Environmental impacts of valorisation of crude glycerol from biodiesel production - A life cycle perspective.

Biodiesel production produces significant quantities of impure crude glycerol as a by-product. Recent increases in the global biodiesel production have led to a surplus of crude glycerol, rendering it a waste. As a result, different methods for its valorisation are currently being investigated. This paper assesses the life cycle environmental impacts of an emerging technology for purification of crude glycerol - a multi-step physico-chemical treatment - in comparison to incineration with energy recovery commonly used for its disposal. For the former, three different acids (H3PO4, H2SO4 and HCl) are considered for the acidification step in the purification process. The results suggest that the H2SO4-based treatment is the best option with 17 net-negative impacts out of the 18 categories considered; this is due to system credits for the production of purified glycerol, heat and potassium salts. In comparison to incineration with energy recovery, the H2SO4-based process has lower savings for the climate change impact (-311 versus -504 kg CO2 eq./t crude glycerol) but it performs better in ten other categories. Sensitivity analyses suggest that that the impacts of the physico-chemical treatment are highly dependent on crude glycerol composition, allocation of burdens to crude glycerol and credits for glycerol production. For example, treating crude glycerol with lower glycerol content would increase all impacts except climate change and fossil depletion due to the higher consumption of chemicals and lower production of purified glycerol. Considering crude glycerol as a useful product rather than waste and allocating to it burdens from biodiesel production would increase most impacts significantly, including climate change (22-40 %), while fossil depletion, freshwater and marine eutrophication would become net-positive. The findings of this research will be of interest to the biodiesel industry and other industrial sectors that generate crude glycerol as a by-product.

Biochar from agricultural wastes: Environmental sustainability, economic viability and the potential as a negative emissions technology in Malaysia.

Biochar used for soil amendment is considered a viable negative emissions technology as it can be produced easily from a wide range of biomass feedstocks, while offering numerous potential agricultural benefits. This research is the first to present a comprehensive sustainability assessment of large-scale biochar production and application in Malaysia. The five feedstocks considered comprise the country's most abundant agricultural wastes from palm oil (empty fruit bunches, fibres, palm fronds and shells) and rice (straw) plantations. Combined with process simulation, life cycle assessment and life cycle costing are used to assess the sustainability of biochar production via slow pyrolysis at different temperatures (300-600 °C), considering two functional units: i) production and application of 1 t of biochar; and ii) removal of 1 t of CO2from the atmosphere. The cradle-to-grave system boundary comprises all life cycle stages from biomass acquisition to biochar use for soil amendment. The positive impacts of the latter, such as carbon sequestration, fertiliser avoidance and reduction in soil N2O emissions, are also included. The global warming potential (GWP) is net-negative in all scenarios, ranging from -436 to -2,085 kg CO2 eq./t biochar and -660 to -933 kg CO2 eq./t CO2 removed. Per t of biochar, the systems with shells have the lowest GWP and those with straw the highest, all showing better performance if produced at higher pyrolysis temperatures. However, the temperature trend is opposite for all other 17 impacts considered, with fibres being the best option and fronds the worst for most categories. Per t CO2 removed, fronds have the highest impact in eight categories, including GWP, and shells the lowest in most categories. All impacts are lower for biochar production at higher temperatures. The main hotspot is the pyrolysis process, influencing the majority of impact categories and contributing 66-75 % to the life cycle costs. The costs range from US$116-197/t biochar and US$60-204/t CO2 removed. The least expensive systems per t biochar are those with straws and per t CO2 removed those with shells, while fronds are the worst option economically for both functional units. Utilising all available feedstocks could remove 6-12.4 Mt of CO2 annually, reducing the national emissions from the agricultural sector by up to 54 % and saving US$36.05 M annually on fertilisers imports. These results will be of interest to policy makers in Malaysia and other regions with abundant agricultural wastes.

Biodegradable and conventional plastic packaging: Comparison of life cycle environmental impacts of poly(mandelic acid) and polystyrene.

Most of plastic packaging waste does not degrade over time, which can lead to harmful effects on aquatic life and humans, highlighting the need for packaging materials that are easily degradable. Poly(mandelic acid) (PMA) is a biodegradable polymer that has been proposed as an alternative to polystyrene for use in packaging. However, its potential to replace the existing packaging materials also depends, among other factors, on the environmental sustainability of its production. This study aims to estimate and compare the life cycle environmental impacts of the production of PMA via polymerisation of 5-phenyl-1,3-dioxolane-4-one (Ph-DOX) and o-carboxyanhydride (OCA) monomers. For each route, the impacts are evaluated for 18 ReCiPe categories for reported laboratory scales and potential scaled-up commercial production. The results suggest that most of the impacts of PMA production via the Ph-DOX route are significantly lower (≥20%) than that of the OCA route for both the laboratory and large scales. However, compared to polystyrene, the impacts of large-scale PMA production via the (better of the two) Ph-DOX route are more than five times higher. This is largely due to the use of benzaldehyde, enzymes, hydrocyanic acid and sodium phosphate in the production of mandelic acid and the solvents utilised in monomer synthesis. A sensitivity analysis shows that the bio-transformation of bio-glycerol to produce mandelic acid would reduce 16 out of 18 life cycle impacts of PMA by 6-77%. The impacts are also sensitive to the assumptions used in the scaling-up of laboratory data for solvents. However, the results indicate clearly that, despite all the uncertainties in the scaling-up method, the proposed production routes for PMA would still have several times higher environmental impacts than polystyrene. Therefore, further research would be needed to improve significantly the production process for (bio-)mandelic acid, synthesis of monomers and their polymerisation before PMA can be considered an environmentally sustainable option for packaging applications.

Energy from forest residues in Turkey: An environmental and economic life cycle assessment of different technologies.

Forest residues, as cheap and abundant feedstock, can replace current fossil-energy sources, helping to reduce greenhouse gas (GHG) emissions and improve energy security. Given 27 % of total lands covered with forests, Turkey has a remarkable potential of forest residues from harvesting and industrial activities. This paper thus focuses on evaluating the life cycle environmental and economic sustainability of heat and electricity generation utilising forest residues in Turkey. Two types of forest residues (wood chips and wood pellets) and three energy conversion options are considered: direct combustion (heat only, electricity only and cogenerated heat and power (CHP)), gasification (for CHP) and co-firing with lignite. Results suggest that direct combustion of wood chips for cogeneration of heat and power has the lowest environmental impacts and levelised costs for both functional units (per MWh heat and per MWh electricity generation) considered. Compared to fossil-fuel sources, energy from forest residues has a potential to reduce the climate change impact as well as fossil-fuel, water and ozone depletion by >80 %. However, it also causes an increase in some other impacts, such as terrestrial ecotoxicity. The bioenergy plants have also lower levelised costs than electricity from the grid (except those using wood pellets and gasification regardless of the feedstock) and heat from natural gas. Electricity-only plants using wood chips achieve the lowest LCC, generating net profits. All biomass plants, except the pellet boiler, pay back in their lifetime; however, the economic feasibility of electricity-only and CHP plants is highly sensitive to subsidies for bioelectricity and efficient use of heat. Utilising the currently available forest residues in Turkey (5.7 Mt/yr) for energy provision could potentially reduce the national GHG emissions by 7.3 Mt/yr (1.5 %) and save $0.5 bn/yr (5 %) in avoided fossil-fuel import costs.

Life cycle environmental impacts of chemical recycling via pyrolysis of mixed plastic waste in comparison with mechanical recycling and energy recovery.

A large portion of plastic produced each year is used to make single-use packaging and other short-lived consumer products that are discarded quickly, creating significant amounts of waste. It is important that such waste be managed appropriately in line with circular-economy principles. One option for managing plastic waste is chemical recycling via pyrolysis, which can convert it back into chemical feedstock that can then be used to manufacture virgin-quality polymers. However, given that this is an emerging technology not yet used widely in practice, it is not clear if pyrolysis of waste plastics is sustainable on a life cycle basis and how it compares to other plastics waste management options as well as to the production of virgin plastics. Therefore, this study uses life cycle assessment (LCA) to compare the environmental impacts of chemical recycling of mixed plastic waste (MPW) via pyrolysis with the established waste management alternatives: mechanical recycling and energy recovery. Three LCA studies have been carried out under three perspectives: waste, product and a combination of the two. To ensure robust comparisons, the impacts have been estimated using two impact assessment methods: Environmental footprint and ReCiPe. The results suggest that chemical recycling via pyrolysis has a 50% lower climate change impact and life cycle energy use than the energy recovery option. The climate change impact and energy use of pyrolysis and mechanical recycling of MPW are similar if the quality of the recyclate is taken into account. Furthermore, MPW recycled by pyrolysis has a significantly lower climate change impact (-0.45 vs 1.89 t CO2 eq./t plastic) than the equivalent made from virgin fossil resources. However, pyrolysis has significantly higher other impacts than mechanical recycling, energy recovery and production of virgin plastics. Sensitivity analyses show that some assumptions have notable effects on the results, including the assumed geographical region and its energy mix, carbon conversion efficiency of pyrolysis and recyclate quality. These results will be of interest to the chemical, plastics and waste industries, as well as to policy makers.

Environmental sustainability of biofuels: a review.

Biofuels are being promoted as a low-carbon alternative to fossil fuels as they could help to reduce greenhouse gas (GHG) emissions and the related climate change impact from transport. However, there are also concerns that their wider deployment could lead to unintended environmental consequences. Numerous life cycle assessment (LCA) studies have considered the climate change and other environmental impacts of biofuels. However, their findings are often conflicting, with a wide variation in the estimates. Thus, the aim of this paper is to review and analyse the latest available evidence to provide a greater clarity and understanding of the environmental impacts of different liquid biofuels. It is evident from the review that the outcomes of LCA studies are highly situational and dependent on many factors, including the type of feedstock, production routes, data variations and methodological choices. Despite this, the existing evidence suggests that, if no land-use change (LUC) is involved, first-generation biofuels can-on average-have lower GHG emissions than fossil fuels, but the reductions for most feedstocks are insufficient to meet the GHG savings required by the EU Renewable Energy Directive (RED). However, second-generation biofuels have, in general, a greater potential to reduce the emissions, provided there is no LUC. Third-generation biofuels do not represent a feasible option at present state of development as their GHG emissions are higher than those from fossil fuels. As also discussed in the paper, several studies show that reductions in GHG emissions from biofuels are achieved at the expense of other impacts, such as acidification, eutrophication, water footprint and biodiversity loss. The paper also investigates the key methodological aspects and sources of uncertainty in the LCA of biofuels and provides recommendations to address these issues.

Assessing the environmental sustainability of an emerging energy technology: Solar thermal calcination for cement production.

Cement production is a highly energy-intensive process, contributing 7% to global CO2 emissions. Over 80% of the energy used in cement production is consumed by the calcination process. This paper considers a novel solar thermal technology for calcination, to investigate if it could help mitigate the climate change and other environmental impacts from cement production on a life cycle basis. The following three solar options are compared to conventional fossil-fuel calcination via life cycle assessment: a full solar system, which provides all the required thermal energy, and two hybrid systems, where the solar system provides 14% and 33% of the thermal energy, respectively. The results show that all three solar options have lower impacts than conventional calcination in 14 out of 17 categories. The full solar system is the best alternative, with major reductions in climate change (48%), fossil depletion (75%), photochemical ozone formation (92%) and terrestrial ecotoxicity (79%). Based on insolation levels in different parts of the world, the solar systems could be applied to 26% of current global cement production. This would reduce the climate change impact by 15-40%, as well as most other impacts by 14-87%, depending on the fuel mix. However, a limiting factor might be two times greater land occupation than by the conventional process. Furthermore, the solar system has higher human toxicity-cancer (102%) and metals and minerals depletion (6%) due to the construction of solar facilities. Coupling conventional calcination with carbon capture and storage (CCS) is more efficient in reducing the climate change impact (63%) than the solar system (48%) relative to conventional calcination without CCS. However, adding CCS to the solar calciner would still be a better option, decreasing the impact by 81% relative to conventional calcination without CCS. These findings will be of interest to the solar and cement industries as well as other industrial sectors using high-temperature processes.

Environmental sustainability in the food-energy-water-health nexus: A new methodology and an application to food waste in a circular economy.

Current studies on the food-energy-water nexus do not capture effects on human health. This study presents a new methodology for assessing the environmental sustainability in the food-energy-water-health nexus on a life cycle basis. The environmental impacts, estimated through life cycle assessment, are used to determine a total impact on the nexus by assigning each life cycle impact to one of the four nexus aspects. These are then normalised, weighted and aggregated to rank the options for each aspect and determine an overall nexus impact. The outputs of the assessment are visualised in a "nexus quadrilateral" to enable structured and transparent interpretation of results. The methodology is illustrated by considering resource recovery from household food waste within the context of a circular economy. The impact on the nexus of four treatment options is quantified: anaerobic digestion, in-vessel composting, incineration and landfilling. Anaerobic digestion is environmentally the most sustainable option with the lowest overall impact on the nexus. Incineration is the second best option but has a greater impact on the health aspect than landfilling. Landfilling has the greatest influence on the water aspect and the second highest overall impact on the nexus. In-vessel composting is the worst option overall, despite being favoured over incineration and landfilling in circular-economy waste hierarchies. This demonstrates that "circular" does not necessarily mean "environmentally sustainable." The proposed methodology can be used to guide businesses and policy makers in interpreting a wide range of environmental impacts of products, technologies and human activities within the food-energy-water-health nexus.

Assessing the economic and environmental sustainability of household food waste management in the UK: Current situation and future scenarios.

The value embedded in food waste is increasingly being recognised, with the UN targeting a 50% reduction in consumer food waste and the EU recycling of 60% of all household waste, both by 2030. Aiming to provide guidance on the most sustainable food waste utilisation routes, this study evaluates the life cycle environmental and economic sustainability of five plausible scenarios for the year 2030. Focusing on the UK for context, these are compared to the current treatment of food waste as well as to its potential future prevention. The scenarios consider a differing share of four widely-used treatment methods: anaerobic digestion, in-vessel composting, incineration and landfilling. The scenario with the highest anaerobic digestion share that recovers both heat and electricity is the best option for seven out of 19 environmental impacts and the second best for life cycle costs. Upgrading anaerobic digestion biogas to biomethane achieves the lowest global warming potential and life cycle costs. Net-negative global warming potential (savings) can be achieved if the heat from anaerobic digestion and incineration or biomethane are utilised to displace natural gas. Displacing a future electricity mix does not lead to significant global warming potential savings due to the expected grid decarbonisation. However, savings are still achieved for metal depletion and human and terrestrial toxicities as they are higher for decarbonised grid electricity due to the increased share of renewables. A greater share of in-vessel composting leads to higher impacts because of the high electricity consumption. Landfill reduction has an economic advantage for all the scenarios, except for the business-as-usual, with life cycle costs 11-75% lower than for the current situation. While future scenarios improve the overall sustainability compared to the current situation, halving food waste by 2030 can save 15 times more greenhouse gas emissions than the best treatment scenario without waste reduction. Therefore, any commitments to improve the sustainability of food waste treatment must be accompanied by an effective waste prevention strategy. The outcomes of this work can help waste treatment operators and policy makers towards more sustainable food waste management. Although the focus is on UK situation, the overall conclusions and recommendations are applicable to other regions.

Environmental and economic implications of recovering resources from food waste in a circular economy.

Around a third of food is wasted globally, requiring significant resources for its treatment and disposal, in addition to wasting valuable resources. Following the circular economy principles, this waste should ideally be avoided, and if not possible, treated to recover resources. This paper considers the life cycle environmental and economic implications of recovering energy and material resources from food waste, focusing on the UK situation. Four treatment methods are considered: anaerobic digestion, in-vessel composting, incineration and landfilling. The results show that per tonne of waste treated, anaerobic digestion has the lowest environmental impacts in 13 out of the 19 categories considered in the study, including net-negative global warming potential. In-vessel composting is the least sustainable option environmentally, in contrast to being preferred over incineration according to the circular economy principles. Incineration has the lowest life cycle costs (£71/t), while landfilling is the costliest option (£123/t). Managing the 4.9 Mt of food waste collected annually from UK households via the four methods generates 340,000 t CO2 eq. and costs £452 m, in addition to causing a number of other environmental impacts. However, it also saves 1.9 PJ of primary energy, primarily due to electricity generation through incineration. If all of this food waste was incinerated, £103 m and 360,000 t CO2 eq./year could be saved compared to current waste management, rendering incineration a carbon-negative technology. This would also result in savings in 14 other impacts, but would increase summer smog by 30% and metal depletion by 56%. The environmental benefits of incineration would be exceeded only if all food waste was treated by anaerobic digestion, which would save 490,000 t CO2 eq./year and produce 50% more electricity per tonne of waste than incineration. Anaerobic digestion would also lead to savings in 14 other impacts compared to the present situation, but would result in a four times higher acidification and three times greater emissions of particulate matter. In addition, it would save £251 m/year compared to the current costs. Nevertheless, prevention of avoidable food waste would realise far greater environmental and economic savings, estimated here at 14 Mt CO2 eq. and £10.7 bn annually.

Life cycle environmental impacts of fruits consumption in the UK.

Fruits are indispensable for a balanced and healthy diet. However, their environmental impacts remain largely unknown. Using a life cycle approach, this work estimates for the first time the impacts of fruits consumed in the UK. What makes the UK a particularly interesting case is that only 7% of fruits are produced domestically, with the rest imported, largely (70%) from outside of Europe. In total, 21 types of fruit and 46 fresh and processed products produced in the UK and abroad are considered to estimate the impacts at both the product and the national levels. The findings at the product level suggest that melons have the lowest and mangoes and avocados the highest impacts as a significant portion of the last two is air-freighted. Processing leads to high impacts of fruit juices, dried and frozen products. Storage has a considerable contribution to the impacts for fruits stored over a long period, such as apples. Packaging used for canned fruits and juices is also a significant contributor to the impacts. Taking the annual consumption into account, the whole UK fruit sector generates 7.9 Mt CO2 eq. and consumes 94 PJ of primary energy. This is equivalent to 4% of the annual GHG emissions and 9% of energy demand of the whole UK food sector. Moreover, fruits require 0.35 Mha of agricultural land and 315 Mm3 eq. of water per year. Oranges, bananas and apples are responsible for more than half of the impacts at the national level as they account for 64% of the total fruit consumption in the UK. It is expected that the results of this study will be of interest to different supply chain actors, including farmers, food processors and consumers, aiding them in reducing the environmental impacts of fruits.

Environmental and economic sustainability of poultry litter gasification for electricity and heat generation.

This work aims to assess the environmental and economic sustainability of poultry litter gasification for heat and electricity generation. The results are compared with gasification of two other biomass feedstocks (Miscanthus and waste wood) and energy from fossil fuels. The findings suggest that poultry litter gasification can lead to significant reductions in 14 out of 16 impacts considered in the study in comparison with fossil-fuel alternatives. Compared to combined heat and power (CHP) from natural gas, most impacts from gasification of the litter are lower by more than 90%, including global warming potential. However, human toxicity and depletion of minerals are 25% and three times higher, respectively. Energy from poultry litter also has lower impacts than from waste woodchips and Miscanthus across all the categories, except for acidification. Owing to high capital costs, the unsubsidised cost of generating heat and electricity from poultry litter is similar to that of natural gas CHP but significantly cheaper than from other fossil-fuel alternatives. However, with the current subsidies in the UK, the payback time for poultry litter gasification is 13.5 years. It is estimated that 4.55 Mt of poultry litter is currently available in the UK, 2.73 Mt of which is suitable for conversion to energy. If this waste is utilised in gasification plants, it could potentially provide 0.6% of electricity and heat in the UK and save 1.7 Mt of GHG per year, equivalent to around 0.4% of UK's GHG emissions. However, the successful uptake of this technology will depend on a future reduction in capital costs.

A methodology for integrating the biomass balance approach into life cycle assessment with an application in the chemicals sector.

Driven by the need to reduce greenhouse gas emissions and dependence on fossil resources, the chemical and other industries are gradually starting to develop bio-based products. For the introduction of bio-feedstocks in existing production pathways in a cost-effective way, a simplified approach based on mass balance has been proposed. This concept is known as the biomass balance (BMB) approach and the resulting products are called BMB products. They do not necessarily contain biomass material but can contribute to sustainable sourcing and production of bio-based products in the supply chain without any performance loss in comparison to the same products derived from fossil resources. The aim of the study is to show how the BMB approach can be used in life cycle assessment (LCA) while following the requirements set out in the ISO 14040 and 14044 standards. To demonstrate that, the proposed BMB approach has been used to estimate life cycle environmental impacts of a polymer product, which can be produced using fossil or bio-feedstocks. For the polymer derived from bio-feedstocks, bio-naphtha and biogas are considered as replacement to naphtha and its impacts are compared with the fossil-based alternative. The paper demonstrates that the BMB approach provides a quick and pragmatic method for establishing the biomass content in chemical and related products while incentivising the industry to continue increasing the proportion of bio-based products in their product portfolio. It also shows that the environmental performance of BMB products is highly dependent on the particular bio-feedstock used, the way it is sourced and on key modelling assumptions, including the assumptions on biogenic carbon uptake in the bio-feedstocks.

Environmental impacts of vegetables consumption in the UK.

A healthy diet depends on the daily intake of vegetables. Yet, their environmental impacts along the full supply chains are scarcely known. Therefore, this paper provides for the first time a comprehensive evaluation of the life cycle environmental impacts of vegetables consumed in UK. The impacts are assessed for 56 fresh and processed products produced domestically and imported from abroad, considering both the product and sectoral levels. At the product level, taking into account the market mix of fresh and processed vegetables for each vegetable type sold in the UK, asparagus has the highest per-kg impacts across most of the 19 impact categories considered, while cabbage, celery and Brussels sprouts are generally environmentally most sustainable. At the sectoral level, the annual consumption of 10.8 t of vegetables generates 20.3 Mt CO2 eq., consumes 260.7 PJ of primary energy and depletes 253 Mt eq. of water. The majority of the impacts are caused by potatoes since they account for 56% of the total amount of vegetables consumed, with crisps and frozen chips contributing most to the total impacts. Importing vegetables grown in unheated greenhouses in Europe has a lower impact than UK vegetables cultivated in heated greenhouses, despite the transportation. The impacts of air-freighted fresh vegetables are around five times higher than of those produced domestically. Even processed products have lower impacts than fresh air-freighted produce. Packaging also contributes significantly to the impacts, in particular glass jars and metal cans used for processed vegetables. Other significant hotspots are open display cabinets at the retailer and cooking of vegetables at home. The results of this study will be useful for food manufacturers, retailers and consumers, helping to identify improvement opportunities along vegetables supply chains.

Environmental sustainability of anaerobic digestion of household food waste.

Consumers are the leading producers of food waste (FW) in developed countries and the majority of household FW is still embedded in general waste where it is incinerated or landfilled. There is increasing awareness in the value of collecting FW as a separate waste stream for production of compost or recovery of energy through anaerobic digestion (AD). This study focuses on AD to evaluate the life cycle environmental sustainability of recovering energy and fertilisers from household FW in the UK. The analysis is carried out for two different functional units: i) treatment of 1 tonne of FW, which is compared to incineration and landfilling; and ii) generation of 1 MWh of electricity, which is compared to other electricity generation options. The former results in net negative greenhouse gas (GHG) emissions (-39 kg CO2-eq./t) and primary energy demand (-2 GJ/t) due to the displacement of grid electricity and mineral fertilisers. AD has lower impacts than both incineration and landfilling across 15 of the 19 impacts. However, the application of digestate to land and the release of ammonia and nitrates lead to higher marine eutrophication (ME), terrestrial acidification (TA) and particulate matter formation (PMF). For the second functional unit, AD electricity emits 203 kg CO2-eq./MWh, compared to 357 kg CO2-eq./MWh for the UK grid mix. Compared to renewables, such as wind and solar, AD electricity has lower energy demand, toxicity potentials and metal depletion. However, it has higher global warming potential, ME, TA and PMF. At the UK level, treating 4.9 Mt of kerbside FW collected annually could provide 0.37% of the national electricity demand and save 190,000 t CO2-eq./yr compared to the grid electricity. The digestate produced could displace 1% of industrial nitrogen fertilisers. Although small fractions of the national demands, they represent a valuable return from a largely unutilised waste stream and help towards implementation of a circular economy.

Accounting for land use, biodiversity and ecosystem services in life cycle assessment: Impacts of breakfast cereals.

This study considers the life cycle impacts of land use on biodiversity and ecosystem services associated with the production of a ubiquitous food type: breakfast cereals. For biodiversity, the impacts on five taxonomic groups have been assessed: mammals, birds, vascular plants, amphibians and reptiles. For ecosystem services, the potential loss in the following ecosystem services of soil has been considered: biotic production, erosion resistance, groundwater regeneration, infiltration and physicochemical filtration. The findings indicate that the main hotspot for the biodiversity loss is cocoa cultivation for all taxonomic groups, with a contribution of 27-67%. Cocoa is also a major contributor (35%) to the loss of biotic production, while rice is the largest contributor to erosion (34%), reduction in groundwater replenishment (43%) and physiochemical filtration (23%). Corn is the main cause of the infiltration reduction, accounting for 44% of the impact. Unlike the biodiversity impacts, which are almost entirely caused by agricultural activities, non-agricultural land use occurring in other life cycle stages (transport, packaging and manufacturing), has significant contribution to the reductions in groundwater replenishment and infiltration. The impacts on ecosystem services are almost entirely driven by land occupation, while the biodiversity impacts are caused by both land use change and occupation. The identification of cocoa as the main hotspot is unexpected as it is used only in very small quantities (<5% by mass) in breakfast cereals. Its high contribution to the impacts is partly due to the land use change in the ecoregion of the Eastern Guinean forests, which are home to a relatively large number of endemic species. The paper also discusses the limitations of the impact assessment methods for evaluating the biodiversity and ecosystem services and highlights the need for further development of indicators and methods to assess the land use impacts in life cycle assessment.

Are stormwater pollution impacts significant in life cycle assessment? A new methodology for quantifying embedded urban stormwater impacts.

Current life cycle assessment (LCA) models do not explicitly incorporate the impacts from urban stormwater pollution. To address this issue, a framework to estimate the impacts from urban stormwater pollution over the lifetime of a system has been developed, laying the groundwork for subsequent improvements in life cycle databases and LCA modelling. The proposed framework incorporates urban stormwater event mean concentration (EMC) data into existing LCA impact categories to account for the environmental impacts associated with urban land occupation across the whole life cycle of a system. It consists of five steps: (1) compilation of inventory of urban stormwater pollutants; (2) collection of precipitation data; (3) classification and characterisation within existing midpoint impact categories; (4) collation of inventory data for impermeable urban land occupation; and (5) impact assessment. The framework is generic and can be applied to any system using any LCA impact method. Its application is demonstrated by two illustrative case studies: electricity generation and production of construction materials. The results show that pollutants in urban stormwater have an influence on human toxicity, freshwater and marine ecotoxicity, marine eutrophication, freshwater eutrophication and terrestrial ecotoxicity. Among these, urban stormwater pollution has the highest relative contribution to the eutrophication potentials. The results also suggest that stormwater pollution from urban areas can have a substantial effect on the life cycle impacts of some systems (construction materials), while for some systems the effect is small (e.g. electricity generation). However, it is not possible to determine a priori which systems are affected so that the impacts from stormwater pollution should be considered routinely in future LCA studies. The paper also proposes ways to incorporate stormwater pollution burdens into the life cycle databases.

Environmental impacts of chocolate production and consumption in the UK.

This study evaluates life cycle environmental impacts associated with chocolate products made and consumed in the UK. The paper focuses on three representative chocolate products occupying 90% of the market: 'moulded chocolate', 'chocolate countlines' and 'chocolates in bag'. The impacts were estimated using life cycle assessment (LCA) as a tool and following the ReCiPe impact assessment method. The water footprint was also considered. For example, the global warming potential ranges between 2.91 and 4.15 kg CO2 eq., primary energy demand from 30 to 41 MJ and the water footprint, including water stress, from 31 to 63 l per kilogram of chocolate. The raw materials are the major hotspot across all impact categories for all three product types, followed by the chocolate production process and packaging. The raw material impacts are mainly due to milk powder, cocoa derivatives, sugar and palm oil. The sensitivity analysis shows that the results for global warming potential are sensitive to land-use change (LUC) associated with cocoa production, increasing the impact of the chocolate products by three to four times if LUC is involved. The improvement opportunities targeting the key contributing stages suggest that GWP of chocolates could be reduced by 14%-19%. Chocolate countlines have the highest contribution to the total impacts at the UK level (37%-43%), followed by chocolates in bag (28%-33%). Moulded chocolates and other chocolate confectionary make up the rest of the impacts, with a roughly equal share each. Chocolate consumption in the UK contributes 4.7% to the primary energy consumption and 2.4% to the GHG emissions from the whole food and drink sector. The results of this work will be of interest to policy makers, chocolate producers and consumers, helping them to make more informed decisions towards sustainable production and consumption of chocolate products.

Life cycle environmental evaluation of kettles: Recommendations for the development of eco-design regulations in the European Union.

Between 117 and 200 million kettles are used in the European Union (EU) every year. However, the full environmental impacts of kettles remain largely unknown. This paper presents a comprehensive life cycle assessment of conventional plastic and metallic kettles in comparison with eco-kettles. The results show that the use stage contributes 80% to the impacts. For this reason, the eco-kettle has over 30% lower environmental impacts due to a greater water efficiency and related lower energy consumption. These results have been extrapolated to the EU level to consider the implications for proposed eco-design regulations. For these purposes, the effects on the impacts of durability of kettles and improvements in their energy and water efficiency have been assessed as they have been identified as two key parameters in the proposed regulations. The results suggest that increasing the current average durability from 4.4 to seven years would reduce the impacts by less than 5%. Thus, improving durability is not a key issue for improving the environmental performance of kettles and does not justify the need for an eco-design regulation based exclusively on it. However, improvements in water and energy efficiency through eco-design can bring relevant environmental savings. Boiling the exact amount of water needed would reduce the impacts by around a third and using water temperature control by further 2%-5%. The study has also considered the effects of reducing significantly the number of kettles in use after the UK (large user of kettles) leaves the EU and reducing the excess water typically boiled by the consumer. Even under these circumstances, the environmental savings justify the development of a specific EU eco-design regulation for kettles. However, consumer engagement will be key to the implementation and achievement of the expected environmental benefits.

Life cycle environmental impacts of vacuum cleaners and the effects of European regulation.

Energy efficiency of vacuum cleaners has been declining over the past decades while at the same time their number in Europe has been increasing. The European Commission has recently adopted an eco-design regulation to improve the environmental performance of vacuum cleaners. In addition to the existing directive on waste electrical and electronic equipment (WEEE), the regulation could potentially have significant effects on the environmental performance of vacuum cleaners. However, the scale of the effects is currently unknown, beyond scant information on greenhouse gas emissions. Thus, this paper considers for the first time life cycle environmental impacts of vacuum cleaners and the effects of the implementation of these regulations at the European level. The effects of electricity decarbonisation, product lifetime and end-of-life disposal options are also considered. The results suggest that the implementation of the eco-design regulation alone will reduce significantly the impacts from vacuum cleaners (37%-44%) by 2020 compared with current situation. If business as usual continued and the regulation was not implemented, the impacts would be 82%-109% higher by 2020 compared to the impacts with the implementation of the regulation. Improvements associated with the implementation of the WEEE directive will be much smaller (<1% in 2020). However, if the WEEE directive did not exist, then the impacts would be 2%-21% higher by 2020 relative to the impacts with the implementation of the directive. Further improvements in most impacts (6%-20%) could be achieved by decarbonising the electricity mix. Therefore, energy efficiency measures must be accompanied by appropriate actions to reduce the environmental impacts of electricity generation; otherwise, the benefits of improved energy efficiency could be limited. Moreover, because of expected lower life expectancy of vacuum cleaners and limited availability of some raw materials, the eco-design regulation should be broadened to reduce the impacts from raw materials, production and end-of-life management.