Optimizing concrete for circularity: a comparative life cycle assessment of geopolymer and ordinary concrete.

Geopolymer concrete is a sustainable construction material developed with industrial by-products to eliminate the use of cement in concrete production. However, a cradle-to-cradle life cycle assessment (LCA) that accounts for the impact of service life is essential to comprehensively assess the environmental advantages of GPC. In this study, a comparative cradle-to-cradle LCA was performed for circular geopolymer concrete (CGPC), geopolymer concrete (GPC), and circular ordinary concrete (COC), as alternatives to Portland cement concrete (PCC). Also, the biases of common LCA resulted from ignoring service life and end-of-life scenarios were identified. Finally, the sustainability potentials of the alternative scenarios were evaluated. According to the cradle-to-cradle LCA using the adopted functional unit, GPC and CGPC significantly alleviated the environmental impact of cement production, such as global warming potential by about 53%. Ignoring the service life and end-of-life scenarios considerably changed the critical midpoint (ionizing radiation for CGPC and GPC) and endpoint indicators (resources for CGPC and GPC) and priority of alternative concretes. Finally, the CGPC and GPC showed a substantial increase of 213% and 276% in sustainability potential compared to PCC, respectively.

Life-Cycle Environmental Impacts of Additive-Related Chemicals in Polyvinyl Chloride Plastics and the Mitigation Potential.

Plastic additive-related chemicals, particularly in polyvinyl chloride (PVC) plastics, have become a key issue in plastic pollution. Although addressing plastic pollution through the life-cycle approach is crucial, the environmental impacts of typical plastic additive-related chemicals in PVC plastics during the cradle-to-gate stage remain unexplored. Consequently, managing the life-cycle environmental impacts of these additives remains challenging. Herein, the environmental impacts of 23 typical plastic additive-related chemicals and six PVC plastic products were evaluated throughout the cradle-to-gate life-cycle stage using a life cycle assessment-material flow analysis (LCA-MFA) coupled model. The results indicate that plastic additives significantly contribute to the environmental impacts of PVC plastic products across various end point indicators, ranging from 8.7 to 40.6%. Additionally, scenario analysis (SA) reveals that conventional strategies for addressing plastic pollution may not be highly effective in mitigating the environmental impacts associated with plastic additives. Specifically, compared to primary polymers, these additives exhibit 4 to 13% lower mitigation potential under the same policy scenarios. However, technical adjustment strategies targeting additives show a mitigation potential of 12 to 39%, suggesting that guiding the plastic additive industry toward green transformation is a key strategy for reducing environmental impacts.

Contribution of waste management to a sustainable textile sector.

With increasing textile consumption and limited sorting and recycling capacities, the EU faces major challenges in terms of managing its textile waste. This study investigates the environmental and socio-economic impacts of explorative policy scenarios for a more sustainable textile waste management system in Europe. These scenarios differ substantially in the amounts of textile waste generated and separately collected, closed-loop recycling capacities and textile waste exports. Our results show that sustainable textile waste management remains highly relevant for the sector. Still, without addressing in parallel prevention of textile waste generation via production and consumption patterns, a climate-neutral and circular textiles sector will be hard to achieve. Interventions in the waste management of textiles could reduce global warming impacts by up to 22.3 Mt CO2 per year, which translates to an 18% sector-wide impact by 2035. Depending on the intervention(s), the estimated required investment at present amounts to between 7 and 33 billion EUR. The study provides a valuable starting point for evidence-based decisions on future textile policymaking in Europe.

Embedding Water-Energy-Food nexus and circularity assessment for organization benchmarking: A case study for dairy farms.

The Water-Energy-Food (WEF) nexus approach is increasingly being used for supporting a transition to sustainable development, with initiatives involving the concept of circular economy (CE). In the agricultural sector in particular, assessing this nexus is crucial to ensure food security, control the consumption of key resources such as water and energy, as well as measure atmospheric emissions linked to climate change. This manuscript aims to propose a novel approach by coupling the WEF nexus with a circularity indicator, seeking to capture in a single index (the WEF+CEi) both performances in a sample of companies. The novel approach is applied to 30 dairy farms located in Galicia (NW Spain) to benchmark them in a holistic manner. To do this, the WEF nexus of each farm was represented through the following indicators: carbon footprint, water footprint, energy footprint, and food productivity. In addition, the percentage of circularity for each farm, and for the agro-industrial cooperative was measured thanks to the application of a circularity tool in percentage terms. Finally, the WEF+CEi indicator was obtained using the multicriteria mathematical tool of Data Envelopment Analysis (DEA). The results show that without considering the agro-industrial cooperative, the system is 51 % circular. On the other hand, considering the farms and the cooperative, the system goes up to 80 % of circularity. Finally, the proposed approach can support decision-making and provide insights for producers and stakeholders in the area.

Environmental impacts of extensive beef production in Colombia by life cycle assessment: a case study.

The increase in the negative effects of global change promotes the search for alternatives to supply the demand for food worldwide aligned with the Sustainable Development Goals (SDGs) to ensure food security. Animal protein, which is a main source of nutrients in the diet of today's society, especially beef, which is one of the most demanded products nowadays, has been criticized not only for its high water consumption and land occupation for production but also for the emission of greenhouse gases (GHG) from enteric methane generated in the fermentation process within the bovine rumen and deforestation for the adaptation of pastures. This study is mainly motivated by the lack of quantifiable scientific information in Colombia on the environmental impacts of beef production. Therefore, it is intended to estimate some of the impacts of beef production in extensive systems using the life cycle assessment (LCA) method under a particular scenario considering all the production phases (from raw material to fattening, where the cattle are ready to be slaughtered). The study was conducted with data supplied by a farm in Antioquia, Colombia, and the functional unit (FU) was defined as 1 kg of live weight (LW). The scope of this study was gate-to-gate. "The 2019 Refinement to the 2006 IPCC Guidelines for National Greenhouse Gas Inventories" (IPCC  2006; IPCC 2019) was used to calculate methane and nitrous oxide emissions. LCA modeling was developed with Ecoinvent database v3.8 and the Umberto LCA + software. It was found that the most affected category of damage was ecosystem quality, which represents 77% of the total, followed by human health at 17% and resources at 6%. The category impact of agricultural land occupation is the one that represents the most significant contribution to the ecosystem quality endpoint, with a percentage of 87%, due to the soil's compaction and the loss of the soil's properties. Additionally, the obtained carbon footprint for the system was 28.9 kg of CO2-eq/kg LW.

Development of a Facile and Green Synthesis Strategy for Brightly Fluorescent Carbon Dots from Various Waste Materials.

Carbon dots (CDs) are fluorescent carbon-based nanomaterials with remarkable properties, making them more attractive than traditional fluorophores. Consequently, researchers focused on their development and application in fields such as sensing and bioimaging. One potential advantage of employing CDs is using organic waste as carbon precursors in their synthesis, providing a pathway for waste upcycling for a circular economy. However, waste-based CDs often have low fluorescence quantum yields (QYFL), limiting their practical applications. So, there is a need for a well-defined strategy to consistently produce waste-based CDs with appreciable QYFL, irrespective of the starting waste material. Herein, we developed a fabrication strategy based on the hydrothermal treatment of waste materials, using citric acid as a co-carbon precursor and ethylenediamine as N-dopant. This strategy was tested with various materials, including corn stover, spent coffee grounds, cork powder, and sawdust. The results showed consistently appreciable QYFL, reaching up to ~40%. A Life Cycle Assessment (LCA) study demonstrated that producing these waste-based CDs has lower environmental impacts compared to CDs made solely from commercial reagents. Thus, we have established a framework for the environmentally friendly production of CDs by upcycling different waste materials without significant sacrifices in performance (QYFL).

Optimizing the greenhouse gas emissions of waste transfer and transport: An integration of life cycle assessment and vehicle routing problem.

This study presents a comprehensive analysis of greenhouse gas (GHG) emissions associated with waste transfer and transport, incorporating derived leachate treatment-a factor often overlooked in existing research. Employing an integration model of life cycle assessment and a vehicle routing problem (VRP) methods, we evaluated the GHG reduction potential of waste transfer and transport system. Two Chinese counties with different topographies and demographics were selected, yielding 80 scenarios that factored in waste source separation as well as vehicle capacity, energy sources, and routes. The functional unit (FU) is transferring and transporting 1 tonne waste and treating derived leachate. The GHG emissions varied from 12 to 39 kg CO2 equivalent per FU. Waste source separation emerged as the most impactful mitigation strategy, not only for the studied system but for an integrated waste management system. Followings are the use of larger capacity vehicles and electrification of the vehicles. These insights are instrumental for policymakers and stakeholders in optimizing waste management systems to reduce GHG emissions.

The impact of green roofs' composition on its overall life cycle.

Green roof systems have been developed to improve the environmental, economic, and social aspects of sustainability. Selecting the appropriate version of the green roof composition plays an important role in the life cycle assessment of a green roof. In this study, 10 compositions of an intensive green roof for moderate zone and 4 green roof compositions for different climatic conditions were designed and comprehensively assessed in terms of their environmental and economic impacts within the "Cradle-to-Cradle" system boundary. The assessment was carried out over a 50-year period for a moderate climate zone. The results showed that asphalt strips and concrete slab produced the highest total emissions. It was found that most greenhouse gases emissions were released in the operational energy consumption phase and in the production phase. The energy consumption phase (48.78%) for automatic irrigation and maintenance caused the highest Global Warming Potential (GWP) value (758.39 kg CO2e) in the worst variant, which also caused the highest life cycle cost (878.47€). On the contrary, in the best variant, planting more vegetation and lower maintenance and irrigation requirements led to a reduction in GWP (445.0 kg CO2e), but in terms of cost (506.6€) this composition didn't represent the best variant. The Global Warming Potential Biogenic (GWP-bio) compared to the Global Warming Potential Total (GWP-total) represents a proportion ranging from 0.8% to 78% depending on the proposed vegetation. Overall higher biogenic carbon values (up to 1525 kg CO2e) were observed for the proposed tall vegetation of Magnolia, Red Mulberry, Hawthorne, Cherry, and Crab-apple Tree. Based on the results of the multicriteria analysis, which included core environmental & economic parameters, biogenic carbon emission levels, the outcome of this paper proposed optimal green roof composition. Optimal intensive green roof composition was subjected to a sensitivity analysis to determine the impact of changing climatic conditions on CO2 emissions and life cycle costs. The results of the sensitivity analysis show that the optimal variant of the green roof can be implemented in the cold and subtropical zone with regard to CO2 emissions, but not with regard to life cycle costs.

Life cycle environmental impacts of urban water systems in China.

Urban water systems in China are facing multiple challenges, including rapid urbanisation, climate change and infrastructure ageing. It is crucial to evaluate their environmental performance from a holistic perspective in planning and management processes. To the best of our knowledge, there is a lack of nationwide life cycle assessment (LCA) studies on China's urban water systems that cover all system stages. Therefore, this study aims to present a comprehensive and nationwide LCA analysis that pinpoints the environmental hotspots and their major sources across China. This study was conducted based on water utility databases at the province level, covering water abstraction and treatment, waterwork sludge treatment, water distribution, sewage collection, stormwater drainage, wastewater treatment and sewage sludge treatment. Nine environmental impact categories were calculated and analysed. The results reveal the inequity of environmental impacts across provinces, with overall impacts geographically higher in the east and south, lower in the west and north. However, at the functional unit level, the impacts in the northern and northeastern provinces are higher than other regions. Most environmental categories are dominated by multiple water system stages. The analyses of underlying drivers found that purchased electricity is the primary source of several environmental impacts. This study provides a holistic understanding of the environmental performance of China's urban water systems, offers some insights for comprehensive decision-making support on sustainable water system management, and can also serve as a benchmark for future scenario analysis to explore options for reducing environmental impact.

How green is my reusable bronchoscope?

INTRODUCTION: Single-use bronchoscopes have replaced reusable ones in many institutions. This study aimed to evaluate the environmental and financial impacts of both strategies: reusable and single-use bronchoscopes. MATERIAL AND METHODS: We conducted a pragmatic study in a 21-bed polyvalent ICU, in Saint-Brieuc, Bretagne, France. The eco-audit consisted of estimating greenhouse gas (GHG) emissions, considering the life cycle of each strategy. Greenhouse gas (GHG) emissions related to construction, packaging, transport and waste elimination were compared between 2 devices: the reusable bronchoscope, a Pentax® FI-16RBS that was disinfected twice daily; and the single-use bronchoscope, the bronchoflex agile® from TSC. RESULTS: For the reusable bronchoscope, GHG emissions were marginally impacted by the number of bronchoscopies performed (from 185 kg eq.CO2 per year to 192 kg eq.CO2 for 10 or 110 bronchoscopies per year). For the reusable device, GHG emissions directly depended on the number of bronchoscopies performed with 3.82 kg eq.CO2 emitted per bronchoscopy. The breakeven point for the reusable bronchoscope was estimated at 50 bronchoscopies in terms of GHG emissions and 96 bronchoscopies for financial considerations. CONCLUSION: Considering current practice in our ICU, reusable bronchoscopes have lower GHG emissions when used more than 50 times a year and a lower cost when used more than 96 times a year as compared with single-use bronchoscopes.

Exploring the environmental impacts of plastic packaging: A comprehensive life cycle analysis for seafood distribution crates.

Annually, 8.3 million tonnes of mismanaged plastic waste enter oceans, prompting the food packaging industry, a major contributor, to minimize its environmental footprint. Within the seafood sector, a nascent number of studies are exploring the impacts of various packaging solutions for distribution, yet clear insights remain elusive. This study tries to fill the gap by comparing the impacts of two seafood packaging options: disposable expandable polystyrene (EPS) boxes and, for the first time, reusable plastic crates (RPC) crafted from high-density polyethylene. Using the life cycle assessment methodology with a 'cradle to grave' approach, the research evaluates the distribution of 1260,000 t of fish from port of Vigo (Spain) to various markets. Similar climate change values emerge in local (5.00·107 kg CO2 eq.) and regional trade (1.20·108 kg CO2 eq.) for both options, but RPCs exhibit around a 12 % increase (6.15·108 kg CO2 eq.) during national distribution, emphasizing package weight and load significance. The findings across all impact categories exhibited general consistent trends. The sensitivity analysis suggests relocating washing facilities to port could enhance RPCs´ environmental benefits for transport within a 160 km range. These findings underscore reusable packaging's potential as an eco-friendlier alternative in specific contexts, aligning with heightened environmental concerns and regulatory pressures surrounding plastic usage.

Life Cycle Assessment and Net Energy Analysis of an Integrated Hydrothermal Liquefaction-Anaerobic Digestion of Single and Mixed Beverage Waste and Sewage Sludge.

The conversion of biomass to bioenergy is one of the approaches to creating a sustainable society. In this study, the life cycle assessment and the net energy analysis of converting mixed sewage sludge and beverage waste into bioenergy via a combined hydrothermal liquefaction-anaerobic digestion (HTL-AD) system was carried out. Primary sludge (PS), winery rose lees (RL), brewery Trub (BT), the mixture of brewery trub and primary sludge (BTPS) and the mixture of winery rose lees and primary sludge (RLPS) were the feedstocks considered. Efficient energy utilization [in form of net energy ratio (NER)], and environmental emissions were evaluated. The NER of BT (2.07) and RL (1.76) increased when mixed with PS (3.18) to produce BTPS (3.20) and RLPS (2.85). Also, the HTL phase of the combined HTL-AD system produced a greater NER than the AD phase in BT, BTPS, and PS and vice-versa in RL and RLPS. Six environmental impact categories were studied namely global warming, terrestrial acidification, ionizing radiation, terrestrial ecotoxicity, human carcinogenic toxicity, and human non-carcinogenic toxicity. RL produced the greatest environmental impact while BTPS produced the least impact, thus indicating the advantage of feedstock combination. This study shows that the combination of feedstocks for bioenergy production in an HTL-AD system does not only increase the quality and quantity of products but also increases the overall NER as well as reducting the environmental impacts. The study also proved that an integrated HTL-AD system is an energy efficient system with greater resource utilization and less environmental footprint than the constituent systems.

Wastewater reuse benefits for municipal complete retention lagoons: Life cycle assessment and dynamic modeling.

Complete retention lagoons with wastewater reuse for agricultural purposes may offer sustainability advantages over alternative systems for small communities in semiarid regions. This study quantifies the environmental life cycle impact of adopting agriculture water reuse systems using case study data to estimate operating and building infrastructure impacts and spatial-temporal modeling to quantify resource trade-offs. Water reuse system benefits are highly dependent on supply-storage-demand dynamics. The relative size of irrigated agricultural land to the lagoon size was the most significant factor influencing site water application rates. The benefits are sensitive to changes in air emissions occurring from the agricultural land and further emphasize the importance of proper fertilizer management when adopting water reuse systems. Wastewater reuse from complete retention lagoons reduce life cycle GHG emissions, primarily through excavation reductions, offset fertilizer use, and especially from increased crop yields from wastewater reuse at previously rainfed sites. PRACTITIONER POINTS: Seven case studies and spatial-temporal modeling quantified resource trade-offs for water reuse to reduce lagoon size. Excavation reductions and offset fertilizer compensated for emissions from electricity and construction. Crop yield increases were the largest environmental benefit of adopting water reuse. System benefits are highly dependent on supply-storage-demand dynamics. Designers should use climatic data to help estimate potential variability in available water for reuse and associated energy and crop production.

Assessing the Carbon Footprint of Telemedicine: A Systematic Review.

Background: Healthcare is responsible for 4% to 10% of carbon emissions worldwide, of which 22% is related to transport. Telemedicine emerged as a potential solution to reduce the footprint, for example, by reducing travel. However, a need to understand which variables to include in carbon footprint estimations in telemedicine limits our understanding of the beneficial impact telemedicine might have on our environment. This paper aims to systematically assess the reported carbon footprint and include variables assessed by the literature, comparing telemedicine with usual care. Methods: The systematic review followed the PRISMA guidelines in PubMed, Medline, Embase and Scopus. A quality assessment was performed using a transparency checklist for carbon footprint calculators. Carbon emissions were evaluated based on four categories, including patient travel, and streamlined life cycle assessment (LCA) for assessing included variables relevant to telemedicine. Results: We included 33 articles from 1117 records for analysis. The average transparency score was 38% (range 18%-68%). The median roundtrip travel distance for each patient was 131 km (interquartile range [IQR]: 60.8-351), or 25.6 kgCO2 (IQR: 10.6-105.6) emissions. There is high variance among included variables. Saved emissions are structurally underestimated by not including external factors such as a streamlined LCA. Conclusions: Telemedicine aids in reducing emissions, with travel distance being the most significant contributor. Additionally, we recommend accounting for the LCA since it highlights important nuances. This review furthers the debate on assessing carbon footprint savings due to telemedicine.

Sustainable repurpose of end-of-life fiber reinforced polymer composites: A new circular pedestrian bridge concept.

In response to global challenges in resource supply, many industries are adopting the principles of the Circular Economy (CE) to improve their resource acquisition strategies. This paper introduces an innovative approach to address the environmental impact of waste Glass Fiber Reinforced-Polymer (GFRP) pipes and panels by repurposing them to manufacture structural components for new bicycle and pedestrian bridges. The study covers the entire process, including conceptualization, analysis, design, and testing of a deck system, with a focus on the manufacturing process for a 7-m-long prototype bridge. The study shows promising results in the concept of a sandwich structure utilizing discarded GFRP pipes and panels, which has the flexibility to account for variabilities in dimensions of incoming products while still meeting mechanical requirements. The LCA analysis shows that the transportation of materials is the governing contributing factor. It was concluded that further development of this concept should be accompanied by a business model that considers the importance of the contributions from the whole value chain.

Assessing the environmental footprint of alternative green biorefinery protein extraction techniques from grasses and legumes.

The significant grasslands of Europe and its member states represents a significant feedstock opportunity for circular bioeconomy development. The development of green biorefineries (GBR), to supply protein for the feed industry from grass, could help many European member states to address significant deficits in protein availability and reduce imports. The current study assesses the environmental footprint of alternative GBR protein extraction techniques from grasses and legumes using life cycle assessment. The focus is on comparing feedstock and technology pathways that could displace soya bean imports. The study finds that leaf protein concentrate (LPC) produced from grass had an improved environmental performance when compared to soya bean meal (SBM), across the assessed feedstock (perennial ryegrass or grass-clover mixtures) and technology pathways (one-stage maceration versus multi-stage maceration). For example, in the case of Climate Change the emission intensity for LPC was 57-85 % lower per tonne of crude protein (CP) compared with SBM. Acidification burdens were 54-88 % lower, and Eutrophication: Freshwater burdens were 74-89 % lower. Some scenarios of GBR produced LPC with a larger Energy Resources: Non-Renewable burden than SBM, though this could be mitigated with higher renewable energy (biogas and wind energy) integration within the scenario. Grass-clover scenarios generally achieved a lower intensity of emissions compared to ryegrass scenarios, particularly in the category of Climate Change, where feedstock cultivation represented a significant contributor to impacts. Overall, GBR can produce high quality protein with a lower environmental burden than SBM, but choice of feedstock and system design are critical factors for overall environmental performance.

Integrating the water-energy-food nexus and LCA + DEA methodology for sustainable fisheries management: A case study of Cantabrian fishing fleets.

The fishing sector constitutes an important source of economic revenue in northern Spain. In this context, various research studies have focused on the application of the five-step Life Cycle Assessment (LCA) and Data Envelopment Analysis (DEA) methodology to quantify environmental impacts of fishing systems. However, some of them have used environmental indicators that focus on individual environmental issues, hindering the goal of achieving integrated resource management. Therefore, in this study, the Water-Energy-Food (WEF) Nexus is employed as an integrative perspective that considers the synergies and trade-offs between carbon footprint, energy requirements, and water demand. The main objective of this study is to evaluate the operational efficiency and environmental impacts of Cantabrian fishing fleets. To this end, the combined use of LCA and DEA, along with the WEF Nexus, was applied to the Cantabrian purse seine fleet. DEA matrices were generated using the LCA-derived WEF nexus values as inputs to calculate efficiency scores for each vessel. Subsequently, based on the efficiency projections provided by the DEA model, a new impact assessment was performed to understand the eco-efficiency and potential environmental benefits of operating at higher levels of efficiency within this fleet. The average efficiency of the fleet was above 60 %. Inefficient units demonstrated a greater potential to reduce their environmental impacts (up to 65 %) by operating according to efficiency projections. Furthermore, the results revealed a strong dependence of environmental impacts on one of the operational inputs, i.e., fuel consumption. These findings highlight the significance of embracing holistic approaches that combine technical, economic, and social factors to achieve a sustainable balance in fisheries systems. In this regard, the five-step LCA + DEA method applied in conjunction with the WEF Nexus emerged as a suitable tool for measuring operational and environmental objectives.

Quantification of the Environmental Impact of Feeding Yeast Probiotic Saccharomyces cerevisiae Actisaf Sc 47 in Dairy Cow: A Life Cycle Assessment Approach.

Today, one of the major challenges of dairy farmers is to reduce their environmental footprint to establish more effective, efficient, and sustainable production systems. Feed additives such as yeast probiotics could potentially allow them to achieve these objectives through the improvement of milk production, feed efficiency, and ration valorization, hence mitigating the environmental impacts of milk production. In this study, the life cycle assessment (LCA) principle was performed to estimate the environmental impact of the production and supplementation of a commercial yeast probiotic (Actisaf Sc 47) in three trials performed in three different countries that are representative for around 50% of the milk production in Europe: France (French trial), United Kingdom (UK trial), and Germany (German trial). For each trial, two groups of animals were compared: control, without Actisaf Sc 47 supplementation, used as baseline; and experimental, with Actisaf Sc 47 supplementation at 5 or 10 g/cow/day. Different impact categories were analyzed for each group to calculate the impact of producing 1 kg of fat- and protein-corrected milk. An initial analysis was done only during the period of Actisaf Sc 47 supplementation and showed than the supplementation with Actisaf Sc 47 reduced, on average by 5%, the carbon footprint during the three trials. A second analysis was done via the extrapolation of all the data of each trial to an annual farm level, including the lactation period (305 days), dry period (60 days), and the period with and without Actisaf Sc 47 supplementation. Reported at a farm annual scale, the average reduction allowed by Actisaf Sc 47 supplementation was 2.9, 2.05, 2.47, 1.67, 2.28, 2.18, 2.14, and 2.28% of the carbon footprint, land use, water use, resource use, acidification, freshwater eutrophication, marine eutrophication, and terrestrial eutrophication, respectively. On average, the production of 1 kg of fat- and protein-corrected milk by using Actisaf Sc 47 was shown to improve environmental impacts compared to control. Regarding Actisaf Sc 47 production, the LCA showed that the production of 1 kg of Actisaf Sc 47 emitted 2.1 kg CO2 eq with a negligible contribution to total the carbon footprint of milk ranging from 0.005 to 0.016%. The use of Actisaf Sc 47 in dairy cows could then result in different positive outcomes: improving performance and efficiency while reducing the global carbon footprint.

Valorization of seafood waste: a review of life cycle assessment studies in biorefinery applications.

The escalating challenges posed by seafood waste generated by the fishing and aquaculture industries underscore the urgent need for innovative solutions that promote both environmental conservation and economic viability within the seafood sector. Seafood waste biorefinery emerges as a promising solution, offering the potential to transform waste materials into valuable products. However, it is essential to recognize that seafood waste biorefinery operations also entail environmental impacts that warrant careful consideration. Environmental assessment tools like Life Cycle Assessment (LCA) provide a valuable framework for assessing these impacts comprehensively. This review critically examines LCA studies in seafood waste biorefinery, focusing on key concepts, emerging technologies, and potential product avenues. Despite the growing body of research in this area, direct comparisons between published studies prove challenging due to discrepancies in feedstocks, processing techniques, value-added products, and LCA methodologies. Nevertheless, the findings consistently demonstrate significant reductions in environmental impacts achieved through seafood waste biorefinery processes. The selection of technologies significantly influences both product quality and sustainability measures. High energy consumption, including diesel fuel consumption in fishing vessels and electricity consumption in processing steps, should be carefully considered and reduced to mitigate associated environmental impacts. In conclusion, while seafood waste biorefinery processes hold significant promise for providing environmental and economic benefits, substantial challenges remain. This review provides invaluable insights for researchers, policymakers, and stakeholders, emphasizing the importance of continuous interdisciplinary collaboration and methodological standardization to advance sustainable waste management practices in the seafood industry.

Multi-objective optimization and life cycle assessment of mass-integrated combined heat and power system.

As the effects of climate change become more widely recognized, technical innovation and green energy will promote the growth of combined heat and power systems. This study proposes a novel mass-integrated combined heat and power system and conducts energy analysis, exergy analysis, and techno-economic analysis for the system. The optimization strategy integrated polynomial regression and non-dominated sorting genetic algorithm III is established, with system thermal efficiency, exergy efficiency, and return on investment (ROI) as objective functions. The system's environmental consequences are then assessed throughout its life cycle using life cycle assessment (LCA) under ideal operating circumstances. The findings reveal that the waste heat recovery heat exchanger has the highest exergy destruction in the system, with a value of 674.61 kW. Furthermore, the intermediate heat exchanger 1 and intermediate heat exchanger 2 (IHX2) with lesser exergy efficiency have an exergy destruction of less than 32.00 kW. The IHX2 is the most expensive equipment in the system, costing $90,931.19, but it also provides the most potential for system improvement. The multi-objective optimization findings suggest that the thermal efficiency, exergy efficiency, and ROI for the system are 0.17, 0.97, and 0.30, respectively. The LCA demonstrates that the system has a negligible influence on global warming and ozone generation with corresponding LCA findings of less than 4.20. The construction and operation phases of the investigation system have the most significant environmental consequences. The correlation between the raw materials necessary for the construction of the equipment in the system and the reaction temperatures, conditions, and waste composition during the preparation of the working fluids is large, so it is necessary to take corresponding environmental protection measures during production and processing to reduce the system's environmental emissions from the source and promote ecologically sustainable development.