cumulative energy demand
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2024 ◽  
Vol 84 ◽  
Author(s):  
F. Ali ◽  
F. Rehman ◽  
R. Hadi ◽  
G. Raza ◽  
N. Khan ◽  
...  

Abstract Life cycle assessment was carried out for a conventional wooden furniture set produced in Mardan division of the Khyber Pakhtunkhwa province of Pakistan during 2018-19. Primary data regarding inputs and outputs were collected through questionnaire surveys from 100 conventional wooden furniture set manufacturers, 50 in district Mardan and 50 in district Swabi. In the present study, cradle-to-gate life cycle assessment approach was applied for a functional unit of one conventional wooden furniture set. Production weighted average data were modelled in the environmental impacts modelling software i.e., SimaPro v.8.5. The results showed that textile used in sofa set, wood preservative for polishing and preventing insects attack and petrol used in generator had the highest contribution to all the environmental impact categories evaluated. Total cumulative energy demand for wooden furniture set manufactured was 30,005 MJ with most of the energy acquired from non-renewable fossil fuel resources.


Author(s):  
Nam-Chol O ◽  
Tong-Hyok Choe ◽  
Jong-Hun Kim ◽  
Chol-Mu Choe

A life cycle assessment of waste management in Pyongyang, Korea was undertaken using a characterisation-based method to analyse cumulative energy demand and energy-related carbon dioxide emissions. The study showed that characterising waste fractions by composition, proportion, water content and heating value rather than simply mass was more effective for energy-related analysis in life-cycle assessments. The results indicated that the energy demand and emissions indicators could be used as appropriate proxies of the environmental impacts in life-cycle phases, since they were closely related. The results also revealed that waste incineration could result in energy credit to the national electricity mix, while waste landfill needed to be replaced with sanitary landfill and/or switched to incineration with energy recovery to be more sustainable.


2021 ◽  
Vol 13 (24) ◽  
pp. 13878
Author(s):  
Hannah Porter ◽  
Abhijit Mukherjee ◽  
Rabin Tuladhar ◽  
Navdeep Kaur Dhami

Microbially Induced Calcium Carbonate Precipitation (MICP) is a natural biocementation that takes place in corals, stromatolites and beach rocks. In recent years, researchers have explored the emulation of this process as a sustainable alternative of engineered cement. Although the natural process is undoubtedly sustainable, its engineered variant deviates substantially from the natural process. In this paper, we investigate the environmental and economic performance of the engineered biocementation process vis-à-vis present manufacturing of calcium carbonate. SimaPro 8.0 software and the Ecoinvent V2.2 database were used for materials inputs and AUSLCI along with Cumulative Energy Demand 2.01 software were used for carbon footprint and eutrophication potential. Our results show that different metabolic pathways of MICP have considerably varying environmental impact. We observe that nature performs MICP sustainably at ambient conditions and geological time scales utilizing naturally occurring sources of carbon and calcium at micromoles concentrations. Due to the mandate on duration of construction projects, highly purified reactants in a high concentration are used in the engineered process. This has a negative environmental impact. We conclude that the sustainability of engineered MICP is directly impacted by the metabolic pathway of bacteria as well as the purity of the input chemicals. A few biotic processes are superior to the present industrial process for manufacturing calcium carbonate if ingredients of laboratory grade purity are replaced by industrial grade products. A bigger dividend can be obtained by introducing industry by-products as nutrients. The results of this study help to direct future research for developing sustainable biocement for the construction industry.


2021 ◽  
Vol 13 (22) ◽  
pp. 12487
Author(s):  
Mayara S. Siverio Lima ◽  
Mohsen Hajibabaei ◽  
Sina Hesarkazzazi ◽  
Robert Sitzenfrei ◽  
Alexander Buttgereit ◽  
...  

This study used a cradle-to-cradle Life Cycle Assessment (LCA) approach to evaluate the environmental potentials of urban pavements. For this purpose, the urban road network of the City of Münster (Germany) was selected as the case study, and comprehensive data for several phases were collected. The entire road network is composed of flexible pavements designed according to specific traffic loads and consists of main roads (MRs), main access roads (MARs), and residential roads (RSDTs). Asphalt materials, pavement structures, and maintenance strategies are predefined for each type of road and are referred to as “traditional” herein. Some pavement structures have two possible maintenance strategies, denoted by “A” and “B”, with distinguished periods of intervention. To evaluate the impact of using recycled materials, we considered alternative pavement structures composed of asphalt materials containing a greater amount of reclaimed asphalt pavement (RAP). The study was carried out considering analysis periods of 20, 50, 80, and 100 years and using two indicators: non-renewable cumulative energy demand (nr-CED) and global warming potential (GWP). The results show that the use of higher amounts of RAP can mitigate negative environmental impacts and that certain structures and maintenance strategies potentially enhance the environmental performance of road pavements. This article suggests initiatives that will facilitate the decision-making process of city administrators to achieve more sustainable road pavement constructions and provides an essential dataset inventory to support future environmental assessment studies, particularly for European cities.


Author(s):  
Alberto Tama Franco

Wind technology is considered to be among the most promising types of renewable energy sources, and due to high oil prices and growing concerns about climate change and energy security, it has been the subject of extensive considerations in recent years, including questions related to the relative sustainability of electricity production when the manufacturing, assembly, transportation and dismantling processes of these facilities are taken into account. The present article evaluates the environmental impacts, carbon emissions and water consumption, derived from the production of electric energy of the Villonaco wind farm, located in Loja-Ecuador, during its entire life cycle, using the Life Cycle Analysis method. Finally, it is concluded that wind energy has greater environmental advantages, since it has lower values of carbon and water footprints than other energy sources. Additionally, with the techniques Cumulative Energy Demand and Energy Return on Investment, sustainability in the production of electricity from wind power in Ecuador is demonstrated; and, that due to issues of vulnerability to climate change, the diversification of its energy mix is essential considering the inclusion of non-conventional renewable sources such as solar or wind, this being the only way to reduce both the carbon footprint and the water supply power.


Author(s):  
Eleonora Atzeni ◽  
Angioletta R. Catalano ◽  
Paolo C. Priarone ◽  
Alessandro Salmi

AbstractAdditive manufacturing (AM) processes allow complex geometries to be produced with enhanced functionality, but technological challenges still have to be dealt with, in terms of surface finish and achieved tolerances. Among the consolidated powder-bed fusion processes, electron beam melting (EBM), which allows almost stress-free parts to be manufactured with a high productivity and minimum use of support structures, suffers from a poor surface quality. Thus, finishing processes have to be performed. The same geometrical complexity, which is considered one of the benefits of AM, becomes an issue when finishing is applied, in particular when internal features are present. Unconventional isotropic superfinishing processes could be a solution to this problem since they can generate a low surface roughness on complex geometries. However, the performance characteristics, with regard to the environmental sustainability and economic aspects, need to be evaluated since they are key factors that must be considered for decision-support tools when selecting a finishing process. The technological feasibility of the isotropic superfinishing (ISF) process, applied to Ti-6Al-4V parts produced by electron beam melting, is investigated in this paper by considering the dimensional and geometrical deviations induced by the finishing treatment, and from observations of the surface morphology. A significant reduction in surface roughness, Sa, to around 4 μm, has been observed on the most irregular surfaces, although the original shape is maintained. Environmental sustainability has been analyzed for all the manufacturing steps, from powder production to part fabrication, to the finishing process, and both the cumulative energy demand and material waste have been accounted for. The economic impact of the whole manufacturing chain has been evaluated, and the advantages of the ISF process are pointed out.


2021 ◽  
Vol 12 (1) ◽  
Author(s):  
P. Takunda Chazovachii ◽  
Madeline J. Somers ◽  
Michael T. Robo ◽  
Dimitris I. Collias ◽  
Martin I. James ◽  
...  

AbstractAn estimated 6.3 billion metric tons of post-consumer polymer waste has been produced, with the majority (79%) in landfills or the environment. Recycling methods that utilize these waste polymers could attenuate their environmental impact. For many polymers, recycling via mechanical processes is not feasible and these materials are destined for landfills or incineration. One salient example is the superabsorbent material used in diapers and feminine hygiene products, which contain crosslinked sodium polyacrylates. Here we report an open-loop recycling method for these materials that involves (i) decrosslinking via hydrolysis, (ii) an optional chain-shortening via sonication, and (iii) functionalizing via Fischer esterification. The resulting materials exhibit low-to-medium storage and loss moduli, and as such, are applicable as general-purpose adhesives. A life cycle assessment demonstrates that the adhesives synthesized via this approach outcompete the same materials derived from petroleum feedstocks on nearly every metric, including carbon dioxide emissions and cumulative energy demand.


Energies ◽  
2021 ◽  
Vol 14 (15) ◽  
pp. 4453
Author(s):  
Rosa Anna Nastro ◽  
Enrica Leccisi ◽  
Maria Toscanesi ◽  
Gengyuan Liu ◽  
Marco Trifuoggi ◽  
...  

Seawater represents a potential resource to ensure sustainable availability of water for population and irrigation purposes, especially in some areas of the world. Desalination processes allow the production of fresh water, but they generate also brine as waste product. Sustainable brine management should be identified to ensure proper disposal and potentially resource recovery. This experimental study showed that emerging technologies such as Microbial Desalination Cells (MDCs) may provide a valuable contribution to the sustainability of the seawater desalination sector. In this paper, we report results on lab-scale desalination brine treatments applying MDCs, which allow energy savings, resource recovery, environmental impact minimization, and reduction of the organic load in municipal wastewater. Our results showed that MDCs’ treatment allows the removal of approximately 33 g of salts (62% of the total)—including chlorides, bromides, and sulphates—from 20 mL of brine within 96 h. The MDCs, according to the source of energy and the presence of mature biofilm at the anode, spent 7.2 J, 7.9 J, and 9.6 J in the desalination process, with the higher amount of energy required by the abiotic system and the lesser by the MDCs fed with just wastewater. Our approach also showed environmental and energy reductions because of potential metal recovery instead of returning them into marine environment. We quantified the avoided life cycle of human and marine eco-toxicity impacts as well as the reduction of cumulative energy demand of recovered metals. The main benefit in terms of avoided toxicity would arise from the mercury and copper recovery, while potential economic advantages would derive from the recovered cobalt that represents a strategic resource for many products such as battery storage systems.


2021 ◽  
Vol 13 (12) ◽  
pp. 6894
Author(s):  
Shakira R. Hobbs ◽  
Tyler M. Harris ◽  
William J. Barr ◽  
Amy E. Landis

The environmental impacts of five waste management scenarios for polylactic acid (PLA)-based bioplastics and food waste were quantified using life cycle assessment. Laboratory experiments have demonstrated the potential for a pretreatment process to accelerate the degradation of bioplastics and were modeled in two of the five scenarios assessed. The five scenarios analyzed in this study were: (1a) Anaerobic digestion (1b) Anaerobic digestion with pretreatment; (2a) Compost; (2a) Compost with pretreatment; (3) Landfill. Results suggested that food waste and pretreated bioplastics disposed of with an anaerobic digester offers life cycle and environmental net total benefits (environmental advantages/offsets) in several areas: ecotoxicity (−81.38 CTUe), eutrophication (0 kg N eq), cumulative energy demand (−1.79 MJ), global warming potential (0.19 kg CO2), and human health non-carcinogenic (−2.52 CTuh). Normalized results across all impact categories show that anaerobically digesting food waste and bioplastics offer the most offsets for ecotoxicity, eutrophication, cumulative energy demand and non-carcinogenic. Implications from this study can lead to nutrient and energy recovery from an anaerobic digester that can diversify the types of fertilizers and decrease landfill waste while decreasing dependency on non-renewable technologies. Thus, using anaerobic digestion to manage bioplastics and food waste should be further explored as a viable and sustainable solution for waste management.


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