Life Cycle Assessment of Thermoelectric Generators (TEGs) in an Automobile Application

2021 ◽  
Vol 13 (24) ◽  
pp. 13630
Author(s):  
Kotaro Kawajiri ◽  
Yusuke Kishita ◽  
Yoshikazu Shinohara

In this paper, a possibility to reduce the environmental burdens by employing thermoelectric generators (TEGs) was analyzed with a cradle-to-grave LCA approach. An upscaling technique was newly introduced to assess the environmental impacts of TEGs over its life cycle. In addition to CO2 emissions, other environmental impacts as well as social impacts were assessed using the Life Cycle Impact Assessment Method based on Endpoint Modeling (LIME2). The analysis was conducted under two scenarios, a baseline scenario with a 7.2% conversion efficiency and a technology innovation scenario with that of 17.7% at different production scales. The results showed that while GHG emissions were positive over the life cycle under the baseline scenario, it became negative (−1.56 × 102 kg-CO2 eq/kg) under the technology innovation scenario due to GHG credits in the use phase. An increase in the conversion efficiency of the TEG and a decrease in the amount of stainless steel used in TEG construction are both necessary in order to reduce the environmental impacts associated with TEG manufacture and use. In addition, to accurately assess the benefit of TEG deployment, the lifetime driving distance needs to be analyzed together with the conversion efficiency.

2008 ◽  
Vol 48 (2) ◽  
pp. 89 ◽  
Author(s):  
T. Hishinuma ◽  
H. Kurishima ◽  
C. Yang ◽  
Y. Genchi

The aim of this study was to use life cycle assessment methods to determine the environmental impacts of manure utilisation by a biogas plant and by a typical manure composting system. The functional unit was defined as the average annual manure utilisation on a dairy farm with 100 cows. The environmental impact categories chosen were emissions of greenhouse gases (GHG) and acidification gases (AG). The GHG emissions were estimated as: 345.9 t CO2-equivalents (e) for solid composting (case 1), 625.4 t CO2-e for solid and liquid composting (case 2), and 86.3–90.1 t CO2-e for the biogas plant system. The AG emissions were estimated as: 10.1 t SO2-e for case 1, 18.4 t SO2-e for case 2, and 13.1–24.2 t SO2-e for the biogas plant system. These results show that a biogas plant system produces low GHG emissions, but comparatively high AG emissions with land application. It is suggested that land application using band spread or shallow injection attachments will decrease AG emissions (NH3) from biogas plant systems.


Buildings ◽  
2018 ◽  
Vol 8 (8) ◽  
pp. 105 ◽  
Author(s):  
Nadia MIRABELLA ◽  
Martin RÖCK ◽  
Marcella Ruschi Mendes SAADE ◽  
Carolin SPIRINCKX ◽  
Marc BOSMANS ◽  
...  

Globally, the building sector is responsible for more than 40% of energy use and it contributes approximately 30% of the global Greenhouse Gas (GHG) emissions. This high contribution stimulates research and policies to reduce the operational energy use and related GHG emissions of buildings. However, the environmental impacts of buildings can extend wide beyond the operational phase, and the portion of impacts related to the embodied energy of the building becomes relatively more important in low energy buildings. Therefore, the goal of the research is gaining insights into the environmental impacts of various building strategies for energy efficiency requirements compared to the life cycle environmental impacts of the whole building. The goal is to detect and investigate existing trade-offs in current approaches and solutions proposed by the research community. A literature review is driven by six fundamental and specific research questions (RQs), and performed based on two main tasks: (i) selection of literature studies, and (ii) critical analysis of the selected studies in line with the RQs. A final sample of 59 papers and 178 case studies has been collected, and key criteria are systematically analysed in a matrix. The study reveals that the high heterogeneity of the case studies makes it difficult to compare these in a straightforward way, but it allows to provide an overview of current methodological challenges and research gaps. Furthermore, the most complete studies provide valuable insights in the environmental benefits of the identified energy performance strategies over the building life cycle, but also shows the risk of burden shifting if only operational energy use is focused on, or when a limited number of environmental impact categories are assessed.


2009 ◽  
Vol 2009 ◽  
pp. 126-126
Author(s):  
R Olea ◽  
J H Guy ◽  
H Edge ◽  
S A Edwards

Formulating the inventory of relevant commodities to assess the life cycle of goods or services (LCI) is highly demanding on time and resources (Suh et al., 2004). Collected information is not always satisfactory to take account of all possible sources of environmental burdens (E-burdens) produced in the commodity supply chain. Several pre-assessment methods have been proposed to serve this function, although these have identified limitations; lack of previous experience and use of subjective cut off criteria are the most frequent weaknesses found (Suh, 2006). An objective pre-assessment method was developed as part of a life cycle analysis (LCA) for different pigmeat supply chain (PSC) scenarios.


2020 ◽  
Vol 32 (5) ◽  
pp. 2977-2995 ◽  
Author(s):  
S. Schade ◽  
T. Meier

Abstract Specific microalgae species are an adequate source of EPA and DHA and are able to provide a complete protein, which makes them highly interesting for human nutrition. However, microalgae cultivation has also been described to be energy intensive and environmentally unfavorable in pilot-scale reactors. Moreover, production in cold temperature zones has not been sufficiently investigated. In particular, the effects of tube materials and cultivation season length have rarely been previously investigated in the context of a comparative LCA of microalgae cultivation. A computational “top-down” model was conducted to calculate input flows for Nannochloropsis sp. and Phaeodactylum tricornutum cultivation in a hypothetical tubular photobioreactor. Cultivation processes were calculated according to detailed satellite climatic data for the chosen location in Central Germany. This model was applied to a set of different scenarios, including variations in photobioreactor material, tube diameter, microalgae species, and cultivation season length. Based on these data, a life cycle assessment (LCA) was performed following ISO standard 14040/44. The impact assessment comprised the global warming potential, acidification, eutrophication, cumulative energy demand, and water scarcity. The results showed that a long cultivation season in spring and fall was always preferable in terms of environmental impacts, although productivity decreased significantly due to the climatic preconditions. Acrylic glass as a tube material had higher environmental impacts than all other scenarios. The cultivation of an alternative microalgae species showed only marginal differences in the environmental impacts compared with the baseline scenario. Critical processes in all scenarios included the usage of hydrogen peroxide for the cleaning of the tubes, nitrogen fertilizer, and electricity for mixing, centrifugation, and drying. Microalgae cultivation in a tubular photobioreactor in a “cold-weather” climate for food is sustainable and could possibly be a complement to nutrients from other food groups. The added value of this study lies in the detailed description of a complex and flexible microalgae cultivation model. The new model introduced in this study can be applied to numerous other scenarios to evaluate photoautotrophic microalgae cultivation in tubular photobioreactors. Thus, it is possible to vary the facility location, seasons, scale, tube dimensions and material, microalgae species, nutrient inputs, and flow velocity. Moreover, single processes can easily be complemented or exchanged to further adjust the model individually, if, for instance, another downstream pathway is required.


2018 ◽  
Vol 77 (9) ◽  
pp. 2292-2300 ◽  
Author(s):  
Karina Cubas do Amaral ◽  
Miguel Mansur Aisse ◽  
Gustavo Rafael Collere Possetti ◽  
Marcelo Real Prado

Abstract Upflow anaerobic sludge blanket (UASB) reactors used in sewage treatment generate two by-products that can be reused: sludge and biogas. At the present time in Brazil, most of this resulting sludge is disposed of in sanitary landfills, while biogas is commonly burned off in low-efficiency flares. The aim of the present study was to use life cycle assessment to evaluate the environmental impacts from four different treatment and final destination scenarios for the main by-products of wastewater treatment plants. The baseline scenario, in which the sludge was sanitized using prolonged alkaline stabilization and, subsequently, directed toward agricultural applications and the biogas destroyed in open burners, had the most impact in the categories of global warming, terrestrial ecotoxicity, and human non-carcinogenic toxicity. The scenario in which heat resulting from biogas combustion is used to dry the sludge showed significant improvements over the baseline scenario in all the evaluated impact categories. The recovery of heat from biogas combustion decreased significantly the environmental impact associated with global warming. The combustion of dried sludge is another alternative to improve the sludge management. Despite the reduction of sludge volume to ash, there are environmental impacts inherent to ozone formation and terrestrial acidification.


Author(s):  
Ben Morelli ◽  
Sarah Cashman ◽  
Xin (Cissy) Ma ◽  
Jason Turgeon ◽  
Sam Arden ◽  
...  

Abstract The wastewater industry is undergoing a paradigm shift from focusing solely on treatment to incorporating concepts aimed at mitigating environmental impacts such as energy and nutrient recovery and water reuse. This study uses life cycle assessment and life cycle cost analysis to investigate the effect of expanding anaerobic digestion (AD) capacity and adding combined heat and power on environmental and cost indicators at a mid-sized wastewater treatment facility (WWTF) in Massachusetts, USA. Since 2014, Massachusetts has banned the disposal of organic waste from commercial organizations producing more than one ton of material per week. The WWTF's additional digester capacity allows the co-digestion of municipal solids with a food-based engineered bioslurry due to this ban. Study data were compiled for several AD feedstock quantity and performance scenarios, and compared to a baseline scenario representative of historic plant operations prior to co-digestion. Reductions in environmental impact are demonstrated for six of eight environmental impacts, including global climate change potential and cumulative energy demand. Eutrophication potential increases by 10 percent and 24 percent across assessed scenarios. Water use remains relatively constant across scenarios. Facility energy production increases dramatically with co-digestion, satisfying 100 percent of the WWTF's thermal energy requirement and producing surplus electricity assuming full AD capacity utilization.


2021 ◽  
Author(s):  
Kristína Kováčiková ◽  
◽  
Antonín Kazda

The paper is focused on the assessment of the environmental impacts of transport infrastructure and individual types of transport using the life cycle assessment method. The paper contains a description of the basic terminology of the problem related to transport, the environment and methods of environmental impact assessment. The paper contains analysis on monitoring carbon dioxide emissions from a global perspective as well as from a regional perspective focused on Slovakia. The aim of the paper is to create a proposal for the assessment of environmental impacts of transport infrastructure, in the form of specification of areas of assessment for selected types of transport with a focus on carbon dioxide emissions. Using the knowledge and principles of the life cycle method, a proposal for relevant indicators and a proposal for a comprehensive assessment of the impacts of selected types of transport, focused on carbon dioxide emissions, is created in the paper


2021 ◽  
Vol 13 (21) ◽  
pp. 11682
Author(s):  
Martin Nwodo ◽  
Chimay Anumba

The relevance of exergy to the life cycle assessment (LCA) of buildings has been studied regarding its potential to solve certain challenges in LCA, such as the characterization and valuation, accuracy of resource use, and interpretation and comparison of results. However, this potential has not been properly investigated using case studies. This study develops an exergy-based LCA method and applies it to three case-study buildings to explore its benefits. The results provide evidence that the theoretical benefits of exergy-based LCA as against a conventional LCA can be achieved. These include characterization and valuation benefits, accuracy, and enabling the comparison of environmental impacts. With the results of the exergy-based LCA method in standard metrics, there is now a mechanism for the competitive benchmarking of building sustainability assessments. It is concluded that the exergy-based life cycle assessment method has the potential to solve the characterization and valuation problems in the conventional life-cycle assessment of buildings, with local and global significance.


Energies ◽  
2019 ◽  
Vol 12 (2) ◽  
pp. 299 ◽  
Author(s):  
Helena Nydahl ◽  
Staffan Andersson ◽  
Anders Åstrand ◽  
Thomas Olofsson

Energy efficiency investments in existing buildings are an effective way of reducing the environmental impact of the building stock. Even though policies in the European Union and elsewhere promote a unilateral focus on operational energy reduction, scientific studies highlight the importance of applying a life cycle perspective to energy refurbishment. However, life cycle assessment is often perceived as being complicated and the results difficult to interpret by the construction sector. There is also a lack of guidelines regarding the sustainable ratio between the embodied and accumulated operational impact. The scope of this study is to introduce a life cycle assessment method for building refurbishment that utilizes familiar economic performance tools, namely return on investment and annual yield. The aim is to use the introduced method to analyze a case building with a sustainability profile. The building was refurbished in order to reduce its operational energy use. The introduced method is compatible with a theory of minimum sustainable environmental performance that may be developed through backcasting from defined energy and GHG emissions objectives. The proposed approach will hopefully allow development of sustainable refurbishment objectives that can support the choice of refurbishment investments.


2018 ◽  
Vol 10 (12) ◽  
pp. 4547 ◽  
Author(s):  
Lei Yang ◽  
Caixia Hao ◽  
Yina Chai

The development of electric delivery trucks has attracted much attention in recent years. The purpose of this study is to assess the greenhouse gas (GHG) emissions and the total cost of ownership (TCO) of light-duty and medium-duty diesel trucks (DTs), plug-in electric trucks (ETs), and battery-swap ETs. A simplified life cycle assessment (LCA) method and a TCO assessment method are used. Numerical results show that the average GHG emission of light-duty ETs is 69% lower than that of light-duty DTs, while that of medium-duty ETs is 9.8% higher than that of medium-duty DTs. As regards TCO, those of plug-in ETs and battery-swap ETs are 37.8% lower and 21% higher than that of light-duty DTs, while for medium-duty trucks, the TCO of plug-in and battery-swap ETs are 6.7% lower and 18.9% higher than that of medium-duty DTs. The main conclusion of this paper is that light-duty plug-in ETs exhibit the best performance in terms of cost saving and GHG emission reduction. Moreover, ETs show more advantages than DTs when the frequency of use is higher or when the driving environment is more congested.


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