Investigation of the environmental impacts of steel deck pavement based on life cycle assessment

To investigate the environmental impacts of steel deck pavement through the whole life cycle,the steel deck pavement was divided into five stages:raw materials production,asphalt mixture mixing,pavement construction,operation management,and pavement removing stage.Based on the process-based life cycle assessment(PLCA)method,the calculation methods of energy consumption and gas emissions of two typical steel deck pavement systems(EA+EA pavement and GA+SMA pavement)were determined.The data lists of two pavements were analyzed,and the calculation model was built.Four characteristic indices including primary energy demand(PED),global warming potential(GWP),acidification potential(AP)and respiratory inorganics(RI)were used to quantify the environmental impacts of two pavements.The results show that the environmental impact of the GA+SMA pavement is more than 1.3 times that of the EA+EA pavement.Moreover,the critical stage of energy-saving and emission-reduction of EA+EA pavement and GA+SMA pavement are the raw material production stage and asphalt mixture mixing stage,respectively.

Life cycle assessment for the "implicit" environmental impact of construction projects

The paper has established an assessment system and a quantitative calculation method of the 'implicit' environmental impact including environmental impact indicator,resources consumption indicator and energy consumption indicator. The quantitative calculation of the environmental impact indicator is based on the life cycle assessment system and the evaluation software BEES. The paper identifies normalization reference values and weights for 12 categories of the environmental impact. It also analyzes the environmental impact indicator in life cycle stages,raw materials,transportation,manufacturing,utilization,and end of life. A university refectory project is studied. The result has shown that human health,global warming and acidification are the first three environmental impacts in 12 categories. The environmental impact indicator per m2 of this project is 18.448×10-2 standard human equivalent weight. Moreover,97.3% of the total environmental impact occurs at the raw material stage,in which the most severe environmental impact is cancerous health effect; the global warming is the main impact at the transportation and manufacturing stages; the indoor air quality impact is at the usage stage.

Environmental impact assessment of China’s primary aluminum based on life cycle assessment

Assessing and accounting for material consumption and environmental impact are necessary to measure environmental externalities of the aluminum industry and to construct an ecological civilization.In this research,life cycle assessment(LCA)theory was used to assess the environmental impact of primary aluminum based on the lime soda Bayer process and different power generation modes,and the sources and distributions of the four selected impact categories were analyzed.The results show that,(1)Negative environmental impact of aluminum industry generally occurs from alumina extraction,carbon anode fabrication and electrolysis,particularly electrolysis and alumina extraction.Primary energy demand(PED),water use(WU),global warming potential(GWP)and freshwater eutrophication potential(FEP)are main environmental impact categories.(2)The environmental load with thermal power is higher than that with hydropower,e.g.,for the former,the greenhouse gas emission coefficient of 21800 kg CO2 eq/t(Al)will be generated,while for the latter,4910 kg CO2 eq/t(Al)will be generated.(3)Both power mode methods reflect the energy structure,whereas direct emissions reflect the technical level,indicating the potential for large energy savings and emission reductions,and some policies,related to clean power,energy efficiency and technological progress,should be made for emission reduction.

Life cycle assessment in the environmental impact evaluation of urbandevelopment--a case study of land readjustment project,Hyogo District, Japan

In this paper, the Life Cycle of Urban Development was firstly analyzed, and the phases of Life Cycle Assessment applied to Urban Development (ULCA) were described. As a case study, ULCA was applied in the environmental impact assessment of the land readjustment project of Hyogo District of Saga, Japan. In addition, mitigation proposals for reducing CO2 were also presented and the relevant environmental ef-fects were simulated.

Life cycle environmental impact assessment of biochar-based bioenergy production and utilization in Northwestern Ontario,Canada

Biochar-based bioenergy production and sub- sequent land application of biochar can reduce greenhouse gas emissions by fixing atmospheric carbon into the soil for a long period of time. A thorough life cycle assessment of biochar-based bioenergy production and biochar land application in Northwestern Ontario is conducted using SimaPro Ver. 8.1. The results of energy consumption and potential environmental impact of biochar-based bioenergy production system are compared with those of conventional coal-based system. Results show that biocbar land application consumes 4847.61 MJ per tonne dry feedstock more energy than conventional system, but reduces the GHG emissions by 68.19 kg CO2e per tonne of dry feed- stock in its life cycle. Biochar land application improves ecosystem quality by 18 %, reduces climate change by 15 %, and resource use by 13 % but may adversely impact on human health by increasing disability adjusted life years by 1.7 % if biomass availability is low to medium. Replacing fossil fuel with woody biomass has a positiveimpact on the environment, as one tonne of dry biomass feedstock when converted to biochar reduces up to 38 kg CO2e with biochar land application despite using more energy. These results will help understand a comprehensive picture of the new interventions in forestry businesses, which are promoting biochar-based bioenergy production.

Environmental impact assessment of magnesium alloy automobile hub based on life cycle assessment

In order to find out the impact of aluminum alloy hub replaced by the magnesium alloy hub on environment,the resource consumption,energy consumption and pollutant emission during hub production and their service life of the two types of hubs are investigated based on the life cycle assessment(LCA)theory.The results indicate that the adverse impact on environment can be effectively reduced by the application of magnesium alloy hubs.Compared with aluminum alloy hubs,the global warming potential(GWP)and human toxicity potential(HTP)are reduced by 39.6%and 24.0%,respectively.CO2 is the main pollutant in the life cycles of the two kinds of hubs,which is generated throughout the whole life cycle including the fabrication process and the service life,while the pollutants of particles mainly come from the fabrication stage.Compared with the aluminum alloy hubs,the green effect brought by magnesium alloy hubs is mainly due to the reduction of fuel consumption caused by weight loss.

RESIDENTIAL LIFE CYCLE ASSESSMENT MODELING: COMPARATIVE CASE STUDY OF INSULATING CONCRETE FORMS AND TRADITIONAL BUILDING MATERIALS

Innovative,sustainable construction products are emerging in response to market demands.One potential product,insulating concrete forms(ICFs),offers possible advantages in energy and environmental performance when compared with traditional construction materials.Even though ICFs are in part derived from a petroleum-based product,the benefits in the use phase outweigh the impacts of the raw material extraction and manufacturing phase.This paper quantitatively measures ICFs’performance through a comparative life cycle assessment of wall sections comprised of ICF and traditional wood-frame.The life cycle stages included raw materials extraction and manufacturing,construction,use and end of life for a 2,450 square foot house in Pittsburgh,Pennsylvania.Results showed that even though building products such as ICFs are energy intensive to produce and thus have higher environmental impacts in the raw materials extraction and manufacturing phase,the use phase dominated in the life cycle.For the use phase,the home constructed of ICFs consumed 20 percent less energy when compared to a traditional wood-frame structure.The results of the impact assessment show that ICFs have higher impacts over wood homes in most impact categories.The high impacts arise from the raw materials extraction and manufacturing phase of ICFs.But there are a number of embedded unit processes such as disposal of solid waste and transport of natural gas that contribute to this high impact and identifying the top unit process and substance contributors to the impact category is not intuitive.Selecting different unit processes or impact assessment methods will yield dissimilar results and the tradeoffs associated with every building product should be considered after studying the entire life cycle in detail.

ENVIRONMENTAL RELATIVE BURDEN INDEX:A STREAMLINED LIFE CYCLE ASSESSMENT METHOD FOR FACILITIES POLLUTION PREVENTION

This paper describes a new semi-quantitative streamlined life cycle assessment(SLCA)method,the Environmental Relative Burden Index(ERBI),for describing and ranking the relative environmental burdens associated with facility operations and maintenance options.The long-range goal is for this ERBI method to serve as a pollution-prevention decision support tool for facilities managers,when faced with competing operations and maintenance alternatives.The specific application pre-sented in this paper evaluates asbestos-containing materials(ACM)and lead-based paint(LBP)management options in public school facilities.The ERBI methodol-ogy is adapted from previous streamlined semi-quantitative LCA methodologies and is described in detail.The ERBI is then employed to evaluate the relative environmental impacts of six management strategies for these hazardous building materials:management in-situ,encapsulation/containment,and full abatement/disposal,for both ACM and LBP.SLCA goal definition,system boundaries,ERBI matrix,and overall ERBI Ratings(RERB)for each material management strategy are presented.The ERBI can be a useful tool in prioritizing building maintenance alternatives,especially in cases where detailed quantitative data are unavailable.

Diagnosing the environmental impacts of typical fatliquors in leather manufacture from life cycle assessment perspective

The environmental impacts of typical fatliquors were diagnosed by the life cycle assessment of industrial production and use(post-tanning)processes.Life cycle impact assessment and sensitivity analysis showed that fatliquor and fatliquoring operation were the major contributors to the environmental impacts of post-tanning because a large amount of fatliquors was consumed during fatliquoring operation.The environmental impacts of fatliquors decreased in the following order:chlorinated paraffin(CP)>sulfonated rape oil(SNR)>sulfated rape oil(SR)>phosphated rape oil(PR)>oxidized-sulfited rape oil(OSR).Sulfuric acid,fuming sulfuric acid,and chlorine used for fatliquor modification gave the main contribution to most impact categories for SR,SNR,and CP production,whereas rape oil contributed the most for PR and OSR production.OSR use process reduced the primary energy demand,abiotic depletion potential,and global warming potential by 38.5%,56.0%,and 48.5%,respectively,compared with CP use process.These results suggested that biomass-derived fatliquors,especially oxidized-sulfited and phosphate modified fatiliquors,helped reduce the environmental burdens in leather manufacturing.

Diagnosing the environmental impacts of typical fatliquors in leather manufacture from life cycle assessment perspective

The environmental impacts of typical fatliquors were diagnosed by the life cycle assessment of industrial production and use(post-tanning)processes.Life cycle impact assessment and sensitivity analysis showed that fatliquor and fatliquoring operation were the major contributors to the environmental impacts of post-tanning because a large amount of fatliquors was consumed during fatliquoring operation.The environmental impacts of fatliquors decreased in the following order:chlorinated paraffin(CP)>sulfonated rape oil(SNR)>sulfated rape oil(SR)>phosphated rape oil(PR)>oxidized-sullfited rape oil(OSR).Sulfuric acid,fuming sulfuric acid,and chlorine used for fatliquor modification gave the main contribution to most impact categories for SR,SNR,and CP production,whereas rape oil contributed the most for PR and OSR production.OSR use process reduced the primary energy demand,abiotic depletion potential,and global warming potential by 38.5%,56.0%,and 48.5%,respectively,compared with CP use process.These results suggested that biomass-derived fatliquors,especially oxidized-sulfited and phosphate modified fatiiliquors,helped reduce the environmental burdens in leather manufacturing.

Assessing environmental impact:Micro-energy network optimization in a Chinese industrial park

Micro-energy systems contribute significantly to environmental improvement by reducing dependence on power grids through the utilization of multiple renewable energy sources.This study quantified the environmental impact of a micro-energy network system in an industrial park through a life cycle assessment using the operation of the micro-energy network over a year as the functional unit and“cradle-to-gate”as the system boundary.Based on the baseline scenario,a natural gas generator set was added to replace central heating,and the light pipes were expanded to constitute the optimized scenario.The results showed that the key impact categories for both scenarios were global warming,fine particulate matter formation,human carcinogenic toxicity,and human non-carcinogenic toxicity.The overall environmental impact of the optimized scenario was reduced by 68%compared to the baseline scenario.A sensitivity analysis of the key factors showed that electricity from the power grid was the key impact factor in both scenarios,followed by central heating and natural gas.Therefore,to reduce the environmental impact of network systems,it is necessary to further optimize the grid power structure.The research approach can be used to optimize micro-energy networks and evaluate the environmental impact of different energy systems.

Exergy Efficiency and Environmental Impact of Electricity of a 620 MW-Natural Gas Combined Cycle

In the first part of this investigation, a Natural Gas Combined Cycle (NGCC) producing 620 MW of electricity was simulated using the commercial software Aspen Hysys V9.0 and the Soave-Redlich-Kwong (SRK) equation of state. The aim of this second part is to use exergy-based analyses in order to calculate its exergy efficiency and evaluate its environmental impact under standard conditions. For the exergy efficiency, the performance index under investigation is the exergy destruction ratio (yD). The results of the study show that the combustor is the main contributor to the total exergy destruction of the power plant (yD = 24.35%) and has the lowest exergy efficiency of 75.65%. On the other hand, the Heat Recovery Steam Generator (HRSG) has the lowest contribution to the exergy destruction (yD = 5.63%) of the power plant and the highest exergy efficiency of 94.37%. For the overall power plant, the exergy efficiency is equal to 53.28%. For the environmental impact of the power plant, the relative difference of exergy-related environmental impacts (rb) is utilized as the performance index for each equipment of the plant and the environmental impact of a kWh of electricity (EIE) is used to represent the performance index of the overall power plant. In agreement with the exergy analysis, the results indicate that the combustor and the HRSG have respectively the highest (rb = 32.19%) and the lowest (rb = 5.96%) contribution to the environmental impact. The environmental impact of a kWh of electricity of the power plant is 34.26 mPts/kWh (exergy destruction only), and 34.42 mPts/kWh (both exergy destruction and exergy loss).

Carbon footprint accounting for cigar production processes: A life cycle assessment perspective

Although the tobacco industry is a significant contributor to energy consumption and carbon emissions its negative environmental impact has received inadequate attention globally.Cigarette factories are a key link in the tobacco industry’s production chain,and using data provided by a cigarette factory in China we conduct a life cycle assessment to account for the carbon footprint of cigar production in cigarette factories.The results of the assessment show that factory air conditioning is the most important contributor to the environmental load of the cigar manufacturing process,while electricity is the key factor that contributes the greatest envi‐ronmental load across all of the processes in the product life cycle.In addition,packaging,including small boxes and cigarette cartons,has a significant impact on the industry’s environmental footprint due to its use of raw materials.We find the carbon footprint of the entire production process for cigar products to be 383.59 kg CO_(2) eq.Based on our findings,we suggest ways to optimize cigar/cigarette factory processes to re‐duce carbon emissions that can help to promote sustainable development in related industries.

Evaluation of Environmental Impacts of Traction Motor Production and Disposal

By the application of life cycle assessment(LCA) methodology, this paper estimates the environmental impacts of production and disposal of traction motors used in electric vehicles in China. The results show that the total energy use, the criteria emissions and the greenhouse gases(GHG) emissions of a traction motor production and disposal are about 2,899,MJ, 4.5,kg and 259.5,kg per motor, respectively. Among the regulated emissions, the SOxemission ranks first by total mass, followed by CO, PM10, NOx, PM2.5, and volatile organic compound(VOC). The motor material production stage accounts for most of the energy consumption and emissions, followed by the assembly stage and the end-of-life disposal stage. In this study, the environmental performance analysis is extended to the comparison between the use of secondary material and primary material for the material production stage. It is found that using 100% secondary material results in a 52.9% reduction in energy consumption, a 49.8% reduction in regulated emissions, and a 49.3% reduction in GHG emissions compared with the use of 100% primary material.

An endpoint damage oriented model for life cycle environmental impact assessment of buildings in China

The midpoint impact assessment methodology and several weighting methods that are currently used by most building Life cycle assessment (LCA) researchers in China, still have some shortcomings. In order to make the evaluation results have better temporal and spatial applicability, the endpoint impact assessment methodology was adopted in this paper. Based on the endpoint damage oriented concept, four endpoints of resource exhaustion, energy exhaustion, human health damage and ecosystem damage were selected according to the situation of China and the specialties of the building industry. Subsequently the formula for calculating each endpoint, the background value for normalization and the weighting factors were defined. Following that, an endpoint damage oriented model to evaluate the life cycle environmental impact of buildings in China was established. This model can produce an integrated indicator for environmental impact, and consequently provides references for directing the sustainable building design.

The significance of resource recycling for coking wastewater treatment:based on environmental and economic life cycle assessment

The sustainability of the coking industry is supported by reasonable production profit and environmental quality requirements.The traditional measures substantially increased the related costs for enterprises to reach standards.This paper aims to develop a comprehensive cost combined environmental impact assessment method that is necessary for the analysis of wastewater treatment systems.Typical three coking wastewater treatment processes in China were evaluated.Results showed that eutrophication dominantly contributed to the overall environmental effect.Improving effluent quality could significantly reduce the total environmental impact.In terms of an economic perspective,the price of raw materials was the main factor that affected the operating cost of comprehensive treatment.Based on subsystem analysis,the pretreatment stage accounted for the majority of environmental and cost burdens,respectively reaching 64%-78%and 64%-86%.Optimizing the pretreatment process by enhancing the efficiency of high concentration raw material recovery and substituting toxic raw materials for extractant could reduce the environmental impact and economic cost by 43.8%and 57%,respectively,which was an effective way to improve the potential performance of coking wastewater treatment plants(WWTPs).

Life cycle assessment on the environmental impacts of different pig manure management techniques

The management of livestock waste is an effective way to achieve emission reduction and carbon fixation in agriculture and rural areas.At present,aerobic composting and anaerobic fermentation are widely used in livestock waste treatment technology.In this study,pig manure management was taken as an example,a comprehensive environmental load index was constructed to quantitatively evaluate the environmental impacts of global warming,environmental acidification,eutrophication,and photochemical ozone synthesis during aerobic composting and anaerobic fermentation based on the life cycle assessment.The results showed that the potential values of aerobic composting and anaerobic fermentation were similar,and the order was global warming,environmental acidification,eutrophication,and photochemical ozone synthesis.Anaerobic fermentation contributed more to global warming,while aerobic composting contributed more to environmental acidification,eutrophication,and photochemical ozone synthesis.In addition,the environmental load index of aerobic composting was significantly higher than that of anaerobic fermentation.There were certainly regional differences in the environmental load index,and the environmental impact effect of anaerobic fermentation was low and more environmentally friendly.These findings provided a technical basis for livestock manure management in different regions of China,which was conducive to promoting animal husbandry emission reduction and carbon sequestration.

Comparison of life cycle assessment of large-scale biogas projects with different raw materials in China

The anaerobic digestion(AD)disposal of stover and cattle manure is of great significance to the development of low-carbon economy and green energy in China,but it will also have an impact on the environment,and the degree of influence is different for various raw materials.In this study,life cycle assessment(LCA)methods were applied to analyze and compare the impact of corn stovers biogas projects(CSBP)and dairy manure biogas projects(DMBP)on the environment during the whole operation stage.The results of inventory analysis were evaluated by ReCiPe2016 Hierarchy(H)mid-point(problem-oriented)and end-point(destruction-oriented)method,respectively.The results showed that the net energy efficiency of CSBP was higher(763.903 kW·h/FU)and the greenhouse gas(GHG)emission reduction of DMBP was more(5541.418 kg CO_(2)-eq/FU).The anaerobic digestion(AD)units have the greatest environmental impacts,and human carcinogenic toxicity is the largest environmental impact category(1.16-1.43 PE).The key to reducing environmental impact is reducing the input of chemical substances and the waste of electric energy.Both CSBP and DMBP have a favorable impact on ecosystem quality and resources,and CSBP is more beneficial to the environment(-10.297 Pt).Co-digestion is an important measure to reduce the environmental damage from biogas projects.These research results provide theoretical support for the selection of raw materials for large-scale biogas projects in China,provide technical basis for reducing the impact of actual operation on the environment,and promote the resource utilization of agricultural waste and carbon dioxide emission reduction and sequestration.

Life-Cycle Impact Assessment of Air Emissions from a Cement Production Plant in Cambodia

Cement industrial emissions account for 32% of air pollution in Cambodia. With that in mind, we examined the environmental impact of Cambodia’s cement industry and identified ways that it could reduce air pollution. The study focused on raw material extraction and preparation, calcination, and cement preparation. Data for the life-cycle inventory were provided by the Kampot Cement Plant. Air emissions were assessed using EMEP/EEA and IPCC criteria, and the impact assessment used ReCiPe (2016). The baseline analysis revealed that calcination contributed the most air pollutants, so mitigation scenarios focused on alternative fuels only during the calcination stage of cement production: 1) 100% coal (S1);2) 93% coal and 7% biomass (S2);3) 85% coal and 15% biomass (S3);4) 70% coal and 30% biomass (S4);and 5) 50% coal and 50% biomass (S5). The results demonstrated that certain mitigation measures reduced major emissions and environmental damage. S5 had the best results, reducing CO2 by 49.97, NOx by 2.233, and SO2 by 49.333%;however, it increased PM2.5 by 19.60% and total heavy metal (Pb, Cd, Hg, As, Cr, Cu, Ni, Se, Zn) output by 28.113%. The results of the study showed reductions in serious health and environmental effects associated with climate change of 48.83%, ozone generation of 9.62%, and particulate matter formation of 28.80%. However, carcinogenic and non-carcinogenic human toxicity increased by 35.66%. Therefore, such mitigation effect would be benefit to carbon reduction target in Cambodia.

ENERGY CONSUMPTION,ENVIRONM ENTAL IMPACTS AND EFFECTIVE MEASURES OF GREEN OFFICE BUILDINGS:ALIFE CYCLE APPROACH

The last few decades have witnessed a rapid development of green buildings in China especially the office sector.The life cycle assessment(LCA)approach has potential to weigh the benefits and costs associated with green building developments.Essentially,the LCA method evaluates the costs and benefits across a building’s life cycle with a system approach.In this study,a green office building in Beijing,China,was analyzed by life cycle assessment to quantify its energy use and evaluate the environmental impacts in each life cycle stage.The environmental impacts can be reduced by 7.3%,1.6%and 0.8%by using 30%gas-fired electricity generation,increasing the summer indoor temperature by 1℃,and switching off office equipment and lighting during lunchtime,respectively.Similarly,by reusing 80%of the selected materials when the building is finally demolished,the three major adverse environmental impacts on human health,ecosystem quality,and resource depletion can be reduced by 11.3%12.7%,and 7.1%respectively.Sensitivity analysis shows that electricity conservation is more effective than materials efficiency in terms of a reduction in environmental impacts.These findings are useful to inform decision makers in different stages of the green building life cycle.