In order to use secondary waste from an incineration plant, it is necessary to process or treat it. Valorization of municipal solid waste incineration bottom ash (MSWIBA) is a popular treatment method. Moreover, there are other possibilities, such as alkaline pre-treatment, which can be used for the rest of the secondary waste from incineration plants, especially hazardous fly ash. The purpose of this study is to show the problem of secondary waste in Poland in relation to the rest of Europe. Due to the physicochemical research of secondary waste, the possibilities of the procedure and its management are indicated. By analyzing the literature and the market, the latest possibilities for improving the physicochemical properties of secondary waste are proposed. Searching for new methods for waste management is essential to the environment. This manuscript presents the problem of the increasing amount of waste, as well as possibilities to close the loop, and minimize the negative impact o... [more]

The electro-mobility of vehicles could solve the negative effects of road transport, by decreasing greenhouse gas emissions. However, some electric vehicles also have a negative impact on the environment related to the nature of electricity used. This paper aims to evaluate the electricity sources for electric vehicles using a Life Cycle Thinking approach. Life cycle assessment, using several midpoints and endpoint methods, highlighted that the most damaging sources were lignite and diesel, while hydropower, wind, and biomass were the most sustainable ones. Cumulative energy demand showed that biomass used the least energy (0.034 MJ eq.), but originates from 100% non-renewable sources. Lignite, which also comes from 100% non-renewable sources, used the most energy (17.791 MJ eq.). The lowest carbon footprints were for wind, biomass, and photovoltaic (1.0 kg CO2 eq.). Considering life cycle costing, photovoltaic electricity generation was the most expensive (0.2107 USD/kWh) while natura... [more]

Life-cycle assessment (LCA) and techno-economic analysis (TEA) were applied to assess the economic feasibility and environmental benefits of utilizing multiple biomass feedstocks for bioenergy products under three different technological pathways with consideration of uncertainties. Three cases were studied for the production of pellets, biomass-based electricity, and pyrolysis bio-oil. A Monte Carlo simulation was used to examine the uncertainties of fossil energy consumption, bioenergy conversion efficiency, stochastic production rate, etc. The cradle-to-gate LCA results showed that pellet production had the lowest greenhouse gas (GHG) emissions, water and fossil fuels consumption (8.29 kg CO2 eq (equivalent), 0.46 kg, and 105.42 MJ, respectively). The conversion process presented a greater environmental impact for all three bioenergy products. When producing 46,929 Mg of pellets, 223,380 MWh of electricity, and 78,000 barrels of pyrolysis oil, the net present values (NPV) indicated... [more]

The potential environmental impacts of producing and using future electric vehicles (EVs) are important given their expected role in mitigating global climate change and local air pollutants. Recently, studies have begun assessing the effect of potential future changes in EVs supply chains on overall environmental performance. This study contributes by integrating expected changes in future energy, iron, and steel production in the life cycle assessment (LCA) of EVs. In this light, the study examines the impacts of changes in these parameters on producing and charging future EVs. Future battery electric vehicles (BEV) could have a 36−53% lower global warming potential (GWP) compared to current BEV. The change in source of electricity generation accounts for 89% of GWP reductions over the BEV’s life cycle. Thus, it presents the highest GWP reduction potential of 35−48%. The use of hydrogen for direct reduction of iron in steelmaking (HDR-I) is expected to reduce vehicle production GWP b... [more]

As both the human population and living standards grow, so does the worldwide electricity demand. However, the power sector is also one of the biggest environmental polluters. Therefore, options are currently being sought aimed at reducing environmental impacts, one of the potential tools for which concerns the use of life cycle assessment. This study, therefore, focuses on the most commonly used nonrenewable (black coal, lignite, natural gas and nuclear) and renewable sources (wind, hydro and photovoltaic) in the Czech Republic in terms of their construction, operation, and decommissioning periods. Environmental impacts are assessed via the use of selected impact categories by way of product environmental footprint methodology. The results highlight the potential environmental impacts associated with electricity generation for each of the primary energy sources. Black coal and lignite power plants were found to contribute most to the global warming, resource use, energy carriers and r... [more]

Increasing interest in bioenergy production in the context of the transition towards a circular economy and the promotion of renewable energy has produced demands for optimization of the value chain of energy production to improve the environmental viability of the system. Hotspot analysis based on life cycle assessment (LCA) contributes to the mitigation of environmental burdens and is a very important step towards the implementation of a bioeconomy strategy. In this study, hotspots identified using two parallel pathways: a literature review and empirical research on four different biogas plants located in Poland. LCA and energy return on investment (EROI) analysis of the whole bioenergy production chain were considered to identify unit processes or activities that are highly damaging to the environment. The biogas plants differ mainly in the type of raw materials used as an input and in the method of delivery. The results show that the most impactful processes are those in the delive... [more]

Landfilling of organic waste is still the predominant waste management method in Canada. Data collection and analysis of the waste were done for the case study city of Montréal in Canada. A life cycle assessment was carried out for the current and proposed waste management system using the IWM-2 software. Using life cycle assessment results, a non-dominated sorting genetic algorithm was used to optimize the waste flows. The optimization showed that the current recovery ratio of organic waste of 23% in 2017 could be increased to 100% recovery of food waste. Also, recycling could be doubled, and landfilling halved. The objective functions were minimizing the total energy consumption and CO2eq emissions as well as the total cost in the waste management system. By using a three-objective optimization algorithm, the optimized waste flow for Montréal results in 2% of waste (14.7 kt) to anaerobic digestion (AD), 7% (66.3 kt) to compost, 32% (295 kt) to recycling, 1% (8.5 kt) to incineration,... [more]

The primary energy consumption and greenhouse gas emissions from nickel smelting products have been assessed through case studies using a process model based on mass and energy balance. The required primary energy for producing nickel metal, nickel oxide, ferronickel, and nickel pig iron is 174 GJ/t alloy (174 GJ/t contained Ni), 369 GJ/t alloy (485 GJ/t contained Ni), 110 GJ/t alloy (309 GJ/t contained Ni), and 60 GJ/t alloy (598 GJ/t contained Ni), respectively. Furthermore, the associated GHG emissions are 14 tCO2-eq/t alloy (14 tCO2-eq/t contained Ni), 30 t CO2-eq/t alloy (40 t CO2-eq/t contained Ni), 6 t CO2-eq/t alloy (18 t CO2-eq/t contained Ni), and 7 t CO2-eq/t alloy (69 t CO2-eq/t contained Ni). A possible carbon emission reduction can be observed by comparing ore type, ore grade, and electricity source, as well as allocation strategy. The suggested process model overcomes the limitation of a conventional life cycle assessment study which considers the process as a ‘black box... [more]

The analyzed research issue provides a model for Carbon Footprint estimation at an early design stage. In the context of climate neutrality, it is important to introduce regenerative design practices in the architect’s design process, especially in early design phases when the possibility of modifying the design is usually high. The research method was based on separate consecutive research works−partial tasks: Developing regenerative design guidelines for simulation purposes and for parametric modeling; generating a training set and a testing set of building designs with calculated total Carbon Footprint; using the pre-generated set to train a Machine Learning Model; applying the Machine Learning Model to predict optimal building features; prototyping an application for a quick estimation of the Total Carbon Footprint in the case of other projects in early design phases; updating the prototyped application with additional features; urban layout analysis; preparing a new approach based... [more]

A screening Life Cycle Assessment (LCA) of tall oil-based bio-polyols suitable for rigid polyurethane (PU) foams has been carried out. The goal was to identify the hot-spots and data gaps. The system under investigation is three different tall oil fatty acids (TOFA)-based bio-polyol synthesis with a cradle-to-gate approach, from the production of raw materials to the synthesis of TOFA based bio-polyols at a pilot-scale reactor. The synthesis steps that give the most significant environmental footprint hot-spots were identified. The results showed the bio-based feedstock was the main environmental hot-spot in the bio-polyol production process. Future research directions have been highlighted.

This paper presents a life cycle assessment (LCA) of photovoltaic (PV) solar modules which have been integrated into electric vehicle applications, also called vehicle integrated photovoltaics (VIPV). The LCA was executed by means of GaBi LCA software with Ecoinvent v2.2 as a background database, with a focus on the global warming potential (GWP). A light utility electric vehicle (LUV) named StreetScooter Work L, with a PV array of 930 Wp, was analyzed for the location of Cologne, Germany. An operation time of 8 years and an average shadowing factor of 30% were assumed. The functional unit of this LCA is 1 kWh of generated PV electricity on-board, for which an emission factor of 0.357 kg CO2-eq/kWh was calculated, whereas the average grid emissions would be 0.435 kg CO2-eq/kWh. Hence, charging by PV power hence causes lower emissions than charging an EV by the grid. The study further shows how changes in the shadowing factor, operation time, and other aspects affect vehicle’s emissions... [more]

This work presents a validated workflow based on an algorithm developed in Grasshopper to parametrically control the building’s shape, by maximizing the solar irradiation incident on the building envelope and minimizing the embodied emissions. The algorithm is applied to a zero-emission building concept in Nordic and Mediterranean climate zones. The algorithm enables conducting both energy and environmental assessments through Ladybug tools. The emissions embodied in materials and the solar irradiation incident on the building envelope were estimated in the early design stage. A three-steps optimization process through evolutionary solvers, such as Galapagos (one-objective) and Octopus (multi-objective), has been conducted to shape the most environmentally responsive ZEB model in both climates. The results demonstrated the replicability of the algorithm to optimize the solar irradiation by producing an increment of solar incident irradiation equal to 35% in the Mediterranean area, and... [more]

Fuel production from hydrogen and carbon dioxide is considered an attractive solution as long-term storage of electric energy and as temporary storage of carbon dioxide. A large variety of CO2 sources are suitable for Carbon Capture Utilization (CCU), and the process energy intensity depends on the separation technology and, ultimately, on the CO2 concentration in the flue gas. Since the carbon capture process emits more CO2 than the expected demand for CO2 utilization, the most sustainable CO2 sources must be selected. This work aimed at modeling a Power-to-Gas (PtG) plant and assessing the most suitable carbon sources from a Life Cycle Assessment (LCA) perspective. The PtG plant was supplied by electricity from a 2030 scenario for Italian electricity generation. The plant impacts were assessed using data from the ecoinvent database version 3.5, for different CO2 sources (e.g., air, cement, iron, and steel plants). A detailed discussion on how to handle multi-functionality was also ca... [more]

Large-scale deployment of both biochemical and thermochemical routes for advanced biofuels production is seen as a key climate change mitigation option. This study addresses techno-economic and environmental aspects of advanced liquid biofuels production alternatives via biomass gasification and Fischer−Tropsch synthesis integrated to a typical sugarcane distillery. The thermochemical route comprises the conversion of the residual lignocellulosic fraction of conventional sugarcane (bagasse and straw), together with eucalyptus and energy-cane as emerging lignocellulosic biomass options. This work promotes an integrated framework to simulate the mass and energy balances of process alternatives and incorporates techno-economic analyses and sustainability assessment methods based on a life-cycle perspective. Results show that integrated biorefineries provide greenhouse gas emission reduction between 85−95% compared to the fossil equivalent, higher than that expected from a typical sugarcan... [more]

Energy saving is at the heart of sustainable development in the context of climate change. Saving energy is not only the amount of energy that we save, but also reducing emissions of pollutants to the atmosphere, as well as reducing the consumption of energy resources that are used to produce energy. Reducing pollutant emissions and the use of energy resources can be achieved by increasing the use of renewable energy sources, but at present, this method of obtaining energy in the world is not representative. It should be noted that renewable energy devices throughout the life cycle generate environmental impact. Similar to this situation, the building’s thermo-modernization, which is focused on reducing the pressure on the environment of the building’s user, also has an impact on the environment throughout the building’s life cycle. Determining this environmental impact and ecological or economic benefits or costs is the purpose of the following article. Thermo-modernization of the bui... [more]

Heat pumps are increasingly seen as efficient and cost-effective heating systems also in industrial applications. They can drastically reduce the carbon footprint of heating by utilizing waste heat and renewable electricity. Recent research on Stirling cycle-based very high temperature heat pumps is motivated by their promising role in addressing global environmental and energy-related challenges. Evaluating the environmental footprint of a heat pump is not easy, and the impacts of Stirling cycle-based heat pumps, with a relatively high temperature lift have received little attention. In this work, the environmental footprint of a Stirling cycle-based very high temperature heat pump is evaluated using a “cradle to grave” LCA approach. The results for 15 years of use (including manufacturing phase, operation phase, and decommissioning) of a 500-kW heat output rate system are compared with those of natural gas- and oil-fired boilers. It is found that, for the Stirling cycle-based HP, the... [more]

With an increasing share of renewable energy technologies in our energy systems, the integration of not only direct emission (from the use phase), but also the total life cycle emissions (including emissions during resource extraction, production, etc.) becomes more important in order to draw meaningful conclusions from Energy Systems Analysis (ESA). While the benefit of integrating Life Cycle Assessment (LCA) into ESA is acknowledged, methodologically sound integration lacks resonance in practice, partly because the dimension of the implications is not yet fully understood. This study proposes an easy-to-implement procedure for the integration of LCA results in ESA based on existing theoretical approaches. The need for a methodologically sound integration, including the avoidance of double counting of emissions, is demonstrated on the use case of Passivated Emitter and Rear Cell photovoltaic technology. The difference in Global Warming Potential of 19% between direct and LCA based emi... [more]

Fossil energy inputs and greenhouse gas (GHG) emissions associated with the cultivation and transport of sugarcane (Saccharum officinarum) for bioethanol production in Tanegashima, Japan, were estimated by life cycle assessment (LCA). The aim was to understand the effects of combined systems of polyethylene mulching treatment (mulching at planting and every ratooning, MM; mulching only at planting, MU; and untreated, i.e., no mulching at all, UU) and cultivar (a cold-tolerant genotype, NiTn18, and a conventional variety, NiF8). The mulch treatments and cultivars were combined to create six cultivation systems that were used to conduct a comparative assessment of cradle-to-gate energy inputs and emissions for bioethanol production. The LCA results showed that the energy inputs and GHG emissions resulting from the MM/NiF8 system were 6.29 MJ L−1 and 0.500 kg CO2e L−1, which were 14% and 23% lower, respectively, than the corresponding values in the UU/NiF8 system. In contrast, the MU/NiF8... [more]

The use of lightweight concrete for the construction of single-family houses has become increasingly popular in Spain. In this paper, single-family houses with different shape factors and window-to-wall ratios are analysed from both a thermal and environmental perspective using Passive House Planning Package (PHPP) software to calculate the energy demand. The study has been carried out for different Atlantic microclimates (coastal, inland, and mountain) in northern Spain. What most affects the thermal energy used for air conditioning is the variation of the microclimates, so the study focuses mainly on this aspect. Operational energy for heating has decreased greatly via the use of high degree of insulation and hence the next task is to decrease the total energy consumed taking into account the embodied energy. Impacts on Primary Energy and Global Warming Potential are calculated using a cradle-to-grave approach. The energy use for heating and domestic hot water is analysed for differe... [more]

The construction industry is responsible for a high percentage of the energy consumed on the planet and the emission of greenhouse gases, therefore it is considered necessary to rethink many of the processes that this industry carries out in order to reduce its environmental impact. For this, one of the paths could take into account the Life Cycle Assessment of the used materials, for which it is necessary to evaluate this aspect through indicators that allow the qualification and quantification of the weight of these environmental impacts. In this context, this article presents a methodological proposal for the quantitative evaluation of the embodied primary energy and CO2 production at each stage of the life cycle of prefabricated structural systems, taking as case studies eight prototypes from the “Solar Decathlon” competition in its editions of Europe (2014), United States (2015) and Latin America (2015), through a Simplified Life Cycle Analysis, using the Eco Audit tool from CES E... [more]

The construction industry is responsible for a high percentage of the energy consumed on the planet and the emission of greenhouse gases, therefore it is considered necessary to rethink many of the processes that this industry carries out in order to reduce its environmental impact. For this, one of the paths could take into account the Life Cycle Assessment of the used materials, for which it is necessary to evaluate this aspect through indicators that allow the qualification and quantification of the weight of these environmental impacts. In this context, this article presents a methodological proposal for the quantitative evaluation of the embodied primary energy and CO2 production at each stage of the life cycle of prefabricated structural systems, taking as case studies eight prototypes from the “Solar Decathlon” competition in its editions of Europe (2014), United States (2015) and Latin America (2015), through a Simplified Life Cycle Analysis, using the Eco Audit tool from CES E... [more]

Few life cycle assessments (LCAs) on willow biomass production have investigated the effects of key geographically specific parameters. This study uses a spatial LCA model for willow biomass production to determine spatially explicit greenhouse gas (GHG) emissions and energy return on investment (EROI), including land use conversion from pasture and cropland or grassland. There were negative GHG emissions on 92% of the land identified as suitable for willow biomass production, indicating this system’s potential for climate change mitigation. For willow planted on cropland or pasture, life cycle GHG emissions ranged from −53.2 to −176.9 kg CO2eq Mg-1. When willow was grown on grassland the projected decrease in soil organic carbon resulted in a slightly positive GHG balance. Changes in soil organic carbon (SOC) associated with land use change, transportation distance, and willow yield had the greatest impacts on GHG emissions. Results from the uncertainty analysis exhibited large variat... [more]

The building envelope is critical to reducing operational energy in residential buildings. Under moderate climates, as in South-Western Europe (Portugal), thermal operational energy may be substantially reduced with an adequate building envelope selection at the design stage; therefore, it is crucial to assess the trade-offs between operational and embodied impacts. In this work, the environmental influence of building envelope construction with varying thermal performance were assessed for a South-Western European house under two operational patterns using life-cycle assessment (LCA) methodology. Five insulation thickness levels (0−12 cm), four total ventilation levels (0.3−1.2 ac/h), three exterior wall alternatives (double brick, concrete, and wood walls), and six insulation materials were studied. Insulation thickness tipping-points were identified for alternative operational patterns and wall envelopes, considering six environmental impact categories. Life-cycle results show that,... [more]

This study aims to design a 16.4 MW photovoltaic solar system located in the Brazilian Northeast and quantify the associated greenhouse gas emissions and environmental payback. The energy system was designed to minimize the Levelized Cost of Energy. The greenhouse gas emissions were quantified with the Life Cycle Assessment methodology, expressing the environmental impact in terms of generated energy (kg CO2-eq/kWh) and following ISO 14040 and 14044. The environmental payback considered the Brazilian electricity mix and degradation of the panels. The results indicated a system capable of producing 521,443 MWh in 25 years, with an emission factor of 0.044 kg CO2-eq/kWh and environmental payback of five years and eight months. The emission factor is at least ten times lower than thermoelectric natural gas power plants. The solar panels were the main contributors to the greenhouse gas emissions, representing 90.59% of overall emissions. It is concluded that photovoltaic energy systems are... [more]

Energy poverty, defined as a lack of access to reliable electricity and reliance on traditional biomass resources for cooking, affects over a billion people daily. The World Health Organization estimates that household air pollution from inefficient stoves causes more premature deaths than malaria, tuberculosis, and HIV/AIDS. Increasing demand for energy has led to dramatic increases in emissions. The need for reliable electricity and limiting emissions drives research on Resilient Hybrid Energy Systems (RHESs), which provide cleaner energy through combining wind, solar, and biomass energy with traditional fossil energy, increasing production efficiency and reliability and reducing generating costs and emissions. Microgrids have been shown as an efficient means of implementing RHESs, with some focused mainly on reducing the environmental impact of electric power generation. The technical challenges of designing, implementing, and applying microgrids involve conducting a cradle-to-grave... [more]