This thesis investigates environmental and energy policies that Turkey needs to adopt on its way to a sustainable development path. A comparative-static, multi-sectoral CGE model, TurkMod, is developed in order to analyze the potential scenarios available for the Turkish economy to attain a low-carbon society with a reduced reliance on fossil fuel imports. Domestic energy demand has significantly increased in Turkey over the past decades and this has put a lot of pressure on policy-makers as the economy greatly depends on imports of natural gas and oil as far as current energy consumption is concerned. The CGE model in this study is based on a 2012 energy-disaggregated Social Accounting Matrix (SAM) constructed as a part of this thesis as well. The energy-disaggregated SAM incorporates 18 sectors for production activities, 11 products as commodities, 2 factors of production as labor and capital, 3 institutional accounts as firms, households, and the government, a separate account for taxes on commodities, taxes on production and taxes on different types of factor use, a capital account, and finally the rest of the world (ROW) account. Disaggregating the electricity sector to include 8 different types of power generating sectors (5 of which are renewable energy sources) enables electric power substitution in the model. The energy-disaggregated SAM is further linked with satellite accounts which include data on derived energy demand and greenhouse gas (GHG) emissions.The macroeconomic and environmental impacts of four distinct sets of scenarios are analyzed with respect to the baseline scenario. The first scenario simulates a 30% increase in energy efficiency in the production sectors and the residential sector and evidence is found for reaching the 21% GHG mitigation target set in Turkey’s pledge for Paris Agreement compliance. The second set of scenarios is the inclusion of a medium-level and high-level carbon tax rates for coal, oil and natural gas. The carbon tax scenarios produce significant effects on both emission reduction targets and substituting fossil fuel technologies with cleaner energy types. The third scenario investigates the sectoral and welfare impacts of providing subsidies for renewable energy sources. Turkey has already adopted a scheme where renewable energies are beings subsidized and promoted, however, this policy does not produce the necessary transformation for the Turkish society when utilized solely on its own. The fourth scenario estimates the effects of changes in world prices of energy on the Turkish economy. A 20% increase in world energy prices, i.e. oil, natural gas, and coal, induces substantial changes in the breakdown of TPES and the power-generating sector, but this scenario is a rather hypothetical one as it cannot be suggested as a viable policy option. All in all, these potential energy scenarios have significant and influential impacts on the Turkish economy and its environment. Notwithstanding, a carbon tax policy proves to be the most viable scenario which leads to reduced energy intensities in all sectors, a 21% GHG emissions abatement, and a transformation of the energy sector towards having a low-carbon content along with a reduced reliance on fossil fuel imports. / Doctorat en Sciences économiques et de gestion / info:eu-repo/semantics/nonPublished

Reservoir fluids are rarely found in homogeneous structures having homogeneous properties. The various elements and processes of the petroleum system result in complex fluid distributions and compositions. A sound understanding of these complexities can avoid disappointing results and costly mistakes when designing the completion and production of the reservoir. The earlier these complexities are understood in the exploration phase, the better are the chances of a successful decision making process in the design phase of the project. Assessing reservoir compartment connectivity is of paramount importance for a optimal field development. Recent technological advances in wireline formation testing and sampling provide asset teams with a new methodology to evaluate in situ fluid properties and reservoir connectivity. After a review of the technology of downhole fluid analysis (DFA), the currently available methods of modeling equilibrated fluid gradients are presented. Fluid composition equilibrium is a stationary state where all components have reached zero mass flux. A reservoir model is designed to simulate numerically equilibration processes over geologic timescales at isothermal conditions where diffusion and gravity are the active mechanisms. A variety of initial conditions and reservoir fluid types is considered. Non-equilibrium fluid gradients and their transient behavior as they evolve towards fluid composition equilibrium are the main interest of this study. The results are compared in case studies, that are available in published literature. The modeling methods allow modeling of vertical and lateral fluid gradients. After a discussion of the cases, this thesis gives recommendations on 1) what fluid properties should be assessed and 2) how many data points are needed to reduce the chance of misinterpretation of non-equilibrium gradients in the presence of faults. To make best use DFA data, the property that exhibits the largest gradient needs to be investigated, as it yields the greatest potential to assess connectivity. The shape of the distribution of fluid composition within a compartment is found to be an important part in investigating reservoir connectivity. During data acquisition efforts should be made to acquire enough data points to reveal this shape. In combination with the presented techniques to identify non-equilibrium conditions, this will optimize DFA data acquisition and maximize the value of the data.

This study uses the Simplified International Model of agricultural Prices, Land use and the Environment, on a Grid (SIMPLE-G­), a partial equilibrium model of agricultural production, to explore how the scale and scope of environmental quality markets influence farm-level production decisions and market performance. I simulate how permit trading affects producers’ input use decisions, and ultimately pollution emissions, by modifying the supply nest structure of the model to include water quality permits as an additional output from agricultural production. Conservation practices improving water quality may also result in ecosystem co-benefits (e.g., reduced greenhouse gas emissions and habitat provision). Hence, I extend SIMPLE-G to quantify these co-benefits and simulate the effects of allowing conservationist producers to “stack” permits (i.e., to supply multiple permit types for each co-benefit). I find that, overall, permit production increases with the scale and scope of the markets. <a>At the smallest market size</a>—which allows trading only within 8-digit hydrological unit code watersheds—unintended policy implications arise as the stacked markets cause one conservation practice to crowd out the other. Meanwhile, the largest market—which allows trading across the Chesapeake Bay Watershed—produces nitrogen permits more efficiently which may lead to less of the secondary permits in comparison to other market configurations. The results of this study support the Environmental Protection Agency’s urging of the expansion of the scale and scope of ecosystem markets.

Over the past few decades, a growing interest in the thermal conversion of alternative fuels such as biomass and waste-derived fuels has been observed among the energy-producing companies. Apart from meeting the increasing demand for sustainable heat and power production, other advantages such as reducing global warming and ameliorating landfilling issues have been identified. Among the available thermal conversion technologies, combustion in grate-fired furnaces is by far the most common mode of fuel conversion. In recent years, Fluidized-Bed (FB) technologies have grown to become one of the most suitable technologies for combustion and gasification of biomass and waste-derived fuels.In spite of the benefits, however, some difficulties are attributed to the thermal conversion of the alternative fuels. Ash-related issues could be a potential problem, as low-grade fuels may include considerable concentrations of ash-forming elements such as K, Na, S, Ca, Mg, P, Si and Cl. These elements undergo many undesirable chemical and physical transformations during the thermal conversion, and often cause operational problems such as deposition-related issues, slag formation in furnaces, corrosion of the heat transfer surfaces, and bed agglomeration of the fluidized-beds. Ash-related problems in the utility boilers are a major concern that may result in decreased efficiency, unscheduled outages, equipment failures, increased cleaning and high maintenance costs.This thesis investigated the ash behavior and ash-related problems in two different FB conversion systems: a Bubbling Fluidized-Bed (BFB) boiler combusting solid waste, and a Dual Fluidized-Bed (DFB) gasifier using biomass as feedstock. Full-scale measurements, chemical analysis of fuel and ash, as well as thermodynamic equilibrium modeling have been carried out for the BFB boiler (Papers I-IV), to investigate the impact of reduced-bed temperature (RBT) and also co-combustion of animal waste (AW) on the ash transformation behavior and the extent of ash-related issues in the boiler. For the DFB gasifier (Paper V), a thermodynamic equilibrium model was developed to assess the risk of bed agglomeration when forest residues are used as feedstock.The experimental results showed that the RBT and AW co-combustion could decrease or even resolve the ash-related issues in the BFB boiler, resulting in a lower deposit-growth rate in the superheater region, eliminating agglomerates, and a less corrosive deposit (in RBT case). Thermodynamic equilibrium modeling of the BFB boiler gave a better understanding of the ash transformation behavior, and also proved to be a reliable tool for predicting the risk of bed agglomeration and fouling. The modeling of the DFB gasifier indicated a low risk of bed agglomeration using the forest residues as feedstock and olivine as bed material, which was in good agreement following the observations in a full-scale DFB gasifier.

This thesis proposes equilibrium models to link the wholesale and retail electricity markets which allow for reconciliation of the differing time scales of responses of producers (e.g., hourly) and consumers (e.g., monthly) to changing prices. Electricity market equilibrium models with time of use (TOU) pricing scheme are formulated as large-scale variational inequality (VI) problems, a unified and concise approach for modeling the equilibrium. The demand response is dynamic in these models through a dependence on the lagged demand. Different market structures are examined within this context. With an illustrative example, the welfare gains/losses are analyzed after an implementation of TOU pricing scheme over the single pricing scheme. An approximation of the welfare change for this analysis is also presented. Moreover, break-up of a large supplier into smaller parts is investigated. For the illustrative examples presented in the dissertation, overall welfare gains for consumers and lower prices closer to the levels of perfect competition can be realized when the retail pricing scheme is changed from single pricing to TOU pricing. These models can be useful policy tools for regulatory bodies i) to forecast future retail prices (TOU or single prices), ii) to examine the market power exerted by suppliers and iii) to measure welfare gains/losses with different retail pricing schemes (e.g., single versus TOU pricing). With the inclusion of linearized DC network constraints into these models, the problem size grows considerably. Dantzig-Wolfe (DW) decomposition algorithm for VI problems is used to alleviate the computational burden and it also facilitates model management and maintenance. Modification of the DW decomposition algorithm and approximation of the DW master problem significantly improve the computational effort required to find the equilibrium. These algorithms are applied to a two-region energy model for Canada and a realistic Ontario electricity test system. In addition to empirical analysis, theoretical results for the convergence properties of the master problem approximation are presented for DW decomposition of VI problems.

This thesis proposes equilibrium models to link the wholesale and retail electricity markets which allow for reconciliation of the differing time scales of responses of producers (e.g., hourly) and consumers (e.g., monthly) to changing prices. Electricity market equilibrium models with time of use (TOU) pricing scheme are formulated as large-scale variational inequality (VI) problems, a unified and concise approach for modeling the equilibrium. The demand response is dynamic in these models through a dependence on the lagged demand. Different market structures are examined within this context. With an illustrative example, the welfare gains/losses are analyzed after an implementation of TOU pricing scheme over the single pricing scheme. An approximation of the welfare change for this analysis is also presented. Moreover, break-up of a large supplier into smaller parts is investigated. For the illustrative examples presented in the dissertation, overall welfare gains for consumers and lower prices closer to the levels of perfect competition can be realized when the retail pricing scheme is changed from single pricing to TOU pricing. These models can be useful policy tools for regulatory bodies i) to forecast future retail prices (TOU or single prices), ii) to examine the market power exerted by suppliers and iii) to measure welfare gains/losses with different retail pricing schemes (e.g., single versus TOU pricing). With the inclusion of linearized DC network constraints into these models, the problem size grows considerably. Dantzig-Wolfe (DW) decomposition algorithm for VI problems is used to alleviate the computational burden and it also facilitates model management and maintenance. Modification of the DW decomposition algorithm and approximation of the DW master problem significantly improve the computational effort required to find the equilibrium. These algorithms are applied to a two-region energy model for Canada and a realistic Ontario electricity test system. In addition to empirical analysis, theoretical results for the convergence properties of the master problem approximation are presented for DW decomposition of VI problems.

The main objective of the dissertation is to develop a dynamic, inter-regional, and multi-sector general equilibrium model of the Belgian economy capable of analysing issues related to the environment, energy, fiscal policies and accounting for distributive effects between household groups. The dissertation focuses on BelMod, a computable general equilibrium model (CGE).<p>BelMod is intended to act as an analytical and quantitative support for decision-making in the energy/environment field and fiscal policies. The tool would be in evaluating ex-ante the cost and benefit of different policies to be implemented. The winners and the losers may easily be identified. BelMod also aims at filling the gaps left by the other models currently used in Belgium, in particular by explicit bottom-up modelling of the three Belgian regions (Brussels, Flanders, Wallonia) in the full integrated framework, by further disaggregating the production and consumption blocks, by distinguishing different types of households to study the distributional effects of environmental and fiscal policies.<p>The effect of let’s say, carbon tax, may affect branches of activities, markets and institutions differently over time and space. Under the “Burden Sharing Agreement”, Belgium committed to reduce its greenhouse gas emissions by 7.5 % by 2008-2012 from the 1990 level. Therefore the efficient way of dealing with this issue requires an analytical tool which can take into account the interactions between institutional agents (regional governments, community’s governments, central government, households, firms and rest of the world), their behaviour and the time horizon. The most adequate tool to do so is the general equilibrium model.<p>A CGE model such as BelMod requires a consistent, detailed and well structured database in the form of a social accounting matrix (SAM). A SAM is a square matrix which takes into account the production, consumption, revenues, expenditures and transactions of institutions at a given period of time. The reference year for our SAM is 2003. The SAM we built contains sixty two (62) branches of activity, sixty nine (69) commodities, three (3) regional governments, the French Community, the Central Government, the capital accounts and the Rest of the World.<p>Finally, to illustrate the capabilities of the model we provide two scenario analyses. In the first policy scenario, we simulate the introduction of a carbon tax at 20 euro per ton of CO2 emissions in 2013-2020 and 30 euro per ton of CO2 emissions in 2021-2050. In the second policy scenario, we simulate a linear and gradual increase of the crude oil price to 150 US dollars per barrel in 2050. The increase starts in 2008 and the target (150 US dollars) is reached in 2050.<p> / Doctorat en Sciences économiques et de gestion / info:eu-repo/semantics/nonPublished

One of the most sustainable pathways of sewage sludge treatment in recent years has been thermal conversion. The benefits of thermal treatment of sewage sludge are the recovery of energy or valuable chemical products, the destruction of harmful organic compounds, the separation of heavy metals from the P-rich coarse ash fraction, and the decreased and sanitized ash volume. The ashes created by these thermal conversion processes of sewage sludge are often rich in P that is mostly present in minerals with low plant-availability such as apatite. Due to the enrichment of P in the created ashes, a variety of post-processing steps have been developed to recover P from sewage sludge ashes. One proven way for the sus-tainable recovery of P from such ashes is thermal post-processing with alkaline salts, e.g., Na2SO4 or K2CO3, which was able to transform less plant-available phosphates in the sewage sludge into more plant-available alkali-bearing phos-phates. Based on these results, one could facilitate creating these phosphates with enhanced plant-availability by providing the chemical potential to form them already during the thermal conversion process of sewage sludge.   This thesis aims to increase the current knowledge about the ash transformation processes of P and to suggest suitable process parameters for the alteration of the phosphate speciation in sewage sludge ashes by co-conversion with alkaline-rich agricultural residues. More specifically, the possibility of incorporating K derived from agricultural residues in phosphate structures derived from sewage sludge was evaluated with respect to the influence of the process temperature, the conver-sion atmosphere, and the fuel mixture. The studied parameters were chosen to generate knowledge relevant for fluidized bed gasification processes, with a spe-cial focus on dual fluidized bed (DFB) gasification systems. The applicability of feldspar bed materials in fluidized bed gasification systems was investigated to enable the substitution of the commonly used olivine, which often contains heavy metals (potentially contaminating recovered ashes), and quartz, which is very reactive towards fuel-derived K and potentially leads to bed material fragmentation and bed agglomeration (Paper I &amp; II). Subsequently, the thermodynamic potential for the alteration of the P-species in sewage sludge ash during co-combustion and co-gasification processes with agricultural residues was investigated (Paper III). Thereafter, an experimental evaluation of the ash transformation chemistry in thermal conversion processes of sewage sludge with different types of alkali-rich agricultural residues in temperatures relevant for flu-idized bed technology was conducted (Paper IV &amp; V). The methodology employed was chosen with respect to the state of technology of the specific investigated process. Paper I &amp; II applied SEM, EDS, XRD, and thermodynamic equilibrium modeling for bed material samples derived from an industrial indirect gasifier. Paper III applied thermodynamic equilibrium calcula-tions to theoretically evaluate ash compositions resulting from co-conversion of sewage sludge and agricultural residues. Paper IV &amp; V employed SEM, EDS, ICP-AES/MS, XRD, and thermochemical modeling on ash samples derived from single pellet lab-scale experiments. The results obtained by analysis of bed material from indirect wood gasification showed the difference in interaction mechanism for K-feldspar and Na-feldspar, most notably the enhanced disintegration of Na-feldspar by K originating from the fuel (Paper I &amp; II). Thermodynamic models employed for fuel mixtures of sewage sludge and agricultural residues showed the thermodynamic preference for the formation of the desired alkali-bearing phosphates (Paper III). Experi-ments conducted with these fuel mixtures (Paper IV &amp; V) supported the theo-retical findings, and the influence of temperature and process conditions could be obtained. However, practical investigations also showed that attainment of the desired ash composition is subject to significant restrictions. Derived from the elaborated results and discussions, it was possible to assess the critical process and fuel parameters for the development of up-scaled gasification processes focusing on the conversion of sewage sludge with the aim of creating improved phosphate formation in the ash. The selection of a suitable bed material in fluidized bed conversion and the transformation mechanisms defining the ash chemistry were found to be of vital importance for future applications. The pur-suit of the predefined aims in reference to P-recovery from sewage sludge has led to a multitude of suggestions for suitable process parameters that must be ad-dressed in future bench- and pilot-scale experimental runs.

<h2><br></h2> <p>This dissertation consists of distinct but related essays that delve into the impacts of changing economic conditions and climate mitigation policies on household consumption, health, and welfare outcomes. The first essay examines the effect of variations in economic factors, such as home values, on unhealthy consumption behaviors in the U.S. The second essay examines the distributional effects and possible health advantages of climate mitigation policies in India. The findings in this dissertation have significant implications for preventive health and environmental justice policies, particularly concerning vulnerable populations. </p> <p>The first essay of this dissertation investigates the impact of home value fluctuations on household tobacco and alcohol consumption in the U.S., specifically focusing on consumption based on homeownership status. First, we utilize high-frequency household transaction panel data and ZIP code-level home values to estimate the causal effect of home value fluctuations (or the housing wealth effect) on household tobacco and alcohol consumption for all U.S. households. Second, we predict household homeownership status by supplementing our primary household panel transaction data with a secondary household survey dataset; this allowed us to estimate the housing wealth effect separately for homeowners and renters. Home values are a leading economic indicator and effectively represent variation in housing wealth, whereas prior literature mainly focuses on lagging economic indicators, such as the unemployment rate. Housing wealth is a significant component of household net worth in the U.S. We leverage temporal and geographic fluctuations in household transactions and local home values to show that changes in housing wealth have a causal effect on household tobacco and alcohol consumption. Our findings show that declining home values increase tobacco and alcohol consumption among homeowners, with no effect on renters. Beer and cigarettes mainly drive this effect. Declining home values substantially increase annual consumption of nicotine, tar, carbon monoxide, and alcohol by volume, exacerbating public health concerns. In contrast, unemployment shocks increase tobacco and alcohol consumption among homeowners and decrease it among renters. The housing wealth effect is most pronounced among bubble states households, heavy-use consumers, low-income, and white households. The study emphasizes the importance of targeted policy interventions to mitigate the negative effects of fluctuations in housing wealth on unhealthy consumption, especially amid the current unpredictable economic environment and volatile real estate market. </p> <p>The second essay of this dissertation analyzes the distributional impacts of climate mitigation policies consistent with India’s 2030 Nationally Determined Contribution and 2070 net-zero target, using a dynamic global computable general equilibrium (CGE) model with heterogeneous Indian households. Specifically, we expand the CGE model to incorporate ten rural and ten urban household income deciles. Additionally, we link the CGE model with a global atmospheric source-receptor model to derive health co-benefits from reduced premature mortality due to lower air pollution. Several policy levers are considered in this study, including carbon pricing, enhanced coal consumption tax (or coal cess), and fossil subsidies phaseout. These are further combined with five alternative revenue recycling options. Our results suggest the potential welfare costs of such mitigation policies are rather moderate and do not exceed 0.5% over 2023-2050, not accounting for health and environmental co-benefits and damages avoided by successfully limiting global temperature rise to well below 2°C. However, health co-benefits from lower air pollution can potentially outweigh the mitigation costs. Combining carbon pricing and fossil subsidy removal is more efficient than carbon pricing alone, generating progressive medium-term welfare gains due to reduced market distortions. Raising coal cess rates is the least efficient policy. Inequality and distributional impacts vary significantly based on the chosen revenue recycling approach. Equal transfer of tax revenue across households proves to be the most efficient and equitable, followed by labor tax subsidies, leading to a Gini index and S20/S80 ratio reduction of 0.01%-1.7% and 0.1%-7%, respectively. Recycling revenues to stimulate green energy investments yields the least favorable distributional impacts and worsens inequality. Trade-offs exist between reducing inequality and fostering investment-driven economic growth when choosing revenue recycling options. Policymakers should prioritize policy mixes and revenue-recycling methods based on their objectives to effectively combat climate change while promoting sustainable growth and reducing income inequality in India. </p>

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