenated renewable diesel (HRD) was carried out using gas chromatography flame ionisation detector (GC-FID) chemical composition testing. The paraffin chain C 15 –C 18 i.e., diesel fuel ranges accounted for the final product’s major composition; miscellaneous components include paraffin and lubricating oils. A hydrogenated renewable paraffinic fuel’s physicochemical characteristics were evaluated and contrasted with those of biodiesel and conventional diesel. When comparing HRD (also known as green diesel), biodiesel and diesel, it is determined that green diesel has the finest physical-chemical qualities. With its high cetane index and favourable cold flow characteristics, HRD is used as a ‘drop-in’ fuel. Conversely, oxidation stability and kinematic viscosity for both diesel and HRD were almost identical. The obtained HRD shows a calorific value (CV) higher than the biodiesel. The elemental analysis for the obtained HRD uses a CHNS elemental analyser. The analysis results show that the carbon-hydrogen content of HRD is comparable to that of diesel and higher than that of biodiesel.

Synergistic RuPt alloy nanoparticles on halloysite nanotubes for efficient decarboxylation of stearic acid to green diesel under mild conditions

Green diesel production via deoxygenation of used cooking oil over metal-support γ-Al₂O₃ catalysts: A comparative study of Ni and Co

Deoxygenation of waste corn oil over γ-Al₂O₃-supported Ni, Mo, and Ni–Mo catalysts for sustainable green diesel production

South Korea has decided to increase the mandatory biodiesel (BD) blending ratio from 5.0% to 8.0% in 2030 to mitigate CO2 emissions. This study provides a nationally representative empirical estimate of public willingness to pay (WTP) specifically for increasing the mandatory BD blending ratio, and addresses a critical gap in the literature on biofuel policy acceptance. Although a one-and-one-half-bound format was employed, the single-bound spike model is adopted as the main specification due to evidence of response effects. This paper seeks to delve into public acceptance of the increase by gathering and analyzing the data on the public’s WTP through the application of contingent valuation (CV). Based on a national CV survey administered over a five-week period from mid-April to mid-May 2025, 1000 valid observations were obtained and analyzed. Since 60.5% of all respondents stated a WTP of 0, a spike model that could account for this was adopted. The key coefficients and the model achieved statistical significance. The average household WTP figure obtained was KRW 5052.3 (USD 3.50) per annum. Expanding this value to the entire population gives us KRW 111.69 billion (USD 77.46 million) annually, based on December 2024 constant prices. The additional costs in 2030 resulting from the increase will reach KRW 456.24 billion (USD 316.41 million). Since the WTP figure is smaller than these additional costs, it seems that public acceptance is not sufficiently high. Therefore, it is necessary to implement policy measures such as government subsidies and research and development support to reduce the price of BD.

In this study, a techno-economic and carbon footprint (GHG, CO2-equivalent) analysis was conducted on two alternative biofuels, green diesel and bio-jet fuel, produced from renewable lipids. The focus of the work is the comparison of various lipid feedstocks, including waste cooking oil, and four types of vegetable oils: cardoon, soybean, palm, and sunflower. Process optimization and design were performed to minimize production costs by using the process simulation software Aspen Plus®. Green diesel and bio-jet fuel were obtained via hydrodeoxygenation and hydroisomerization/hydrocracking, respectively. Sensitivity analyses confirmed consistent results across the tested vegetable oils. Hydrodeoxygenation achieved triglyceride molar conversions exceeding 97%, with overall mass yields into the diesel fraction surpassing 79%. Conversely, hydroisomerization/hydrocracking of green diesel resulted in over 90% conversion of n-paraffins and more than 50% overall mass yield. The economic analysis showed that the primary cost factor influencing the payback selling price of the biofuels is the price of the lipid feedstocks. Biofuels are economically viable only when lipid prices are below 1000 €/ton and hydrogen prices are below 3000 €/ton. An important aspect is also represented by the combined-cycle energy recovery system, which strongly affects the overall capital cost and increases internal power generation efficiency. The carbon footprint calculated over a cradle-to-grave boundary showed shows net GHG reductions versus the fossil reference fuels for all scenarios. Net avoided emissions range from 1.74 to 3.63 kgCO2-eq/kg green diesel and from 0.80 to 3.70 kgCO2-eq/kg bio-jet fuel across the investigated feedstocks, approximately 40–84% and 20–95% of the respective savings relative to the fossil reference fuels under the stated background and logistics assumptions. Results are expressed per kg of produced fuel as a functional unit, using literature-derived upstream emission factors for oil supply and background inputs (hydrogen, Italian grid electricity and transport). For the bio-jet configuration, co-product burdens were partitioned by mass; the Discussion section highlights the sensitivity of the GD vs. BJF comparison to co-product handling and allocation choices. In this context, the choice of feedstock is essential in establishing the resulting GHG intensity of the two biofuels. From both economic and climate change perspectives, waste cooking oil emerges as the most promising option, particularly given its classification as waste-derived feedstock in the system boundary, unlike the virgin oil sources.

Abstract This study examines the impact of increasing the dolomite catalyst preparation’s physicochemical characteristics and catalytic effectiveness in converting used cooking oil into green diesel from laboratory scale (100 g) to 1 kg. Catalysts were synthesised using calcination under uniform temperature, duration, and heating rate parameters. A comprehensive catalyst characterisation was performed via BET surface area, SEM, and XRD analysis, while the composition of green diesel was assessed through GC-MS. The lab-scale catalyst (CMD LS ) displayed a greater surface area, larger macropores (63.07 nm), and higher crystallinity as compared to the upscaled catalyst (CMD US ). Catalyst characterization demonstrated that CMD LS achieved superior deoxygenation efficiency (52.75 % elimination of oxygenates), enhanced hydrocarbon compound (53.68 %), and reduced coke formation. These findings highlight the necessity for meticulous optimisation of pore structure and crystallinity during scaling up to maintain catalytic efficiency.

Similar global transcription patterns in mouse lung tissue following pulmonary exposure to renewable and conventional diesel engine exhaust particles.

Catalytic pyrolysis of macauba oils over eggshell-derived and commercial CaO for sustainable biohydrocarbon production to biogasoline, SAF, and green diesel formulation

Mechanical stirring (MS) and ultrasound (US) frequency are two key factors commonly used to reduce mass-transfer resistance during the reaction between methanol (MeOH) and triglycerides (TG), facilitating the efficient production of biodiesel (BD) from various feedstocks such as rapeseed oil and Jatropha curcas oil. In this study, a comparative model analysis has been conducted to evaluate the performance efficacy of optimum mechanical stirring (MS) and optimum ultrasound (US) frequency using rapeseed oil biodiesel production. Sensitivity and uncertainty analyses have been conducted using Latin hypercube sampling (LHS) and Partial Rank Correlation Coefficients (PRCCs) to identify the key kinetic and transport parameters influencing biodiesel yield. An optimal control framework has also been applied to regulate MS speed and US frequency over time to overcome initial mass-transfer resistance between oil and methanol. The influence of mixing intensity on biodiesel conversion has been examined at different temperatures and MeOH:oil molar ratios using mass-transfer correlations for both MS and US frequency. Numerical results show that, at a MeOH:TG molar ratio of 6:1 and temperature of 50 °C, optimal US frequency achieves a maximum biodiesel conversion of 97.67% within 40 min, whereas optimal MS attains 95.32% conversion after 60 min. The results further indicate that ultrasound provides faster mass-transfer enhancement and a superior production profile compared to mechanical stirring. This study addresses two key questions: whether rapeseed oil is a suitable feedstock for biodiesel production, and which mixing strategy, MS or US frequency, more effectively minimizes the mass-transfer resistance over time.

With no precedent in the literature, steel slag, an inexpensive and plentiful by-product of the steel industry, was discovered to be a highly selective and active catalyst for the hydrodeoxygenation (HDO) of triglycerides and fatty acids. This material, which is not always recyclable, proved to perform in the virgin state (without any chemical pretreatment), actually fostering the conversion, via a hydrothermal reaction, of palmitic and stearic acids into the corresponding (C16 and C18) alkanes with selectivity above 90%. In addition, by moving to a more complex system such as soybean oil, a complete conversion and the possibility of recycling the catalyst were maintained. Catalytic material, which came from an Italian steel industry (Acciaierie d’Italia), was characterized by XRF, XRD, N2 physisorption analyses, TPR, and TPD techniques. Catalytic performance was successfully correlated with the characterization results, and mechanistic proofs were provided on the catalytic role played by the several iron species present in the slag. The results reported in this work represent a significant contribution to the large-scale production of green diesel and, thanks to the possibility of using a catalyst based on steel slag in HDO processes, open the way to decarbonization and climate neutrality processes.

Abstract Fabricating effective reusable catalysts for biomass deoxygenation is essential for sustainable fuel production. In this study, Ni nanoparticles (15–25 wt%) were incorporated into UiO-66 through solvothermal synthesis, followed by partial carbonization at 300°C to improve thermal stability, dispersion and catalytic efficiency in palm fatty acid distillate deoxygenation. Structural analysis confirmed that the UiO-66 framework remained intact after Ni incorporation, with X-ray photoelectron spectroscopy indicating well-dispersed Ni species (Ni2p3/2 at 855.6–856.7 eV). The acid–base characteristics and high surface area supported the cleavage of C–O and C–C bonds. Among the catalysts tested, C-UiO-66@Ni-20wt% showed the best performance, achieving an 87.65% hydrocarbon yield under conditions (3.14 h, 3.28 wt% catalyst, 340°C) optimized by response surface methodology. The reliability of the model was confirmed by a high R² value (99.47%) and statistical significance (p < 0.0001). The catalyst maintained stable activity over seven cycles, with only a 2–7% yield reduction per cycle, before significant deactivation occurred in the eighth cycle owing to pore blockage and active site agglomeration. This study illustrates that Ni-doped UiO-66, with its balanced acidity, structural integrity and efficiency at low temperatures, is a promising catalyst for scalable biofuel production, offering both high reactivity and reusability.

Abstract Green diesels are excellent alternatives to fossil fuels because these are non‐toxic to the environment and renewable. These green biodiesels are produced through the upgradation of bio‐oil by the Hydro deoxygenation method (HDO). Various feedstocks like comestible and non‐comestible oil, animal fats, and algal oil are used. HDO is a viable route to produce liquid fuel through fat pyrolysis. Several kinds of catalysts are reported for HDO; among them noble and non‐noble metals have received great attention. The current study critically comprehends Nano catalyst usage, their advances, and challenges with a detailed summarization of the literature review about HDO. In this review study, other nanocatalysts like oxides, reduced transition metals, phosphide, carbide, and many other alternative catalysts are discussed in detail. HDO of several lignin and the literature on carbohydrate‐derived oxygenates are collated, and their techniques are addressed. It has been reported in this study that the HDO process is also influenced by variables including temperature, hydrogen/oil ratio, pressure, catalyst, and space velocity. Finally, the catalyst deactivation and key challenges are explained in depth. The obstacle in HDO industrialization is catalyst deactivation and short lifespan; hence, HDO catalysts must be regenerated to save operating cost. The aforementioned causes are the main challenges of using nanocatalysts in the HDO process for green diesel production.

Fatty acid methyl ester (FAME) biodiesel has been widely adopted as a renewable alternative to fossil diesel due to its relatively simple production process and established blending frameworks. Nevertheless, intrinsic limitations associated with its oxygenated ester structure such as oxidative instability, hygroscopicity, cold-flow constraints, and restricted blend ratios, continue to limit its long-term suitability for advanced diesel engines and fuel systems. Green diesel, also known as renewable diesel, is a hydrocarbon fuel produced from renewable and waste lipid feedstocks through catalytic deoxygenation pathways, yielding paraffinic hydrocarbons that closely resemble conventional petroleum diesel.

This study aimed to maximise carbon utilisation in the biodiesel (BD) production from transesterification of oil-bearing seed and subsequent pyrolytic valorisation of defatted biomass waste. Peach seed (PS) was selected as a model for the oil-bearing seed. After extracting PS oil (PSO) (56.3 wt% of PS), the defatted PS (DPS) was subjected to CO₂-assisted pyrolysis over a nickel catalyst, resulting in enhanced conversion of DPS into syngas, particularly CO. The homogeneous reaction between CO 2 and VM liberated from DPS led to reduced CO 2 formation and its oxidation with VM, resulting in enhanced CO evolution. Compared with pyrolysis under inert N₂ conditions, syngas production increased by 39.0 % in the presence of CO₂. PSO was converted into BD via thermally induced transesterification, yielding superior BD yield compared to alkali-catalysed conversion. Indeed, the BD yield from thermally induced transesterification was 98.15 wt%, whereas the BD yield from alkali-catalysed transesterification was 87.10 wt%. To further enhance the transesterification kinetics, biochar produced from the pyrolysis of DPS served as a catalyst. This approach resulted in a BD yield of 98.34 wt% at 340 ˚C. CO₂ mitigation potential was evaluated by integrating the pyrolysis of DPS with the BD production process from PSO. • Peach seed (PS) was valorized through pyrolysis and transesterification. • CO 2 enhanced pyrogenic oil conversion to syngas during defatted PS pyrolysis. • Biochar promoted BD yield from PS oil via thermally induced transesterification. • Potential to mitigate the CO 2 emissions from biodiesel and syngas was evaluated

The role of nanoparticles in advancing both research and practical applications is crucial at the present. This study focuses on the enhancement of engine performance and emission characteristics by incorporating titanium dioxide nanoparticles into biodiesel (BD) produced from cashew nut shell oil. The presence of nanoparticles facilitates smoother ignition and earlier combustion, resulting in reduced cylinder heat and high pressure during peak load conditions. BD blends with various proportions and a fixed 75 mg of nanoparticles were tested in a single-cylinder diesel engine with varying speeds. The emission characteristics of the blends were compared with those of conventional diesel. The mixture showed the best performance with an approximate brake thermal efficiency increase in 18%, a brake-specific fuel consumption decrease in about 21%, and carbon monoxide and hydrocarbon emissions reduction owing to an approximate 32% and 28%, when compared to that of diesel. The introduction of BD blends like BD10 A in the presence of TiO2 additives can offer a cleaner-burning, renewable and more efficient source than diesel. The Whale Optimization Algorithm is also presented to reduce output responses, including fuel blend and load, at the same time through the analysis of the parameters in order to carry out optimal engine performance. The proposed algorithm would be contextually pointed out at its performance as compared with the Grasshopper, Dragonfly, Antlion, and Jaya algorithms.