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[en] Highlights: • This work defines the minimum work of separation (MWS) for a capture process. • Findings of the analysis indicated a MWS of 0.158 GJ/t for post-combustion. • A review of commercially available processes based on chemical absorption was made. • A review of learning models was conducted, with the addition on a novel model. • A learning curve for post-combustion carbon capture was successfully designed. - Abstract: Carbon capture is one of the most important alternatives for mitigating greenhouse gas emissions in energy facilities. The post-combustion route based on chemical absorption with amine solvents is the most feasible alternative for the short term. However, this route implies in huge energy penalties, mainly related to the solvent regeneration. By defining the minimum work of separation (MWS), this study estimated the minimum energy required to capture the CO2 emitted by coal-fired thermal power plants. Then, by evaluating solvents and processes and comparing it to the MWS, it proposes the learning model with the best fit for the post-combustion chemical absorption of CO2. Learning models are based on earnings from experience, which can include the intensity of research and development. In this study, three models are tested: Wright, DeJong and D and L. Findings of the thermochemical analysis indicated a MWS of 0.158 GJ/t for post-combustion. Conventional solvents currently present an energy penalty eight times the MWS. By using the MWS as a constraint, this study found that the D and L provided the best fit to the available data of chemical solvents and absorption plants. The learning rate determined through this model is very similar to the ones found in the literature
[en] The selection of protective measures and strategies for remediation of contaminated areas after a nuclear accident must be based on previously established criteria in order to prevent stress of the population and the unnecessary exposure of workers. After a nuclear accident resulting in environmental contamination, decisions on remediation of areas is complex due to the large numbers of factors involved in decontamination processes. This work is part of a project which aims to develop a multi-criteria tool to support a decision-making process in cases of a radiological or a nuclear accident in Brazil. First, a database of remediation strategies for contaminated areas was created. In this process, the most relevant aspects for the implementation of these strategies were considered, including technical criteria regarding aspects related to the generation of wastes in a reference urban area, which are discussed in this paper. The specific objective of this study is to define criteria for the aspects of radioactive wastes, resulted by the implementation of some urban measures, in order to be incorporated in a multi-criteria decision tool. Main aspects considered were the type, the amount and the type of treatment necessary for each procedure. The decontamination procedures are then classified according to the selected criteria in order to feed the multi-criteria decision tool. This paper describes the steps for the establishment of these criteria and evaluates the potential for future applications in order to improve predictions and to support the decisions to be made. (author)
[en] This paper estimates the potential for energy-related greenhouse gas emission (GHG) reductions in Brazil, their abatement costs and proposes a number of policies to achieve these reductions. The Brazilian energy system is very peculiar as renewable energy accounts for some 45% of total primary energy and 85% of electricity production. The following sectors are covered in this paper: industry, transports and petroleum sector. Compared to a business-as-usual reference scenario, results show a potential to reduce future energy-related GHG emissions by 27% in 2030. However, in spite of that, the mitigation potential identified here is not large enough, in absolute terms, to reduce energy-related GHG emissions below the current level in Brazil by 2030. - Highlights: ► We estimate the potential for energy-related GHG emission reductions in Brazil. ► We cover industry, transports and petroleum sector. ► The potential to reduce energy-related GHG emissions is around 27% in 2030. ► The low carbon scenario in 2030 is above the current level emission in Brazil.
[en] Highlights: • Literature review of empirical megaproject cost overrun and construction delays (power and O&G). • Index proposed to assess inter-regional capex cost differences of energy projects named Z-Factor. • Z-Factors implemented in energy system model to assess impact of cost overruns and delays in Brazil. • Result: delays and cost overruns impact Brazil energy security, increase oil products imports. • Non-hydro renewables fill the gap, indicating they should be the preferred option ex-ante. - Abstract: Cost minimization is arguably the most important criterion governing decisions about energy sector infrastructure construction. Usually, a winning project is picked among similar alternatives based on lowest levelized cost of energy, because, ceteris paribus, economies of scale drive down the unit cost of energy delivered. As such, megaprojects – here defined as costing more than a benchmark US$ 1 billion – are perceived as more competitive than smaller-scale options. However, megaprojects are prone to construction cost overruns and delays that, if included ex ante, may change the optimality of decision for a given project. We hypothesize that optimistic assumptions on techno-economic performance of megaprojects favor their inclusion in the solution of integrated assessment models (IAMs), preventing higher shares of non-hydro renewables, energy efficiency and other low-carbon options. To test this hypothesis, we ran the COPPE-MSB energy system cost-optimization model for infrastructure expansion. We estimate a factor (named Z factor, for zillions) to determine cost differences both within Brazil and vis-à-vis international parity and adjust the model's parameters for CAPEX and construction times of projects qualifying as megaprojects. Results show decreased coal and increased wind power generation, and a reduction in the number of new refineries leading to higher imports of diesel and gasoline.
[en] The methodology for classifying areas according to soil properties for the vulnerability to a 137Cs contamination is of high importance to the preparedness related to nuclear and/or radiological accidents that lead to release of radionuclides to the environment with the consequent contamination of agricultural areas. The priority of research for agricultural areas should then focus on the surrounding areas of nuclear power plant that have higher probability of public exposure through the ingestion pathway. The objective of this work was to create a rank order for priority of areas to be mapped based on EMBRAPA database on soil properties. The 16 municipalities previously selected to define parameters for dose assessment simulations related to the Brazilian Nuclear Power Plants, located in the district of Angra dos Reis, Rio de Janeiro, have been investigated in order to create this rank order to direct the research on radio vulnerability mapping, considering their relevance to public exposure based on their agricultural productivity. The two aspects selected in this study account for the maximum loss of income and to the collective doses that can be averted due to the banning of agricultural products. These quantities are inputs to optimization analysis. The priority defined shall then guide research on both the adequate values for the transfer factors and on the agricultural countermeasures suitable to each area according to the cause(s) of their vulnerability and their typical agricultural crops. (author)
[en] Under the environmental modeling Project of radioecology research area of IRD (CNEN), several tools have been developed to support post-emergency activities. Currently, a multi-criteria model is in development with the aim of supporting decision-making processes under the radiological protection point of view. At this stage, we are focusing on the decontamination of urban areas. The model includes five calculation modules: (1) averted doses to the public due to remediation procedures; (2) occupational exposure of remediation workers; (3) properties of the wastes generated by a remediation procedure; (4) classification of each procedure for a specific urban scenario based on previously calculated quantities; and, (5) multi-criteria rank calculation. The classification of procedures is based on two types of criteria previously defined, both also included as input data of the model. The first type, called Subjective Criteria, is based on experts' opinions collected through questionnaires. The second type, called Technical Criteria, is calculated according to the outputs of the three first modules of the program. The output of the model is a rank order list indicating the priority of procedures to use for each different type of urban environment. The use of results based on criteria and methods developed previously to the occurrence of a contamination event intends not only to provide an input to decision-making processes but also to improve public confidence on authorities responsible for the remediation decisions. (author)
[en] The present analysis of the contributions (INDCs) submitted by Member States to the United Nations Framework Convention on Climate Change (UNFCCC) in the run-up to COP21 was conducted by leading research teams from Brazil, China, Japan, India, the United States and the European Union within the MILES Project (funded by the European Commission). By investigating the concrete implications of INDCs for the low-carbon transformation by and beyond 2030, from energy systems, buildings to transport and industry, this study complements the upcoming cutting-edge assessments by UNFCCC and UNEP of the impact of INDCs on global emissions and the global temperature goal. The 'Modelling and Informing Low-Emission Strategies' (MILES) project is an international research project bringing together 16 leading research teams in order to build capacity and knowledge on low-emissions development strategies. The objective of this report is to understand the implications of INDCs of the 5 countries and 1 region covered by the project (US, China, Japan, EU, Brazil and India), both at a national and global level, by investigating the concrete implications of INDCs for the low-carbon transformation by and beyond 2030, from energy systems, buildings to transport and industry. A significant transition appears in the electricity sector, where INDCs will further drive the transition towards renewables and other low-emissions forms of electricity production. In the six major economies assessed individually, carbon dioxide emissions per unit of electricity production falls by about 40% between 2010 and 2030 and renewable electricity becomes the dominant source of electricity production at about 36% of the electricity mix. Some crucial low-carbon solutions, like CCS, electric vehicles, advanced biofuels, sustainable urban planning, appear unlikely to be developed under the INDCs at the scale and speed required for a 2 deg. C scenario. Likewise, the report highlights that INDCs would leave too much inefficient and unabated fossil fuel capacity online in 2030 to be coherent with a 2 degrees scenario. This highlights the risks of lock-in into a high carbon trajectory if action is not strengthened quickly. Post-Paris policy efforts need to stimulate technology innovation, deployment and diffusion in order to drive down costs in such sectors where insufficient progress is being seen. The INDCs imply a significant acceleration of climate action but as currently submitted may not be enough to keep the below 2 deg. C goal in reach. The Paris Agreement should establish a clear mechanism to allow the regular, predictable and timely revision of national contributions and the global framework. New contributions should be based on a vision for the deep decarbonization of national energy systems. The Paris agreement should foster the development of national deep decarbonization pathways around 2018