Search Results (56)

As the popularity of electric vehicles (EVs) continues to increase, the need for effective and efficient driveline lubricants and dielectric coolants has become crucial. Commercially used mineral oils or synthetic ester-based coolants, despite performing satisfactorily, are not environmentally friendly. The fatty esters of vegetable oils, after overcoming their shortcomings (like poor oxidative stability, higher viscosity, and pour point) through chemical modification, have recently been used as potential dielectric coolants in transformers. The benefits of natural esters, including a higher flash point, breakdown voltage, dielectric character, thermal conductivity, and most importantly, readily biodegradable nature, have made them a suitable and sustainable substitute for traditional coolants in electric transformers. Based on their excellent performance in transformers, research on their application as dielectric immersion coolants in modern EVs has been emerging in recent years. This review primarily highlights the beneficial aspects of natural esters performing dual functions—cooling as well as lubricating, which is necessary for “wet” e-motors in EVs—through a comparative study with the commercially used mineral and synthetic coolants. The adoption of natural fatty esters of vegetable oils as an immersion cooling fluid is a significant sustainable step for the battery thermal management system (BTMS) of modern EVs considering environmental safety protocols. Continued research and development are necessary to overcome the ongoing challenges and optimize esters for widespread use in the rapidly expanding electric vehicle market. Full article

Significant wastes such as bagasse, molasses, and vinasses are produced during sugarcane processing. Due to their high sugar content, these wastes are commonly used as low-cost substrates for biofuel production. However, these substrates are also suitable for the microbial synthesis of high-value biochemicals like biosurfactants. Sporisorium scitamineum, a smut fungus capable of growing on sugarcane residues and producing mannosylerythritol lipids (MELs) and cellobiose lipids (CBLs), was identified as a promising candidate for valorizing sugarcane wastes. This study investigated MEL and CBL co-production from pure sugars and sugarcane molasses using an S. scitamineum strain isolated from sugarcane residues originating from KwaZulu-Natal, South Africa. Among the sugars tested, sucrose supported the highest glycolipid production, yielding 0.24 g/L MELs and 2.73 g/L CBLs. Lower titers were achieved with fructose, and no production occurred with glucose. Sugarcane molasses also proved to be an effective substrate, yielding 1.46 g/L CBLs—the highest reported titer from an industrial waste to date. However, all titers remained far below those of other glycolipids, which consistently exceed 50 g/L. Future efforts should focus on enhancing CBL production through process optimization or genetic engineering. Full article

Ammonia is a critical compound for numerous industrial processes; however, the conventional methods for its production present substantial environmental challenges. Co-producing biofuels and ammonia from biomass through anaerobic digestion offers a promising alternative to address these concerns. This study presents a theoretical assessment of the co-production of biomethane and ammonia from microalgae and cyanobacteria, utilising water from abandoned mine and quarry pit-lakes—specifically focusing on the Alessandria district as a case study. The analysis is based on the average values reported in the literature for the anaerobic digestion of selected biomass types. The results highlight Arthrospira platensis, Chlamydomonas reinhardtii, Chlorella spp., and Chlorella pyrenoidosa as the most promising species due to their superior yields of both ammonia and biomethane. This work aims to promote new opportunities for repurposing disused mining pit-lakes, contributing to the development of sustainable pathways for the integrated production of biofuels and ammonia. In this context, exploring integrated biorefinery systems within a bio-based economy represents an auspicious direction for future research, potentially enhancing the process efficiency and reducing costs. Full article

The growing demand for biofuels, especially ethanol produced from corn, has driven the production of co-products such as dried distillers grains with solubles (DDGS). With a high protein content (around 30%), fiber, and minerals, DDGS presents an economical alternative for animal nutrition, replacing traditional sources like soybean meal while maintaining productive performance and reducing costs. This study evaluated the total replacement of soybean meal with DDGS in the diet of confined Holstein cattle, focusing on weight gain, feed intake, digestibility, feed efficiency, animal health, meat quality, and economic viability. The 24 animals received diets with 80% concentrate, containing either DDGS or soybean meal, and no significant differences were observed in terms of body weight (p = 0.92), feed intake (p = 0.98), or feed efficiency (p = 0.97) between the two treatments. The average daily gain was 1.25 and 1.28 kg for cattle in the DDGS and soybean meal groups, respectively (p = 0.92). Regarding metabolic and digestive parameters, no relevant changes were found in blood levels, except for higher serum cholesterol (p = 0.03) levels in animals fed DDGS. The digestibility of neutral detergent fiber (NDF) (p = 0.03) and acid detergent fiber (ADF) (p = 0.05) was lower in the DDGS group, while the digestibility of ether extract was higher (p = 0.02). Rumen fluid analysis revealed an increase in the production of short-chain fatty acids (p = 0.01), such as acetic and butyric acids (p = 0.01), in the DDG-fed animals. In terms of meat quality, animals fed DDGS produced meat with lower levels of saturated fatty acids (SFA) (p = 0.05) and higher levels of unsaturated fatty acids (UFA) (p = 0.02), especially oleic acid (p = 0.05). This resulted in a healthier lipid profile, with a higher UFA/SFA ratio (p = 0.01). In terms of economic viability, DDGS-based diets were 10.5% cheaper, reducing the cost of production per animal by 7.67%. Profitability increased by 110% with DDGS compared to soybean meal, despite the high transportation costs. Therefore, replacing soybean meal with DDGS is an efficient and economical alternative for feeding confined cattle, maintaining zootechnical performance, increasing meat lipid content and improving fatty acid profile, and promoting higher profitability. This alternative is particularly advantageous in regions with easy access to the product. Full article

Global demands for sustainable energy and advanced therapeutics necessitate innovative interdisciplinary solutions. Integrated biorefining emerges as a strategic response, enabling the co-production of biofuels and pharmaceutical compounds through biomass valorization. This integrated model holds promise in enhancing resource utilization efficiency while ensuring economic viability. Our critical review methodically evaluates seven pivotal methodologies: seven key strategies: microbial metabolites, synthetic biology platforms, biorefinery waste extraction, nanocatalysts, computer-aided design, extremophiles, and plant secondary metabolites. Through systematic integration of these approaches, we reveal pivotal synergies and potential technological innovations that can propel multi-product biorefinery systems. Persistent challenges, particularly in reconciling complex metabolic flux balancing with regulatory compliance requirements, are analyzed. Nevertheless, advancements in systems biology, next-generation bioprocess engineering, and artificial intelligence-enhanced computational modeling present viable pathways for overcoming these obstacles. This comprehensive analysis substantiates the transformative capacity of integrated biorefining in establishing a circular bioeconomy framework, while underscoring the imperative of transdisciplinary cooperation to address existing technical and policy constraints. Full article

Vegetables and fruits, high in starch and sugars, are promising substrates for bioethanol production, but can also yield valuable nootropic compounds, such as α-glycerylphosphorylcholine (α-GPC). This compound is a known cognitive enhancer that works by increasing the release of acetylcholine, a neurotransmitter essential for learning and memory. In this study, select root and tuber crops, as well as fruits, were subjected to Saccharomyces cerevisiae fermentation to observe the co-production of ethanol and α-GPC. The ethanol yields from these substrates were comparable to those from wheat (var. AC Andrew), ranging from 30.44 g/L (beet) to 70.04 g/L (lotus root). Aside from ethanol, α-GPC was also produced, with purple top turnip yielding 0.91 g/L, the second highest concentration after wheat (used as a reference), which produced 1.25 g/L. Although α-GPC yields in the tested substrates were lower than those from cereal grains (e.g., wheat and barley), a noteworthy observation was the production of methanol in many of these substrates. Methanol was detected in all feedstocks except wheat, with concentrations ranging from 0.10 g/L (cassava) to 1.69 g/L (purple top turnip). A linear regression analysis revealed a strong correlation between methanol and α-GPC content (R² = 0.876; slope = 0.52), suggesting a potential link in their biosynthetic pathways. These feedstocks not only proved effective as substrates for bioethanol production, but also showed potential for generating value-added compounds such as α-GPC. This dual-purpose potential presents new market opportunities for producers by leveraging both biofuel and nootropic compound production. Furthermore, the observed relationship between methanol and α-GPC production warrants further investigation to elucidate the metabolic pathways involved. Full article

The supply of waste glycerol is rising steadily, partially due to the increased global production of biodiesel. Global biodiesel production totals about 47.1 billion liters and is a process that involves the co-production of waste glycerol, which accounts for over 12% of total esters produced. Waste glycerol is also generated during bioethanol production and is estimated to account for 10% of the total sugar consumed on average. Therefore, there is a real need to seek new technologies for reusing and neutralizing glycerol waste, as well as refining the existing ones. Biotechnological means of valorizing waste glycerol include converting it into gas biofuels via anaerobic fermentation processes. Glycerol-to-bioenergy conversion can be improved through the implementation of new technologies, the use of carefully selected or genetically modified microbial strains, the improvement of their metabolic efficiency, and the synthesis of new enzymes. The present study aimed to describe the mechanisms of microbial and anaerobic glycerol-to-biogas valorization processes (including methane, hydrogen, and biohythane) and assess their efficiency, as well as examine the progress of research and implementation work on the subject and present future avenues of research. Full article

In recent years, the employment of artificial neural networks (ANNs) has risen in various engineering fields. ANNs have been applied to a range of geotechnical engineering problems and have shown promising outcomes. The aim of this article is to enhance the effectiveness of estimating unfamiliar intermediate values from existing shear stress data by employing ANNs. Artificial neural network modelling was undertaken through the Regression Learner program that is integrated with the Matlab 2023a software package. This program offers a user-friendly graphical interface for developing AI models absent of the need for any coding. The validation and training of the ANNs were executed by relying on shear box test data which had been conducted at the Geotechnical Laboratory situated at Iowa State University. The objective of these experiments was to explore the potential of biofuel co-products (BCPs) in soil stabilization. The data should be structured with input and output parameters in columns and samples in rows. The dataset comprises a 216 × 6 matrix. The data columns provide information on soil type (pure soil—unadulterated; and 12% BCP-adulterated soil), time (1, 7, and 28 days), normal stress (0.069-DS10, 0.138-DS20, and 0.207-DS30 MPa), moisture content (OMC−4%, OMC%, and OMC+4%), and corresponding shear stress (σ, MPa) values. The AI predictions for the test data output provide an outstanding R² score of 0.94. This indicates that employing ANN to teach shear test data facilitates gaining a large quantity of data more efficiently, with fewer experiments and in less time. Such an approach seems encouraging for geotechnical engineering. Full article

The objectives of this study were to investigate the effect of newly developed blend-pelleted products based on carinata meal (BPPCR) or canola meal (BPPCN) in combination with peas and lignosulfonate on ruminal fermentation characteristics, degradation kinetics, intestinal digestion and feed milk values (FMV) when fed to high-producing dairy cows. Three dietary treatments were Control = control diet (common barley-based diet in western Canada); BPPCR = basal diet supplemented with 12.3%DM BPPCR (carinata meal 71.4% + pea 23.8% + lignosulfonate4.8%DM), and BPPCN = basal diet supplemented with 13.3%DM BPPCN (canola meal 71.4% + pea 23.8% + lignosulfonate 4.8%DM). In the whole project, nine mid-lactating Holstein cows (body weight, 679 ± 124 kg; days in milk, 96 ± 22) were used in a triplicated 3 × 3 Latin square study for an animal production performance study. For this fermentation and degradation kinetics study, the experiment was a 3 × 3 Latin square design with three different dietary treatments in three different periods with three available multiparous fistulated Holstein cows. The results showed that the control diet was higher (p < 0.05) in total VFA rumen concentration (138 mmol/L) than BPPCN. There was no dietary effect (p > 0.10) on the concentration of rumen ammonia and ruminal degradation kinetics of dietary nutrients. There was no significant differences (p > 0.10) among diets on the intestinal digestion of nutrients and metabolizable protein. Similarly, the feed milk values (FMV) were not affected (p > 0.10) by diets. In conclusion, the blend-pelleted products based on carinata meal for a new co-product from the bio-fuel processing industry was equal to the pelleted products based on conventional canola meal for high producing dairy cattle. Full article

The economic viability of guayule as an industrial crop for natural rubber production depends largely on the potential valorization of these co-products. According to the studies carried out on the subject, there is a broad consensus on the added value of the resin and bagasse in different fields of application. The process of extracting natural rubber from guayule produces mainly bagasse (±80% of the total dry mass) and resin (±10% of the total dry mass). According to guayule research, high-value co-products significantly improve the economic viability of guayule as an industrial crop and offset a substantial portion of the cultivation and processing costs. According to studies, resin remains the most fluctuating value; reducing this uncertainty, through future research on resin applications, it is essential to the success of guayule as a natural rubber raw material. It finds applications in different industrial fields, such as coatings, varnishes, paints, treated wood, biocontrol agents and controlled-release formulations. Bagasse is composed primarily of cellulose, hemicellulose, lignin and resin, and has a high calorific value, making bagasse a suitable fuel for on-site combustion to produce electricity and thermal energy. Bagasse combustion in this scenario is less complex than the logistics of biofuel production. Resin-containing guayule bagasse has been combined with a plastic binder to make high-density composite panels resistant to termite degradation. In addition, the resinous material can be solvent-extracted and used to impregnate wood with raw resin extract so that the wood is protected from destructive organisms. Guayule bagasse containing resin can modify the soil nature and improve the growth of vegetables compared to de-resinated bagasse. Full article

Biomass deacetylation with alkali prior to dilute acid pretreatment can be a promising approach to reduce the toxicity of the resulting hydrolysates and improve microbial fermentation. In this study, the effect of mild alkaline treatment of oil palm trunk (OPT) biomass on succinic acid production was evaluated. Deacetylation was carried out under different conditions: NaOH loadings (1–5%, w/v) and reaction times (15–90 min) at 100 °C. Deacetylation using 1% (w/v) NaOH within 15 min was sufficient to achieve a high acetic acid removal of 5.8 g/L with minimal sugar loss. Deacetylation under this condition resulted in a total sugar concentration of 55.8 g/L (18.0 g/L xylose and 37.8 g/L glucose), which was 37% higher than that of non-deacetylated OPT. Subsequently, succinic acid production using Actinobacillus succinogenes was also improved by 42% and 13% in terms of productivity and yield, respectively, at 10% (w/v) solid loading. This further demonstrated that mild alkaline treatment prior to dilute acid pretreatment is a promising strategy to improve succinic acid production. This study provides a facile approach for reducing the most influential inhibitory effect of acetic acid, and it can be applied to the exploitation of lignocellulosic biomass resources for succinic acid, biofuels, and/or other biochemical co-production in the future. Full article

This study evaluated the effects of dietary macauba pulp on the growth performance, carcass, and pork traits of growing-finishing pigs; and whether differences in residual feed intake breeding values could influence the pigs’ growth responses to macauba pulp inclusion in the diet. A total of 282 (34.8 ± 4.40 kg) pigs (barrows and females), progeny of sires with high (HRFI) or low (LRFI) breeding value for residual feed intake, were pair-housed on the basis of sex, breeding value, and initial BW. Diets with (macauba) or without (control) of 50 g/kg of macauba pulp inclusion were randomly assigned to the experimental pens. There were eight treatment groups: HRFI barrows were fed the control diet; HRFI barrows were fed the macauba diet; LRFI barrows were fed the control diet; LRFI barrows were fed the macauba diet; HRFI female pigs were fed the control diet; HRFI female pigs were fed the macauba diet; LRFI female pigs were fed the control diet; and LRFI female pigs were fed the macauba diet. The trial lasted 90 days and was divided into four phases: growing phase 1 (G1) and 2 (G2); and finishing phases 1 (F1) and 2 (F2). There was no interaction between sex, breeding value, and diet for performance, carcass, and pork traits. Barrows had higher feed intake (ADFI), daily gain (ADG), feed conversion rate (FCR), and final body weight than female pigs. The breeding value had no effect on performance measurements. The inclusion of macauba pulp in the pigs’ diets did not affect any growth parameter during G1, G2 and F1 phases. However, reduced ADFI and improved FCR were observed in F2. Female pigs had lower backfat thickness (BF) and higher loin eye area (LEA) than barrows. HRFI pigs had higher hot carcass weight and LEA, and lower BF than LRFI pigs. There was no effect of macauba pulp inclusion on carcass traits. Pork from barrows presented lower Warner–Bratzler shear force and higher fat content than pork from the females. There was no effect of breeding value on pork traits. Pork from pigs fed the macauba diet showed lower moisture content and water-holding capacity. In conclusion, macauba pulp can partially replace corn without reducing the performance of pigs. Regardless of sex and breeding value for RFI, pigs responded similarly to macauba pulp inclusion in diets. Full article

Lignocellulose-rich empty fruit bunches (EFBs) have high potential as feedstock for second-generation biofuel and biochemical production without compromising food security. Nevertheless, the major challenge of valorizing lignocellulose-rich EFB is its high pretreatment cost. In this study, the preliminary techno-economic feasibility of expanding an existing pellet production plant into an integrated bio-refinery plant to produce xylitol and bioethanol was investigated as a strategy to diversify the high production cost and leverage the high selling price of biofuel and biochemicals. The EFB feedstock was split into a pellet production stream and a xylitol and bioethanol production stream. Different economic performance metrics were used to compare the profitability at different splitting ratios of xylitol and bioethanol to pellet production. The analysis showed that an EFB splitting ratio below 40% for pellet production was economically feasible. A sensitivity analysis showed that xylitol price had the most significant impact on the economic performance metrics. Another case study on the coproduction of pellet and xylitol versus that of pellet and bioethanol concluded that cellulosic bioethanol production is yet to be market-ready, requiring a minimum selling price above the current market price to be feasible at 16% of the minimum acceptable return rate. Full article

Among the different alternatives for the production of biofuels, food waste could be a favorable bioenergy source. Using food waste as a feedstock has the potential to meet the expectations of the second generation of biofuels, in terms of environmental savings and revenue-generation, and which, along with other valuable co-products, can contribute to biorefinery profits. This study aimed to investigate the early stages of life-cycle assessment (LCA) for restaurant food waste processed into bioethanol, biomethane, and oil, split over different scenarios. Based on a life cycle inventory analysis, the environmental impacts were assessed using an IMPACT 2002+ methodology. The characterized impacts were then normalized against the average impacts, and the normalized results were weighted and aggregated to provide single score LCA results. The overall findings showed that electricity consumption and condensates included VFAs, as well as enzymes, yeast, and n-hexane, were the main contributors to the environmental burdens in all impact categories. Considering the sensitivity analysis, the results demonstrated that the enzyme dosage loading in the hydrolysis process and n-hexane utilization in the fat extraction process can change the environmental performance, along with the process efficiency. This study can provide an approach to foresee environmental hotspots in the very early developmental stages of food waste valorization into biofuels, and for highlighting drawbacks connected to the implementation of conversion processes at pilot and industrial scales. Full article

Millions of tons of textile waste are landfilled or incinerated in the world every year due to insufficient recycle value streams and the complex composition of textile end products. The goal of this review is to highlight pathways for simplifying and separating textile wastes into valuable raw material streams that will promote their recovery and conversion to useful products. The discussion focuses on advances in sorting, separation, decolorization and conversion of polyester and cotton, the two most common textile fibers. Sorting processes are gaining automation using spectroscopic methods that detect chemical composition differences between materials to divide them into categories. Separation, through dissolving or degrading, makes it possible to deconstruct blended textiles and purify polymers, monomers and co-products. Waste cotton can produce high quality regenerated cellulose fibers, cellulose nanocrystals (CNCs) or biofuels. Waste polyester can produce colored yarns or can be chemically converted to its starting monomers for the recreation of virgin polymer as a complete closed loop. The current strategies for decolorization are presented. Life cycle assessment (LCA) studies found that recycling polyester/cotton blended fabrics for subsequent uses is more sustainable than incineration, and research on producing biomass-based poly-ester also offers feasible avenues for improving textile sustainability and promoting circular processing. Full article