• Refine Query
  • Source
  • Publication year
  • to
  • Language
  • 29
  • 6
  • 4
  • 3
  • 2
  • 2
  • 2
  • 1
  • 1
  • 1
  • 1
  • 1
  • 1
  • Tagged with
  • 64
  • 64
  • 14
  • 13
  • 13
  • 11
  • 11
  • 10
  • 10
  • 9
  • 9
  • 8
  • 7
  • 6
  • 6
  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
1

Joint implementation in the Framework Convention on Climate Change and the Second Sulphur Protocol : an empirical and institutional analysis

Ridley, Michael Antony January 1997 (has links)
No description available.
2

What drives technology transfer? A study of Clean Development Mechanism projects in China

Shen, Xufei January 2017 (has links)
Thesis advisor: Richard Sweeney / With climate change becoming a global problem more people are paying attention to, a common goal to reduce Greenhouse Gas (GHG) emissions is recognized by most countries. However, usually emission reduction is more difficult to achieve in developing countries because of the lack of advanced emission reduction technology. Thus,one of the important ways to improve emission reduction technology in developing countries is through technology transfer, which is to import more advanced emission reduction technology from developed countries to developing countries. In this study, I explore the level and determinants of technology transfer using data of projects from four sectors under the CDM(Clean Development Mechanism) in China. I find that large scale projects with higher emission reduction amount tend to have higher probability of technology transfer. Also, more economically and technologically advanced provinces tend to have more projects with technology transfer. / Thesis (BA) — Boston College, 2017. / Submitted to: Boston College. College of Arts and Sciences. / Discipline: Departmental Honors. / Discipline: Economics.
3

Wet and dry deposition in the Derbyshire Peak District, Northern England

Driejana, Ir January 2002 (has links)
No description available.
4

Optimal generation expansion planning for a low carbon future

Yuan, Chenchen January 2013 (has links)
Due to energy scarcity coupled with environment issues, it is likely to see the biggest shift in generation portfolio in the UK and world wide, stimulated by various governmental incentives policies for promoting renewable generation and reducing emission. The generation expansion in the future will be driven by not only peak demand growth but also emission reduction target. Thus, the traditional generation expansion planning (GEP) model has to be improved to reflect this change against the new environment. The policy makers need a better assessment tool to facilitate the new environment, so they can make appropriate policies for promoting renewable generation and emission reduction, and guide the generation mix to evolve appropriately over time. Since the expansion of new generation capacities is highly capital intensive, it makes the improvement of GEP quite urgent and important. The thesis proposes the GEP modelling improvement works from the following aspects: • Integrating short-term emission cost, unit commitment constraints in an emission target constrained GEP model. • Including the network transmission constraints and generation location optimization in an emission constrained GEP. • Investigating the impacts of multi-stage emission targets setting on an emission constrained GEP problem and its overall expansion cost. • Incorporating the uncertain renewable generation expansion and short-term DSR into the GEP problem and find out its potential contributions to the GEP problem. A real case study is made to determine the optimal generation mix of the Great Britain in 2020 in order to meet the 2020 emission reduction target. Different optimal generation mixes of the UK in 2020 are identified under a series of scenarios. The scenarios are constructed according to different GB network transmission capacity hypotheses and demand side response (DSR) level scenarios.
5

Emissions trading scheme for South Africa : opportunities and challenges

Jooste, Dustin 03 1900 (has links)
ENGLISH ABSTRACT: This research report aims to determine whether an emissions trading scheme or carbon tax is the most suitable market-based emissions reduction mechanism for South Africa, given its multiple environmental, social and economic objectives. Key factors considered in this comparison include: environmental effectiveness; economic efficiency; social welfare impacts; public finance considerations; administrative complexity and costs; and, finally, the relationship to global greenhouse gas reduction mechanisms. These factors are compared in the short and long term to determine which mechanism is most likely to deliver South Africa’s emissions reduction targets within the given time frames. The comparison of these factors involves a non-empirical literature review, followed by a rating of the mechanisms in order to distil a best fit in terms of the various aspects of an effective emissions reduction mechanism, taking into account the specific needs and conditions of South Africa. The research found that, in the short term, a carbon tax was best suited to the South African context. This is because of the fiscal certainty inherent in this mechanism, which provides clear price signals and a stable public income. However, the reasons for these comparative advantages over an emissions trading scheme relate to the long lead times and structure of the latter mechanism, which requires years of implementation and favours environmental effectiveness over economic efficiency. Further reasons include a lack of understanding and buy-in in terms of market-based mechanisms, a situation that favours familiarity over effectiveness in some instances. Taking these issues into account, the research shows that an emissions trading scheme is better suited to the South African context in the long term. Once properly implemented, this mechanism provides superior results in terms of the above-mentioned factors, and specifically in terms of environmental effectiveness and the potential for benefit through international integration. This research report concludes that the South African government has failed to take a long-term view of the mechanisms available for emissions reduction, choosing instead to implement a carbon tax, which favours economic growth at the expense of the environment and future generations. A general lack of understanding of the structures and opportunity costs of the two mechanisms necessitates an investigation by government of the applicability and structure of an emissions trading scheme in the South African context before market-based mechanisms can play an effective part in the future development of the country’s environmental regulatory regime.
6

Application of Environmental Technology Management (ETM) to Automobile Exhaust Emission Reduction

Al-Harbi, Meshari 19 November 2010 (has links)
Vehicle emissions, arising from incomplete fuel combustion and reactions between N2 and O2 leading to NOX, have detrimental effects on human health and environment quality. Engine exhaust contains a variety of regulated components, such as hydrocarbons, CO, nitrogen oxides (NOX), and particulate matter (PM). Government environmental agencies have been continuously establishing regulations for automobile manufacturers to reduce these emissions. Lean-burn engines operate with an excess of oxygen, which makes the reduction of NOX, challenging, with a coincident challenge for diesel engines being PM. Diesel particulate filters have been successfully employed to reduce PM. NOX storage and reduction (NSR) catalysts and selective catalytic reduction (SCR) catalysts are two promising technologies used to mitigate NOX emissions. A diesel oxidation catalyst (DOC) is usually placed upstream of these to reduce hydrocarbons and CO emissions and oxidize NO to NO2, which leads to improved performance over these catalysts. In this study, the performance of DOCs and NSR catalysts, individually and in series, has been investigated as a function of temperature, gas composition, catalyst length, and catalyst configuration. The catalytic oxidation of CO, hydrocarbons, and NO, both individually and in mixtures with NO2, was investigated over a monolith-supported DOC. The data clearly show mutual inhibition effects between these species. Addition of each gas to the inlet gas mixture caused an increase in the light-off temperatures of the other species, mainly due to site adsorption competition. CO was less affected by other species because its light-off temperatures began prior to those of NOX and other hydrocarbons, and it is likely the primary surface species poisoning the active sites at low temperature. Hydrogen production via hydrocarbon steam reforming and water gas shift reactions was also investigated over a DOC during steady-state and cycling conditions (to mimic NSR catalyst operation) along the catalyst length. C3H6 and dodecane steam reforming started at 375 and 450°C, respectively, whereas the water gas shift reaction started at 225°C, and proceeded further than hydrocarbon steam reforming in terms of H2 production. It should be mentioned that H2 production via the hydrocarbon steam reforming and water gas shift reactions during cycling experiments, was higher than that observed during steady-state experiments. According to temperature programmed oxidation experiments performed after steam reforming, the better performance during cyclic operation is because less coke was deposited compared to that with steady-state experiments. Experiments were also performed over a NSR catalyst. The evaluations included testing the performance as a function of NOX source, NO or NO2, testing different regeneration protocols, and evaluating different reducing agents (hydrocarbons, H2, or CO). For NO and NO2 as the NOX source, the trapping and reduction performance was better when NO2 was used at all operating temperatures except 300ºC, likely due to high NO oxidation activity and rapid trapping of NO2 at 300ºC. Numerous reasons were provided to explain the improved performance with NO2 at other tested temperatures. The foremost reason though, is treating the monolith as an integral reactor. With NO2 as the NOX source, NO2 can be readily trapped at the very inlet and along the catalyst length, resulting in a higher trapping amount. Along the same concept, the released NOX from the inlet of the catalyst has more residence time and contact with downstream Pt sites, but more importantly more interaction between reductant and stored NOX. In the second set of experiments, different regeneration protocols were used. Different regeneration times, 4, 8 and 16 seconds with 4, 2, and 1% H2 as the reductant amounts, and constant lean times were evaluated. The data clearly show an improvement with longer regeneration times in both NOX trapping and overall reduction performance at all temperatures except 500°C, where the more significant NOX release resulted in an overall decrease in NOX conversion with increasing regeneration time. The improved performance at the lower temperatures is due to more extensive nitrate/nitrite decomposition with longer regeneration times, thus leading to more extensive surface cleaning. The performance of the NSR catalyst was also investigated using hydrocarbons, H2, or CO as reducing agents. H2 was found the best at T ≤ 250°C, where the decreased performance with CO and hydrocarbons was due to Pt site poisoning at 200°C and as a result of slow kinetics at 250°C. CO and hydrocarbons, however, proved to regenerate the catalyst as efficiently as H2 at T ≥ 300°C. Hydrogen production via steam reforming experiments can not explain the improved performance with hydrocarbons, since propylene steam reforming occurred at 375°C, with only a small amount of H2 generated, and dodecane or m-xylene reforming did not occur below 450°C. TPR data show that propylene started to activate as low as 217°C and the complete reduction of NO by propylene was achieved at 287°C. For surface chemisorbed NOX species, propylene was observed to reduce these species at T > 200°C, with high rates by 264°C, with this activity eventually leading to comparable performance with either CO or H2 at similar temperatures during NOX cycling experiments. The performance of two different hybrid DOC+NSR systems was also investigated. In the first configuration, a DOC and NSR catalyst were placed in series while in the other configuration, the DOC and NSR catalysts were divided into two equal volumes and placed in series (DOC + NSR + DOC + NSR). Overall, the data show an increase in the NOX performance with the split configuration at all temperatures tested, with small changes at 200°C due to poisoning effects of Pt and Ba sites by CO and hydrocarbons being significant. The improved performance with the split configuration was related to further NO oxidation occurring over the 2nd DOC, more H2 formed from steam reforming and WGS reactions, and reduced inhibition of the WGS reaction by hydrocarbons.
7

Optimal Deployment Plan of Emission Reduction Technologies for TxDOT's Construction Equipment

Bari, Muhammad Ehsanul 2009 August 1900 (has links)
The purpose of this study was to develop and test an optimization model that will provide a deployment plan of emission reduction technologies to reduce emissions from non-road equipment. The focus of the study was on the counties of Texas that have nonattainment (NA) and near-nonattainment (NNA) status. The objective of this research was to develop methodologies that will help to deploy emission reduction technologies for non-road equipment of TxDOT to reduce emissions in a cost effective and optimal manner. Three technologies were considered for deployment in this research, (1) hydrogen enrichment (HE), (2) selective catalytic reduction (SCR) and (3) fuel additive (FA). Combinations of technologies were also considered in the study, i.e. HE with FA, and SCR with FA. Two approaches were investigated in this research. The first approach was "Method 1" in which all the technologies, i.e. FA, HE and SCR were deployed in the NA counties at the first stage. In the second stage the same technologies were deployed in the NNA counties with the remaining budget, if any. The second approach was called "Method 2" in which all the technologies, i.e. FA, HE and SCR were deployed in the NA counties along with deploying only FA in the NNA counties at the first stage. Then with the remaining budget, SCR and HE were deployed in the NNA counties in the second stage. In each of these methods, 2 options were considered, i.e. maximizing NOx reduction with and without fuel economy consideration in the objective function. Thus, the four options investigated each having different mixes of emission reduction technologies include Case 1A: Method 1 with fuel economy consideration; Case 1B: Method 1 without fuel economy consideration; Case 2A: Method 2 with fuel economy consideration; and Case 2B: Method 2 without fuel economy consideration and were programmed with Visual C++ and ILOG CPLEX. These four options were tested for budget amounts ranging from $500 to $1,183,000 and the results obtained show that for a given budget one option representing a mix of technologies often performed better than others. This is conceivable because for a given budget the optimization model selects an affordable option considering the cost of technologies involved while at the same time maximum emission reduction, with and without fuel economy consideration, is achieved. Thus the alternative options described in this study will assist the decision makers to decide about the deployment preference of technologies. For a given budget, the decision maker can obtain the results for total NOx reduction, combined diesel economy and total combined benefit using the four models mentioned above. Based on their requirements and priorities, they can select the desired model and subsequently obtain the required deployment plan for deploying the emission reduction technologies in the NA and NNA counties.
8

The Effect of Transaction Costs on Greenhouse Gas Emission Mitigation for Agriculture and Forestry

Kim, Seong Woo 2011 May 1900 (has links)
Climate change and its mitigation is rapidly becoming an item of social concern. Climate change mitigation involves reduction of atmospheric greenhouse gas concentrations through emissions reduction and or sequestration enhancement (collectively called offsets). Many have asked how agriculture and forestry can participate in mitigation efforts. Given that over 80 percent of greenhouse gas emissions arise from the energy sector, the role of agriculture and forestry depends critically on the costs of the offsets they can achieve in comparison with offset costs elsewhere in the economy. A number of researchers have examined the relative offset costs but have generally looked only at producer level costs. However there are also costs incurred when implementing, selling and conveying offset credits to a buyer. Also when commodities are involved like bioenergy feedstocks, the costs of readying these for use in implementing an offset strategy need to be reflected. This generally involves the broadly defined category of transaction costs. This dissertation examines the possible effects of transactions costs and storage costs for bioenergy commodities and how they affect the agriculture and forestry portfolio of mitigation strategies across a range of carbon dioxide equivalent prices. The model is used to simulate the effects with and without transactions and storage costs. Using an agriculture and forestry sector model called FASOMGHG, the dissertation finds that consideration of transactions and storage costs reduces the agricultural contribution total mitigation and changes the desirable portfolio of alternatives. In terms of the portfolio, transactions costs inclusion diminishes the desirability of soil sequestration and forest management while increasing the bioenergy and afforestation role. Storage costs diminish the bioenergy role and favor forest and sequestration items. The results of this study illustrate that transactions and storage costs are important considerations in policy and market design when addressing the reduction of greenhouse gas concentrations in climate change related decision making.
9

Application of Environmental Technology Management (ETM) to Automobile Exhaust Emission Reduction

Al-Harbi, Meshari 19 November 2010 (has links)
Vehicle emissions, arising from incomplete fuel combustion and reactions between N2 and O2 leading to NOX, have detrimental effects on human health and environment quality. Engine exhaust contains a variety of regulated components, such as hydrocarbons, CO, nitrogen oxides (NOX), and particulate matter (PM). Government environmental agencies have been continuously establishing regulations for automobile manufacturers to reduce these emissions. Lean-burn engines operate with an excess of oxygen, which makes the reduction of NOX, challenging, with a coincident challenge for diesel engines being PM. Diesel particulate filters have been successfully employed to reduce PM. NOX storage and reduction (NSR) catalysts and selective catalytic reduction (SCR) catalysts are two promising technologies used to mitigate NOX emissions. A diesel oxidation catalyst (DOC) is usually placed upstream of these to reduce hydrocarbons and CO emissions and oxidize NO to NO2, which leads to improved performance over these catalysts. In this study, the performance of DOCs and NSR catalysts, individually and in series, has been investigated as a function of temperature, gas composition, catalyst length, and catalyst configuration. The catalytic oxidation of CO, hydrocarbons, and NO, both individually and in mixtures with NO2, was investigated over a monolith-supported DOC. The data clearly show mutual inhibition effects between these species. Addition of each gas to the inlet gas mixture caused an increase in the light-off temperatures of the other species, mainly due to site adsorption competition. CO was less affected by other species because its light-off temperatures began prior to those of NOX and other hydrocarbons, and it is likely the primary surface species poisoning the active sites at low temperature. Hydrogen production via hydrocarbon steam reforming and water gas shift reactions was also investigated over a DOC during steady-state and cycling conditions (to mimic NSR catalyst operation) along the catalyst length. C3H6 and dodecane steam reforming started at 375 and 450°C, respectively, whereas the water gas shift reaction started at 225°C, and proceeded further than hydrocarbon steam reforming in terms of H2 production. It should be mentioned that H2 production via the hydrocarbon steam reforming and water gas shift reactions during cycling experiments, was higher than that observed during steady-state experiments. According to temperature programmed oxidation experiments performed after steam reforming, the better performance during cyclic operation is because less coke was deposited compared to that with steady-state experiments. Experiments were also performed over a NSR catalyst. The evaluations included testing the performance as a function of NOX source, NO or NO2, testing different regeneration protocols, and evaluating different reducing agents (hydrocarbons, H2, or CO). For NO and NO2 as the NOX source, the trapping and reduction performance was better when NO2 was used at all operating temperatures except 300ºC, likely due to high NO oxidation activity and rapid trapping of NO2 at 300ºC. Numerous reasons were provided to explain the improved performance with NO2 at other tested temperatures. The foremost reason though, is treating the monolith as an integral reactor. With NO2 as the NOX source, NO2 can be readily trapped at the very inlet and along the catalyst length, resulting in a higher trapping amount. Along the same concept, the released NOX from the inlet of the catalyst has more residence time and contact with downstream Pt sites, but more importantly more interaction between reductant and stored NOX. In the second set of experiments, different regeneration protocols were used. Different regeneration times, 4, 8 and 16 seconds with 4, 2, and 1% H2 as the reductant amounts, and constant lean times were evaluated. The data clearly show an improvement with longer regeneration times in both NOX trapping and overall reduction performance at all temperatures except 500°C, where the more significant NOX release resulted in an overall decrease in NOX conversion with increasing regeneration time. The improved performance at the lower temperatures is due to more extensive nitrate/nitrite decomposition with longer regeneration times, thus leading to more extensive surface cleaning. The performance of the NSR catalyst was also investigated using hydrocarbons, H2, or CO as reducing agents. H2 was found the best at T ≤ 250°C, where the decreased performance with CO and hydrocarbons was due to Pt site poisoning at 200°C and as a result of slow kinetics at 250°C. CO and hydrocarbons, however, proved to regenerate the catalyst as efficiently as H2 at T ≥ 300°C. Hydrogen production via steam reforming experiments can not explain the improved performance with hydrocarbons, since propylene steam reforming occurred at 375°C, with only a small amount of H2 generated, and dodecane or m-xylene reforming did not occur below 450°C. TPR data show that propylene started to activate as low as 217°C and the complete reduction of NO by propylene was achieved at 287°C. For surface chemisorbed NOX species, propylene was observed to reduce these species at T > 200°C, with high rates by 264°C, with this activity eventually leading to comparable performance with either CO or H2 at similar temperatures during NOX cycling experiments. The performance of two different hybrid DOC+NSR systems was also investigated. In the first configuration, a DOC and NSR catalyst were placed in series while in the other configuration, the DOC and NSR catalysts were divided into two equal volumes and placed in series (DOC + NSR + DOC + NSR). Overall, the data show an increase in the NOX performance with the split configuration at all temperatures tested, with small changes at 200°C due to poisoning effects of Pt and Ba sites by CO and hydrocarbons being significant. The improved performance with the split configuration was related to further NO oxidation occurring over the 2nd DOC, more H2 formed from steam reforming and WGS reactions, and reduced inhibition of the WGS reaction by hydrocarbons.
10

Land of Mercury-Tinted Water: An Investigation of Methylmercury as an International Economic By-Product Pollutant and Local Cultural Detriment in the State of Minnesota

Krievans, Liga 01 January 2015 (has links)
This thesis covers how global mercury emissions are effecting the Great Lakes region, specifically focusing on Minnesota. Minnesota is sensitive to mercury due to its abundant waters and love of fishing. Establishing state regulation and diversifying the State's economy only addresses a small percentage of emitted mercury prominent in Minnesota. Therefore, Minnesota must look to and promote out of State regulation to significantly decrease mercury exposure.

Page generated in 0.092 seconds