scholarly journals Should biogenic carbon be analysed separately in the calculation of the GWP indicator?

2021 ◽  
Vol 2042 (1) ◽  
pp. 012168
Author(s):  
Endrit Hoxha ◽  
Alexander Passer

Abstract The life cycle assessment method is widely accepted for calculating the environmental impacts of buildings. However, the approaches used to translate greenhouse gas emissions to a global warming potential score are largely criticised. By following a static approach (known as 0/0) and a time-dependent approach (known as dynamic) in this paper, we assessed the environmental impacts of two buildings with structures made of reinforced concrete and wood, respectively. The relative difference between the results calculated with the 0/0 approach and the time-dependent approach were larger for the building with the wooden structure. A more detailed analysis identified biogenic carbon as the source that was most responsible for this difference in results. For this reason, biogenic carbon should be treated separately and must be calculated with the time-dependent approach. Meanwhile, the impacts from fossil energy sources should be calculated with the 0/0 approach.

Author(s):  
Md.Musharof Hussain Khan ◽  
Ivan Deviatkin ◽  
Jouni Havukainen ◽  
Mika Horttanainen

Abstract Purpose Waste recycling is one of the essential tools for the European Union’s transition towards a circular economy. One of the possibilities for recycling wood and plastic waste is to utilise it to produce composite product. This study analyses the environmental impacts of producing composite pallets made of wood and plastic waste from construction and demolition activities in Finland. It also compares these impacts with conventional wooden and plastic pallets made of virgin materials. Methods Two different life cycle assessment methods were used: attributional life cycle assessment and consequential life cycle assessment. In both of the life cycle assessment studies, 1000 trips were considered as the functional unit. Furthermore, end-of-life allocation formula such as 0:100 with a credit system had been used in this study. This study also used sensitivity analysis and normalisation calculation to determine the best performing pallet. Result and discussion In the attributional cradle-to-grave life cycle assessment, wood-polymer composite pallets had the lowest environmental impact in abiotic depletion potential (fossil), acidification potential, eutrophication potential, global warming potential (including biogenic carbon), global warming potential (including biogenic carbon) with indirect land-use change, and ozone depletion potential. In contrast, wooden pallets showed the lowest impact on global warming potential (excluding biogenic carbon). In the consequential life cycle assessment, wood-polymer composite pallets showed the best environmental impact in all impact categories. In both attributional and consequential life cycle assessments, plastic pallet had the maximum impact. The sensitivity analysis and normalisation calculation showed that wood-polymer composite pallets can be a better choice over plastic and wooden pallet. Conclusions The overall results of the pallets depends on the methodological approach of the LCA. However, it can be concluded that the wood-polymer composite pallet can be a better choice over the plastic pallet and, in most cases, over the wooden pallet. This study will be of use to the pallet industry and relevant stakeholders.


2021 ◽  
Vol 13 (5) ◽  
pp. 2525
Author(s):  
Camila López-Eccher ◽  
Elizabeth Garrido-Ramírez ◽  
Iván Franchi-Arzola ◽  
Edmundo Muñoz

The aim of this study is to assess the environmental impacts of household life cycles in Santiago, Chile, by household income level. The assessment considered scenarios associated with environmental policies. The life cycle assessment was cradle-to-grave, and the functional unit considered all the materials and energy required to meet an inhabitant’s needs for one year (1 inh/year). Using SimaPro 9.1 software, the Recipe Midpoint (H) methodology was used. The impact categories selected were global warming, fine particulate matter formation, terrestrial acidification, freshwater eutrophication, freshwater ecotoxicity, mineral resource scarcity, and fossil resource scarcity. The inventory was carried out through the application of 300 household surveys and secondary information. The main environmental sources of households were determined to be food consumption, transport, and electricity. Food consumption is the main source, responsible for 33% of the environmental impacts on global warming, 69% on terrestrial acidification, and 29% on freshwater eutrophication. The second most crucial environmental hotspot is private transport, whose contribution to environmental impact increases as household income rises, while public transport impact increases in the opposite direction. In this sense, both positive and negative environmental effects can be generated by policies. Therefore, life-cycle environmental impacts, the synergy between policies, and households’ socio-economic characteristics must be considered in public policy planning and consumer decisions.


Energies ◽  
2021 ◽  
Vol 14 (9) ◽  
pp. 2472
Author(s):  
Karel Struhala ◽  
Milan Ostrý

Contemporary research stresses the need to reduce mankind’s environmental impacts and achieve sustainability. One of the keys to this is the construction sector. New buildings have to comply with strict limits regarding resource consumption (energy, water use, etc.). However, they make up only a fraction of the existing building stock. Renovations of existing buildings are therefore essential for the reduction of the environmental impacts in the construction sector. This paper illustrates the situation using a case study of a rural terraced house in a village near Brno, Czech Republic. It compares the life-cycle assessment (LCA) of the original house and its proposed renovation as well as demolition followed by new construction. The LCA covers both the initial embodied environmental impacts (EEIs) and the 60-year operation of the house with several variants of energy sources. The results show that the proposed renovation would reduce overall environmental impacts (OEIs) of the house by up to 90% and the demolition and new construction by up to 93% depending on the selected energy sources. As such, the results confirm the importance of renovations and the installation of environmentally-friendly energy sources for achieving sustainability in the construction sector. They also show the desirability of the replacement of inefficient old buildings by new construction in specific cases.


2018 ◽  
Vol 10 (11) ◽  
pp. 3868 ◽  
Author(s):  
Kailun Feng ◽  
Weizhuo Lu ◽  
Thomas Olofsson ◽  
Shiwei Chen ◽  
Hui Yan ◽  
...  

Construction accounts for a considerable number of environmental impacts, especially in countries with rapid urbanization. A predictive environmental assessment method enables a comparison of alternatives in construction operations to mitigate these environmental impacts. Process-based life cycle assessment (pLCA), which is the most widely applied environmental assessment method, requires lots of detailed process information to evaluate. However, a construction project usually operates in uncertain and dynamic project environments, and capturing such process information represents a critical challenge for pLCA. Discrete event simulation (DES) provides an opportunity to include uncertainty and capture the dynamic environments of construction operations. This study proposes a predictive assessment method that integrates DES and pLCA (DES-pLCA) to evaluate the environmental impact of on-site construction operations and supply chains. The DES feeds pLCA with process information that considers the uncertain and dynamic environments of construction, while pLCA guides the comprehensive procedure of environmental assessment. A DES-pLCA prototype was developed and implemented in a case study of an 18-storey building in Northeast China. The results showed that the biggest impact variations on the global warming potential (GWP), acidification potential (AP), eutrophication (EP), photochemical ozone creation potential (POCP), abiotic depletion potential (ADP), and human toxicity potential (HTP) were 5.1%, 4.1%, 4.1%, 4.7%, 0.3%, and 5.9%, respectively, due to uncertain and dynamic factors. Based on the proposed method, an average impact reduction can be achieved for these six indictors of 2.5%, 21.7%, 8.2%, 4.8%, 32.5%, and 0.9%, respectively. The method also revealed that the material wastage rate of formwork installation was the most crucial managing factor that influences global warming performance. The method can support contractors in the development and management of environmentally friendly construction operations that consider the effects of uncertainty and dynamics.


2020 ◽  
Vol 8 (9) ◽  
pp. 660
Author(s):  
Sang Soo Hwang ◽  
Sung Jin Gil ◽  
Gang Nam Lee ◽  
Ji Won Lee ◽  
Hyun Park ◽  
...  

In this study, the environmental impacts of various alternative ship fuels for a coastal ferry were assessed by the life cycle assessment (LCA) analysis. The comparative study was performed with marine gas oil (MGO), natural gas, and hydrogen with various energy sources for a 12,000 gross tonne (GT) coastal ferry operating in the Republic of Korea (ROK). Considering the energy imports of ROK, i.e., MGO from Saudi Arabia and natural gas from Qatar, these countries were chosen to provide the MGO and the natural gas for the LCA. The hydrogen is considered to be produced by steam methane reforming (SMR) from natural gas with hard coal, nuclear energy, renewable energy, and electricity in the ROK model. The lifecycles of the fuels were analyzed in classifications of Well-to- Tank, Tank-to-Wake, and Well-to-Wake phases. The environmental impacts were provided in terms of global warming potential (GWP), acidification potential (AP), photochemical potential (POCP), eutrophication potential (EP), and particulate matter (PM). The results showed that MGO and natural gas cannot be used for ships to meet the International Maritime Organization’s (IMO) 2050 GHG regulation. Moreover, it was pointed out that the energy sources in SMR are important contributing factors to emission levels. The paper concludes with suggestions for a hydrogen application plan for ships from small, nearshore ships in order to truly achieve a ship with zero emissions based on the results of this study.


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.


2019 ◽  
Vol 25 (3) ◽  
pp. 456-477 ◽  
Author(s):  
Heini Elomaa ◽  
Pia Sinisalo ◽  
Lotta Rintala ◽  
Jari Aromaa ◽  
Mari Lundström

Abstract Purpose Currently, almost all cyanide-free gold leaching processes are still in the development stage. Proactively investigating their environmental impacts prior to commercialization is of utmost importance. In this study, a detailed refractory gold concentrate process simulation with mass and energy balance was built for state-of-the-art technology with (i) pressure oxidation followed by cyanidation and, compared to alternative cyanide-free technology, with (ii) pressure oxidation followed by halogen leaching. Subsequently, the simulated mass balance was used as life cycle inventory data in order to evaluate the environmental impacts of the predominant cyanidation process and a cyanide-free alternative. Methods The environmental indicators for each scenario are based on the mass balance produced with HSC Sim steady-state simulation. The simulated mass balances were evaluated to identify the challenges in used technologies. The HSC Sim software is compatible with the GaBi LCA software, where LCI data from HSC-Sim is directly exported to. The simulation produces a consistent life cycle inventory (LCI). In GaBi LCA software, the environmental indicators of global warming potential (GWP), acidification potential (AP), terrestrial eutrophication potential (EP), and water depletion (Water) are estimated. Results and discussion The life cycle assessment revealed that the GWP for cyanidation was 10.1 t CO2-e/kg Au, whereas the halogen process indicated a slightly higher GWP of 12.6 t CO2-e/kg Au. The difference is partially explained by the fact that the footprint is calculated against produced units of Au; total recovery by the halogen leaching route for gold was only 87.3%, whereas the cyanidation route could extract as much as 98.5% of gold. The addition of a second gold recovery unit to extract gold also from the washing water in the halogen process increased gold recovery up to 98.5%, decreasing the GWP of the halogen process to 11.5 t CO2-e/kg Au. However, both evaluated halogen processing scenarios indicated a slightly higher global warming potential when compared to the dominating cyanidation technology. Conclusions The estimated environmental impacts predict that the development-stage cyanide-free process still has some challenges compared to cyanidation; as in the investigated scenarios, the environmental impacts were generally higher for halogen leaching. Further process improvements, for example in the form of decreased moisture in the feed for halide leaching, and the adaptation of in situ gold recovery practices in chloride leaching may give the cyanide-free processing options a competitive edge.


Buildings ◽  
2020 ◽  
Vol 10 (3) ◽  
pp. 54
Author(s):  
Amir Oladazimi ◽  
Saeed Mansour ◽  
Seyed Abbas Hosseinijou

Given the fact that during the recent years the majority of buildings in Iran have been constructed either on steel or concrete frames, it is essential to investigate the environmental impacts of materials used in such constructions. For this purpose, two multi-story residential buildings in Tehran with a similar function have been considered in this study. One building was constructed with a steel frame and the other was constructed with a concrete frame. Using the life cycle assessment tool, a complete analysis of all the stages of a building’s life cycle from raw material acquisition to demolition and recycling of wastes was carried out. In this research, the environmental impacts included global warming potential in 100 years, acidification, eutrophication potential, human toxicity (cancer and non-cancer effects), resource depletion (water and mineral), climate change, fossil fuel consumption, air acidification and biotoxicity. It could be concluded from the results that the total pollution of the concrete frame in all eleven aforementioned impact factors was almost 219,000 tonnes higher than that of the steel frame. Moreover, based on the results, the concrete frame had poorer performance in all but one impact factor. With respect to global warming potential, the findings indicated there were two types of organic and non-organic gases that had an impact on global warming. Among non-organic emissions, CO2 had the biggest contribution to global warming potential, while among organic emissions, methane was the top contributor. These findings suggest the use of steel frames in the building industry in Iran to prevent further environmental damage; however, in the future, more research studies in this area are needed to completely investigate all aspects of decision on the choice of building frames, including economic and social aspects.


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


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