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.

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 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.

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.

Environmental Impact Assessment for an Absorption Heat Transformer

This study presents the environmental impact assessment of an absorption heat transformer designed to recover 1 kW of thermal energy from each 2 kW of waste heat supplies. The net contribution of the heat transformer is a load avoided of 0.665 kg CO2 equivalents;the recovery process avoids 0.729 kg CO2 equivalents and the major contribution to the environment impacts is the pumping process with 0.0437 kg CO2 equivalents for each 1 kWh recovered. The study results show that absorption heat transformer is a good environmental option because it produces useful energy from waste heat and the final result is an environmental impact diminution.

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).

Environmental impact evaluation for high-speed railway

Environmental impact evaluation system boundary of high-speed railway was defined based on the total life cycle theory,and the index system to evaluate the environmental impact of high-speed railway was established with the fuzzy analytic hierarchy method,and the matter-element evaluation model was established on the basis of the extension theory.By calculating its comprehensive interrelatedness,the evaluation rank of environment impacts of high-speed railway was determined.The numerical example shows that the model has vast prospect,which can not only expand the application areas of extension theory,but also change the traditional evaluation methods and provide new ideas and means for environmental impact evaluation of high-speed railway.

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.

Environmental impact improvements due to introducing automation into underground copper mines

A life-cycle assessment(LCA) model was developed to comparatively analyze the use of manual and automated mining equipment in underground copper mine sites.Processes and key variables that were determined to contribute to the environmental impact of operations were identified for six mine sites in a range of geographical locations around the world.Our model successfully calculated carbon dioxide(CO_(2) eq.) emissions to within 4.9% of the reported annual emissions from the site's respective companies.The implementation of automation was found to decrease global warming potential by a range of 11.4%-18.0% or 3.9-17.9 kg CO_(2) eq./t ore.The model was also used to estimate the average reductions across several impact potentials including,acidification(11.9%-17.8%),eutrophication(7.6%-13.7%),and human toxicity(16.0%-20.0%).World-wide the mining industry is moving toward introducing significantly more automation to enhance productivity and safety.This novel work demonstrates an important third dimension that can support this move,reduced environmental impact.

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.

Environmental impact assessment of emissions from non-recycled plastic-to-energy processes

Generally,plastics pose a variety of environmental impacts due to their increased use and non-biodegradability.End-of-life treatment is a viable way of recovering energy from plastics while at the same time reducing the amount of plastics disposed of in landfills.This paper studies the environmental impact of Non-Recycled Plastics(NRP)-to-energy processes.Three waste treatment processes were considered for NRP:pyrolysis,waste-to-energy(WtE),and landfill.The environmental impact assessment results indicated that conversion technologies such as pyrolysis and WtE are preferred over landfill.The total energy consumed in the pyrolysis process was 24635.7 MJ/tonne.The conversion technologies have a lower environmental impact and produced net positive energy from NRP.The global warming potential shows that pyrolysis(3.91 kg eq.CO_(2))contributes the least to global warming than waste-to-energy(18.56 kg eq.CO_(2))and landfill(17.5 kg eq.CO_(2)).However,sensitivity analysis suggested that the inefficiencies of the current conversion technologies should be addressed.Between the two technologies studied,pyrolysis contributed less environmental burden,having a lower global warming potential,a higher efficiency in energy conversion,and less harmful emissions such as selenium and methane.

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.

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.

Chinese life cycle impact assessment factors

The methodological basis and procedures for determination of Chinese normalization references and weighting factors according to the EDIP-method is described. According to Chinese industrial development intensity and population density, China was divided into three regions and the normalization references for each region were calculated on the basis of an inventory of all of the region's environmental emissions in 1990. The normalization reference was determined as the total environmental impact potential for the area in question in 1990(EP(j)90) divided by the population. The weighting factor was determined as the normalization reference (ER(j)90) divided by society's target contribution in the year 2000 based on Chinese political reduction plans, ER(j)T2000. This paper presents and discuss results obtained for eight different environmental impact categories relevant for China: global warming, stratospheric ozone depletion, acidification, nutrient enrichment, photochemical ozone formation and generation of bulk waste, hazardous waste and slag and ashes.

Environmental impact assessment of aircraft elevator made with new lightning protection material

The non-metallic lightning strike protection film covering carbon fiber reinforced polymers(NM-LSP covering CFRP)can reduce the weight and thus the fuel consumption of aircraft by replacing the traditional lightning strike protection(LSP)materials.In the present study,in order to study the environmental influence of utilizing NM-LSP covering CFRP in an aircraft elevator,a new elevator was designed and manufactured,replacing the aluminium net and glass fiber reinforced polymers(GFRP)with NM-LSP covering CFRP,with the same mechanical and LSP abilities.A comparative life cycle assessment was conducted between the two kinds of aircraft elevators,including material extraction,transportation,elevator manufacturing phase,service phase,and end-of-life procedures.Additionally,the environmental impacts of producing two LSP materials were compared by considering the environmental effects of different buy-to-fly ratios and recycling strategies on the production of aluminium net.The analysis indicates that the new elevator achieved reduction for all the environmental impact categories used,such as human toxicity potential and marine aquatic ecotoxicity potential(3.83%and 3.20%reduction).Furthermore,it is found that the service phase makes the greatest contribution to the environmental impact of the elevators under investigation.When recycling is excluded,NM-LSP covering CFRP is more environmentally friendly than the traditional material.At the same time,CFRP prepreg and electricity from the production of NM-LSP covering CFRP contribute to a higher environmental impact compared to the NM-LSP film.From the sensitivity analysis,it is believed that NM-LSP covering CFRP can reduce environmental impact compared with traditional LSP materials.

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.