Circularity of new composites from recycled high density polyethylene and leather waste for automotive bumpers. Testing performance and environmental impact.

New composite materials (suitable for automotive bumpers), composed of recycled high-density polyethylene (rHDPE) and leather buffing dust waste (BF) ranging from 20 to 50 wt%, were produced and investigated for mechanical properties. Optimal mechanical performance was achieved with composites containing 30 % wt BF. The environmental performance of automotive bumper production from both virgin and recycled HDPE reinforced with 30 % wt BF (HDPE-BF, rHDPE-BF) composites was compared to that of conventional polypropylene (PP) by performing a cradle to gate life cycle assessment. A component-based approach, instead of a comprehensive LCA assessment for the entire car was adopted using various functional units (FU) such as mass (FU1), volume (FU2), and volume of raw material fulfilling a specific impact strength requirement (FU3), thus enriching the paper with methodological discussions. The rHDPE-BF system provided better environmental performance compared to the virgin PP system, when considering both mass and volume-related functional units, mainly due to the avoidance of virgin polymer production. Even with the inclusion of the use phase in FU2 and a slightly higher density (+1.7 %) of composites than PP-based bumpers, the rHDPE system still provides better environmental performance (10 % less impact). The sensitivity analysis highlighted the significance of car type and final density of the bumper on the impact results. Finally, when using FU3, due to its higher impact strength, HDPE-BF system is clearly the best environmental alternative (50 % less impact) followed by rHDPE-BF system. In all cases, rising the content of recycled materials in the bumpers increases its circularity. The paper illustrates the importance of selecting a suitable functional unit, based on a specific application (i.e., automotive bumpers), to evaluate the environmental impact of new composite materials in comparison to traditional options. Expanding the assessment to encompass multiple functions provides a more accurate portrayal of reality but also introduces greater result uncertainty.

Extraction of Bioactive Compounds from Spent Coffee Grounds Using Ethanol and Acetone Aqueous Solutions.

Given global coffee consumption, substantial quantities of spent coffee grounds (SCGs) are generated annually as a by-product of brewing coffee. SCG, although rich in bioactive compounds, is nowadays disposed of. The objective of this study is to compare, for the first time and from the same SCG, the efficiency of ethanol-water mixtures and acetone-water mixtures for the recovery of total polyphenols, chlorogenic acid, and caffeine. Acetone at 20% (m/m) was the most convenient solvent to extract all three bioactive compounds simultaneously, yielding 4.37 mg of GAE/g SCG for total polyphenols, chlorogenic acid (0.832 mg 5-CQA/g SCG), and caffeine (1.47 mg/g SCG). Additionally, this study aims to address some challenges associated with the industrial-scale utilization of SCG as a raw material, encompassing factors such as pre-treatment conditions (natural drying and oven drying), storage duration, and the kinetics of the extraction process. No significant difference was observed between the natural drying and oven drying of SCG. In terms of storage duration, it is advisable to process the SCG within less than 3-4 months of storage time. A significant decline of 82% and 70% in chlorogenic acid (5-CQA) and caffeine contents, respectively, was observed after eight months of storage. Furthermore, the kinetic study for the recovery of total polyphenols revealed that the optimal extraction times were 10 min for acetone at 20% and 40 min for water, with a yield increase of 28% and 34%, respectively. What is remarkable from the present study is the approach considered, using the simplest operating conditions (minimal time and solvent-to-solid ratio, and ambient temperature); hence, at an industrial scale, energy and resource consumption and equipment dimensions can be together reduced, leading to a more industrially sustainable extraction process.

Environmental and Yield Comparison of Quick Extraction Methods for Caffeine and Chlorogenic Acid from Spent Coffee Grounds.

This study aims to provide an overview of different extraction methods to obtain chlorogenic acid (CA) and caffeine (Caf) from spent coffee grounds (SCG). This overview shows that the quantity extracted is highly dependent on the type of SCG, so experiments using the same SCG are needed to compare different methods. Three easy and simple extraction methods will be tested at a laboratory scale and environmentally compared. All three experiments were of 1 min duration: first, using supramolecular solvent; second, with water and vortex; and third, with water assisted by ultrasound. Water extraction assisted by ultrasound at room temperature yielded the greatest quantity of chlorogenic acid and caffeine, with 1.15 mg CA/g and 0.972 mg Caf/g, respectively. Extraction using supra-solvent leads to a lower content of CA in the supra-phase since it has more affinity for the water-based inferior phase. An environmental assessment using life cycle assessment has been carried out to compare water and supra extraction methods for the manufacture of two different commercial products: a face cream and an eye contour serum. Results show that the type of solvent and the amount of active substance extracted have a great influence on the environmental results. The results presented here are important for companies willing to obtain these active substances at an industrial scale.

Carbon Footprint: The Case of Four Chicken Meat Products Sold on the Spanish Market.

Despite its relatively low environmental impact within the livestock sector, the poultry sector still faces its own environmental challenges that need to be addressed. The present paper uses life cycle assessment to quantify greenhouse gas emissions, from cradle to slaughterhouse gate, of four chicken meat products: whole carcass, wings, breast fillets, and leg quarters. The main contribution of the present study is that it provides a detailed analysis of different chicken meat cuts, testing mass and economic allocation choices and showing that economic allocation better reflects the causality of the cutting process. We recommend that a distinction should be made between whole carcass and meat cuts, as there are significant differences in meat content and climate change results between these two categories. This is not so clear in the literature, nor in the LEAP guideline for the poultry sector. The study was performed by using disaggregated inventory data from Spain, for the first time. Results show that the major contributors to environmental impact are feed production (>70%), electricity use (10.2%), and fossil fuel combustion (8.1%). Packaging did not significantly contribute to the climate change impact of the chicken products evaluated (0.4−3.4% contribution, depending on the type of packaging and product considered).

Classification of Textile Samples Using Data Fusion Combining Near- and Mid-Infrared Spectral Information.

There is an urgent need to reuse and recycle textile fibers, since today, low recycling rates are achieved. Accurate classification methods for post-consumer textile waste are needed in the short term for a higher circularity in the textile and fashion industries. This paper compares different spectroscopic data from textile samples in order to correctly classify the textile samples. The accurate classification of textile waste results in higher recycling rates and a better quality of the recycled materials. The data fusion of near- and mid-infrared spectra is compared with single-spectrum information. The classification results show that data fusion is a better option, providing more accurate classification results, especially for difficult classification problems where the classes are wide and close to one another. The experimental results presented in this paper prove that the data fusion of near- and mid-infrared spectra is a good option for accurate textile-waste classification, since this approach allows the classification results to be significantly improved.

Post-Consumer Textile Waste Classification through Near-Infrared Spectroscopy, Using an Advanced Deep Learning Approach.

The textile industry is generating great environmental concerns due to the exponential growth of textile products' consumption (fast fashion) and production. The textile value chain today operates as a linear system (textile products are produced, used, and discarded), thus putting pressure on resources and creating negative environmental impacts. A new textile economy based on the principles of circular economy is needed for a more sustainable textile industry. To help meet this challenge, an efficient collection, classification, and recycling system needs to be implemented at the end-of-life stage of textile products, so as to obtain high-quality recycled materials able to be reused in high-value products. This paper contributes to the classification of post-consumer textile waste by proposing an automatic classification method able to be trained to separate higher-quality textile fiber flows. Our proposal is the use of near-infrared (NIR) spectroscopy combined with a mathematical treatment of the spectra by convolutional neural networks (CNNs) to classify and separate 100% pure samples and binary mixtures of the most common textile fibers. CNN is applied for the first time to the classification of textile samples. A total of 370 textile samples were studied-50% used for calibration and 50% for prediction purposes. The results obtained are very promising (100% correct classification for pure fibers and 90-100% for binary mixtures), showing that the proposed methodology is very powerful, able to be trained for the specific separation of flows, and compatible with the automation of the system at an industrial scale.

Water-Energy-Food Nexus and Life Cycle Thinking: A New Approach to Environmental and Nutritional Assessment of Potato Chips.

The water-energy-food (WEF) nexus has become a key concept to promote the cross-sectoral coordination toward sustainable development. In particular, understanding the interdependences of these pillars, as well as addressing a life cycle perspective, is essential when evaluating food production systems. This study explores the environmental impacts and nutritional quality of potato chips, addressing life cycle thinking and a WEF nexus approach. For this purpose, the combined application of life cycle assessment (LCA) and the Nutrient-Rich Food 9.3 (NRF9.3) index was considered to identify the main environmental hotspots and advanced opportunities. The results indicated a major contribution of the cultivation stage on water use, whereas the processing accounted for most of the impacts in energy-related indicators and eutrophication potentials. Improvement opportunities reside in the joint application of drip irrigation, allowing to achieve important water savings, as well as the use of natural gas or pellets instead of diesel, which constitute cleaner energy sources. On the other hand, a poor nutritional density of potato chips became evident from the quantification of the NRF9.3, which can be significantly improved if potatoes undergo a roasted process instead of frying.

Valorization Strategy for Leather Waste as Filler for High-Density Polyethylene Composites: Analysis of the Thermal Stability, Insulation Properties and Chromium Leaching.

Leather waste (BF) and high-density polyethylene (HDPE) were compounded in a lab scale internal mixer and processed by means of injection molding. In this study, leather waste and HDPE composites were characterized by instrumental techniques such as differential scanning calorimetry (DSC), thermo-gravimetric Analysis (TGA), and Fourier transform infrared spectroscopy (FTIR). Physical integrity of composites against chemical exposure and chromium-leaching properties of the composites were also investigated. This study shows that the incorporation of 30% leather waste fiber into HDPE composites decreases the thermal conductivity of the composite samples by 17% in comparison to that of neat HDPE samples. Composites showed no thermal degradation during processing cycle. Strong interfacial bonding between leather waste and polymer results in comparable low-leachate levels to maximum allowed concentration for nonhazardous waste, and good chemical resistance properties. The BF/HDPE composites could be a promising low-cost alternative in industrial application areas of HDPE, where high-mechanical strength and low-thermal conductivity is required.

Towards a Water-Energy-Food (WEF) nexus index: A review of nutrient profile models as a fundamental pillar of food and nutrition security.

The Water-Energy-Food (WEF) nexus approach should be promoted as a tool for sustainable management of resources through the interconnection of these three fundamental pillars. Particularly, food security must ensure healthy and balanced diets for everyone, but selecting individual indicators to assess all slants covered by this element is not an easy task. Hence, the objective of this paper is two-fold, to review nutrient profiling (NP) models that allow to categorize foods and evaluate diets based on their nutritional quality, and to choose the most appropriate model to be used within a WEF nexus index. To address this issue, a total of 159 documents were assessed, appraising the geographic distribution, and time evolution of the publications, as well as the characteristics and potential applications of the NP systems. The review concludes that the NRF9.3. model is the most liable option to be used in a WEF nexus index, presenting the best characteristics by means of the definition of scores and thresholds, and the use of an 'across-the-board' criteria and a reference quantity of 100 kcal, alongside offering higher ability to assess diets and foods than the other competitive model (HEI) through the evaluation of nutrients to encourage instead of foods. A secondary outcome of the review is the identification of the NP models as a useful tool to enable institutions with information to establish policies in the field of public health and facilitating the decision-making process according to the current healthy claims.

Multi-Objective Optimization of Nutritional, Environmental and Economic Aspects of Diets Applied to the Spanish Context.

Current food consumption patterns must be revised in order to improve their sustainability. The nutritional, environmental, and economic consequences of these dietary patterns must be taken into consideration when diet guidelines are proposed. This study applied a systematic optimization methodology to define sustainable dietary patterns complying with nutritional, environmental, and economic issues. The methodology was based on a multi-objective optimization model that considered a distance-to-target approach. Although the three simultaneous objectives (maximal nutritional contribution, minimal greenhouse gas emissions, and minimal costs) could be divergent, the proposed model identified the optimal intake of each food product to achieve the maximal level of nutritional, environmental, and economic diets. This model was applied to six different eating patterns within the Spanish context: one based on current food consumption and five alternative diets. The results revealed that dietary patterns with improved nutritional profiles and reduced environmental impacts could be defined without additional costs just by increasing the consumption of vegetables, fruits, and legumes, while reducing the intake of meat and fish.

Leather Waste to Enhance Mechanical Performance of High-Density Polyethylene.

Leather buffing dust (BF) is a waste from tannery which is usually disposed on landfills. The interest in using wastes as fillers or reinforcements for composites has raised recently due to environmental concerns. This study investigates the potential use of BF waste as filler for a high density polyethylene matrix (HDPE). A series of HDPE-BF composites, containing filler concentrations ranging from 20 to 50wt%, were formulated, injection molded and tested. The effect of filler contents on the mechanical properties of the composites were evaluated and discussed. Composites with BF contents up to 30wt% improved the tensile strength and Young's modulus of the matrix, achieving similar mechanical properties to polypropylene (PP). In the case of flexural strength, it was found to be proportionally enhanced by increasing reinforcement content, maintaining high impact strength. These composites present great opportunities for PP application areas that require higher impact resistance. The materials were submitted to a series of closed-loop recycling cycles in order to assess their recyclability, being able to maintain better tensile strength than virgin HDPE after 5 cycles. The study develops new low-cost and sustainable composites by using a waste as composite filler.

Environmental and nutritional impacts of dietary changes in Spain during the COVID-19 lockdown.

The COVID lockdown has affected food purchases and eating habits. In this regard, this short communication assesses the nutritional and environmental impacts of these changes during the COVID lockdown in Spain, by applying Life Cycle Assessment and an energy- and nutrient-corrected functional unit. Three environmental impacts were studied (Global Warming Potential, Blue Water Footprint and Land Use) and a total of seven weekly diet scenarios were designed: two pre-COVID diets for March and April in 2019 (MAR19, APR19), one COVID diet (COVID) and two alternative diets, one based on the National Dietary Guidelines (NDG) and another one on the Planetary Health Diet (PHD). Results show that the COVID diet had larger energy intake and lower nutritional quality, as well as higher environmental impacts (between 30 and 36%) than the pre-COVID eating patterns. Further research is needed to account for food affordability within this assessment, as well as to analyze how eating patterns will evolve after the COVID lockdown. Finally, the definition of short guidelines for sustainable food behaviors for future possible lockdowns is suggested, as well as the introduction of sustainable indicators within NDGs.

Polylactic Acid/Polycaprolactone Blends: On the Path to Circular Economy, Substituting Single-Use Commodity Plastic Products.

Circular economy comes to break the linear resource to waste economy, by introducing different strategies, two of them being: using material from renewable sources and producing biodegradable products. The present work aims at developing polylactic acid (PLA), typically made from fermented plant starch, and polycaprolactone (PCL) blends, a biodegradable polyester, to study their potential to be used as substitutes of oil-based commodity plastics. For this, PLA/PCL blends were compounded in a batch and lab scale internal mixer and processed by means of injection molding. Tensile and impact characteristics were determined and compared to different thermoplastic materials, such as polypropylene, high density polyethylene, polystyrene, and others. It has been found that the incorporation of PCL into a PLA matrix can lead to materials in the range of 18.25 to 63.13 megapascals of tensile strength, 0.56 to 3.82 gigapascals of Young's modulus, 12.65 to 3.27 percent of strain at maximum strength, and 35 to 2 kJ/m2 of notched impact strength. The evolution of the tensile strength fitted the Voigt and Reuss model, while Young's modulus was successfully described by the rule of mixtures. Toughness of PLA was significantly improved with the incorporation of PCL, significantly increasing the energy required to fracture the specimens. Blends containing more than 20 wt% of PCL did not break when unnotched specimens were tested. Overall, it was found that the obtained PLA/PCL blends can constitute a strong and environmentally friendly alternative to oil-based commodity materials.

Life cycle assessment of carrier bags and development of a littering indicator.

Increased plastic consumption has resulted in high amounts of plastic waste ending up in the environment. Recently, the European Commission (EC) has identified a list of single-use plastics, including plastic bags, most commonly found in the European beaches. As a response, alternatives for plastic carrier bags have been more of a concern. Many life cycle assessment (LCA) studies have been performed to evaluate the environmental profile of different carrier bags; however, without considering the possibility of contribution to the littering problem. Therefore, in this study, an indicator has been introduced, based on an LCA study of carrier bags which was performed in Spain. The indicator is influenced by parameters such as: number of bags to fulfill the functional unit, weight, surface, fee, and biodegradability. In this paper, a comparative LCA of HDPE, LDPE, PP, paper and biodegradable plastic bags is presented. Following that, a littering indicator is introduced to allow a comparison of the risk of littering of the different carrier bags in marine environment. The results given by the Littering Potential indicator rank the bags oppositely to the results given by the LCA as usual. Further research is needed to refine the model and include additional contributing variables.

Are functional fillers improving environmental behavior of plastics? A review on LCA studies.

The use of functional fillers can be advantageous in terms of cost reduction and improved properties in plastics. There are many types of fillers used in industry, organic and inorganic, with a wide application area. As a response to the growing concerns about environmental damage that plastics cause, recently fillers have started to be considered as a way to reduce it by decreasing the need for petrochemical resources. Life cycle assessment (LCA) is identified as a proper tool to evaluate potential environmental impacts of products or systems. Therefore, in this study, the literature regarding LCA of plastics with functional fillers was reviewed in order to see if the use of fillers in plastics could be environmentally helpful. It was interesting to find out that environmental impacts of functional fillers in plastics had not been studied too often, especially in the case of inorganic fillers. Therefore, a gap in the literature was identified for the future works. Results of the study showed that, although there were not many and some differences exist among the LCA studies, the use of fillers in plastics industry may help to reduce environmental emissions. In addition, how LCA methodology was applied to these materials was also investigated.

Tackling the Relevance of Packaging in Life Cycle Assessment of Virgin Olive Oil and the Environmental Consequences of Regulation.

Production and consumption of olive oil is very important in Europe, being this product a basic element in the Mediterranean diet since long ago. The project objective is two-fold: a study of the contribution of virgin olive oils (VOOs) usual packaging to the whole life cycle of the product and a study of the environmental consequences of the Spanish Government regulation on VOO packaging. A life cycle assessment (LCA) according to ISO 14044 has been performed using the CML methodology for the impact assessment. The results show that the packaging influence varies from 2 to 300%, depending on the impact category and type of packaging (glass, tin or polyethylene terephtalate). Glass, which is related to higher quality perception by consumers, was found to be the most influencing material (due to its weight); however, this impact may be fairly reduced by applying ecodesign strategies (such as weight reduction and recycled-glass percentage increase). A new Spanish regulation on the mandatory use of non-refillable oilers in HORECA establishments (hotels, restaurants and caterings) aims to provide more quality assurance and better information to consumers; however, it was also found to mean a 74% increase in greenhouse gases emissions. This regulation was deeply discussed at European level and its application was withdraw due to consumers rejection, except for Spain. The findings of the present case study show that LCA and ecodesign should be important tools to be promoted and applied in policy making to reduce non-desirable consequences of regulation.

Corporate carbon footprint for country Climate Change mitigation: A case study of a tannery in Turkey.

Assessment of carbon emissions and environmental impact of production is indispensable to achieve a sustainable industrial production in Turkey, especially for those companies willing to compete in new international green markets. In this case study, corporate carbon footprint of a representative Turkish tanning company was analyzed. Inventory and impact data are presented to help in the environmental decision-making process. The results indicate that significant environmental impacts were caused during the landfilling of solid wastes as well as the production of the electricity and fuel required in the tannery. Turkish tannery inventory data presented here for the first time will be useful for leather tanning company managers to calculate sustainability key indicators. Improving alternatives at country level were identified (increasing the renewable sources on electricity production and promote energy recovery in landfills) which would be useful not only to decrease greenhouse gas (GHG) emissions of tanning sector but also of other industries requiring electricity and producing organic wastes. Considering the substantial contribution of industrial processes to the Turkish carbon emissions (15.7%) (TUIK, 2013), work done on those areas would provide a sound improvement in environmental profile of Turkey. The importance to promote a national strategy to reduce GHG emissions in Turkey was discussed here, as well as its relation to corporate carbon footprint assessments. One of the significant points revealed from the case study is the lack of published country specific emission factors for Turkey, which is a fundamental prerequisite to promote corporate carbon footprint assessment within the country.

Inventory analysis and carbon footprint of coastland-hotel services: A Spanish case study.

Tourism is a key industry in the Spanish economy. Spain was in the World top three ranking by international tourist arrivals and by income in 2015. The development of the tourism industry is essential to maintain the established economic system. However, if the environmental requirements were not taken into account, the country would face a negative effect on depletion of local environmental resources from which tourism depends. This case study evaluates, through a life cycle perspective, the average carbon footprint of an overnight stay in a Spanish coastland hotel by analyzing 14 two-to-five-stars hotels. Inventory and impact data are analyzed and presented both for resource use and greenhouse gases emissions, with the intention of helping in the environmental decision-making process. The main identified potential hotspots are electricity and fuels consumption (6 to 30kWh/overnight stay and 24 to 127MJ/overnight stay respectively), which are proportional to the number of stars and unoccupancy rate and they produce more than 75% of the impact. It is also revealed that voluntary implementation of environmental monitoring systems (like EMAS regulation) promotes collection of more detailed and accurate data, which helps in a more efficient use of resources. A literature review on LCA and tourism is also discussed. Spanish hotels inventory data presented here for the first time will be useful for tourism related managers (destination managers, policy makers and hotel managers among others) to calculate sustainability key indicators, which can lead to achieve real sustainable-tourism goals. Further data collection will be needed in future projects to gather representative data from more hotels, other accommodation facilities and also other products/services offered by tourist sector in Spain (like transport of tourists, food and beverage, culture-sports & recreation and others).

Product vs corporate carbon footprint: Some methodological issues. A case study and review on the wine sector.

Carbon footprint (CF) is nowadays one of the most widely used environmental indicators. The scope of the CF assessment could be corporate (when all production processes of a company are evaluated, together with upstream and downstream processes following a life cycle approach) or product (when one of the products is evaluated throughout its life cycle). Our hypothesis was that usually product CF studies (PCF) collect corporate data, because it is easier for companies to obtain them than product data. Six main methodological issues to take into account when collecting corporate data to be used for PCF studies were postulated and discussed in the present paper: fugitive emissions, credits from waste recycling, use of "equivalent factors", reference flow definition, accumulation and allocation of corporate values to minor products. A big project with 18 wineries, being wine one of the most important agri-food products assessed through CF methodologies, was used to study and to exemplify these 6 methodological issues. One of the main conclusions was that indeed, it is possible to collect corporate inventory data in a per year basis to perform a PCF, but having in mind the 6 methodological issues described here. In the literature, most of the papers are presenting their results as a PCF, while they collected company data and obtained, in fact, a "key performance indicator" (ie., CO2eq emissions per unit of product produced), which is then used as a product environmental impact figure. The methodology discussed in this paper for the wine case study is widely applicable to any other product or industrial activity.

A cumulative energy demand indicator (CED), life cycle based, for industrial waste management decision making.

Life cycle thinking is a good approach to be used for environmental decision-support, although the complexity of the Life Cycle Assessment (LCA) studies sometimes prevents their wide use. The purpose of this paper is to show how LCA methodology can be simplified to be more useful for certain applications. In order to improve waste management in Catalonia (Spain), a Cumulative Energy Demand indicator (LCA-based) has been used to obtain four mathematical models to help the government in the decision of preventing or allowing a specific waste from going out of the borders. The conceptual equations and all the subsequent developments and assumptions made to obtain the simplified models are presented. One of the four models is discussed in detail, presenting the final simplified equation to be subsequently used by the government in decision making. The resulting model has been found to be scientifically robust, simple to implement and, above all, fulfilling its purpose: the limitation of waste transport out of Catalonia unless the waste recovery operations are significantly better and justify this transport.