Life Cycle Analysis Method Research Articles

Analysis of Carbon Emission during Hot In-Place Recycling Asphalt Pavement Construction

To analyze carbon emission during hot in-place recycling asphalt pavement construction, the construction period is divided into material production and pavement construction using the life cycle analysis method. Then, a carbon emission model is established according to the multiplication principle of the carbon emission coefficient and activity data. On the basis of an engineering example, carbon emission during pavement construction is calculated; carbon emission with different new material ratios, recycled material haul distances, and utilization rates of recycling asphalt mixture is quantified; and the carbon emissions of four pavement maintenance technologies are compared. Results show the following conditions. (1) The carbon emissions of material production and pavement construction account for 20% and 80%, respectively. (2) Carbon emission increases by 2% with an increase of 1% in hot in-place recycling new material ratio. (3) The haul distance of recycled asphalt mixture is 42 km when hot mix plant recycling with 100% utilization rate of recycled asphalt mixture produces equal carbon emission with hot in-place recycling. When the haul distance is over 42 km, the carbon emission of hot in-place recycling is less than that hot mix plant recycling. When the utilization rate of recycling asphalt mixture is lower than 75%, the carbon emission of hot in-place recycling is always less than that of hot mix plant recycling regardless of haul distance. (4) Compared with that in hot in-place recycling, the increase in amplitude of carbon emission on micro-surface, ultra-thin overlay, and mill-and-resurface asphalt pavement is 53%, 72%, and 79%, respectively.

Life Cycle Analysis of Distributed Energy System Projects’ Energy Consumption and GHG Emission – A Case of Beer Brewery Auxiliary Power Supply in China

In this paper, we used Life Cycle Analysis (LCA) method to evaluate the energy consumption and GHG emission of Distributed Energy System projects. We studied the China Resources Snow Breweries Natural Gas Distributed Energy System project, and designed another 5 cases with different energy pathways to compare their energy consumption and emission performance. The result shows the All Natural Gas project saves 8% energy and reduces 38% GHG emission compared with tradition project using coal and grid electricity. Although renewable energy projects’ emission reduction effect is not as significant as that of All Natural Gas project, we found renewable energy projects have the potential to develop in the future. We concluded that policy makers should support the development of gas based distributed energy system projects and further research should be made to shed light on corporate's decision making.

Carbon Footprint of Copying Paper: Considering Temporary Carbon Storage Based on Life Cycle Analysis

In the era of climate change, life cycle analysis (LCA) has been acknowledged as a useful method for examining carbon footprints of products or services., Once captured and stored by trees and other plants, biogenic CO2 would re-enter the atmosphere sooner or later after the use phase of the product. And many LCA studies did not calculate the temporary carbon storage in biogenic carbon. Thus, this paper proposed a hybrid LCA approach to provide a structured methodology for evaluating carbon footprint of copying paper in consideration of temporary carbon storage. The developed method was then applied to a paper mill of China. It is indicated that the hybrid LCA method could provide a comprehensive methodology for accounting carbon footprints as well as assessing effects of delaying GHG emissions. The results shows that the carbon footprint of 1000kg copying paper was 647.89kg CO2 under scenario 1 and -5094kg CO2 under scenario 2. Concurrently, the effect of delaying the emission of the temporarily stored carbon in copying paper was 7.67%, 15.52%, or 23.58% for a certain period of time (i.e., 10, 25, or 30 years).

大修工程厂拌冷再生基层能耗与排放量化分析

针对高速公路沥青路面大修工程中的旧路面铣刨、原材料生产以及冷再生混合料施工三个阶段，采用全寿命周期法，建立路面冷再生基层能源消耗与排放的量化分析模型，在现场数据调查基础上，量化分析冷再生基层的能耗与排放。结果表明，生产1 t再生集料的能耗与排放相比于生产1 t石灰岩集料减少34.0%和40.9%。1 t冷再生混合料(原材料生产期、施工期)的能耗与排放为7.246 kgce、20.17 kg，冷再生混合料施工期能耗、排放占比较低，分别是生产期和施工期总和的13.6%、12.6%。每铺筑1 t冷再生基层总能耗与排放比大粒径沥青碎石基层分别下降42.5%、41.6%，可减少能耗与排放5.36 kgce、14.34 kg，冷再生基层的能耗降低最主要在于拌和环节，减少能耗4.06 kgce。 In view of the milling of old pavement, the producing of raw materials and the constructing of recycling pavement, the quantitative analysis model for energy consumption and emissions of cold recycling roadbase was established with life cycle analysis method, analyzing energy consumption and emissions of plant-mixed cold recycled roadbase base on the field survey data. The results show that compared with producing 1 t limestone aggregate, the energy consumption and emissions of producing 1 t recycled aggregated are declined by 34.0% and 40.9%. The energy consumption of construction stage of plant-mixed cold recycling roadbase is only 13.6% of the total which are 7.246 kgce and the emissions is only 12.6% of the total which is 20.170 kg. The total energy consumption and emissions of paving 1 t roadbase by plant-mixed cold recycled mixture are declined by 42.5% and 41.6% compared with large stone asphalt mixture roadbase, it can reduce the energy consumption and emissions 5.36 kgce and 14.34 kg, reducing the energy consumption 4.06 kgce which is mainly lies in the mixing process.

Feasibility Studies of Energy Retrofits – Case Studies of Nearly Zero-energy Building Renovation

This paper analyses the feasibility of Nearly Zero-Energy Building Renovation from the technical, environmental, economic and social point of view using the energy consumption calculations for country-specific reference case buildings before renovation, after a traditional renovation and after a Nearly Zero-Energy Building Renovation (NZEBR) as the starting point. Technical feasibility is analyzed by examining the proven technology level, possible technical risks in renovation or with respect to the energy performance and assessment of the overall technical feasibility for individual NZEBR measures. Social feasibility is analyzed by examining the impact on living space and other social aspects and the overall assessment of social feasibility for individual NZEBR measures. Environmental feasibility is analyzed by comparing the reduction of greenhouse gas emissions of traditional renovation and NZEBR using the Life Cycle Analysis (LCA) method. Economic feasibility is analyzed by comparing traditional renovation with NZEBR using the Life Cycle Costing (LCC) method.

Carbon balance effects of U.S. biofuel production and use

The use of liquid biofuels has expanded over the past decade in response to policies such as the U.S. Renewable Fuel Standard (RFS) that promote their use for transportation. One rationale is the belief that biofuels are inherently carbon neutral, meaning that only production-related greenhouse gas (GHG) emissions need to be tallied when comparing them to fossil fuels. This assumption is embedded in the lifecycle analysis (LCA) modeling used to justify and administer such policies. LCA studies have often found that crop-based biofuels such as corn ethanol and biodiesel offer at least modest net GHG reductions relative to petroleum fuels. Data over the period of RFS expansion enable empirical assessment of net CO2 emission effects. This analysis evaluates the direct carbon exchanges (both emissions and uptake) between the atmosphere and the U.S. vehicle-fuel system (motor vehicles and the physical supply chain for motor fuels) over 2005–2013. While U.S. biofuel use rose from 0.37 to 1.34 EJ/yr over this period, additional carbon uptake on cropland was enough to offset only 37 % of the biofuel-related biogenic CO2 emissions. This result falsifies the assumption of a full offset made by LCA and other GHG accounting methods that assume biofuel carbon neutrality. Once estimates from the literature for process emissions and displacement effects including land-use change are considered, the conclusion is that U.S. biofuel use to date is associated with a net increase rather than a net decrease in CO2 emissions.

Life Cycle Analysis applied to acrylic acid production process with different fuels for steam generation

Acrylic acid, one of the most important monomers, has a wide range of uses e.g. in the paints adhesives, textile finishing, leather processing or super absorbents. The production process from propylene is well known and used at industrial scale in the USA, Europe, and Asia. The present paper focuses on the evaluation of the environmental impact of the acrylic acid production process from propylene. Steam is a major raw material in the process under study, consequently different paths to obtain steam are investigated. The process was simulated using commercial software (Aspen Plus, PROII). A productivity capacity of 50,000 tones/year of acrylic acid has been considered. The environmental assessment, evaluated using Life Cycle Analysis method, depends on the material and energy balances generated by simulations. The present work uses a cradle-to-grave approach. The functional unit, to which all the environmental results for the cases under study are reported, is one tone of acrylic acid produced. The boundaries of the system cover: i) acrylic acid production; ii) upstream processes for example catalyst and molten salt production; steam production using various fuels (e.g. natural gas, anthracite, lignite, heavy fuel oil, light fuel oil and biomass) and iii) downstream processes for example: acrylic acid and acetic acid transport to other chemical plants for further processing. The CML (An LCA method developed by the Center of Environmental Science of Leiden University) 2001 impact assessment method was used for comparison between different case studies. The best value for Global Warming Potential (GWP) e.g. 1094.5 kg CO2-Equiv./tone is obtained when biomass is used to generate the steam required by the process. For other indicators such as Acidification Potential (AP), Photochemical Oxidation Potential (PCOP) and Eutrophication Potential (EP), the best value is obtained when steam is generated from natural gas. A sensitivity analysis of the environmental impact categories using the different combination of natural gas and biomass was also investigated. The study investigates also the association of the post-combustion amine-based carbon capture technologies with the conventional acrylic acid production process. Such association decreases the value of some environmental impact categories (e.g. GWP) while other impact categories are increasing e.g. AP, Human Toxicity Potential (HTP), Terrestrial Ecotoxicity Potential (TETP).

Cost effective greenhouse gas reductions in the steel industry from an Organic Rankine Cycle

Large quantities of low grade heat (LGH) are genera ted within many process industries, and the recovery of LGH is a potentially significan t means of improving process efficiency, but it is often difficult to find an ap propriate internal heat load. One alternative is to use appropriate technologies to c onvert the low grade heat to electricity for use on site. This paper describes the environme ntal and techno-economic evaluation of a case study examining the potential application of an Organic Rankine Cycle (ORC) to generate electricity from LGH from the stacks of a coke oven used in steel production. 21 MW of LGH was available for recovery at the plant and resource accounting and lifecycle analysis methods were used to evaluate the environmental and economic benefits of the operation of an ORC. The r esults showed that between 1 and 3% of the CO 2 emitted directly through the production of coke wo uld be offset by installation of an ORC, with lifecycle environmenta l impacts of coke production reduced by less than 1%, although this was sufficie nt to offset over 10,000 t CO 2 annually. However, the amount of electricity gener ated was sufficient to replace all currently imported electricity and economic analysi s indicated a relatively attractive discounted payback period of between 3 and 6 years, suggesting this may be a commercially viable option, which could present a r elatively cost effective method of achieving greenhouse gas savings in the process ind ustries.

Flow Synthesis of Silver Nanowires for Semitransparent Solar Cell Electrodes: A Life Cycle Perspective.

Silver nanowires (AgNWs) were prepared on a 5 g scale using either the well-known batch synthesis following the polyol method or a new flow synthesis method. The AgNWs were employed as semitransparent electrode materials in organic photovoltaics and compared to traditional printed silver electrodes based on micron sized silver flakes using life cycle analysis and environmental impact analysis methods. The life cycle analysis of AgNWs confirms that they provide an avenue to low-impact semitransparent electrodes. We find that the benefit of AgNWs in terms of embodied energy is less pronounced than generally assumed but that the toxicological and environmental benefits are significant.

The influence of the level of definition of functional specifications on the environmental performances of a complex system. EcoCSP approach

The tendency towards a homogenous mode of development modelled on that of Western countries means that sustainable development has become increasingly urgent. It is necessary to thoroughly redefine products and their expected performances in such a way that the consequences are compatible with sustainable development. In the domain of product design, this means that it is no longer sufficient to use assessment tools “after the fact” to check the impact of products whose functional unit (FU) was defined prior to production; it is now necessary to rethink the definition of the FU itself. This article aims to present an approach based on a combination of life cycle analysis methods and problem-solving by constraint satisfaction. This original approach makes it possible to vary the design of the different dimensions of the FUs of a complex system and thus to make it easier to identify the best architecture along with the best functional definition of the system. In this study, the EcoCSP approach is applied to define the functional performances of an ecological passenger ferry. The complexity of couplings between subsystems and the sheer number of those subsystems mean that the designer has to use “intelligent” tools. These simulate a great number of scenarios and help him/her to fine-tune the system and make the right technological choices with regard to the right functional specifications.

A Decision Support Tool for Product Design for Remanufacturing

The decision to include remanufacturing as part of product life cycle should be made as early as possible, as many barriers that occur during the remanufacturing process can be mitigated through proper product design at an early stage. The main objective of this research is to develop a Design for Remanufacturing and Remanufacturability Assessment (DRRA) tool to be used at early product definition stage. The design support tool will adopt the Fuzzy TOPSIS method to facilitate product design for remanufacturing from four major design perspectives, namely material selection, material joining methods, structure design and surface coating methods. Simplified Life Cycle Analysis methods have also been incorporated into the decision support tool to justify and improve the robustness of the design decision making. The utility of this tool is demonstrated using automotive parts design.

Energy and Carbon Assessment of Ground Improvement Works. II: Working Model and Example

AbstractA streamlined energy and emissions assessment model (SEEAM) is presented that is based on life cycle analysis (LCA) methods. The SEEAM provides geotechnical engineers with the means to quantify the embodied energy (EE) and carbon dioxide (CO2) emissions associated with ground improvement projects. A companion paper (Shillaber et al. 2015) provides detailed background for sustainable development and environmental impact assessment, which are at the foundation of the SEEAM. This paper presents the boundary conditions and methodology for this model. Construction of levee LPV 111 in New Orleans, LA is used as a case history example to illustrate the use of the model. This project involved supporting an earthen embankment by deep soil mixing (DSM) elements. Results of a SEEAM analysis of the DSM supported embankment indicate that constructing the levee involved 1,174,000 GJ of EE and 147,000 t of CO2 emissions. For comparison, the SEEAM was also used to estimate the EE and CO2 emissions associated with...

Energy Consumption and Greenhouse Gas Emission Studies of Jatropha Biodiesel Pathway by Life Cycle Assessment in India

In the present study, life cycle energy consumption, efficiency and greenhouse gas (GHG) emissions of Jatropha-based biodiesel was analysed by life cycle analysis method using GREET (Greenhouse Gases, Regulated Emissions, and Energy Use in Transporta­tion) model. This study quantitatively explicates the life cycle energy saving and GHG emissions of Jatropha-derived biodiesel. The functional unit was defined as 1 mile distance driven by the vehicle and the fuel blend was about 20%. The results indicated that Jatropha biodiesel production and its usage in India have positive environmental performance at the current technical levels. Well-to-pump energy efficiency of Jatropha biodiesel production was found to be 75%. As compared with that of gasoline fuel, the use of 20% blended Jatropha biodiesel leads to the reduction of GHG emission about 22.3% and brings about energy saving 9%. Further improvement of production technology would reduce emissions and increase the energy saving markedly.

Assessing the Environmental Impacts of Different IPSS Deployment Scenarios for the Light Commercial Vehicle Industry

IPSS are popular in different fields of transport, mainly for personal use (car-sharing, bike-sharing). Their usage in urban goods transport is not still generalized but those systems present a good potential. This paper proposed to assess and analyze four different scenarios for urban goods transport to compare IPSS configurations to a business as usual situation, in terms of environmental impacts. Those impacts will be estimated via a life cycle analysis (LCA) method. First, the four scenarios are presented. The first scenario is the reference one, i.e. the business as usual situation. The other three scenarios represent possible IPSS configuration, i.e. a vehicle leasing system, a vehicle sharing system and an urban consolidation system. Second, the methodology for scenario assessment using LCA is described, and the main proposed indicators defined. Third, the main results of the scenario assessment are presented, analyzed and discussed. Finally, future researches are proposed.

A simplified method for optimal design of solar water heating systems based on life-cycle energy analysis

Significant energy mismatch exists in solar water heating systems as the time and amount of solar energy supply are usually different from that of hot water demand. Using a hot water storage tank can reduce or eliminate such mismatch in short term while it is difficult to avoid this mismatch in long term. In many optimal design and life-cycle analysis methods, the energy mismatch is ignored which causes the system performance to be overestimated and also misleads the optimal design of the system. This paper presents a simplified method for optimizing the key parameters of solar water heating systems based on life-cycle energy analysis. This optimal method considering the energy mismatch phenomenon can be implemented through two steps. In the first step, a simplified energy model based hourly energy matching different components of the system, is developed for determining the operating performance of system with different solar collector areas and water storage volumes. In the second step, the law of diminishing marginal utility is employed to determine the optimum size of the system. The optimum size is identified when the maximal life-cycle net energy saving is achieved. A case study on the application of the proposed method in a building is presented as well.

Energy efficiency and environmental performance of bioethanol production from sweet sorghum stem based on life cycle analysis.

Life cycle analysis method was used to evaluate the energy efficiency and environmental performance of bioethanol production from sweet sorghum stem in China. The scope covers three units, including plant cultivation, feedstock transport, and bioethanol conversion. Results show that the net energy ratio was 1.56 and the net energy gain was 8.37 MJ/L. Human toxicity was identified as the most significant negative environmental impact, followed by eutrophication and acidification. Steam generation in the bioethanol conversion unit contributed 82.28% and 48.26% to total human toxicity and acidification potential, respectively. Fertilizers loss from farmland represented 67.23% of total eutrophication potential. The results were significantly affected by the inventory allocation methods, vinasse reusing approaches, and feedstock yields. Reusing vinasse as fuel for steam generation and better cultivation practice to control fertilizer loss could significantly contribute to enhance the energy efficiency and environmental performance of bioethanol production from sweet sorghum stem.

A hybrid MCDA-LCA approach for assessing carbon foot-prints and environmental impacts of China’s paper producing industry and printing services

Abstract Background Labeling of carbon foot-prints (CFPs) for products and services is regarded as a convenient and effective method for reducing greenhouse gas (GHG) emissions. Life cycle analysis (LCA) is a useful tool for examine CFP of relevant products and services. However, the corresponding standards for CFP of products and services can hardly be satisfactorily adopted. Also, most of the previous studies were based on an individual indicator, which can hardly reflect multiple dimensions of sustainable implications of products and services. Results Thus, in this research, a hybrid life cycle analysis (LCA) and multi-criteria decision analysis (MCDA) method was proposed for helping evaluate CFP of products and services under multiple environmental indicators. The results indicated: (a) Air pollution caused by coal consumption was the primary environmental impact in China’s paper-production industry, and (b) in printing industry, air pollution caused by VOC was the primary environmental impact in China. At the same time, CFP of 1,000 kg copying paper was 1,415.39 kg CO2e based on LCI data of a paper factory in China. CFP of printing services was varied from each printing activity. Conclusions When purchasing copying paper, consumers should pay attention on coal consumption of the product. In printing industry, VOC of printing services should be taken serious consideration in China.

The Effect of Renewable Energy Development on Carbon Emission Reduction: An Empirical Analysis for the EU-15 Countries

The increased concerns about climate change have made renewable energy sources an important topic of research. Several scholars have applied different methodologies to examine the relationships between energy consumption and economic growth of individual and groups of countries and to analyze the environmental effects of energy policies. Previous studies have analyzed carbon emission savings, using renewable energy usage as an individual source or in combination with traditional sources of energy (e.g., hybrid plants) in connection with lifecycle analysis methods. It is shown that after a certain period, economic growth leads to the promotion of environmental quality. However, econometric modelling critiques have opposed the results of these studies. One reason is that the effectiveness of governance-related parameters has previously been neglected. In this research, we analyze the impact of renewable energy development on carbon emission reduction. We estimate a model to evaluate the effectiveness of renewable energy development, technological innovation, and market regulations in carbon emission reduction. The empirical results are based on a panel data estimation using the EU-15 countries data observed from 1995 to 2010. The elasticities of CO2 emissions are estimated, in order to evaluate the effectiveness of each parameter. The findings show that the effects of a negative climate change could be mitigated by governance-related parameters instead of economic development.

How to Improve Environmental Performance by Negotiating Functional Specifications of Complex System?

This article aims to present an approach based on a combination of life cycle analysis methods (LCA) and problem solving by constraint satisfaction (CSP). This original approach makes it possible to vary the design of the different dimensions of the functional units of a complex system and thus to make it easier to identify the best architecture along with the best functional definition of the system. Our approach (EcoCSP) presented allows to negotiate performance to move towards an environmental optimum corresponding to a set of acceptable specifications. The EcoCSP approach is implemented to define the functional performance of a green passengers’ ferry.

Environmental Evaluation of Different Heating Systems

This study compares environmental impact of different heating systems with life cycle analysis, and get out if heat pump system has advantage in replacing boiler heating systems. Systems energy use are compared in one-year operation phase for residential buildings located in Tianjin city, including waste water heat pump system, coal boiler system and gas boiler system. In order to analyzed the environment performance of heat pump system in different conditions. The power structure impact to heat pump systems is analyzed using life cycle analysis method. The results indicate that with COP=4, even if 100% coal power is used, heat pump has advantage in the most impact factors, and if more clean power is used, the environment impact in heat pump system will be reduced obviously. The result also shows that waste water use in heat pump system impact the result little for its small quantity. Nomenclature GW, Global Warming; NRC: Non-renewable Resource Consumption; OD: Ozone Depletion; ACI, Acidification; EUT, Eutrophication; SPO, Synthesis of photochemical ozone; SW, Solid Waste; HW, Hazardous Waste; SD, Smoke and Dust. RC: Renewable Resource Consumption