Life cycle energy consumption by roads and associated interpretative analysis of sustainable policies

2021 ◽  
Vol 141 ◽  
pp. 110823
Author(s):  
Fusong Wang ◽  
Jun Xie ◽  
Shaopeng Wu ◽  
Jiashuo Li ◽  
Diego Maria Barbieri ◽  
...  
2020 ◽  
Vol 13 (1) ◽  
pp. 158
Author(s):  
Sishen Wang ◽  
Hao Wang ◽  
Pengyu Xie ◽  
Xiaodan Chen

Low-carbon transport system is desired for sustainable cities. The study aims to compare carbon footprint of two transportation modes in campus transit, bus and bike-share systems, using life-cycle assessment (LCA). A case study was conducted for the four-campus (College Ave, Cook/Douglass, Busch, Livingston) transit system at Rutgers University (New Brunswick, NJ). The life-cycle of two systems were disaggregated into four stages, namely, raw material acquisition and manufacture, transportation, operation and maintenance, and end-of-life. Three uncertain factors—fossil fuel type, number of bikes provided, and bus ridership—were set as variables for sensitivity analysis. Normalization method was used in two impact categories to analyze and compare environmental impacts. The results show that the majority of CO2 emission and energy consumption comes from the raw material stage (extraction and upstream production) of the bike-share system and the operation stage of the campus bus system. The CO2 emission and energy consumption of the current campus bus system are 46 and 13 times of that of the proposed bike-share system, respectively. Three uncertain factors can influence the results: (1) biodiesel can significantly reduce CO2 emission and energy consumption of the current campus bus system; (2) the increased number of bikes increases CO2 emission of the bike-share system; (3) the increase of bus ridership may result in similar impact between two systems. Finally, an alternative hybrid transit system is proposed that uses campus buses to connect four campuses and creates a bike-share system to satisfy travel demands within each campus. The hybrid system reaches the most environmentally friendly state when 70% passenger-miles provided by campus bus and 30% by bike-share system. Further research is needed to consider the uncertainty of biking behavior and travel choice in LCA. Applicable recommendations include increasing ridership of campus buses and building a bike-share in campus to support the current campus bus system. Other strategies such as increasing parking fees and improving biking environment can also be implemented to reduce automobile usage and encourage biking behavior.


Energies ◽  
2021 ◽  
Vol 14 (11) ◽  
pp. 3287
Author(s):  
Alireza Tabrizikahou ◽  
Piotr Nowotarski

For decades, among other industries, the construction sector has accounted for high energy consumption and emissions. As the energy crisis and climate change have become a growing concern, mitigating energy usage is a significant issue. The operational and end of life phases are all included in the building life cycle stages. Although the operation stage accounts for more energy consumption with higher carbon emissions, the embodied stage occurs in a time-intensive manner. In this paper, an attempt has been made to review the existing methods, aiming to lower the consumption of energy and carbon emission in the construction buildings through optimizing the construction processes, especially with the lean construction approach. First, the energy consumption and emissions for primary construction materials and processes are introduced. It is followed by a review of the structural optimization and lean techniques that seek to improve the construction processes. Then, the influence of these methods on the reduction of energy consumption is discussed. Based on these methods, a general algorithm is proposed with the purpose of improving the construction processes’ performance. It includes structural optimization and lean and life cycle assessments, which are expected to influence the possible reduction of energy consumption and carbon emissions during the execution of construction works.


Robotics ◽  
2021 ◽  
Vol 10 (1) ◽  
pp. 33
Author(s):  
Florian Stuhlenmiller ◽  
Steffi Weyand ◽  
Jens Jungblut ◽  
Liselotte Schebek ◽  
Debora Clever ◽  
...  

Modern industry benefits from the automation capabilities and flexibility of robots. Consequently, the performance depends on the individual task, robot and trajectory, while application periods of several years lead to a significant impact of the use phase on the resource efficiency. In this work, simulation models predicting a robot’s energy consumption are extended by an estimation of the reliability, enabling the consideration of maintenance to enhance the assessment of the application’s life cycle costs. Furthermore, a life cycle assessment yields the greenhouse gas emissions for the individual application. Potential benefits of the combination of motion simulation and cost analysis are highlighted by the application to an exemplary system. For the selected application, the consumed energy has a distinct impact on greenhouse gas emissions, while acquisition costs govern life cycle costs. Low cycle times result in reduced costs per workpiece, however, for short cycle times and higher payloads, the probability of required spare parts distinctly increases for two critical robotic joints. Hence, the analysis of energy consumption and reliability, in combination with maintenance, life cycle costing and life cycle assessment, can provide additional information to improve the resource efficiency.


2018 ◽  
Author(s):  
Sierra Spencer ◽  
Malia Scott ◽  
Nelson Macken

Biofuels have received considerable attention as a more sustainable solution for heating applications. Used vegetable oil, normally considered a waste product, has been suggested as a possible candidate. Herein we perform a life cycle assessment to determine the environmental impact of using waste vegetable oil as a fuel. We present a cradle to fuel model that includes the following unit processes: soybean farming, soy oil refining, the cooking process, cleaning/drying waste oil, preheating the oil in a centralized heating facility and transportation when required. For soybean farming, national historical data for yields, energy required for machinery, fertilizers (nitrogen, phosphorous and potassium), herbicides, pesticides and nitrous oxide production are considered. In soy oil refining, steam production using natural gas and electricity for machinery are considered inputs. Preprocessing, extraction using hexane and post processing are considered. In order to determine a mass balance for the cooking operation, oil carryout and waste oil removal are estimated. During waste oil processing, oil is filtered and water removed. Data from GREET is used to compute global warming potential (GWP) and energy consumption in terms of cumulative energy demand (CED). Mass allocation is applied to the soy meal produced in refining and oil utilized for cooking. Results are discussed with emphasis on improving sustainability. A comparison is made to traditional fuels, e.g., commercial fuel oil and natural gas. The production of WVO as fuel has significantly less global warming potential but higher cumulative energy consumption than traditional fuels. The study should provide useful information on the sustainability of using waste cooking oil as a fuel for heating.


2018 ◽  
Vol 913 ◽  
pp. 1018-1026
Author(s):  
Yan Qiong Sun ◽  
Yu Liu ◽  
Su Ping Cui

In this paper, a variety of blocks were grouped into the autoclaved blocks and fired blocks as far as the productive technology is concerned. In order to compare the life cycle impacts of the two kinds of the blocks, a life cycle assessment of two products on the functional unit 1m3 was carried out through the exploitation of mineral stage, transportation stage and the production of the blocks stage on the considering of the resource and energy consumption and the pollutant discharges. The results demonstrated that the fired blocks appeared to have less impact than autoclaved concrete blocks on human health, marine ecotoxicity toxicity and terrestrial ecotoxicity toxicity nearly 30%. The raw coal led to the serious impacts on the fossil depletion through the cement production stage of the autoclaved concrete blocks accounting for 45.86% and the gangue exploitation stage of the fired blocks accounting for 42.5%. Assessment of the data quality that the data was of pretty high or within the permission. The sensitivity analysis and contribution analysis assessment showed that the conclusion were robust.


2021 ◽  
Vol 13 (9) ◽  
pp. 4886
Author(s):  
Katia Perini ◽  
Fabio Magrassi ◽  
Andrea Giachetta ◽  
Luca Moreschi ◽  
Michela Gallo ◽  
...  

Urban greening provides a wide range of ecosystem services to address the main challenges of urban areas, e.g., carbon sequestration, evapotranspiration and shade, thermal insulation, and pollution control. This study evaluates the environmental sustainability of a vertical greening system (VGS) built in 2014 in Italy, for which extensive monitoring activities were implemented. The life-cycle assessment methodology was applied to quantify the water–energy–climate nexus of the VGS for 1 m2 of the building’s wall surface. Six different scenarios were modelled according to three different end-of-life scenarios and two different useful lifetime scenarios (10 and 25 years). The environmental impact of global-warming potential and generated energy consumption during the use phase in the VGS scenarios were reduced by 56% in relation to the baseline scenario (wall without VGS), and showed improved environmental performance throughout the complete life cycle. However, the water-scarcity index (WSI) of the VGS scenarios increased by 42%. This study confirms that the installation of VGSs offers a relevant environmental benefit in terms of greenhouse-gas emissions and energy consumption; however, increased water consumption in the use phase may limit the large-scale application of VGSs.


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