An environmental assessment of wood and steel reinforced concrete housing construction

Comparative Assessment of the Environmental Impacts of Hydro-Electric, Nuclear and Wind Power Plants in China: Life Cycle Considerations.

Pitched battles are a regular occurrence in northern Alberta, Canada, as development of the province’s oil sands continues to expand. One ongoing battle—with another salvo launched in February 2011 with the leak of a European Commission report1—concerns how dirty oil sands are, relative to other fuels. Another concerns the influence of the oil sands industry in monitoring its own activity.2 In an effort to cut through the rhetoric of health advocates, industry representatives, environmentalists, government officials, and local residents, the Royal Society of Canada (RSC) selected and covered expenses for an expert panel to winnow out the facts. In a report issued 15 December 20103 the panel cited substantial evidence that efforts to extract oil from the Alberta deposits have degraded air, land, and water quality to varying degrees. The extent of the degradation is sometimes controversial; water quality data, in particular, are subject to differing interpretations and attributions of causality. However, the panel says that, based on publicly available evidence, there appear to be no significant human health threats to the general population either now or from development anticipated in the next decade or so. But the panel also warns that their conclusions come with a major caveat: there are major gaps in health and environmental data, risk assessments, government oversight, information transparency, industry efforts, and disaster preparedness. The health of the region could hinge on these gaps being addressed, particularly since, according to Travis Davies, a spokesman for the Canadian Association of Petroleum Producers, 97% of projected oil extraction and processing is still to come. After the RSC panel reviewed reams of publicly available information on factors such as health status, air and water pollution, greenhouse gas emissions, land disturbance, and energy and water consumption, it concluded that “[t]he claim by some critics of the oil sands industry that it is the most environmentally destructive project on earth is not supported by the evidence. However, for Canada and Alberta, the oil sands industry involves major environmental issues on many fronts which must be addressed as a high priority.”3p293

Air emissions related to up-stream petroleum operations include carbon dioxide, nitrogen oxides, sulphur oxides (which are products of combustion), methane, volatile organic components (which are the result of the release of hydrocarbons), and chlorofluoro/bromo carbons (which are used extensively for refrigeration and fire-extinguishing). The emission of some of these substances has a localised effect on the environment, while others have a major contribution to environmental problems of global interest, such as greenhouse effects, acid rain and the depletion of ozone layer. The upstream operations contribute to these harmful air emissions and with proper operational practices this contribution can be minimised. Introduction Hazardous atmospheric emissions from oil and gas production operations is an issue which has not yet received adequate and serious consideration. Although the environmental impact caused by the production and transportation of fossil fuels is much lower than that caused by their consumption, nevertheless the upstream operations must be aimed at reducing these impacts. This is especially so since the public image towards the industry is generally hostile. In the context of a growing concern towards the environmental impacts of all industrial activities, the subject is now becoming considered at the board room levels and attempts are being made to evaluate the contribution of the upstream oil industry to the overall emissions. As far as environmental effects of oil and gas up-stream operations are concerned, the issues involved are air emissions (combustion gases, hydrocarbons and chlorofluoro/bromo carbons), waste streams (oil contamination, heavy metals, naturally occurring radioactive materials and chemicals; and wastes associated with drilling operations such as cuttings, chemicals, etc.), decommissioning and abandonment of production installations, and oil spills and oil contamination from tanker operations. Some environmental issues such as ‘smog’, ‘acid rain’ and greenhouse effect have become almost synonymous in the public mind with air pollution. Such well publicised, and simple terms have been used to describe a multitude of complex chemical processes and have helped to draw attention to the possible effects of air pollution on the environment. Historically in the period following World War II local sources of pollution were the main concern. In the 1960‘s photochemical smog’s, pointed to the automobile as an important contributor. Later the acid rain debate highlighted the possible long-range effects of pollutants; and now the greenhouse effect and global warming is considered to be the most important environmental issue facing human beings. Some progress has been made around the world in reducing air pollution and its ‘local’ ill effects. However, it is now recognised that the long-range air pollution is more serious than its immediate and local effects, but it is more difficult to tackle. In this paper the main sources of air emissions related to the up-stream petroleum operations and the ways to minimise these emissions are discussed. Detailed effects of major air emission products Air emissions related to the upstream oil industry include carbon dioxide (CO2), nitrogen oxides (NOx), sulphur oxides (SOx), methane (CH4), volatile organic compounds (VOC), chlorofluoro/bromo carbons (CFC's), particulates etc. The emission of some of these substances has a more localised effects on the environment (e.g. VOC), while some others (e.g. carbon dioxide) have a major contribution to environmental problems of global interest like the greenhouse effect and acid rain. P. 43^

Carbon capture and sequestration (CCS) has the ability to dramatically reduce carbon dioxide (CO2) emissions from power production. Most studies find the potential for 70 to 80 percent reductions in CO2 emissions on a life-cycle basis, depending on the technology. Because of this potential, utilities and policymakers are considering the wide-spread implementation of CCS technology on new and existing coal plants to dramatically curb greenhouse gas (GHG) emissions from the power generation sector. However, the implementation of CCS systems will have many other social, economic, and environmental impacts beyond curbing GHG emissions that must be considered to achieve sustainable energy generation. For example, emissions of nitrogen oxides (NOx), sulfur oxides (SOx), and particulate matter (PM) are also important environmental concerns for coal-fired power plants. For example, several studies have shown that eutrophication is expected to double and acidification would increase due to increases in NOx emissions for a coal plant with CCS provided by monoethanolamine (MEA) scrubbing. Potential for human health risks is also expected to increase due to increased heavy metals in water from increased coal mining and MEA hazardous waste, although there is currently not enough information to relate this potential to actual realized health impacts. In addition to environmental and human health impacts, supply chain impacts and other social, economic, or strategic impacts will be important to consider. A thorough review of the literature for life-cycle analyses of power generation processes using CCS technology via the MEA absorption process, and other energy generation technologies as applicable, yielded large variability in methods and core metrics. Nonetheless, a few key areas of impact for CCS were developed from the studies that we reviewed. These are: the impact of MEA generation on increased eutrophication and acidification from ammonia emissions and increased toxicity from MEA production and the impact of increased coal use including the increased generation of NOx from combustion and transportation, impacts of increased mining of coal and limestone, and the disposal of toxic fly ash and boiler ash waste streams. Overall, the implementing CCS technology could contribute to a dramatic decrease in global GHG emissions, while most other environmental and human health impact categories increase only slightly on a global scale. However, the impacts on human toxicity and ecotoxicity have not been studied as extensively and could have more severe impacts on a regional or local scale. More research is needed to draw strong conclusions with respect to the specific relative impact of different CCS technologies. Specifically, a more robust data set that disaggregates data in terms of component processes and treats a more comprehensive set of environmental impacts categories from a life-cycle perspective is needed. In addition, the current LCA framework lacks the required temporal and spatial scales to determine the risk of environmental impact from carbon sequestration. Appropriate factors to use when assessing the risk of water acidification (groundwater/oceans/aquifers depending on sequestration site), risk of increased human toxicity impact from large accidental releases from pipeline or wells, and the legal and public policy risk associated with licensing CO2 sequestration sites are also not currently addressed. In addition to identifying potential environmental, social, or risk-related issues that could impede the large-scale deployment of CCS, performing LCA-based studies on energy generation technologies can suggest places to focus our efforts to achieve technically feasible, economically viable, and environmentally conscious energy generation technologies for maximum impact.

The production of equipment and materials used for transportation facilities and services can have significant environmental effects. Considerable effort is expended to reduce such effects as efficiently and ef- fectively as possible. In this paper, we estimate external environmental costs resulting from the production of common transportation equipment, materials, and services. These external cost estimates only include the effects from air emissions of conventional pollutants, including carbon monoxide, greenhouse gases (or global warming potential), volatile organics, sulfur dioxide, particulate matter, and nitrogen oxides. The estimates include all the direct and indirect supply chain emissions, such as electricity generation and mining. The cost estimates are uncertain and are likely to be underestimates of total external costs. However, the estimates should be useful for an initial assessment of the total social costs of transportation projects, and to indicate products and processes worthy of additional pollution prevention efforts. In particular, we find that additional external environmental costs may range from as low as 1% to as high as 45% for transportation services. External environmental costs of transportation equipment manufacturing range between 0.3 and 11%, while the external environmental costs of transportation construction and operation materials are estimated to vary between 1 and 100%.

Comparative assessment of the environmental impacts of nuclear, wind and hydro-electric power plants in Ontario: A life cycle assessment

Preparing emission inventories is essential to the assessment and management of our environment. In this study, Japanese air pollutant emissions, energy consumption, and CO2 emissions categorized by approximately 400 sectors (as classified by Japanese input-output tables in 1995) were estimated, and the contributions of each sector to the total amounts were analyzed. The air pollutants examined were nitrogen oxides (NOx), sulfur oxides (SOx), and suspended particulate matter (SPM). Consumptions of about 20 fossil fuels and five other fuels were estimated according to sector. Air pollutant emission factors for stationary sources were calculated from the results of a survey on air pollution prevention in Japan. Pollutant emissions from mobile sources were estimated taking into consideration vehicle types, traveling speeds, and distances. This work also counted energy supply and emissions from seven nonfossil fuel sources, including nonthermal electric power, and CO2 emissions from limestone (for example, during cement production). The total energy consumption in 1995 was concluded to be 18.3 EJ, and the annual total emissions of CO2, NOx, SOx, and SPM were, respectively, 343 Mt-C, 3.51 Mt, 1.87 Mt, and 0.32 Mt. An input-output analysis of the emission inventories was used to calculate the amounts of energy consumption and emissions induced in each sector by the economic final demand.

End of Life (EOL) is a vital phase in environmental life cycle impact assessment. However, most of studies either do not consider this phase or make its assessment based on certain assumptions, thus limiting the actual contributions. A proper pre-assessment of such environmental impacts during planning can achieve an optimum sustainable design inception at an early stage. The current work evaluates the carbon footprint potential of the EOL phase of conventional housings in a tropical climate of Malaysia. Conventional units with varying areas, height and type of construction have been analyzed. The life cycle inventory was achieved by developing the virtual prototypes of selected units using Building information Modeling (BIM). Partial life cycle assessment (LCA) methodology was used to obtain carbon emissions. The study highlighted a contribution of 2.5 to 3.0 tons-CO2 with average intensity of 1.00 kg-CO2 per unit area. The dismantling operation dominated the hauling operations by 50%. Concrete and bricks were the top two materials dominating the hauling activity. Statistical technique, regression, highlighted a significant relationship between dependent (carbon footprint) and independent (area) variables. Study, being one of the few addressing conventional low cost housing sector in tropical climate, is expected to act as mile stone and guideline baesed upon actual data of facilities for a realistic environmental conscious and optimum sustainable decision.

Three main categories of pollutant emissions into the atmosphere from Croatian oil and natural gas activities are: fuel combustion, fugitive and carbon dioxide separated from natural gas. The pollutants (or pollutant classes) emitted into the air are: main greenhouse gases such as CO2, CH4; indirect greenhouse gases such as NOx, CO and NMVOC gases (with no direct greenhouse effect, but they influence generation and disintegration of tropospheric and stratospheric ozon who has properties of a greenhouse gases); suspended particulate matter (SPM) and sulphur dioxide (SO2). These pollutants are emitted into the air during normal well operations, production, processing and distribution of gas and oil products. SNAP94 for CORINAIR inventory three level hierarchical emission source nomenclatures (covers 4 main sectors, 9 sub-sectors and 33 activities) has been used to characterise the cause of the emissions and to relate it to anthropogenic activity in petroleum industry. Point, line and area sources of air pollution in petroleum industry are considered. Emission estimations are based on detailed activity/technology information covering stationary sources. IPCC simplified method (Tier 1-production based average emission factor approach) for estimating CO2 non-CO2 greenhouse gases emissions, based on activity level and average emission factors, has been used. EMEP/CORINAIR detailed method (mass balance approach) to estimate fugitive emissions of ozone precursors (NOx, CO and NMVOC) from oil and natural gas activities has been also used. Comparison (in graph form) between emissions of air pollutants from INA- Petroleum Industry and emissions in Croatia has been made. Introduction Three main categories of pollutant emissions into the atmosphere from INA Croatian petroleum industry are: fuel combustion, fugitive emissions and emissions of carbon dioxide removed from natural gas. Fuel combustion result in emissions of carbon dioxide (CO2), and non-CO2 emissions such as emissions of methane (CH4), nitrous oxide (N2O), oxides of nitrogen (NOx), carbon monoxide (CO), nonmethane volatile organic compounds (NMVOC) and sulfur dioxide (SO2). Result of fugitive emissions are emissions of methane from oil and natural gas activities, emissions of ozone percursors (CO, NOx, NMVOC) and emission of SO2 from oil refining. Removal of CO2 by amine scrubbing result in subseqent emissions of CO2 into the atmosphere. The emissions of these polutants influence the air quality on local, regional and global level. Local level: Emissions of NOx, SO2, (fines) suspended particulate matter (SPM), heavy metals (HM), such as Pb, Hg, Cd, As, Ni and smoke from emission sources (stationary fuel combustion, oil refining) at petroleum refineries contribute to air quality in the urban areas where refineries are located (Rijeka, Sisak). Today, ground level concentrations of SO2 and soot at the sources at petrolum rafineries primarily due to combustion of gas instead of liquid fuel has been decreased to degree that the air quality at this urban areas belongs to first category. Regional level: Emissions from petroleum industry contribute to the problems on regional level, such as acid rains (SO2, NOx), eutrophication (NOx), high concentrations of tropospheric ozon (NOx), and pollutions with heavy metals and persistent organic pollutants (POP) such as polycyclic aromatic hydrocarbons (PAH) and dioxin. According to data, emissions of SO2, NOx from refineries (Sisak, Rijeka) contribute with 8 percent to total emissions of SO2, NOx from liquid fuels in Croatia (1).

This study aimed to create a comprehensive evaluation method for sewage sludge (SS) treatment and disposal technologies, considering carbon emission and environmental impacts. Life cycle assessment (LCA) were conducted on six SS treatment and disposal technologies in China. The assessments used the IPCC emission factor approach to calculate carbon emissions and the CML2001 method to determine environmental impact factors. Additionally, a colour-coded method was implemented to quantify the evaluation results. The study found that S1 (anaerobic digestion + land application) had the lowest carbon emissions and environmental impact, making it the optimal technology. The S1 scenario had carbon emissions of 669 kg CO2(t DS)−1 and environmental impacts of 5.20E-10. A sensitivity analysis was conducted to show the impacts of each unit in the six technologies on total carbon emissions and environmental impacts. The results showed that landfilling has a high sensitivity to carbon emissions and environmental impacts. Therefore, controlling greenhouse gases and toxic substances in sludge landfills is crucial for reducing carbon emissions and environmental pollution.

As the increasing global consumption of concrete drives notable environmental burdens from its production, particularly greenhouse gas (GHG) emissions, interest in mitigation efforts is increasing. Yet current environmental impact quantification tools rely on user decision-making to select data for each concrete constituent, have inconsistent scopes and system boundaries, and often utilize third-party life cycle inventories. These factors limit customization or tracking of data and hinder the ability to draw robust comparisons among concrete mixtures to mitigate its environmental burdens. To address these issues, we introduce a cohesive, unified dataset of material, energy, and emission inventories to quantify the environmental impacts of concrete. In this work, we detail the synthesis of this open dataset and create an environmental impact assessment tool using this data. Models can be customized to be region specific, expanded to varying concrete mixtures, and support data visualization throughout each production stage. We perform a scenario analysis of impacts to produce a representative concrete mixture across the United States, with results ranging from 189 kg CO2-eq/m3 of concrete (California) to 266 kg CO2-eq/m3 of concrete (West Virginia). The largest driver of GHG, nitrogen oxide, sulfur oxide, and volatile organic compound emissions as well as energy demand is cement production, but aggregate production is the largest driver of water consumption and particulate matter smaller than 2.5 microns (PM2.5) emissions.

In this study, the objective is to develop an intelligent system for making decisions on the choice of methods for cleaning exhaust gases from sulfur and nitrogen oxides using the Case-Based Reasoning- (CBR). The task of automating the selection of effective methods for cleaning waste gases is urgent and meets the paradigm of sustainable development. 
 A database on methods for cleaning exhaust gases from nitrogen and sulfur oxides was created. The potential use of intelligent inference on precedents from the database to select the most appropriate cleaning method for new emission stream data is considered. The work of the CBR method is represented as a life cycle, which has four main stages: Retrieving, Reusing, Revising and Retaining.
 The following characteristics of precedents were considered: degree of purification, initial concentration, temperature, presence of impurities, obtained product, material consumption, and energy consumption. All of these characteristics (in CBR attributes), except for the fourth and fifth, are given by numerical values with respective units of measurement and can be easily normalized. The presence of impurities and the product are categorical attributes with a certain set of values (classes).
 One of the main problems in CBR was solved: the problem of choosing the type of indexes. A set of all input characteristics of the precedent as indices is suggested to be used for the proposed decision support system (DSS) for methods of cleaning gas emissions.
 The first two phases of the CBR lifecycle use the k-nearest neighbor method to Retrieving and Reusing. The Euclidean metric is used to estimate the distances between precedents in the developed system. During the third and fourth phases of CBR, the intervention of the decision maker is provided. The process finishes with the adoption of the found solution and the possible storage of this solution in the base of use cases.
 An intelligent decision-making system has been developed for the selection of methods for cleaning exhaust gases from sulfur and nitrogen oxides based on the method of inference by precedents (CBR), which has been done for the first time for such tasks of chemical technology.

Th is paper reports a study on the preference level for the use of interlocking masonry over the conventional types in sustainable housing delivery in Nigeria. Globally, buildings are the largest energy consumers and greenhouse gases emitters, consuming over 50% in som e cases. Co mmon materials used for masonry works in housing delivery in Nigeria such as sandcrete blocks and burnt bricks impact high energy and greenhouse gases on the environment due to the production processes involved. Intelligent choice of building materials capable of reducing energy used in buildings is imperative towards achieving materials efficiency and cost reduction. In this study, a comparative survey was carried out empirically among selected professionals in the building industry from 4 out the 6 geo-political zones in Nigeria through the use of questionnaire, direct observations, and interview schedules. Analyses of Chi-square test for significance of differences between materials price rating and acceptability of interlocking masonry as well as level o f willingness of respondents to use the selected materials for future pro jects were conducted. Findings signify shorter time of construction and reduced cost of construction expended when interlocking blocks are used. The study concludes that interlocking masonry is a good replacement to the conventional types in construction of housing in Nigeria.

The use of greenhouse gas (GHG) emissions as a criterion for decision-making within the rail industry is increasing. The demand for considering this criterion affects the type of decision models acceptable by railway infrastructure managers in the planning, construction, and maintenance of railway assets. The total amount of GHG emitted from a track solution in tunnels during its service life depends on the track form (i.e., ballasted track or ballastless track), the type of construction, maintenance machines used, current traffic profile, and tunnel length. However, the development in the design of ballastless track systems during recent decades to make them environmentally friendly motivates infrastructure managers to rethink and consider the use of the system. This study examines the effect of several design and maintenance factors not adequately addressed in previous research. These factors are (i) the modulus of elasticity of track support affecting the design of track forms, (ii) differences in maintenance and renewal required for track forms in the corresponding line condition, and (iii) recent developments in optimizing the environmental impact of ballastless tracks. The GHG emissions, represented by life cycle carbon dioxide equivalent (CO2e) emissions, are calculated using the climate impact software developed by the Swedish Transport Administration Trafikverket. The result is compared with the estimated emission from the conventional ballasted tracks. The method proposed in this paper is applied in a case study to study the effect of applying the optimized ballastless track system Rheda 2000® in a railway tunnel (the Hallsberg-Stenkumla tunnel) as part of a new line project in Sweden. The model applied in the study is an integral part of an integrated decision support system for effectively selecting track solutions from a lifecycle perspective. The study´s findings are: (i) the life cycle CO2 equivalent emissions by a ballastless track during its life cycle are 10% lower than that of the ballasted track, (ii) the primary total emission driver for both track form solutions is the emissions generated at the manufacturing of rails. (iii) the second important emission factor for the ballasted track solution is the emission from the renewal of the track form during its life cycle, and (iv) the second important emission factor for the ballastless track solution is concrete manufacturing.

PurposeHow to build in more environmentally sustainable manner? This issue is increasingly coming to the fore in construction sector, which is responsible for a relevant share of resource depletion, solid waste, and greenhouse gas (GHG) emissions. Carbon-reinforced concrete (CRC), as a disruptive innovation of composite building material, requires less resources and enables new forms — but does it make CRC more environmentally sustainable than steel-reinforced concrete (SRC)? This article aims to assess and compare the environmental impact of 45 material and production scenarios of a CRC with a SRC double wall.MethodsThe life cycle assessment method (LCA) is used to assess environmental impacts. The functional unit is a double wall and the reference flows are 1 m3 for concrete and 1 kg for fiber. CML methodology is used for life cycle impact assessment (LCIA) in the software GaBi© ts 10.0. A sensitivity analysis focuses on electricity grid mixes, concrete mixes, and steel production scenarios.ResultsThe midpoint indicator climate change respective global warming potential (in kg CO2e) ranges between 453 kg CO2e and 754 kg CO2e per CRC double wall. A comparable SRC double wall results in emissions of 611–1239 kg CO2e. Even though less raw material is needed for CRC, it does not represent a clear advantage over SRC in terms of climate change. In a comparison, the production of steel (blast furnace vs. electric arc furnace vs. recycled steel) and the choice of cement type are of decisive relevance. For concrete mixes, a mixture of Portland cement and blast furnace slag (CEM III) is beneficial to pure Portland cement (CEM) I. For fiber production, styrene-butadiene rubber (SBR) has an advantage over epoxy resin (EP) impregnation and the use of renewable energy could reduce emissions of fiber production up to 60%.ConclusionCRC requires less material (concrete cover) than SRC, however, exhibits comparable CO2e to SRC — depending on the production process of steel. In the future, fiber production and impregnation should be studied in detail. Since in terms of climate change neither wall (CRC vs. SRC) clearly performs better, the two other pillars of sustainability (economic and social, resulting in LCSA) and innovative building components must be focused on.Graphical