This work focused upon design and operation of biodiesel production facilities in support of the broader goal of developing a strategic approach to the development of biorefineries. Biodiesel production provided an appropriate starting point for these efforts. The work was segregated into two stages. Various feedstocks may be utilized to produce biodiesel, to include virgin vegetable oils and waste cooking oil. With changing prices, supply, and demand of feedstocks, a need exists to consider various feedstock options. The objective of the first stage was to develop a systematic procedure for scheduling and operation of flexible biodiesel plants accommodating a variety of feedstocks. This work employed a holistic approach and combination of process simulation, synthesis, and integration techniques to provide: process simulation of a biodiesel plant for various feedstocks, integration of energy and mass resources, optimization of process design and scheduling, and techno-economic assessment and sensitivity analysis of proposed schemes. An optimization formulation was developed to determine scheduling and operation for various feedstocks and a case study solved to illustrate the merits of the devised procedure. With increasing attention to the environmental impact of discharging greenhouse gases (GHGs), there has been growing public pressure to reduce the carbon footprint associated with fossil fuel use. In this context, one key strategy is substitution of fossil fuels with biofuels such as biodiesel. Design of biodiesel plants has traditionally been conducted based on technical and economic criteria. GHG policies have the potential to significantly alter design of these facilities, selection of feedstocks, and scheduling of multiple feedstocks. The objective of the second stage was to develop a systematic approach to design and scheduling of biodiesel production processes while accounting for the effect of GHG policies. An optimization formulation was developed to maximize profit of the process subject to flowsheet synthesis and performance modeling equations. The carbon footprint is accounted for through a life cycle analysis (LCA). The objective function includes a term reflecting the impact of the LCA of a feedstock and its processing to biodiesel. A multiperiod approach was used and a case study solved with several scenarios of feedstocks and GHG policies.

Thesis (PhD(Agricultural Economics, Extension and Rural Development))--University of Pretoria, 2007. / Includes bibliographical references.

Greenhouse gases in the Earth’s atmosphere play an important role in regulating surface temperatures. The UK is signatory to international agreements that legally commit the UK to reduce its greenhouse gas emissions, and there is a scientific and political need to better understand greenhouse gas sources on regional scales. The current methods used to provide greenhouse gas emission inventories rely on ‘bottom-up’ techniques and have large associated errors. However, it is also possible to use observations of atmospheric concentrations of greenhouse gases and models of atmospheric transport to link the observations with source regions in order to estimate emissions in a ‘top-down’ approach. The key findings presented in this thesis are (a) UK emissions can be retrieved from the Angus tall tower in Scotland using the NAME inversion technique at a finer spatial resolution than has previously been reported using similar ‘top-down’ inverse methods; (b) atmospheric measurements from the Angus tall tower in Scotland have been used for the first time with the NAME inversion technique in order to estimate UK emissions of methane, nitrous oxide and sulfur hexafluoride for the years 2006 to 2009; (c) increasing the number of towers in UK network substantially increases the spatial resolution of greenhouse gas emission estimates. The errors and uncertainties associated with the NAME inversion over the UK domain are discussed and potential future improvements to this approach are presented. Overall, the work presented in this thesis has contributed to our understanding of the spatial and inter-annual variability of UK greenhouse gas emissions.

Geothermal Energy is one of the common talks at present. It has the potential to run long term and can provide base-load energy, at the same time it helps to reduce the greenhouse gas emissions. It is found almost everywhere on earth. The resources of geothermal energy range from shallow ground to hot water or hot rock, which can be found few kilometers below the surface and even deeper to magma where the temperature is extremely high. Since its discovery from the ancient times, many technologies have been developed to understand or use geothermal energy properly.  This report is based on literature survey of geothermal energy compared to other energy sources in terms of construction, supply energy and the advantage-disadvantage of the system. From this study it has been found that geothermal power plant does not need external fuel to operate, that’s why the price of geothermal energy does not go up like oil and gas, in USA the cost of geothermal electricity ranges from $0.06 to $0.10 per kilowatt-hour and besides it is one of the most clean, reliable and renewable energy source, which is environment friendly and cheaper than other energy sources.

Peatlands cover approximately 2-3% of the world’s land area yet represent approximately a third of the worlds estimated total soil carbon pool. They therefore play an important role in regulating global atmospheric CO2 and CH4 concentrations, and even minor changes in their ability to store carbon could potentially have significant effects on global climate change. Much previous research has focussed primarily on land-atmosphere fluxes. Where aquatic fluxes have been considered, they are often in isolation from the rest of the catchment and usually focus on downstream losses, ignoring evasion (degassing) from the water surface. However, as peatland streams have been repeatedly shown to be highly supersaturated in both CO2 and CH4 with respect to the atmosphere, they potentially represent an important pathway for catchment GHG losses. This study aimed to a) create a complete GHG and carbon budget for Auchencorth Moss catchment, Scotland, linking both terrestrial and aquatic fluxes, and b) understand what controls and drives individual fluxes within this budget. This understanding was further developed by a short study of C exchange at the peat-aquatic interface at Mer Bleue peatland, Canada. Significant variability in soil-atmosphere fluxes of both CH4 and N2O emissions was evident at Auchencorth Moss; coefficients of variation across 21 field chambers were 300% and 410% for CH4 and N2O, respectively. Both in situ chamber measurements and a separate mesocosm study illustrated the importance of vegetation in controlling CH4 emissions. In contrast to many previous studies, CH4 emissions were lower and uptake greater where aerenchymous vegetation was present. Water table depth was also an important driver of variability in CH4 emissions, although the effect was only evident during either periods of extreme drawdown or when the water table was consistently near or above the peat surface. Significant pulses in both CH4 and N2O emissions were observed in response to fluctuations in water table depth. Despite the variability in CH4 and N2O emissions and the uncertainty in up-scaled estimates, their contribution to the total GHG and carbon budgets was minor. Concentrations of dissolved CO2 in peatland drainage waters ranged from a mean of 2.88 ± 0.09 mg C L-1 in the Black Burn, Scotland, to a mean of 7.64 ± 0.80 mg C L-1 in water draining Mer Bleue, Canada. Using non-dispersive infra-red (NDIR) CO2 sensors with a 10-minute measurement frequency, significant temporal variability was observed in aquatic CO2 concentrations at the 2 contrasting field sites. However, the drivers of this variability differed significantly. At Mer Bleue, Canada, biological activity in the water column led to clear diurnal cycles, whereas in the Black Burn draining Auchencorth Moss, dilution due to discharge was the primary driver. The NDIR sensor data also showed differences in soil-stream connectivity both between the sites (connectivity was weak at Mer Bleue) and across the range of conditions measured at Auchencorth Moss i.e. connectivity increased during periods of stormflow. Compiling the results from both the terrestrial and aquatic systems at Auchencorth Moss indicated that the catchment was functioning as a net sink for GHGs (382 kg CO2-eq ha-1 yr-1) and a net source of carbon (143 kg C ha-1 yr-1). The greatest flux of GHGs was via net ecosystem exchange (NEE). Terrestrial emissions of CH4 and N2O combined returned only ~5% of CO2-equivalents captured by NEE to the atmosphere, whereas evasion of CO2, CH4 and N2O from the stream surface returned ~40%. The budgets clearly show the importance of aquatic fluxes at Auchencorth Moss and highlight the potential for significant error in source/sink strength calculations if they are omitted. Furthermore, the process based understanding of soil-stream connectivity suggests the aquatic flux pathway may play an increasingly important role in the source-sink function of peatlands under future management and climate change scenarios.

Biochar is a carbon sequestration technology that has shown potential to inhibit greenhouse gas (GHG) emission and nutrient leaching from soils, however the majority of biochar research thus far has focused on arable cropland rather than livestock systems or grasslands. Livestock production is an important agricultural system, and manure generated from livestock systems is a source of GHG emission as well as nutrient loading to surface- and groundwater. The high environmental impact of livestock production in the very areas that biochar has shown potential may suggest that this would be an ideal system for biochar incorporation. However, as grassland systems in the context of livestock production often receive high nutrient inputs in the form of manure which increases the potential for nutrient leaching or runoff, the high-nutrient ash content of biochar may potentially exacerbate this problem rather than suppress nutrient loss from soils. As private companies and government-funded programmes discuss the possibility of scaling the global manufacturing and soil-incorporation of biochar to a rate of gigatonnes per year, understanding the potential of biochar for use within a livestock system could be crucial in helping to develop an appropriate deployment plan for this material. This thesis is therefore focused on the use of biochar in grassland and livestock systems. It first examines the nutrient release from biochar in a sequential leaching experiment. Phosphorus (P) release indicated that provision of soil P (though quantitatively small) may be sustained over time whilst potassium (K+) release was quantitatively large but declined rapidly following the first extraction. An incubation study was then carried out using soil columns amended with farmyard manure, liquid manure (slurry) or fertiliser (plus an unamended control), each with and without biochar, which sought to determine the impact of biochar on N2O release and N and P leaching from soils with diverse nutrient sources. N2O emission from the columns was significantly suppressed by the presence of biochar, as was the leaching of mineral N. However, the amount of PO4 3--P in leachate was increased in biocharamended columns, relative to their unamended counter-parts. A slurry incubation study was then conducted, with a control slurry and four biochar-amended treatments, which explored whether biochar could suppress GHG and NH3 emission from manure prior to land application. The resulting data indicated that biochar demonstrates potential for GHG suppression but does not demonstrate potential for NH3 suppression from slurry in storage. Finally, a one-year field-based experiment was completed which analysed the impact of biochar on CH4, N2O, and NH3 emission as well as nutrient leaching from grassland soils that had been amended with a high rate of manure application (151.4 m3 ha-1 or 409 kg N ha-1). In this study, biochar demonstrated the potential to suppress each of the three types of gaseous emissions from manure-amended soil, though the differences between mean values were not statistically significant. Extracts from ion exchange resins indicated that annual cumulative K+ leached from biochar-amended plots was significantly higher than the control, and that P and NH4 + leached from biochar-amended plots was higher than the control at the time of the first rain event following biochar and manure application. Together, the results of these component studies indicate that biochar may indeed have potential to suppress GHG emissions from livestock systems, most likely through suppression of microbial activity by organic compounds that are sorbed to the char, though (as the mechanisms of GHG suppression by biochar are thus far not well understood) the capacity of biochar to do so may vary based on the type of biochar used, the soil characteristics, and other factors. Overall, the results of these studies suggest that some types of biochar should be used with caution in systems with high rates of nutrient application, unless the ash is removed prior to soil application.

A critical evaluation of the national profile of energy supply and demand and the associated greenhouse gas (OHO) emissions in China has been conducted. The contribution of the transport sector in China, the road transport sector in particular, to China's overall energy demand and OHO emissions has been assessed and compared with values for other countries. Approaches for reducing energy demand and OHO emissions in the road transport sector worldwide have been reviewed. A detailed bottom-up model has been developed using 'LEAP' software, to estimate future energy demand and OHO emissions in China's road transport sector, incorporating China's recent efforts in alternative fuel promotion. Modelling approach and historical data used have been tested and verified to ensure reliability. Two scenarios have been designed to describe the future strategies relating to the development of China's road transport sector between 2005 and 2030. The 'Business as Usual' scenario is used as a baseline reference scenario, in which the government is assumed to do nothing to influence the long-term trends of road transport energy demand. The 'Best Case' scenario is considered to be the most optimized case where a series of available reduction measures are assumed to be implemented. Energy demand and OHO emissions in China's road transport sector up to 2030 are estimated in these two scenarios. The reduction potential and the relative contribution of each measure have been estimated. A 'life cycle assessment' model for the road transport sector has been developed. The life cycle energy demand and OHO emissions in China's road transport sector are estimated using the model. The reduction potential and the relative contribution of each measure have been re-assessed from a life cycle perspective. Potential impacts on global oil resources, availability and prices are discussed. The importance of life cycle assessment in evaluating the effects of different reduction measures is discussed. Policy implications are presented.

As part of the response to the threat of dangerous climate change a variety of methods have emerged for measuring greenhouse gas emissions to the atmosphere, assigning responsibility for those emissions, and informing decisions on mitigation actions. Many of these greenhouse gas accounting methods have developed in semi-isolated fields of practice, and this raises questions about how these different methods relate to each other, and whether they form ‘families’ of conceptually similar approaches. A useful distinction has developed within the field of life cycle assessment (LCA) between attributional and consequential methods, and this thesis explores the possibility of extending that distinction to categorise other forms of greenhouse gas accounting. Broadly, attributional methods are inventories of emissions/removals for a defined inventory boundary, while consequential methods aim to estimate system-wide changes in emissions that result from a decision or action. This thesis suggests that national greenhouse gas inventories, city inventories, corporate inventories, and attributional LCA are all attributional in nature, while project-level assessments, policy-level assessments, and consequential LCA are all consequential in nature. The potential benefits from creating this categorical framework include ensuring that individual methods are conceptually coherent, transposing lessons between methods of the same categorical type, and ensuring that the correct type of method is used for a given purpose. These various benefits are explored conceptually through the analysis of existing greenhouse gas accounting standards, and also empirically with the use of a bioenergy case study. The findings suggest that the attributional-consequential distinction is highly useful for conceptualising and developing greenhouse gas accounting methods, which is important, ultimately, for addressing dangerous climate change.

Dairy production systems are an important global contributor to anthropogenic greenhouse gas (GHG) emissions including methane (CH4), nitrous oxide (N2O) and carbon dioxide (CO2). Due to the role GHG play in climate change, it is important to investigate ways to minimise their global warming potential (GWP) and to maximise the efficiency of dairy production systems. Finding a balance between improving productivity and suppressing the range and quantity of GHG produced in dairy production is crucial in order to maintain sustainability in the future. The Langhill herd is part of a long term genetic x feeding systems study, representative of a range of dairy production systems which may be found in the UK. Two feeding regimes (low forage (LF) and high forage (HF)) were applied to each of two genetic lines (control (C) and select (S) genetic merit for milk fat plus protein) giving four contrasting dairy production systems (LFC, LFS, HFC, HFS). Biological efficiency (production and energetic) and environmental efficiency (GWP) were assessed by way of life cycle analysis (LCA), accounting for dairy system inputs and outputs from off-farm production of imported feeds and fertilisers to raw milk leaving the farm gate over a period of seven years. Calculations were conducted using the Intergovernmental Panel on Climate Change (IPCC) methods, with system specific data implemented where possible. Select genetic line under low forage regime (LFS) had the highest gross production and energetic efficiencies (p<0.001). In LFS, milk yields were 56% higher per cow than the lowest ranked HFC system, representing a difference of around 3500kg per cow. Milk solids yield per kg dry matter intake was 18% higher in LFS compared to HFC. High forage with control genetic line required 17% more net energy intake than LFS to produce each kg of milk solids. LFS allocated the highest proportion of net energy to lactating after accounting for body maintenance (p<0.001). Rate of change in efficiency throughout lactation varied significantly (p<0.001) amongst systems, with loss of efficiency minimised in LFS and greatest in HFC. However, LFS involuntary culling rate was significantly higher than other systems (p<0.001). LFS was the most environmentally efficient system and HFC the least (p<0.001), both per unit productivity and per unit total land use. Implementing low forage regime with select genetic line lowered GWP per kg energy corrected milk (ECM) by 24% compared to HFC (p<0.001). GWP of LFC was around 8% lower per kg ECM than HFS (p<0.001). Methane from enteric fermentation contributed the greatest proportion of overall GWP (46-49%) in all systems. However, key factors in the differences amongst systems were higher off-farm CO2 equivalent emissions under low forage, and higher on-farm N2O emissions under high forage regime. HFC produced 91% more nitrous oxide per kg ECM from animal manures compared to LFS, and 65% more N2O from applied manufactured fertilisers (p<0.001). Conversely GWP associated with off-farm production of imported feeds in LFS was 11% higher than in HFC (p<0.001). In low forage systems high gross emissions were offset by high productivity but this was not the case for the high forage systems. Cows of high genetic merit managed under a Low Forage feeding regime had improved production, energetic and environmental efficiencies. However, issues with animal health and fertility raise questions about long term sustainability of the LFS dairy production system, emphasising the importance of examining trade offs between systems.

The purpose of this dissertation is to assess the current state of climate policy and greenhouse gas (GHG) emission trends in the state Florida and its local governments. The research is guided by three research questions 1) What has been the policy response from state and local governments to the threat of climate change; 2) What were the GHG emission trends from 2000 to 2010 in Florida and its local governments and what were the drivers of change?; and, 3) what were the issues related to the data and methodologies to quantify GHG emissions at the local government level? Policymakers need accurate data and a framework by which to measure progress towards reduction targets and mitigation strategies aimed at reducing GHG emissions. To date, there has not been a comprehensive assessment in Florida despite the proliferation of reduction targets and action planning in state and local governments. Research was conducted to systematically catalogue climate policy at the state and specific actions at the local government level. Actions taken at the local government level included participation in one or more of eight climate networks and completion of a GHG inventory and/or climate action plan. A comprehensive GHG inventory was completed for the state (2000 through 2010) and for all 477 local governments (2000 and 2010). GHG emissions were summarized for total GHG emissions, per capita GHG emissions, per land area GHG emissions, and by sector (i.e., energy, transportation, industrial processes, agriculture, waste, carbon sequestration, and miscellaneous other categories). The ambitious 2007 policies of Governor Crist to curb state GHG emissions floundered once he left office and was replace by the new Governor Rick Scott. It was then left to local governments to respond to the threat of global warming with 117 of 477 local governments pledging to take action (as evidenced through participation in climate action networks). However, only a small minority actually tried to go beyond to complete a GHG inventory and develop a climate action plan. Of these, only two have conducted a follow-up GHG inventory with resultant increases of over 30 percent which falls far short of county-wide reduction targets of 20 percent. GHG emissions from the 39 local governments who undertook GHG inventories found increases in GHG emissions of 10 percent. GHG emissions in the state have increased by 14 percent from 2000 to 2010. In both 2000 and 2010, transportation and electricity consumption were the largest contributors of GHG emissions in both the state and its local governments. Industrial and agricultural emissions were also contributors but these emissions not equally distributed throughout local governments in Florida due to the location of these industries across the state. The rates of change from 2000 to 2010 were not equal in all categories. GHG emission increases were observed in the majority of categories but at different rates; however, reductions were observed in industrial sources and livestock and other agricultural sources. The research identifies drivers of GHG emission change in the state to include population size, Florida gross domestic product (FGDP), land use change, and national energy policies (i.e., natural gas over coal and increased fuel efficiency standards). When assessing methodologies for states and local governments, nine separate GHG methodologies were identified all of which used different approaches and categorical coverage. In addition, the procedures that are used may not be appropriate for the scale of a local jurisdiction due to problems associated with generalizing or averaging emissions data. Data availability at the state level is robust; however, readily-available data at the local government level for certain categories were deemed to be insufficient to avoid highly uncertain assumptions. Review of the completed GHG inventories indicates the use of different approaches makes comparisons between the published GHG emissions impossible. It is recommended that a standardized methodology and data collection framework be used for all local governments for more accurate comparisons and to assess the impacts of policy at a local government scale. While the local government GHG inventory required the use of some uncertain assumptions due to data limitations, such a framework was developed for this dissertation. The framework could be refined with more accurate data for future inventories and could also be adapted for other states.