This research aimed to conduct a bibliometric review on Acrocomia aculeata (Jacq.) Lodd. ex Mart., popularly known as “macaúba”, a palm tree of the Arecaceae family with great potential to promote sustainable practices. The review focused on the applications associated with the oil, pulp, and almonds of the fruit, products that can be used in industries such as food, cosmetics, and bioenergy, contributing to the development of more ecological production chains with less environmental impact. Data were collected from the Scopus, Web of Science, and ScienceDirect databases for publications related to phytochemical and bioactive aspects, while only Web of Science was used for data on energy aspects. The documents found were analyzed in the VOSviewer software (version 1.6.20), allowing the creation of bibliometric networks (clusters) and tables on scientific production. The analyses included authors, co-authors, countries, institutions, journal sources, and keywords. For phytochemical and bioactive aspects, the search resulted in 1026 articles, of which 261 were selected after applying the exclusion criteria. For energy aspects, 99 publications were found. Based on the data, it was possible to analyze the existing research on A. aculeata, identifying the state of the research and possible gaps in studies related to this oilseed. The results highlight the importance of macaúba as a sustainable alternative for diversifying agricultural and bioindustrial products, promoting the bioeconomy and contributing to the mitigation of environmental impacts. In addition, the research allowed us to identify the universities and researchers most dedicated to this species, their main results and the areas that still require investment to advance research. Thus, A. aculeata emerges as a relevant option to strengthen sustainable practices in key sectors, integrating economic, social, and environmental benefits.

The improper discharge of industrial effluents containing dyes, such as methylene blue, represents a serious environmental problem. The present study, therefore, aimed to evaluate the potential of biochar derived from carnauba stalks as an adsorbent for removing dyes from aqueous media. The raw stalks were subjected to carbonization under an inert atmosphere to yield biochar, and both materials were characterized by proximate and elemental analyses, SEM/EDS, PSD, XRD, FTIR, and thermal analyses. Batch adsorption experiments were monitored by UV-Vis spectrophotometry. Pyrolysis resulted in an increase in aromatic fixed carbon (+26.5%) and ash content (+23.8%), while simultaneously reducing volatile matter (-39.3%), moisture, and the atomic H/C (0.39) and O/C (0.07) ratios. Furthermore, thermal stability was enhanced without causing a significant alteration to the average particle size (similar to 30 mu m). Adsorption tests showed a maximum uptake of 32.5 mg.g(-1) at low dosage (2 mg), corresponding to 8.66% removal, while 27.83% removal was achieved at higher dosage (25 mg). Equilibrium data were best described by the Langmuir model (q(m) = 210.7 mg.g(-1); R-2 = 0.971), with q(m) representing a theoretical fitting parameter. These findings of this study demonstrate the adsorption potential of carnauba stalk biochar and support its evaluation as a lignocellulosic material for dye removal applications.

Increased corrosivity of biodiesel toward metallic components has motivated the search for environmentally friendly corrosion inhibitors. However, studies investigating plant extracts as inhibitors in biodiesel systems remain limited, particularly for babassu biodiesel. In this work, the ethanolic extract of Myracrodruon urundeuva (“Aroeira-do-Sertão”) leaves was investigated for the first time as a green corrosion inhibitor for AISI 4340 carbon steel exposed to babassu biodiesel. Static immersion tests were conducted for 2592 h (108 days) at 45 °C, and the inhibitory performance was compared with that of the commercial antioxidant Trolox™. Corrosion behavior was evaluated by gravimetric weight loss measurements and surface morphology analysis using scanning electron microscopy. Phytochemical screening, FTIR, and 1H NMR spectroscopy revealed the presence of phenolic compounds, flavonoids, and tannins containing hydroxyl functional groups and conjugated aromatic systems. The 1H NMR spectrum exhibited characteristic signals in the δ 6.6–6.4 ppm region, which were attributed to aromatic protons of phenolic compounds and flavonoids, while signals between δ 5.4 and 4.9 ppm indicated vinyl and olefinic protons associated with unsaturated secondary metabolites. These findings are consistent with FTIR results, confirming the presence of hydroxyl-rich phenolic structures and conjugated systems capable of promoting adsorption onto the metal surface. The extract exhibited a corrosion inhibition efficiency of 89%, significantly higher than that obtained with Trolox™ (27.9%). SEM analysis confirmed a substantial reduction in surface degradation in the presence of the extract. These results demonstrate the strong potential of Myracrodruon urundeuva leaf extract as a sustainable corrosion inhibitor for metallic materials in biodiesel environments.

This study aims to evaluate the synthesis of ethyl esters via enzymatic esterification of free fatty acids (FFA) from neem oil (Azadirachta indica) using ethyl alcohol and Eversa Transform 2.0 (ET2) lipase as the biocatalyst. The experimental design was based on the Taguchi method to optimize ester production. In addition, characterizations were carried out on the reaction product, including Gas Chromatography/Mass Spectrometry, Nuclear Magnetic Resonance, Fourier Transform Infra-red Spectroscopy, density, and viscosity. Analysis of the Taguchi method revealed the ideal conditions for synthesis: a molar ratio of 1:9 (mol/mol) between FFA and alcohol, 15% (w/w) biocatalyst, a reaction time of 6 h, and a temperature of 40 degrees C. This optimized reaction resulted in 91.6% conversion. The characterizations confirmed the changes in the FFA profiles, corroborating the experimental results and indicating that the calculated conversion had taken place. The density and viscosity studies showed that the esters produced are in line with the values found in esters produced by the chemical route. Theoretical molecular docking studies were also conducted, which indicated affinity and specificity for the ET2 lipase, primarily at residues Ser83 and Ser146. Thus, this study achieved its objectives related to optimizing the synthesis of ethyl esters from neem oil FFA, confirming its potential in this process, as well as the use of ET2 lipase as a biocatalyst.

This work employs temperature-dependent density functional theory (DFT) calculations at gas phase to evaluate the hydrogen carrier potential of heterocyclic compounds: 2-(1,3-dihydroimidazol-2-ylidene)-1,3-dihydroimidazole (TAF), 2-(2H-imidazole-2-ylidene)-2H-imidazole (2IMDZ), 2-(1H-imidazole-2-yl)-1H-imidazole (2BMDZ), and their fully hydrogenated derivative, 2-imidazolidin-2-ylimidazolidine (TAFSAT). Thermodynamic parameters (Delta H, Delta S, and Delta G) revealed that hydrogenation is exergonic for all systems. Notably, 2BMDZ exhibits a temperature-dependent inversion of Delta G, thermodynamically enabling reversible hydrogen uptake and release under appropriate conditions. In contrast, 2IMDZ favors hydrogen storage but shows limited spontaneous dehydrogenation. Molecular orbital and electrostatic potential analyses reveal that the electron density in 2IMDZ is more symmetric distributed due to its planarity, while 2BMDZ displays asymmetric charge density and nodal HOMO features. Global reactivity descriptors support these trends, with 2IMDZ showing higher electrophilicity and 2BMDZ demonstrating characteristics conducive to reversibility. These insights and an additional benchmark comparison reveals 2IMDZ as a hydrogen storage-oriented system and 2BMDZ as a promising reversible hydrogen carrier. Further experimental and kinetic validation is necessary to assess physical properties and catalytic performance.

This study focused on optimizing the enzymatic synthesis of biolubricants using a 20% blend of Nile tilapia (Oreochromis niloticus) and neem (Azadirachta indica) oils catalyzed by Eversa Transform 2.0. The optimal conditionsthe molar ratio of 1:5 (mol/mol), 10% biocatalyst load, and a reaction time of 48 hachieved a predicted ester conversion of 97%, with experimental validation confirming 92.80 ± 0.03%. Molecular docking demonstrated stable complexes, particularly with decanoic and linoleic acids, showing Root Mean Square Deviation (RMSD) values below 2.0 Å, indicating minimal conformational changes. Gas chromatography and mass spectrometry (GC-MS) analysis identified key esters like 2-ethylhexyl and octyl, which enhance thermal stability, lubricity, and oxidation resistance. Fourier Transform Infrared Spectroscopy (FT-IR) analysis confirmed effective ester formation, corroborating experimental results. Viscosity (2.4511 mm2/s) and density (0.84259 g/cm3) values aligned with ISO VG 3 (International Organization for Standardization Viscosity Grade) standards, suitable for low-load and low-speed applications.

Hydroesterification is a synthetic route involving hydrolysis followed by esterification. This study aimed to investigate the production of ethyl esters via enzymatic hydroesterification through theoretical and experimental approaches. Complete hydrolysis of residual frying oil was achieved using a 1:1 mass solution at 40 °C for 4 h with 0.4% Eversa Transform 2.0 lipase relative to the oil mass. A combination of Eversa Transform 2.0 and lipase B from Candida antarctica (CAL B) was used in the esterification step. A Taguchi statistical design evaluated the effects of enzyme combination (1:1, 1:2, 1:3), FFA/alcohol molar ratio (1:1, 1:8, 1:15), biocatalyst percentage (5%, 10%, 15%), and reaction time (2, 4, 6 h). Optimal conditions were identified as a 1:8 molar ratio (FFA/ethanol), 10% biocatalyst, and a 1:3 enzyme combination for 6 h, theoretically yielding 80.1 ± 0.02% conversion. Experimentally, a 71.4 ± 0.1% conversion was achieved, slightly lower due to biocatalyst susceptibility to interferences affecting catalytic activity. Viscosity and density analyses confirmed the potential of the produced ethyl esters for future applications. This combined theoretical and experimental study highlights the feasibility of enzymatic hydroesterification using waste frying oil and combilipases as a sustainable approach for biodiesel production.

The fuel industry remains closely tied to oil-based fuels. This relationship is responsible for increasing greenhouse gas emissions. Biofuels are an alternative to petroleum-based fuels that could make industrial production lines more sustainable. Neem oil (Azadirachta indica) was tested as a raw material for the enzymatic synthesis of biolubricants. Eversa Transform 2.0 lipase was tested as a biocatalyst during this process. The Taguchi method was used to determine the optimal point for maximizing production. The best result was achieved with a molar ratio of 1:5 (mol mol-1) between free fatty acids and 2-ethylhexan-1-ol, using 10% biocatalyst at 40 degrees C for 96 h. Theoretical conversion was 89.9%, whereas the experimental value was 89.2% +/- 0.04%. A theoretical study showed that eicosanoic acid interacts with His 268 (NAC), a component in the enzyme's active site, displaying favorable free energy and forming specific hydrogen bonds along with alkyl and pi-alkyl interactions. Finally, the characterization analyses - gas chromatography-mass spectrometry (GC-MS) and Fourier transform infrared (FTIR) spectroscopy - confirm the efficient production of biolubricants from neem oil. This vegetable oil is thus a promising source of biofuels.

Fishing waste and byproducts, whether naturally occurring or from industrial processing, are important sources of high‐value compounds. Fertilizers, biomaterials, cosmetics, biolubricants, and biodiesel are some of the substances that can be obtained from these residues. The objective of this study was to conduct a theoretical and experimental investigation of the biocatalytic production of ethyl esters through the enzymatic hydroesterification of residual tilapia ( Oreochromis niloticus ) oil. Eversa Transform 2.0 lipase was used during the esterification stage, with the Taguchi methodology applied to assess the effects of varying parameters: temperature (25, 40, and 55 °C), molar ratio of free fatty acids (FFA) to ethanol (1:1, 1:5, and 1:9), biocatalyst concentration (1%, 5%, and 9%), and reaction time (1, 3, and 5 h). Statistical analysis revealed that the amount of biocatalyst was the most significant factor, followed by temperature. The optimal levels identified were 5 h of reaction at 25 °C, with a 1:1 (FFA/ethanol) molar ratio and 9% biocatalyst, resulting in an experimental conversion of 89.94 ± 0.09%. A docking and molecular dynamics study was also conducted, evaluating the stability of Eversa Transform 2.0 lipase with FFAs, and the coupling of the enzyme's catalytic site with the substrate was observed. Myristic and oleic acids bound near the enzyme's active site, exhibiting favorable free energy and forming hydrogen bonds, alkyl interactions, and π ‐alkyl interactions, as revealed by an in silico study. This research aligns with key Sustainable Development Goals (SDGs), including SDG 7 (Affordable and Clean Energy) and SDG 9 (Industry, Innovation, and Infrastructure), and SDG 12 (Responsible Consumption and Production), by fostering the use of renewable energy and supporting more sustainable industrial processes.

Biolubricants are produced from renewable biological raw materials using sustainable methods, such as enzymatic catalysis and the esterification of vegetable oils and animal fats, representing a promising alternative. Enzymatic biocatalysts, in particular, have high specificity in synthesizing new products, making them a fundamental tool in producing biolubricants. This study aims to conduct a detailed bibliometric analysis to evaluate the primary studies on the enzymatic synthesis of biolubricants. It also identifies prominent countries, authors, journals, and research areas contributing to the topic. Describe the characteristics, advantages, and challenges associated with biolubricants, including the types of enzymes, substrates, and raw materials used, the mechanisms of enzymatic synthesis, and the techniques used for production, optimization, and characterization. The keywords "biofuel", "biolubricant" and "enzyme" were used for the database. The search was carried out in Scopus, covering the period from 2014 to June 2024. The analysis returned 358 articles and revealed significant international collaboration, especially between Brazil, India, and China. Brazil leads the field, contributing 19.27 % of the publications. Brazilian institutions have shown remarkable specialization in producing lubricants, using the country's rich biodiversity and biomass resources to promote research and innovation. Thus, this study presents a complete contextualization of the production of biolubricants, with an overview of world production in the area and a literature review that addresses relevant topics such as production routes and product analysis.

Blends of diesel-biodiesel are a crucial alternative for petrodiesel substitution. However, biodiesel faces challenges such as high density and kinematic viscosity, which can affect the properties and performance of the blends. Based on this, the investigation of the impact of adding biodiesel into diesel fuel at percentages of 12%, 15%, 18%, and 21% using molecular dynamic simulations is presented. The density of the blends was experimentally measured and calculated with good agreement, which indicates a favorable description of the interactions by the OPLS-AA force field. Obtained results suggest that alkanes and isoalkanes showed higher fluctuations and were most sensitive to the variation of the percentage of biodiesel in diesel. The other classes of molecules did not show significant variations in interactions, suggesting that it-it interactions are unaffected by the biodiesel addition. The spatial distribution functions revealed that diesel molecules are organized homogeneously around methyl oleate and methyl linoleate, whereas aliphatic hydrocarbon and aromatic molecules are in distinct regions. The diffusion coefficients (Di) showed that the diesel molecules possess higher values, and the biodiesel addition increases the Di of the blend due to the methyl esters carbon chains, which present lower diffusion than diesel molecules. Finally, physical parameters and simulations revealed that the biodiesel addition into diesel fuel in the proportion up to 21% did not negatively impact the density and viscosity limits established by standards ASTM, EN, and ANP Resolution.

The present study evaluated the applicability of 1H NMR and UV-Vis spectroscopies as analytical techniques for the characterization and determination of biodiesel conversion and for monitoring the oxidative stability of biodiesel samples with antioxidants. For this study, safflower and babassu biodiesels were obtained through transesterification, and physicochemical properties confirmed the success of both reactions. A bench-top accelerated oxidation system was used as an alternative to the Rancimat® method, with samples of 6.0 g heated at 110 ± 5 °C and collected every 2 h for 12 h. The agreement for biodiesel conversions was good, with divergences between 2% and 0.4% for safflower biodiesel and 1.9% for babassu biodiesel. As for UV-Vis spectroscopy, the technique showed the same trend as the Rancimat® method, showing efficiency in evaluating the oxidative stability of safflower biodiesel and in the performance of antioxidants BHT and DMP-30. The accuracy of NMR signals integration for mixtures of safflower oil and safflower biodiesel and the use of UV-Vis spectroscopy associated with a bench-top accelerated oxidation system to investigate the performance of phenolic and amine antioxidants in safflower and babassu biodiesel were explored for the first time, showing results close to the standard methods. Therefore, 1H NMR and UV-Vis spectroscopies could be applied as alternatives to the GC and Rancimat® methods to determine conversion and monitor the oxidative stability of biodiesel rapidly and practically.

The production of energy, food, water, and other utensils by fossil fuels generates pollution that causes constant climate change. To minimize and avoid this phenomenon, opting for less polluting energy production sources is increasingly necessary. Green hydrogen (H2), a renewable and clean fuel, is analyzed in bibliometric terms in the present work, emphasizing photosynthetic H2. The data were obtained through the journal database list in Web of Science, in which a total of 1507 was published between January 2010 to September 2022, dealing with the production of photosynthetic green hydrogen. The country with the most significant publication is China, with respectively 24.50% of the publications, and the Chinese Academy of Sciences has 60 co-authored papers, the largest in co-authorship—most papers published in the international journal of hydrogen energy, with 19.49% of the publications. The raw materials identified as emerging are cyanobacteria and microalgae, Rhodobacter capsulatus, synechocystis sp pcc6803 and Chlamydomonas reinhardtii pointed out as the microalgae of most significant interest. However, it is necessary to improve them, given the decrease in inactivity provided by the Calvin-Benson cycle. Life cycle assessment studies are needed, as well as H2 storage. There is a need to reduce the levelized cost of H2 production, which is around 9.65–25.22 USD/gallon. Studies also point to using cyanobacteria and microalgae to produce other biofuels (bioethanol biodiesel) and materials (supercapacitors, batteries, and polymers).

The objective of this research was to analyze the energetic properties of the cashew nut husk and babassu coconut husk residues, as well as the blend of different ratios of these biomasses to evaluate the potential of them through the production of solid biofuels (briquettes), aiming the insertion of renewable sources in the fuel national market. These wastes are common in Brazil and according to the literature to generate about 80.484 tons (cashew nut husk), and 800.00 tons (babassu coconut husk) per year. However, these biomasses are not used frequently as biofuels, probably due to the lack of information about their energy potentials. So, the authors present the energetic potential of these residues in this paper. The agro-residues characterization was carried out by proximate and elemental analysis, higher heating value, bulk, and energetic (MJ m-3). The production of briquettes derived from cashew nut husk, babassu coconut husk, and their blends represents an environmentally appropriate way to reuse these wastes as biofuels, adding economic value to these residues.

Flavor esters are organic compounds widely used in the food industry to enhance the aroma and taste of products. However, most chemical processes for the production of these flavoring compounds use toxic organic solvents. Some organic solvents derived from petroleum can leave behind residual traces in food products, which may raise concerns about potential health risks and contamination. In this study, we employ Eversa Transform 2.0, a commercial lipase derived from the lipase from Thermomyces lanuginosus, to produce geranyl butyrate in aqueous media. The chemical process was optimized using the Taguchi method, and a conversion of 93% was obtained at the optimal reaction conditions of: 1:5 molar ratio (v/v), 15% biocatalyst load (w/w), at 50 °C, in 6 h. Classic (molecular dynamics) and quantum (density functional theory) simulations unveiled amino acid residues involved in the stabilization of the enzyme-substrate complex. Detailed QM/MM mechanistic studies identified the nucleophilic attack of the deacylation reaction as the rate-limiting step of the entire mechanism, which has a free energy barrier of 14.0 kcal/mol.

Brazil is among the world’s largest producers of green coconut, which contributes to inappropriate disposal and socioenvironmental impacts. Concomitantly, some of its coastal cities produce a great diversity of fish and large amounts of solid waste. This paper reports on the use of samples of fish scales (100FS) and green coconut shells (100GCS) and their mixtures in 75%FS:25%GCS (B25), 50%FS:50%GCS (B50), and 25%FS:75%GCS (B75) proportions and quantification of their Higher Heating Values (HHV) and Lower Heating Values (LHV), and Ultimate (UA) and Proximate Analyses (PA). Their thermal behavior was investigated by thermogravimetry (TG/DTG) and differential scanning calorimetry (DSC), whereas scanning electron microscopy (SEM), energy dispersive spectroscopy (EDS), X-ray diffraction (XRD), and Fourier transformed infrared (FTIR) were employed for analyses of their physicochemical and morphostructural properties. When compared to in natura samples, SEM images of the blends detected a structural disorder and a highly fibrous structure with an elongated chain and surface roughness. HHV were superior in samples with 100GCS (16.64 MJ kg−1), B75 (15.80 MJ kg−1), and B50 (14.98 MJ kg−1), and lower in B25 (14.16 MJ kg−1) and 100FS (13.03 MJ kg−1), with acceptable values for different biomasses. TG/DTG and DSC curves showed similarities among the samples, with the detection of their main thermoconversion stages. According to the data, the samples can be applied as renewable energy sources to mitigate socioecological illnesses and social vulnerabilities resulting from the archaic and inadequate management of solid waste.

Thermogravimetric pyrolysis of carnauba straw and carnauba stalk was studied for the first time. The experi-ments were carried out at four different heating rates (5-20 degrees C min-1) and the kinetic parameters were calcu-lated using three isoconversional methods such as Friedman (differential), KAS (integral), and OFW (integral). The activation energies and R2 were calculated for the conversions between 0.10 and 0.90. The average acti-vation energies were found to be 225.28 (+/- 26.83 kJ mol-1) for carnauba straw and 218.13 (+/- 28.06 kJ mol- 1) for carnauba stalk by the Friedman method; 223.17 (+/- 17.72 kJ mol-1) for carnauba straw and 211.04 (+/- 18.82 kJ mol-1) for carnauba stalk by KAS method; and 212.71 (+/- 23.19 kJ mol-1) for carnauba straw and 217.94 (+/- 17.85 kJ mol-1) for carnauba stalk by OFW method. The FTIR spectra showed bands characteristic of hemicellulose, cellulose, and lignin at 3331 cm-1 (O-H) and 3345 cm-1 (O-H); 2919 cm-1 (C-H) and 2928 cm-1 (C-H); and 1733 cm-1 (C--O) and1723 cm-1 (C--O). The carnauba straw presented molar ratios of 1.43 (H/C) and 0.78 (O/C), and the carnauba stalk of 1.39 (H/C) and 0.81 (O/C). The kinetic parameters, FTIR spectra, and molar ratios are in good agreement with other reported biomasses.

The work presents an optimization of the extraction and purification processes of the anacardic acids mixture and its evaluation as a potential antichagasic drug. The purified mixture was obtained by chromatography techniques and characterized by 1H and 13C NMR. The cytotoxicity was evaluated in Rhesus monkey Kidney Epithelial Cells (LLC-MK2) after 24 h of exposure in concentrations between 400 and 6.25 µg/ml. The new procedure was efficient for the purification of the anacardic acid mixture and separating them, with a 31.6

The growing demand for energy and the concern about environmental impacts reinforce the necessity for renewable energy sources such as biofuels. In this study, cake generated in the babassu oil extraction was evaluated as a potential feedstock for solid biofuel production, and it contains a blend of cashew nutshell, sugarcane bagasse, carnauba straw, and carnauba stalk. All samples were characterized by proximate analysis and Higher Heating Value. Carbonization was used to improve energy performance and compaction to understand the mechanism and the characteristics of the biomasses compacted. In the extraction of babassu oil, fresh and aged (90 days) kernel samples were used. The fresh samples reached a yield of 59.8%, and the aged samples reached a yield of 70.66%. The carbonization of babassu cake was carried out in a Muffle furnace at temperatures of 250, 300, 350, and 400 °C. The fresh babassu cake showed an HHV of 23.06 MJ kg−1 and after carbonization of 28.07 (250 °C), 30.69 (300 °C), 28.24 (350 °C), and 18.27 MJ kg−1 (400 °C). At 400 °C, a decrease in HHV of 20.8% occurred, and an increase in Ash (%) of 195% occurred. Proximate analysis showed that biomasses are compatible, with some having a higher compatibility than other biological materials already used as fuels in the industry.