Search Results (3,582)

γ-valerolactone (GVL), derived from biomass, is a crucial platform compound for biofuel synthesis and various industrial applications. Current methods for synthesizing GVL involve expensive catalysts and high-pressure hydrogen, prompting the search for greener alternatives. This study focuses on a novel zirconium phosphate (ZrP)-pillared zeolite MCM-36 derivative catalyst for converting levulinic acid (LA) to GVL using alcohol as a hydrogen source. The incorporation of ZrP significantly contributes to mesoporosity and greatly enhances the acidity of the catalysts. Additionally, we employed ³¹P MAS NMR to comprehensively investigate the influence of phosphorus species on both the acidity and the catalytic conversion of LA to GVL. By adjusting the Zr-to-P ratios, we synthesized catalysts with enhanced acidity, achieving high conversion of LA and selectivity for GVL. The catalyst exhibited high recyclability, showing only minor deactivation over the course of five cycles. Furthermore, the catalyst was successfully applied to the one-pot conversion of furfural to GVL, showcasing its versatility in biomass conversion. This study highlights the potential of the MCM-ZrP1 catalyst for sustainable biomass conversion and offers insights for future research in renewable energy technologies. Full article

The circular economy, driven by waste elimination, material circulation and nature regeneration, is crucial for business, people, and the environment. With the increasing demand for distilled beverages, managing agricultural waste like spent grains is paramount. While previous studies focused on individual beverages, investigating technologies across different types of beverages has been overlooked. This paper provides a systematic review of agricultural waste valorisation over the past five years, focusing on four representative distilled beverages: whisk(e)y, tequila, baijiu and shochu. Research efforts have primarily focused on bioenergy production from whisk(e)y and tequila waste, whereas extracting functional substances is common for baijiu and shochu. Through integrating different technologies, a “Three-level Valorisation System” was proposed to enhance the translation of agricultural waste into value-added products like proteins. This system is directly relevant to the distilled beverage industry globally and applicable to associated industries such as biofuel and food production. Full article

The environmental impacts of the postindustrial era, which rely on fossil fuels, have compelled a reconsideration of the future of energy and chemical industries. Fungi are a valuable resource for improving a circular economy through the enhanced valorization of biomass and plant waste. They harbor a great diversity of oxidative enzymes, especially in their secretome. Enzymatic breakdown of the plant cell wall complex and lignocellulosic biomass yields sugars for fermentation and biofuel production, as well as aromatic compounds from lignin that can serve as raw materials for the chemical industry. To harness the biocatalytic potential, it is essential to identify and explore wild-type fungi and their secretomes. This study successfully combined genome mining and activity screening to uncover the oxidative potential of a collection of underexploited ascomycetes and basidiomycetes. The heme peroxidase and laccase activities of four promising candidates, Bipolaris victoriae, Colletotrichum sublineola, Neofusicoccum parvum and Moesziomyces antarcticus, were investigated to gain a deeper insight into their enzyme secretion. Furthermore, a plant-based medium screening with the phytopathogen C. sublineola revealed that soybean meal is a beneficial component to trigger the production and secretion of enzymes that catalyze H₂O₂-dependent oxidations. These results demonstrate that understanding fungal secretomes and their enzymatic potential opens exciting avenues for sustainable biotechnological applications across various industries. Full article

Sugarcane (Saccharum spp.) is a prominent renewable biomass source valued for its potential in sustainable and efficient second-generation biofuel production. This review aims to assess the genetic enhancement potential of sugarcane, emphasizing the use of advanced genetic engineering tools, such as CRISPR-Cas9, to improve traits crucial for biomass yield and biofuel production. The methodology of this review involved a thorough analysis of the recent literature, focusing on the advancements in genetic engineering and biotechnological applications pertinent to sugarcane. The findings reveal that CRISPR-Cas9 technology is particularly effective in enhancing the genetic traits of sugarcane, which are essential for biofuel production. Implementing these genomic tools has shown a significant rise in biomass output and, ultimately, the effectiveness of bioethanol manufacturing, establishing sugarcane as a feasible and reliable source of biofuel implications of these advancements extend. These advancements have a profound impact not only on agricultural productivity but also on enhancing the efficiency and scalability of the bioethanol industry. Developing superior sugarcane varieties is expected to boost economic returns and advance environmental sustainability through carbon-neutral biofuel alternatives. This review underscores the transformative role of genetic engineering in revolutionizing sugarcane as a bioenergy crop. The evolution of genetic engineering tools and methodologies is crucial for tapping into the full potential of sugarcane, and thereby supporting global efforts towards sustainable energy solutions. Future research should focus on refining these biotechnological tools to meet increasing energy demands sustainably, ensure food security, and mitigate negative environmental impacts. Full article

The Green Deal targets, along with tightening emissions legislation, foster research on alternative propulsion systems. In non-road mobile machinery (NRMM), these efforts largely rally around sustainable fuels while keeping the benefits of energy security (multi-fueling) high. In this context, the blends of Hydrogenated Vegetable Oil (HVO) and Methanol (MEOH) are amongst the most promising yet under-researched alternatives and, as such, need dedicated methods for determining their suitability in engine applications. In this paper, we evaluate the feasibility of Fourier transform infrared (FTIR) analytics for determining the stability of MEOH-HVO mixtures. The research considers temperature effects during storage by conditioning the test samples at −20 °C and +20 °C. The stability of the blends and different co-solvents is analysed after six weeks, and FTIR spectra are used to identify the chemical bonds. From FTIR analysis, blending MEOH20 with 1-dodecanol results in stable homogenous alkyl-ether fuels, while the MEOH20 blend with methyl-butyrate results in ester fuels. There are observable differences in the blend samples according to their storage temperatures. In conclusion, both fuel blend samples formed different fuel types, which are stable and homogenous at room temperature, posing great potential for their applicability in different NRMM types. Full article

The research presents weight estimation and analysis of the energy and carbon potential of the pericarp cover of four hazelnut varieties. A technical and elementary biofuel analysis was carried out for the biomass studied, as well as a correlation and principal component analysis to demonstrate the influence of individual characteristics on the parameters achieved. In addition, emission factors and the composition and volume of flue gases from the combustion of the material studied were estimated based on stoichiometric equations. The research showed that the highest calorific value (LHV) was characterised by the pericarp cover of the ‘Olga’ variety (14.86 MJ·kg⁻¹) and the lowest by the ‘Kataloński’ variety (14.60 MJ·kg⁻¹). In the case of exhaust volume, the highest volume was obtained from the ‘Olbrzymi z Halle’ variety (250.06 Nm³·kg⁻¹) and the lowest from the ‘Kataloński’ variety (12.43 Nm³·kg⁻¹). The correlation analysis carried out showed that the HHV and LHV parameters in the covers showed a very strong positive correlation with sulphur content and SO₂ emissions, and a moderate correlation with nitrogen content and its associated NO_x emissions, indicating their direct influence on the higher calorific value of biomass. Full article

Barley is indeed a versatile cereal crop, valued for its uses in food, animal feed, and increasingly in biofuel production. As interest grows in developing new barley genotypes that are better adapted to diverse environmental conditions and production systems, integrating agro-morphological evaluations with molecular marker analyses in barley breeding programs is essential for developing new genotypes. It is necessary to explore the genetic diversity of those germplasm to predicate their responses to targeted environments and regions. The current study explored the phenotypic and genotypic relations among Saudi advanced germplasm to facilitate the development of superior barley cultivars suitable for desert environments. Molecular microsatellites (SSR) markers revealed considerable wide genetic variation among Saudi germplasm and checks. Population structure analyses revealed four main groups. Those groups were validated using similarity analyses and coefficients. As well, principal components analysis (PCA) and heat map analyses separated the studied genotypes into four main groups. The improved Saudi germplasm, selected from the barley breeding program, revealed considerably wide genetic and phenotypic diversities, indicating the feasibility of selection to improve for semi-arid conditions. The improved line KSU-BR-C/G-2 had the highest grain yield and harvest index in the first season. Rihana/Lignee was followed by the KSU-BR-C/G-2 genotype, with a grain yield averaging 6734.07 (kg ha⁻¹), in the first season. KSU-BR-88-29-10 yielded 20,000 kg ha⁻¹ for biomass yield. In the second year, KSU-BR-30-7 had the highest biomass yield, with 27,037.04 kg ha⁻¹. Full article

In the current study, the cultivation of microalgae on wastewater-based substrates is investigated for an effective natural wastewater treatment that also generates biofuels and value-added products beneficial to human health. Additionally, the health of ecosystems can be evaluated via microalgae. The utilization of microalgae as bioindicators, biofuel producers, and wastewater treatment providers, under the biorefinery concept, is covered in this article. In fact, bioremediation is feasible, and microalgae culture can be used to efficiently process a variety of effluents. Along with wastewater processing and the creation of value-added substances, bioconversion concurrently offers a viable and promising alternative for reducing CO₂ greenhouse gas emissions to contribute to climate change mitigation. The microalgal biorefinery being considered as the third generation is unique in that it addresses all the aforementioned problems, in contrast to lignocellulosic biomass from agricultural waste in second-generation biorefineries and edible crops in first-generation biorefineries. In particular, one of the most promising natural resources for the manufacture of biofuel, including biodiesel, bioethanol, biomethane, and biohydrogen, is found to be microalgae. Furthermore, products of high value, like fatty acid methyl esters, astaxanthin, β-carotene, DHA, and EPA can be made. Hence, microalgal biomass offers a substitute for the development of biofertilizers, bioplastics, pharmaceuticals, cosmetics, animal and aquatic feeds, and human nutrition products, thus promoting human and environmental health. Full article

Typically, citrus waste is composted on land by producers or used as livestock feed. However, the biorefinery approach offers a sustainable and economically viable solution for managing and valorizing these agricultural residues. This review examines research from the period 2014 to 2024. Citrus waste can be utilized initially by extracting the present phytochemicals and subsequently by producing value-added products using it as a raw material. The phytochemicals reported as extracted include essential oils (primarily limonene), pectin, polyphenolic components, micro- and nano-cellulose, proteins, and enzymes, among others. The components produced from the waste include bioethanol, biogas, volatile acids, biodiesel, microbial enzymes, and levulinic acid, among others. The review indicates that citrus waste has technical, economic, and environmental potential for utilization at the laboratory scale and, in some cases, at the pilot scale. However, research on refining pathways, optimization, and scalability must continue to be an active field of investigation. Full article

In the field of convective drying, several models have been proposed by different research groups, both theoretical and empirical. However, research on theoretical mathematical models has been superficial and needs to be extended. Empirical models present difficulties in their implementation in other research. It is suggested that further research should focus on obtaining models adaptable to different species and environmental conditions. The aim of this work was to analyse the current state of research on the drying process and mass transfer. It is concluded that drying is a mathematically complex process that must be modelled with differentiated equations in two stages: constant drying rate stage and decreasing drying rate stage. The modelling of the constant drying phase can be based on the convective mass transfer equation, although the prediction of the coefficient with analogies to heat transfer has deviations in biomass. Modelling of the variable rate drying phase should focus on the variation of water diffusivity in porous materials or vapour permeability as a function of material moisture and temperature. A database of homogenised equations particularised for each material needs to be generated to predict drying rates and times under predetermined convection conditions. This represents a scientific challenge and suggests that research in drying kinetics still needs development. Full article

The Amazon region contains numerous areas dedicated to sustainable timber extraction. This operation has low yields and generates a large amount of waste. However, this waste can be repurposed for energy generation, providing income for locals and reducing reliance on non-renewable energy sources prevalent in the region. This study aimed to assess the impact of torrefaction on various wood residues for briquette production. Wood residues from Mimosa scabrella Benth (Bracatinga), Dipteryx odorata (Aubl.) Willd. (Cumaru), and Aspidosperma populifolium A.DC. (Peroba mica) were torrefied at temperatures ranging from 180 to 220 °C for sixty minutes under a nitrogen atmosphere. Briquettes were produced using laboratory equipment with loading pressures between 7 and 14 MPa. Torrefied particle properties were evaluated based on proximate composition and calorific value tests, while briquette quality was assessed for physical and mechanical properties. The results demonstrated the briquetting potential of different wood species before and after torrefaction, with optimal outcomes achieved by torrefaction at 220 °C due to its enhancement of energy density. Briquettes showed optimal characteristics at compression pressures of 14 MPa, resulting in increased density (between 1.10 and 1.24 g·cm⁻³) and compression strength (between 7.20 and 21.02 MPa). The ash values were low and met the requirements. The utilization of waste for briquette production offers a significant alternative for energy generation in economically disadvantaged communities, while also enabling the replacement of non-renewable energy sources. Full article

In recent years, algae have emerged as a promising feedstock for biofuel production, due to their eco-friendly, sustainable, and renewable nature. Various methods, including chemical, biochemical, and thermochemical processes, are used to convert algal biomass into biofuels. Pyrolysis, a widely recognized thermochemical technique, involves high temperature and pressure to generate biochar and bio-oil from diverse algal sources. Various pyrolytic processes transform algal biomass into biochar and bio-oil, including low pyrolysis, fast pyrolysis, catalytic pyrolysis, microwave-assisted pyrolysis, and hydropyrolysis. These methods are utilized to convert a range of microalgae and cyanobacteria into biochar and bio-oil. In this publication, we will discuss catalytic pyrolysis using mesoporous materials, such as SBA-15. Mesoporous catalysts have earned significant attention for catalytic reactions, due to their high surface area, facilitating the better distribution of impregnated metal. Pyrolysis conducted in the presence of a mesoporous catalyst is viewed more as efficient, compared to reactions occurring within the smaller microporous cavities of traditional zeolites. SBA-15 supports with incorporated Zr and/or Ce were synthesized using the direct hydrothermal synthesis method. The catalyst was characterized using structural and morphological technical analysis and utilized for the pyrolysis reaction of the algal biomass. Full article

Efforts are intensifying to identify new biofuel sources in response to the pressing need to mitigate environmental pollutants, such as greenhouse gases, which are key contributors to global warming and various worldwide calamities. Algae and microalgae present themselves as excellent alternatives for solid-gaseous fuel production, given their renewable nature and non-polluting characteristics. However, making biomass production from these organisms economically feasible remains a challenge. This article collates various studies on the use of lignocellulosic waste, transforming it from environmental waste to valuable organic supplements for algae and microalgae cultivation. The focus is on enhancing biomass production and the metabolites derived from these biomasses. Full article

Azolla is the only plant with a co-evolving nitrogen-fixing (diazotrophic) cyanobacterial symbiont (cyanobiont), Nostoc azollae, resulting from whole-genome duplication (WGD) 80 million years ago in Azolla’s ancestor. Additional genes from the WGD resulted in genetic, biochemical, and morphological changes in the plant that enabled the transmission of the cyanobiont to successive generations via its megaspores. The resulting permanent symbiosis and co-evolution led to the loss, downregulation, or conversion of non-essential genes to pseudogenes in the cyanobiont, changing it from a free-living organism to an obligate symbiont. The upregulation of other genes in the cyanobiont increased its atmospheric dinitrogen fixation and the provision of nitrogen-based products to the plant. As a result, Azolla can double its biomass in less than two days free-floating on fresh water and sequester large amounts of atmospheric CO₂, giving it the potential to mitigate anthropogenic climate change through carbon capture and storage. Azolla’s biomass can also provide local, low-cost food, biofertiliser, feed, and biofuel that are urgently needed as our population increases by a billion every twelve years. This paper integrates data from biology, genetics, geology, and palaeontology to identify the location, timing and mechanism for the acquisition of a co-evolving diazotrophic cyanobiont by Azolla’s ancestor in the Late Cretaceous (Campanian) of North America. Full article