Search Results (29)

Background: In agricultural supply chains, unequal bargaining power often leads to economic inequality, particularly for farmers. The fair profit distribution (FPD) approach offers a solution by optimizing supply chain flows (materials, information, and money) to promote economic equity among members. However, our literature review highlights a gap in applying the FPD approach to the facility location-allocation problem in supply chain network design (SCND), particularly in sugarcane-derived biofuel supply chains. Methods: Consequently, we propose a multi-period optimization model based on FPD to design a sugarcane biofuel supply chain. The methodology involves four steps: constructing a conceptual model, developing a mathematical model, designing a solution strategy, and generating insights. This model considers both investment (crop development, biorefinery construction) and operational phases over a long-term planning horizon, focusing on farm location and crop allocation. Results: By comparing the FPD model to a traditional centralized planning supply chain (CSC) approach, we examine the impact of the planning horizon, number of farms, and sugarcane prices paid by biorefineries on financial performance. While the FPD model results in lower overall system profits, it fosters a fairer economic scenario for farmers. Conclusions: This study contributes to economic justice in supply chains and offers insights to promote fair trade among stakeholders. Full article

A complex evaluation of antimicrobial activities of microalgae, including those relevant to wastewater treatment (WWT), in light of the integrated biorefinery concept, is performed. An example of this concept is linking a commercial microalgal system to plants, factories, or farms that emit polluted wastewater (WW). The microalgae would not only metabolize the pollutants—such as nitrogen (N) and phosphorus (P)—from the WW, thus fueling their biomass, but they would exert an antibacterial effect against the pathogenic bacteria there. The biomass then could be harvested and used for biofertilizers, biofuels, and bioplastics and might possibly be utilized as animal feed, antimicrobial and other pharmaceutical agents. A large amount of the research on the antimicrobial activity and WWT potential focuses on the families Chlorellaceae and Scenedesmaceae, which are also some of the most commercially used strains of microalgae. For that reason, they are the species chosen for the current review. Furthermore, the increasing antimicrobial resistance necessitates the search for antibiotic alternatives, and the antibacterial and antifungal activity of Chlorellaceae and Scenedesmaceae is very promising. Microalgae are rich in antibacterial compounds like polyunsaturated fatty acids (PUFAs), polysaccharides, carotenoids, proteins, etc., and for that reason, their extracts possess antimicrobial effects. The in vitro antimicrobial activity of Chlorellaceae and Scenedesmaceae families has varied in a broad range from low to strong activity or no effect. Several strains have fulfilled the criteria for outstanding and high activity, especially C. vulgaris and other Chlorellaceae spp., with an effect equal to or better than the control antibiotics. There were several strains with minimum inhibitory concentrations (MIC) below 80 µg/mL and even 10 and 1.5 µg/mL; some species also had inhibition zones (IZ) over 30 mm, even as high as 48 mm. In vivo results are also promising but scarce, and all this warrants further in vivo and in situ studies—from animal models to clinical and environmental trials. Altogether, important data in the light of the circle economy, the urgent necessity to decrease CO₂ emissions to fight climate change, and to curb the harmful influence of future pandemics are presented. This review paves the way for further utilizing the total potential of a microalgal system. Full article

Owing to the growing concerns about the dwindling fossil fuel reserves, increasing energy demand, and climate emergency, it is imperative to develop and deploy sustainable energy technologies to ensure future energy supply and to transition to the net-zero world. In this context, there is great potential in the biorefinery concept for supplying drop in biofuels in the form of biodiesel. Biodiesel as a fuel can certainly bridge the gap where electrification or the use of hydrogen is not feasible, for instance, in heavy vehicles and in the farm and marine transportation sectors. However, the biodiesel industry also generates a large amount of crude glycerol as the by-product. Due to the presence of several impurities, crude glycerol may not be a suitable feedstock for all high-value products derived from glycerol, but it fits well with glycerol esterification for producing glycerol acetins, which have numerous applications. This review critically looks at the processes using nanostructured solid/liquid acid catalysts for glycerol esterification, including the economic viability of the scale-up. The homogeneous catalysts reviewed herein include mineral acids and Brønsted acidic ionic liquids, such as SO₃H-functionalized and heteropoly acid based ionic liquids. The heterogeneous catalysts reviewed herein include solid acid catalysts such as metal oxides, ion-exchange resins, zeolites, and supported heteropoly acid-based catalysts. Furthermore, the techno-economic analysis studies have shown the process to be highly profitable, confirming the viability of glycerol esterification as a potential tool for economic value addition to the biorefinery industry. Full article

This review provides an overview of grassland studies on the effects of manure application and herbivore excreta on plant and soil properties in temperate grasslands. Grass biomass from grazing or mowing is mainly used for animal products such as milk or meat, as well as for energy or raw materials for biorefineries. Manure application or grazing has a significant impact on several plant and soil properties. There are effects on soil chemical properties, such as increased carbon sequestration, improved nutrient availability, and increased pH. Additionally, several physical soil properties are improved by manure application or grazing. For example, bulk density is reduced, and porosity and hydraulic conductivity are greatly improved. Some biological parameters, particularly microbial biomass and microbial and enzyme activity, also increase. The use of manure and grazing can, therefore, contribute to improving soil fertility, replacing mineral fertilizers, and closing nutrient cycles. On the other hand, over-application of manure and overgrazing can result in a surplus of nutrients over plant needs and increase losses through emission or leaching. The lost nutrients are not only economically lost from the nutrient cycle of the farm but can also cause environmental damage. Full article

To create carbon efficient sources of bioenergy feedstocks and feedstuff for aquaculture and terrestrial livestock, it is critical to develop and commercialize the most efficient seaweed cultivation approach with a sustainable nutrient input supply. Here, we present data for a novel, onshore tropical macroalgae cultivation system, based on influent deep seawater as the nutrient and carbon sources. Two red algal species were selected, Agardhiella subulata and Halymenia hawaiiana, as the basis for growth optimization. Highest productivity in small-scale cultivation was demonstrated with A. subulata in the 10% deep seawater (64.7 µg N L⁻¹) treatment, growing at up to 26% specific growth rate day⁻¹ with highest yields observed at 247.5 g m⁻² day⁻¹ fresh weight. The highest yields for H. hawaiiana were measured with the addition of 10% deep seawater up to 8.8% specific growth rate day⁻¹ and yields at 63.3 g fresh weight m⁻² day⁻¹ equivalent. Biomass should be culled weekly or biweekly to avoid density limitations, which likely contributed to a decrease in SGR over time. With a measured 30–40% carbon content of the ash-free dry weight (20–30% of the dry weight) biomass, this translates to an almost 1:1 CO₂ capture to biomass ratio. The compositional fingerprint of the high carbohydrate content of both Agardhiella and Halymenia makes for an attractive feedstock for downstream biorefinery applications. By focusing on scaling and optimizing seaweed farming technologies for large-scale onshore farms, the opportunities for yield potential, adaptability to cultivation conditions, and meeting global sustainability goals through novel, carbon-negative biomass sources such as seaweed can be realized. Full article

Seaweeds are among the most important biomass feedstocks for the production of third-generation biofuels. They are also efficient in carbon sequestration during growth and produce a variety of high-value chemicals. Given these characteristics together with the relatively high carbohydrate content, seaweeds have been discussed as an ideal means for CO₂ capture and biofuel production. Though third-generation biofuels have emerged as some of the best alternatives to fossil fuels, there is currently no large-scale production or mainstream use of such liquid fuels due to the many technical challenges and high production costs. The present study describes the concept of coastal marine biorefineries as the most cost-effective and sustainable approach for biofuel production from seaweeds, as well as atmospheric carbon capture and storage (CCS). The suggested refinery system makes use of marine resources, namely seawater, seaweed, and marine microorganisms. Firstly, extensive screening of the current literature was performed to determine which technologies would enable the emergence of such a novel biorefinery system and its merits over conventional refineries. Secondly, the study investigates various scenarios assessing the potential of seaweeds as a means of carbon sequestration. We demonstrate that the removal of 100 Gigatons of excess CO₂ using seaweed farms can be achieved in around 4 months to less than 12 years depending on the area under cultivation and the seaweed species. The total bioethanol that could be generated from the harvested biomass is around 8 trillion litres. In addition, high-value chemicals (HVC) that could potentially be recovered from the process represent a considerable opportunity with multi-billion-dollar commercial value. Overall, coastal marine biorefineries have strong potential for a sustainable green economy and represent a rapid approach to climate change mitigation. Full article

As the global population rises, agriculture and industry are under increasing pressure to become more sustainable in meeting this growing demand, while minimizing impacts on global emissions, land use change, and biodiversity. The development of efficient and symbiotic local bioeconomies can help to respond to this challenge by using land, resources, and side streams in efficient ways tailored to the needs of different regions. Green biorefineries offer a unique opportunity for regions with abundant grasslands to use this primary resource more sustainably, providing feed for cows, while also generating feed for monogastric animals, along with the co-production of biomaterials and energy. The current study investigates the impact of a green biorefinery co-product, leaf protein concentrate (LPC), for input to a pig farm, assessing its impact on pig diets, and the extended impact on the bioenergy performance of the pig farm. The study found that LPC replaced soya bean meal at a 50% displacement rate, with pigs showing positive performance in intake and weight gain. Based on laboratory analysis, the resulting pig slurry demonstrated a higher biogas content and 26% higher biomethane potential compared with the control slurry. The findings demonstrate some of the local synergies between agricultural sectors that can be achieved through extended green biorefinery development, and the benefits for local bioeconomy actors. Full article

The United States (U.S.) has a nearly USD 17 billion seafood trade deficit annually. However, the U.S. aquaculture industry faces strict micronutrient (e.g., phosphorus and nitrogen) level mandates that negatively impact fish production, especially for the state of Idaho, which produces 70–75% of the nation’s rainbow trout. This study investigates the sustainability benefits of producing engineered biomaterials from lignocellulosic-based feedstocks near collection sites via portable biorefineries for use by fish farms to reduce eutrophication (oversupply of micronutrients) impacts. In this study, sustainability assessments are performed on a case study in southern Idaho, the largest U.S. commercial producer of rainbow trout. The results show that 20 and 60 min of water treatment, using small particle size biomaterial from lodgepole pine, has the highest total phosphorus removal rate, at 150–180 g of phosphorus per 1 metric ton of engineered biomaterials. The results of techno-economic and environmental impacts studies indicate that pinewood-based biomaterials production cost ranges from USD 213 USD 242 per ton and reduces the eutrophication potential by 5–17 kg PO₄eq/ton. Additionally, the environmental impact results show that the total greenhouse gas emission for biomaterial production is 47–54 kg CO₂eq/ton; however, the used biomaterials after water treatment can be sold for around USD 850 per ton as nutrient-rich soil conditioners. This study concluded that engineered biomaterials from lignocellulosic-based feedstocks could be a sustainable solution to the challenge that aquaculture faces, particularly capturing micronutrients from eutrophic water and reusing them as fertilizers. Full article

Natural resources are becoming increasingly scarce, and the need to control their consumption and recycle their use is growing. Water is one of the essential resources for human survival. Therefore, there has been an increasing interest in ways to save, recycle and treat water supplies. Aquaculture is one of the most polluting activities as it produces a significant wastewater volume, which needs proper treatment before being discharged into the environment or recycled. Microalgae are a potential solution for wastewater treatment. Due to their numerous advantages, the use of microalgal biomass is being studied, and, at present, there is already a market and room for profit in the sale of microalgal components in various forms, such as animal and human supplements. From a biorefinery point of view, it is important to take advantage of all the qualities and benefits that microalgae have by combining their great capacity to treat wastewater and exploit the produced biomass, analysing its composition for subsequent valorisation, for example. In this study, Chlorella vulgaris was used to treat aquaculture wastewater from a trout farm aquaculture facility, and the treatment efficiency was evaluated. To valorise the resulting biomass, its composition was also assessed. C. vulgaris successfully grew in the effluent with growth rates of 0.260 ± 0.014 d⁻¹ and with average productivity of 32.9 ± 1.6 mg L⁻¹ d⁻¹. The achieved removal efficiencies were 93.5 ± 2.1% for total nitrogen, 98.0 ± 0.1% for nitrate-nitrogen and 92.7 ± 0.1% for phosphate-phosphorus. Concerning biomass composition, the lipids (15.82 ± 0.15%), carbohydrates (48.64 ± 0.83%), and pigment contents (0.99 ± 0.04% for chlorophyll a + b and 0.21 ± 0.04% for carotenoids) were similar to the values of similar studies. However, the protein content obtained (17.93 ± 1.21%) was lower than the ones mentioned in the literature. Full article

The European Commission’s European Innovation Partnership for Agricultural Productivity and Sustainability (EIP-AGRI), part of the European Commission’s Europe 2020 strategy, aims to ‘achieve more and better from less’ by bringing together a diversity of innovation actors to harness their combined knowledges to creatively achieve sustainability goals. The creation and novel use of biomaterials remains both a significant challenge and opportunity and bringing together all the relevant actors from primary production through to refinement and processing is anticipated to make progress in bringing into practice pilot operational approaches on the ground. For the bioeconomy, a nascent sector, it is a significant challenge for it to become established; grow; innovate and engage all the relevant actors. It has been noted internationally that primary producers, among other cohorts, remain marginalised from bioeconomy activities, which significantly compromises how inclusive and innovative the bioeconomy is likely to be henceforth. In this context, an interesting case study is the Biorefinery Glas Operational Group (OG), located in Ireland. The OG was a ‘small-scale-farmer-led green biorefinery supporting farmer diversification into the circular bioeconomy’. The central research question of this paper concerns the dynamics of farmers’ participation in the OG, focusing specifically on how their knowledges shaped the operation of the OG and bioeconomy activities within it. This paper presents a social network graph illustrating the diverse actors involved in the OG, their relative degrees of connectedness to each other, and an overview of the differing levels of actors’ influence in the network. Interrogating the roles of different actors further, a lens of power theory is used to explore how farmers’ knowledges were used in combination with others’ knowledges to shape the development of the OG and innovation within it. The overall conclusion from an analysis of interviews conducted with farmer and non-farmer participants in the OG is that while farmers were highly connected with other members of the OG and viewed their involvement in the OG positively, the level of influence they had in decision-making processes in some areas of the OG was relatively limited. Different types of members of the OG tended to work in a relatively segmented way, with farmers contributing as input suppliers and on the practical side at the farm level, while other members of the OG such as scientists worked on more technical aspects. This paper concludes by providing conclusions and lessons of relevance to innovation-brokers and practitioners, and for the operation of OGs involving farmers elsewhere. Full article

Small-scale photobioreactors (PBRs) in the inoculum stage were designed with internal (red or green) and external white LED light as an initial step of a larger-scale installation aimed at fulfilling the integral biorefinery concept for maximum utilization of microalgal biomass in a multifunctional laboratory. The specific growth rate of Scenedesmus obliquus (Turpin) Kützing biomass for given cultural conditions was analyzed by using MAPLE software. For the determination of total polyphenols, flavonoids, chlorophyll “a” and “b”, carotenoids and lipids, UHPLC-HRMS, ISO-20776/1, ISO-10993-5 and CUPRAC tests were carried out. Under red light growing, a higher content of polyphenols was found, while the green light favoured the flavonoid accumulation in the biomass. Chlorophylls, carotenoids and lipids were in the same order of magnitude in both samples. The dichloromethane extracts obtained from the biomass of each PBR synergistically potentiated at low concentrations (0.01–0.05 mg/mL) the antibacterial activity of penicillin, fluoroquinolones or oregano essential oil against the selected food-borne pathogens (Staphylococcus aureus, Escherichia coli and Salmonella typhimurium) without showing any in vitro cytotoxicity. Both extracts exhibited good cupric ion-reducing antioxidant capacity at concentrations above 0.042–0.08 mg/mL. The UHPLC-HRMS analysis revealed that both extracts contained long chain fatty acids and carotenoids thus explaining their antibacterial and antioxidant potential. The applied engineering approach showed a great potential to modify microalgae metabolism for the synthesis of target compounds by S. obliquus with capacity for the development of health-promoting nutraceuticals for poultry farming. Full article

This study analyzes the effects of N fertilizer application rates on profitability of growing switchgrass and using the feedstock in a pyrolysis biorefinery facility to create a source of sustainable aviation fuel (SAF) supply in Tennessee. Switchgrass (Panicum virgatum L.) is a perennial bunchgrass native to North America with traits suitable for biofuel and co-product production. Previous chemical analysis has shown that ash content in switchgrass is related to the amount of nitrogen applied to the field, while at the biorefinery level, the percentage ash content reduces the biorefinery fuel output. To obtain optimal nitrogen (N) application rates for the switchgrass producers and the biorefinery, a two-part analysis is employed. First, a partial budgeting profitability analysis is conducted for this cropping enterprise at the farm-gate level without considering downstream implications of biomass quality, i.e., ash content. Second, the effects of higher ash content as a percentage of the feedstock on biorefinery output are analyzed. Results show farm-gate profit is maximized when N fertilizer is applied at 111 kg/ha, while as a result of increased production levels and decreased percentage ash content, biorefinery profit is maximized when N is applied at 157 kg/ha. Lower ash could lead to premium prices paid to switchgrass producers if higher quality feedstock were to be demanded as part of an integrated biofuel industry. Full article

Perennial rye grass is a widely used forage species in Ireland, on which the ruminant sector of agriculture is heavily dependent. While this species of grass is the primary source of fodder for cows, it is also abundant in plant protein, which could form a potential alternative ingredient in monogastric animal feed using a green biorefinery approach. In this study, perennial rye grass was processed using a novel biorefining process to extract value added products including protein as a potential replacement for soybean meal in monogastric feeds. Feed trials were conducted on a commercial farm with 55 weaner pigs for 31 days until slaughter. The diets comprised a control and a trial diet which integrated the green biorefinery protein concentrate. The effects of the new diet were determined by measuring the daily feed intake (DFI), average weight gain (AWG) and feed conversion ratio (FCR). Amino acid profiles of grass protein concentrate and soybean meal were comparable, with the latter having a slightly higher amount of total protein content, lysine and cysteine. The DFI and ADW indicated that the treatment diet was superior to the control. DFI for the treatment diet (1.512 kg/d) was 8% higher than the control diet (1.400 kg/d) by the end of the trial. Additionally, the ADW for the treatment diet was 6.44% higher than that achieved in the control sample. Meanwhile, FCR calculations indicated that the treatment diet is just as efficient as the conventional diet. Overall, the results of the study indicate positive potential for perennial ryegrass-derived green biorefinery protein concentrate as an alternative protein source for pig feed formulations in Ireland. Full article

Managing the concentration of atmospheric CO₂ requires a multifaceted engineering strategy, which remains a highly challenging task. Reducing atmospheric CO₂ (CO2R) by converting it to value-added chemicals in a carbon neutral footprint manner must be the ultimate goal. The latest progress in CO2R through either abiotic (artificial catalysts) or biotic (natural enzymes) processes is reviewed herein. Abiotic CO2R can be conducted in the aqueous phase that usually leads to the formation of a mixture of CO, formic acid, and hydrogen. By contrast, a wide spectrum of hydrocarbon species is often observed by abiotic CO2R in the gaseous phase. On the other hand, biotic CO2R is often conducted in the aqueous phase and a wide spectrum of value-added chemicals are obtained. Key to the success of the abiotic process is understanding the surface chemistry of catalysts, which significantly governs the reactivity and selectivity of CO2R. However, in biotic CO2R, operation conditions and reactor design are crucial to reaching a neutral carbon footprint. Future research needs to look toward neutral or even negative carbon footprint CO2R processes. Having a deep insight into the scientific and technological aspect of both abiotic and biotic CO2R would advance in designing efficient catalysts and microalgae farming systems. Integrating the abiotic and biotic CO2R such as microbial fuel cells further diversifies the spectrum of CO2R. Full article

Meeting biorefineries’ demands for lignocellulosic biomass will require sourcing feedstock without affecting the food or animal-feed supply. A decision-aid model can assess the dual use of switchgrass (Panicum virgatum L.) to maintain animal production while providing biomass. We simulated a mixed-farm operation with 156 ha of hay+pasture, 96 beef cows (Bos spp.), and poultry (Gallus gallus L.) production wherein the hay land was converted to switchgrass for dual use as biomass and forage. The cow-calf simulator tracked changes in forage and cattle production, economic returns, and net greenhouse gas (GHG) emissions. Dual use of switchgrass consisted of harvesting the first cutting (mid-June) for hay and the second cutting (October-November) for biomass. Dual use required a modest increase in fertilizer application and supplementing cows with corn grain to meet nutritional requirements. Converting hay land to dual-use switchgrass produced 122 Mg of switchgrass, reduced net GHG emissions for autumn- and spring-calving operations by 3.4 and 3.6%, respectively, and increased the farm profit by approximately $1500 when priced at $50 Mg⁻¹ regardless of the calving season. This simulation provided evidence that conversion of hay lands (in a beef cow-calf and poultry farm) to dual-use switchgrass can avoid displacing food production, while supplying bioenergy feedstock and reducing climate-forcing gases. Full article