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Plastic grocery bags are one of the most ubiquitous single-use packaging products. Recently, 'eco-friendly' options of plastic grocery bags have gained traction such as kraft paper, cotton, biodegradable, and reusable polypropylene non-woven bags. However, the impact of using various grocery bags in cities with dense population, well-developed infrastructure and thermal treatment as an end-of-life waste management option has been insufficiently documented. In this study, commonly found single-use (HDPE, biodegradable plastic, kraft paper) bags and reusable (cotton, polypropylene non-woven) bags were considered for the life cycle assessment (LCA). The usage characteristics (reusability, dimensions, carrying capacity) of bags, the production process (raw materials extraction, production processes), and emissions were determined as the significant factors contributing to the negative environmental impacts. In a model city with confined waste management, the assessment determined that the reusable polypropylene non-woven bag (PNB) caused the least overall negative environmental impacts when there are 50 instances of reuse, followed by single use HDPE plastic bag (HPB). The global warming potential (excluding biogenic carbon) was 14, 81, 17 and 16 times higher for HDPE plastic, kraft paper, cotton woven and biodegradable polymer bags, respectively, when compared to PNB. Moreover, kraft paper or cotton woven bags demonstrated the highest negative impacts for the impact categories including abiotic fossil depletion, freshwater-, marine- and terrestrial-ecotoxicities, human toxicity, acidification and eutrophication potentials. Further, sensitivity analysis indicated that the inflexion point for the PNB was minimum 4 reuses to avoid emission equivalent to the HPB. Singapore was adopted as the model city with confined waste management structure that imports most of the grocery bags, either as finished goods or as raw materials. Through comprehensive insights based on the new outlook of the integrated LCA model (cradle-to-grave) that included full-scale transportation component, the usage of the real case data from a city to develop the life cycle inventory, and consideration of the existing grocery bags options, the environmental assessment along with critical evaluation was conducted. • Case specific life cycle assessment of grocery bags in the context of Singapore. • Plastic bags presented lower environmental footprint than paper and cotton bags for Singapore. • Plastics are an environmental friendly option for waste management structures with end-of-life thermal treatment. • Multiple reuse of plastics is a means to minimize environmental footprint. [ABSTRACT FROM AUTHOR]

In the last decades, environmental footprint of the product manufacture has emerged as an important public concern, causing manufacturers to re-assess their product's environmental impacts. Responding to global outcry on global warming, world leaders have agreed to limit global temperature rise to less than 2 °C above the temperature in pre-industrial times. As a result, governments and industrial leaders around the world have proposed a roadmap for 80% emissions reduction by 2050. The aim of this work develops a novel approach of linking Life Cycle Assessment (LCA) and Lean manufacturing to reduce the negative environmental impacts of a plastic injection moulded product. Products that use plastic as their primary source of raw materials are mainly produced by plastic injection processes. Although plastic injection moulding has many benefits such as ‘high production rates’, there is a lack of through investigation on the effects of this process has on the environment such as climate change, ozone depletion etc. This paper proposes a novel cross-functional mapping approach of linking lean-thinking and LCA. The implementation case study has been presented with the view to re-assess carbon footprint of an existing plastic product. The reported implementation work demonstrates that the adaptation of lean thinking and LCA could significantly minimise negative environmental impacts of a plastic injection product. A case study indicates that the overall environmental impact has been reduced by approximately 40% in climate change, human toxicity, photochemical oxidant formation, acidification and eco-toxicity. [ABSTRACT FROM AUTHOR]

Cold storage is a valid solution for the energy peak reduction in the air conditioning field, which strongly affects the energy consumption in the civil sector. An innovative storage device, called ColdPeak , has been already tested in a recently published work, demonstrating unparalleled properties in terms of charging/discharging storage power. Now, the unit is analyzed from the environmental point of view by means of a LCA (Life Cycle Assessment) methodology: the air conditioning system integrating the ColdPeak unit has been compared with a conventional system from the environmental point of view, assuming the same potentiality of cold energy and including a sensitive analysis on the energy saving potential of the innovative device (5–25% of the energy required by the conventional system). In the sensitivity analysis, the energy saving is counter-balanced by the energy load required for the manufacturing and installation of an additional component in the air conditioning system (the ColdPeak device itself). The environmental footprint that considers the material and the energy to fabricate the ColdPeak is very low if compared with the amount of energy saved thanks to its application. As a matter of fact, the LCA study reports that the integration of the cold storage unit allows a significant reduction of environmental footprint in terms of Global Warming Potential (−17%), Acidification Potential (−15.5%), Eutrophication Potential (−18%), Eco-toxicity (−16%), Human Health (−18%) and Fossil Depletion (−18%). The paper also reports the temporal trend of the environmental footprint that shows a pay-back period for the construction of the innovative integrated system of less than one year for all the investigated categories. [ABSTRACT FROM AUTHOR]

In response to the impending international maritime regulation, MARPOL Annex VI Reg. 14, to curb sulphur oxides (SO x) arising from shipping activities, this paper aimed to evaluate the environmental impacts of the entire life cycle of three different SO x reduction scrubber systems: (1) 'wet open-loop' , (2) 'wet closed-loop' , and (3) 'wet hybrid'. To achieve this goal, the paper developed 'the Parametric Trend Life Cycle Assessment (PT-LCA)' which was introduced to proceed the extensive analysis for a number of case ship studies and quantify various emissions, such as greenhouse gases (GHG), sulphur oxides (SO x), nitrogen oxides (NO x), associated with the proposed systems from cradle to grave. A case study designed with the database consisting of 1,565 ocean-going Ro-Ro vessels based on Lloyd's Register has revealed that, in terms of Global Warming Potential (GWP) and Acidification Potential (AP), closed-loop scrubbers were proven more environmentally friendly than open-loop scrubbers, but the opposite was true for Eutrophication Potential (EP). By identifying specific trends in scrubber systems in relation to various input parameters, the assessment contributed to improving environmental sustainability, as well as the total estimated amount of numerical environmental impacts that the scrubber systems have for the international fleets. The proposed framework enabled us not only to evaluate the different emission levels of systems applied to various ships but also to obtain the general trends of emission levels over ship parameters, which were expressed as formulae. The novelty of this paper can be placed on the provision of an insight into the optimal selection of scrubber systems depending on ship characteristics. It could also offer an insight into the improvement of current environmental regulations and guidelines by means of PT-LCA. • The current challenges of LCA application for the maritime vessels and systems were discussed. • Parametric Trend LCA (PT-LCA) was introduced to understand the relations between ships and emissions. • PT-LCA was applied to evaluate the environmental impacts of SO x scrubber systems for 1,354 Ro-Ro ships. • It provided an insight that PT-LCA should be used extensively in future regulatory frameworks. [ABSTRACT FROM AUTHOR]

In this paper, we use life cycle assessment (LCA) methodology to determine whether the strategy of material composition in a popular Volkswagen Golf model has reduced its environmental load over the last 30 years. The main parameter of our simplified model of LCA was the weight of the materials used to build the car, with the impact on the environment assessed in terms of greenhouse gas emissions. The obtained results indicate a systematically increasing impact on climate that is 49% greater in the Golf Mk6 than in the oldest model, the Golf Mk1. The increased load associated with the production stage is only compensated to a small degree during the operation of a car. For example, by replacing the Mk5 model with the Mk6 model, the environmental benefits begin only after 21 years of use. [ABSTRACT FROM AUTHOR]

Global food systems are as vital for human survival as they constitute a major threat to the environment, being key drivers of climate change, water use, toxic emissions and habitat change. In a business as usual scenario, these impacts will most likely increase, driven by population and economic growth, which will lead to a higher demand for food, and probably for the most environmentally intensive food categories: meat and dairy products. Existing literature suggests deep paradigmatic changes to address this situation, such as (i) large-scale dietary changes on the consumption side, and (ii) structural changes towards more efficient food supply chains on the production side. As both of these measures are related to urban systems, in terms of food consumption habits and the potential of local production, Urban and Peri-Urban Agriculture (UPA) may assume a relevant role in food systems sustainability. In order to estimate to what extent the implementation of UPA would play a role in mitigating the environmental impacts of urban food systems, this paper uses life cycle assessment (LCA) to estimate their respective mitigation potential. The Global Warming Potential (GWP) and Land use (LU) were assessed for per capita Current Average Consumption (CAC) in Lisbon, and this baseline model was subsequently adapted in order to measure the effects of changes: (i) in the diet, through a comparison with the Recommended Healthy Diet (RHD) model; and (ii) in the food supply chain, by measuring the impacts of eliminating losses and wastage across the food supply chain and shortening transportation distances through local food production. The results show that the highest potential for environmental impacts mitigation is related to dietary changes. However, strategies for enhancing the efficiency of the food supply chain are relevant, as reducing losses and wastage, shortening transportation distances and taking into account technology improvements can further increase the mitigation potential. [ABSTRACT FROM AUTHOR]

This paper evaluates several Wastewater treatment plant (WWTP) processes, an integrated sludge management system, and waste sludge disposal methods in a large city based on life cycle analysis (LCA) and economic efficiency analysis (EEA) together. Among the three WWTP processes considered, the A2O process (S-WWTP) showed the lowest eutrophication potential (EP) and global warming potential (GWP), but the highest acidification potential (AP) and human toxicity potential (HTP). Simple integration of sludge treatment by combining two sludge treatment lines resulted in enhanced anaerobic digestion and production of less sludge. For final sludge disposal, incineration with integrated sludge management showed the highest reduction of life cycle impact analysis (LCIA) in all four categories. The simple integration of sludge management could reduce the sludge handling cost by 6.1%. As a final sludge disposal method, incineration with integration of sludge management was the most economic: reducing operation and management (O&M) cost by 33%. These results demonstrated that application of LCA and EEA would be a useful tool for optimizing an integrated sludge-management system. The proposed integrated sludge-management alternatives could provide a valuable example for managing several WWTPs in a large city. [ABSTRACT FROM AUTHOR]

Agricultural production and further processing to food and drink have large impacts on the environment. However, there are still few examples of LCA studies on beverages such as whisky. This paper presents a life cycle assessment of Swedish single malt whisky and different environmental improvements of the production chain are discussed. The functional unit is one bottle (70 cl) of whisky and results are obtained for global warming potential (GWP), Acidification Potential (AP), Eutrophication potential (EP) and primary energy (PE). The contribution to GWP is dominated by CO 2 emissions from transport of stillage. When avoided emissions from use of biogas are included, the net result is 2.1 tonnes CO 2 -eq. Acidification is mainly due to emissions of SO 2 from bottle production, transport and barley cultivation which ends up to 14.6 kg SO 2 -eq. Eutrophication results are totally dominated by barley cultivation, in total 8.6 kg PO 4 3 − . The total use of primary energy is 53.5 MJ/FU with a 50/50 distribution in renewable and non-renewable. Non-renewables emanate from fossil fuels used for transports and in glass production, whereas renewables are mostly used for heating in the distillery. Improvement analysis of transports included; (1) decreasing need of transport, (2) change of fuel and (3) change of transport mode. Decreasing transport of stillage is an efficient measure to reduce GWP and use of non-renewable energy. Substituting diesel with biodiesel for all road transports is an even more efficient measure for these categories, but increases other environmental impact. For all impact categories except use of renewable energy a scenario combining all improvements is the most efficient measure to reduce environmental impact. The results can be used by the manufacturer, but an improved and expanded LCA on product level can be used for a more specific eco-labelling of the different whisky editions. [ABSTRACT FROM AUTHOR]

The paper analyzes biodiesel chains of rapeseed ( Brassica napus ) and carinata ( Brassica carinata ) cultivated in Central and Southern Italy, assessing the impact on Global Warming Potential by means of the Life Cycle Assessment methodology. The production chains differed in use of the oilcake, as animal feed for rapeseed and as biofumigant for B. carinata . The allocation of emissions across co-products was first calculated on the basis of their energy content according to the criterion proposed by European Commission for biofuel production. The resulting impacts were then compared to those obtained through the substitution approach (system expansion method), which considers emissions that are saved by replacing the equivalent conventional product with co-product bio-based materials i.e. soybean meals, nematicidal fumigants, fertilizers and glycerol. The results showed that this method is sensitive to pointing out the importance of the valorization of co-products to the sustainability of bioenergy supply chain. Among the different options taken into consideration, in the case of the B. carinata biodiesel chain, the substitution of conventional fumigants and fertilizers with biofumigants and amendments is able to determine a global net saving of 134 g CO 2 eq per MJ of biodiesel, reversing the sustainability assessment obtained through the energy allocation method. Overall, the results suggest that, when planning future biorefineries, environmental assessment should take the substitution approach into account in order for valorization of co-products and diversification of processes to be rewarded. [ABSTRACT FROM AUTHOR]

The simplification of life cycle inventories (LCIs) by reducing the number of elementary flows is a major issue regarding their use in sector-specific applications. It can ease the understanding of complete LCIs and focus on the most relevant elementary flows. Current LCIs that have been created for Environmental Product Declarations (EPDs) differ from databases provided by academics, in which more than a thousand flows are considered, as they contain a reduced list of substances. In this paper, we examine the consequences of these simplified LCIs on the accuracy of the life cycle impact assessment (LCIA) step. We consider the specific case of an LCI database for building products that was developed in France. Three environmental midpoint and endpoint indicators are analysed: the global warming potential (GWP), the photochemical ozone formation potential (POCP), and the disability-adjusted life years (DALY). The results for 110 building materials indicate that a simplification is not always relevant, as large uncertainties were detected in the final results, especially for the environmental indicators describing the photochemical ozone creation and the damage to human health that require a larger number of LCI flows. In the case of the GWP indicator, the simplification is relevant for approximately 95% of the building materials. The analysis of the key elementary flows for each indicator enables the identification of missing elementary flows in the simplified LCI. Perspectives and recommendations are provided to improve the level of details of simplified LCIs according to the impact assessment methods. [ABSTRACT FROM AUTHOR]

Concrete is responsible for a significant share of global GHG emissions, which can be mainly ascribed to the production of clinker. Alkali-activated concretes have been investigated in literature as a possible alternative, but the sustainability still appears reduced by the high embodied energy of chemicals typically used for the activation step. This paper investigates concrete belonging to strength classes 35, 50 and 70 MPa and produced with a silicate activator derived from waste glass (AABR). Through a Life Cycle Assessment (LCA), the investigation aims to compare the AABR to Ordinary Portland Cement (OPC) concrete and alkali-activated concrete produced with commercially available chemicals (AABC). The effects produced by the variations of some key parameters (impact allocation of precursors, energy mix, amount of activator in the concrete, distance of procurement of raw materials) over the total impact of the AABR are also investigated. Results show that the adoption of alkali-activated concretes instead of OPC concrete allows a significant reduction in environmental categories of global warming (averagely 64% reduction for AABC and 70% for AABR), acidification potential (averagely 23% for AABC and 35% for AABR), and terrestrial eutrophication (averagely 53% for AABC and 60% for AABR). In addition, the study evidenced that the use of waste glass-based activator allows a significant reduction in every environmental category when compared to the use of commercially available chemicals. • LCA was carried out on alkali activated concrete with waste-derived activator. • Comparisons to OPC and AAC with commercial activators were performed. • AAC with waste activator allows 70% reduction of global warming. • Waste derived activator has lower impacts than commercially available chemicals. • Impacts of key parameters from the use of waste-derived activator were assessed. [ABSTRACT FROM AUTHOR]