• Refine Query
  • Source
  • Publication year
  • to
  • Language
  • 464
  • 150
  • 63
  • 59
  • 18
  • 14
  • 13
  • 7
  • 6
  • 4
  • 3
  • 3
  • 2
  • 2
  • 1
  • Tagged with
  • 922
  • 922
  • 922
  • 377
  • 277
  • 273
  • 176
  • 162
  • 161
  • 147
  • 141
  • 135
  • 134
  • 122
  • 120
  • 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.
41

Life Cycle Assessment of a Pilot Scale Farm-Based Biodiesel Plant

Wasserman, Eli Shawn Jordan 07 May 2013 (has links)
This study used environmental life cycle assessment (LCA) to investigate waste vegetable oil (WVO) biodiesel production at the University of Guelph, Ridgetown Campus, Centre for Agricultural Renewable Energy and Sustainability (CARES). CARES production data and Natural Resources Canada’s GHGenius LCA data were utilized to conduct a well-to-gate LCA. A range of scenarios were studied including using soybean oil feedstock and implementing methanol recovery. Results suggest that methanol is the environmental bottleneck of the WVO biodiesel production system. Results also suggest soybean biodiesel production released more GHG emissions and consumed more energy than both WVO biodiesel or petroleum diesel production. LCA is an iterative process. Due to the study’s limited scope, and status as a screening study, it is recommended that the study of the impacts of the CARES facility be redone with more reliable facility data, that it include the anaerobic digester, as well as a well-to-wheels boundary. / University of Guelph
42

Environmental and Performance Analysis of a 5kW Horizontal Axis Wind Turbine in East Central Alberta

Rooke, Braden Unknown Date
No description available.
43

Bio-oil Transportation by Pipeline

Pootakham, Thanyakarn Unknown Date
No description available.
44

Material flows in the waterjet industry : an environmental perspective

Abbatelli, Daniele January 2014 (has links)
Abrasive Waterjet cutting (AWJ) presents many advantages over competing machining techniques, but several issues are related to the high volume of materials (and in particular of abrasive) used in the process. In this study, the environmental impact of the material flows in the abrasive waterjet industry has been analyzed adopting a life cycle perspective in order to individuate which phases place the largest burden on the environment. Moreover, three alternative abrasives (crushed rock, recycled glass and synthetic abrasive) and three disposal practices (in-site recycling, off-site recycling and recycling as construction material) have been also evaluated to estimate the benefits that can be achieved if these could be used in place of garnet abrasives and landfilling. The transportation of the abrasive resulted to be the phase that has the largest influence in every case and thus should be reduced as much as possible. For what concerns the alternative options, the usage of recycled glass and the in-site recycling of the abrasive were the two alternatives with the best environmental performances. However, crushed rock could be the best option for what concerns the global warming potential if carbon sequestration due to carbonation of silicate rocks is taken into account. Off-site recycling and recycling as construction material are good options only if the transportation to the recycling site can be reduced. Synthetic abrasive are instead found to have a much larger impact compared to every other alternative examined.
45

A platinum life cycle assessment : potential benefits to Anglo Platinum / I. Caddy.

Caddy, Irene January 2011 (has links)
There has been an increased awareness of the inter-dependence between man and the environment since the 1960’s. Environmental awareness has evolved from representing fairly radical views opposing all development, to a current emphasis on sustainable development between development and the environment. Life Cycle Assessment (LCA) is defined as the identification and quantification of the environmental impacts of a product, process or service during the entire life cycle being studied. The life cycle starts at the extraction of raw materials and the production of energy used to create the product through the use and final disposal of the product. LCA therefore considers the production, use and disposal of a product, which constitutes the life cycle of the product. LCA can be combined with methodologies that study other parameters such as costs in order to optimise the benefits from LCA. It is suggested that cost implications of processes to reduce environmental impacts should be included in a methodology used for a Platinum LCA. A comment that is consistently raised in the case studies is that the minerals industry regards LCA as an effective tool to determine the impacts of the industry, however extraction & beneficiation of minerals are often grouped together, with accurate data not being available, and databases either not available or not updated. The case studies indicated several benefits from the various LCA’s conducted. A Platinum LCA should clearly define and group the environmental impacts being studied into categories such as greenhouse gas emissions, global warming, acidification, and resource consumption. A Platinum LCA will be resource- and time intensive due to the large scale of the processes involved. It is suggested that a Platinum LCA firstly focuses on the production phase, i.e. cradle-to-gate, with potential future work done on the use and end-of-life stages. It is suggested that individual facility-based LCA’s for AMPLATS and other platinum producers are conducted in order to get a true reflection of the environmental burden of each company, and then selectively share technological improvements to reduce the environmental burden without disclosing sensitive information. The benefit of LCA in the case of platinum will be optimised if it can be used to make business decisions, together with consideration of financial and production benefits in addition to anticipated environmental benefits of alterations to processes. It is essential that LCA is seen as a business tool that will assist the company to make informed business decisions about process improvements, as well as new projects and design of new facilities. LCA on its own will not determine which product or process is the most cost effective or works best. The information developed in a LCA study should be used as one component of a more comprehensive decision making process assessing the trade-offs with cost and performance. The results from a LCA could be used to make informed decisions about optimisation between costs and reduced environmental impacts. / Thesis (M. Environmental Management)--North-West University, Potchefstroom Campus, 2011.
46

A platinum life cycle assessment : potential benefits to Anglo Platinum / I. Caddy.

Caddy, Irene January 2011 (has links)
There has been an increased awareness of the inter-dependence between man and the environment since the 1960’s. Environmental awareness has evolved from representing fairly radical views opposing all development, to a current emphasis on sustainable development between development and the environment. Life Cycle Assessment (LCA) is defined as the identification and quantification of the environmental impacts of a product, process or service during the entire life cycle being studied. The life cycle starts at the extraction of raw materials and the production of energy used to create the product through the use and final disposal of the product. LCA therefore considers the production, use and disposal of a product, which constitutes the life cycle of the product. LCA can be combined with methodologies that study other parameters such as costs in order to optimise the benefits from LCA. It is suggested that cost implications of processes to reduce environmental impacts should be included in a methodology used for a Platinum LCA. A comment that is consistently raised in the case studies is that the minerals industry regards LCA as an effective tool to determine the impacts of the industry, however extraction & beneficiation of minerals are often grouped together, with accurate data not being available, and databases either not available or not updated. The case studies indicated several benefits from the various LCA’s conducted. A Platinum LCA should clearly define and group the environmental impacts being studied into categories such as greenhouse gas emissions, global warming, acidification, and resource consumption. A Platinum LCA will be resource- and time intensive due to the large scale of the processes involved. It is suggested that a Platinum LCA firstly focuses on the production phase, i.e. cradle-to-gate, with potential future work done on the use and end-of-life stages. It is suggested that individual facility-based LCA’s for AMPLATS and other platinum producers are conducted in order to get a true reflection of the environmental burden of each company, and then selectively share technological improvements to reduce the environmental burden without disclosing sensitive information. The benefit of LCA in the case of platinum will be optimised if it can be used to make business decisions, together with consideration of financial and production benefits in addition to anticipated environmental benefits of alterations to processes. It is essential that LCA is seen as a business tool that will assist the company to make informed business decisions about process improvements, as well as new projects and design of new facilities. LCA on its own will not determine which product or process is the most cost effective or works best. The information developed in a LCA study should be used as one component of a more comprehensive decision making process assessing the trade-offs with cost and performance. The results from a LCA could be used to make informed decisions about optimisation between costs and reduced environmental impacts. / Thesis (M. Environmental Management)--North-West University, Potchefstroom Campus, 2011.
47

Bio-oil Transportation by Pipeline

Pootakham, Thanyakarn 11 1900 (has links)
Bio-oil which is produced by fast pyrolysis of biomass has high energy density compared to as received biomass. Two cases are studied for pipeline transport of bio-oil, a coal-based and hydro power based electricity supplies. These cases of pipeline transport are compared to two cases of truck transport (trailer and super B-train truck). The life cycle GHG emissions from the pipeline transport of bio-oil for the two sources of electricity are 345 and 17 g of CO2 m-3 km-1. The emissions for transport by trailer and super B-train truck are 89 and 60 g of CO2 m-3 km-1. Energy input for bio-oil transport is 3.95 MJ m-3 km-1 by pipeline, 2.59 MJ m-3 km-1 by trailer, and 1.66 MJ m-3 km-1 by super B-train truck. The results show that GHG emissions in pipeline transport are largely dependent on the source of electricity; substituting 250 m3 day-1 of pipeline-transported bio-oil for coal can mitigate about 5.1 million tonnes of CO2 per year in the production of electricity. The fixed and variable components of cost are 0.0423 $/m3 and 0.1201 $/m3/km at a pipeline capacity of 560 m3/day and for a distance of 100. It costs less to transport bio-oil by pipeline than by trailer and super B-train tank trucks at pipeline capacities of 1,000 and 1,700 m3/day, and for a transportation distance of 100 km. Power from pipeline-transported bio-oil is expensive than power that is produced by direct combustion of wood chips and transmitted through electric lines.
48

Comparative life cycle assessment of rice husk utilization in Thailand

Prasara-A, Jittima, s3126806@student.rmit.edu.au January 2010 (has links)
Thailand is one of the largest rice producing nations in the world. Moreover, there is a trend for Thai rice exports to increase. This could imply that if the trend continues, there will be an increased quantity of rice husk in the future. Rice husk is a co-product of rice products generated in the rice milling process, accounting for about 23 percent of the total paddy weight. To make use of this large quantity of rice husk, the husk has traditionally been used as an energy source in the rice mills themselves. More recently, the Thai government has promoted the use of biomass to substitute for fossil fuel consumption and to reduce the environmental impacts caused by using fossil fuels. Therefore, rice husk, which is one of the main sources of biomass in Thailand, has already been used on a commercial scale. However, the environmental impacts associated with different rice husk applications have not yet been widely investigated in the Thai context. While there is a need to find ways of dealing with rice husk disposal, it is also important to ensure that this husk is used in ways that harm the environment least. This research aims to identify the most environmentally friendly use of rice husk for Thailand. To achieve this, the research is divided into three main stages; identification of main current and potential uses of rice husk in Thailand; data collection; and data analysis using Life Cycle Analysis approach. A range of methods such as literature review, questionnaires with rice mill owners, and interviews with industry personnel, were used to help in identifying the current and potential uses of rice husk. The major current and potential rice husk uses chosen to be examined in this research are those uses of rice husk in electricity generation, in cement manufacture and in cellulosic ethanol production. The second stage is to collect detailed data about the processes of the selected rice husk uses to be examined. This was undertaken by literature review, questionnaires and interviews with involved industry personnel. The last stage is to analyse the data collated. Life Cycle Assessment (LCA) approach and the L CA software package SimaPro (version 7.1.6) were used to assess the environmental impacts of the selected rice husk uses. Results from the LCA are reviewed in the context of critical policy issues, including the Thai government biomass policies; the capacity of the production process of rice husk use options; and the infrastructure availability and practicality of the rice husk use options. Based on the goal and scope of the study, the data available for this study and the review of the issues just mentioned, it is concluded that, in the short term, the most practical environmentally friendly use of rice husk across the three uses investigated is the use of rice husk in electricity generation. However, with expected oil shortages in the future, rice husk should also be considered for use in cellulosic ethanol production, as this option helps to save some amount of petrol.
49

Integrated environmental assessment of industrial products

Sun, Mingbo, Mechanical & Manufacturing Engineering, Faculty of Engineering, UNSW January 2004 (has links)
Life Cycle Assessment (LCA) has been successfully used as an environmental assessment tool for the development of ecologically sustainable products. The application of LCA in the early design stage has been constrained by the requirement of large amounts of data and time for carrying out the assessment. In addition, the complexity of LCA causes further difficulties for product developers. In order to integrate the environmental assessment into the process of product development, this research proposes an integrated decision model for sustainable product development and a simplified LCA approach for the application in the early stage of product design. The main advantage of the proposed model is that it incorporates the environmental aspects of product development into the existing product development framework. It enables designers to strike a balance between the product???s environmental performance and other traditional design objectives. The simplified LCA approach is based on the concept and application of Environmental Impact Drivers. Material-based environmental impacts and Energy-based environmental impacts are used to predict the total environmental impact of a product. Two sets of impact drivers were developed accordingly. The Material-based Impact Drivers were identified by classifying materials into 16 groups according to the nature of the materials and their environmental performance. Energy-based Impact Drivers were developed for various energy sources in major industrial regions. Product LCA cases were used to verify the proposed methods. The results computed by the application of the impact drivers were compared with the results of full LCA studies. It is concluded that with the proposed approach, the product???s environmental performance can be assessed in a very short time and with very basic data input requirements and acceptable accuracy.
50

Integrated environmental assessment of industrial products /

Sun, Mingbo. January 2004 (has links)
Thesis (Ph. D.)--University of New South Wales, 2004. / Also available online.

Page generated in 0.1143 seconds