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Traditional technologies of carbon capture and storage (CCS) are being focused on capturing CO 2 in large-scale demonstrations, which has been proved to result in the high cost and energy penalty. Meanwhile, typical innovative measures, commonly defined as the second generation CCS technologies, elude conventional ones by integrating with solar energy and thus contributing to a more energy-efficient conversion of CO 2 . However, few reviews pay attention to thermodynamic processes and parameters of these novel technologies, and there is a lack of systematic evaluation and comparison among them. This paper firstly presents a guided tour on the state-of-art of typical and innovative CCS technologies integrated with solar energy. An overview on thermodynamic processes, including chemical reactions, operating conditions and efficiency indexes of five typical technologies is presented so that the current development level can be clarified. Since the high energy requirement and related operating cost are the main barriers to the application of existing CCS technologies, the minimum work and second-law efficiency are applied as the main indicators in the second part of this paper which relates to performance evaluation. In addition, the performance windows for innovative technologies are illustrated for the comparison of technological maturity. The results show that energy requirement of innovative CCS technologies from the flue gas is avg. 100–200 kJ/mol CO 2 and the second-law efficiency of them is only 5–12%. Therefore, the maturity and popularity of these novel technologies are still relatively low. But the well-integrated systems and diversified output of these technologies can benefit existing energy infrastructures in a long period. [ABSTRACT FROM AUTHOR]

Abstract: The IEA CCS Roadmap highlighted the significance that CCS will need to play in achieving an atmospheric CO2 concentration stabilization of 450 ppm. In the scenario it is based on, CCS will provide approximately 20% of the total CO2 emissions reductions out to 2050. Achieving this contribution of emissions reductions will require an ambitious CCS growth-path, with 100 projects needed globally by 2020 and over 3000 by 2050. In both 2020 and 2050 the major developing countries, including South Africa will need to contribute to CCS deployment. South Africa has a heavily coal-dependent economy with 94 % of electricity production coming from coal. In addition to this, South Africa also meets approximately 30% of its domestic fuel -oil demand through the conversion o f coal and gas to transportation fuels. The combination of these two factors means that South Africa is as dependant on coal as any country in the world, placing the country as the 13th largest CO2 emitter in the world. Currently South Africa is experiencing electricity shortages where the reserve margin is below desired levels on a daily basis. Consequently, deployment of electricity generation capacity is seen as a priority. With the slow development of renewable energy and the deployment of nuclear energy currently under review, the required short term increase in electricity production is likely to come from new, coal plant that will be expected to be in operation for 50–60 years, thus continuing the country’s dependence on coal for some time to come. At the climate change negotiations in Copenhagen, South Africa announced that it would take nationally appropriate mitigation actions to enable a reduction in national GHG emissions equating to a deviation of 34% below the “Business as Usual” emissions growth trajectory by 2020 and a 42% deviation below the below “Business as Usual” emissions growth trajectory by 2025, pended upon the provision of sufficient funding and technology support. Given all these factors, CCS could be a crucial technology for South Africa in the near future. This paper looks to discuss the current status of CCS in South Africa. This includes looking at the key outcomes of the recently released South African CCS Research and Development Roadmap and the milestones it outlines, such as the development of a geological storage atlas by 2010, a CO2 test injection by 2016, and a demonstration project operating by 2020. It also looks at how the South African government is positioned toward CCS, including how CCS fits with the countries priorities of poverty alleviation, economic growth, sustainable development, job creation and ensuring the most efficient use of domestic resources. In addition the paper looks at the manner in which the South African government could go about regulating the operation of CCS projects. The paper will discuss the options available to South Africa to fund CCS demonstration and deployment domestically including via the clean development mechanism (in the event that the question of using this mechanism in the CCS context is dealt with at the international level), development banks and other, appropriate, development finance institutions. Public awareness and engagement on CCS will also be covered, given the crucial role the public play in the smooth progress of projects. Finally the paper will look at international collaboration on CCS including the role South Africa can play internationally and what more the international CCS community can offer. [Copyright &y& Elsevier]

The carbon capture by adsorption (CCA) is regarded as an available engineering technology because of its low energy-consumption, easy to control, and possible integration with renewable energy. The recent advances in CCA research comprises mainly about the performance improvement of adsorbents, design and optimization of engineering process. However, considering the time-consuming and intensive funding required for experimental investigation, the numerical simulation has been widely applied in CCA. In numerical simulation field of CCA, the adsorption process is commonly simplified into mathematical models group comprised of adsorption kinetics model, the adsorption equilibrium model, pressure drop model and heat transfer model. However, few studies’ focus is to provide a detailed review of the research methodology of mathematical modeling in CCA simulation. This paper presents a pathway map on CCA mathematical modeling through literature review and case study. An overview of model screening and modeling method of CCA is provided in the review part. This part also provides a short guided tour on how to combine the fundamental models about heat and mass transfer together to form a model group for various application scenarios in CCA. Then the pathway map on CCA modeling, which is summarized based on the review, is applied to a case study. In this part, the adsorption of CO 2 /N 2 mixtures on activated carbon under the conditions of high temperature and low pressure is numerically investigated based on the established models. The performance indicators comprise gas temperature, mole fraction, and adsorbate amount of the fixed bed, are applied in the evaluation performance of CCA. Based on the proposed methodology, the CCA modeling demonstrates a more fluent design process relative to the real physical scenario, with a possible access to further optimization. Particularly, the simulation results showed that the optimized dimensionless velocity for the highest utilization efficiency of the fixed bed can be obtained and thus is proposed as 1.2–1.4 for the most suitable feed velocity to fit different size of fixed bed and different types of adsorbents for the engineering design. [ABSTRACT FROM AUTHOR]

In this paper, a novel carbon capture and utilization process is proposed. It is based on using a fraction of the captured carbon dioxide to produce sodium bicarbonate, a widely used product in the chemical and food industries. The process couples the Dry Carbonate process for carbon dioxide capture with sodium bicarbonate production. Raw material is trona or sodium sesquicarbonate dehydrate, which is a relatively abundant mineral composed by approximately 46% sodium carbonate and 35% sodium bicarbonate by weight. In the process, trona is firstly converted into sodium carbonate in a fluidized bed reactor operated at 180–200 °C and 1 bar. Heat required in the fluidized bed reactor for decomposing trona can be supplied by renewable sources such as low/medium temperature solar energy or biomass. A fraction of the sodium carbonate generated is recirculated for carbon dioxide capture by means of the dry carbonate process. The rest is converted to sodium bicarbonate in a carbonating tower through the reaction with carbon dioxide and water. After separation of sodium bicarbonate and other salts from water, the sodium bicarbonate produced is suitable for direct sale. The use of renewable sources for supplying the energy required at the sorbent regenerator and for trona decomposition yields a near-zero carbon dioxide emissions global system. As case of study, carbon dioxide capture coupled to sodium bicarbonate production has been analysed for a 15 MW el coal fired power plant. Heat required in the carbon capture process penalizes the global system efficiency by a 10.2%, which is reduced just to the electricity parasitic consumption for solids transport and carbon dioxide compression (∼3%) if renewable energy sources are integrated. From an economic perspective, the penalty in electricity consumption is fully compensated by the new by-product sales. Taking into account the reduction of electricity sales and current prices of trona and sodium bicarbonate a return of investment is obtained in the range between 3 and 8.7 years with an internal rate of return over 12%. These values improve the current forecast of any other carbon capture and storage process up to date, which suggests a high interest of the proposed conceptual integration specially for regions where trona is widely available. [ABSTRACT FROM AUTHOR]

Carbon capture and storage (CCS) will be a critical component of a portfolio of low-carbon energy technologies required to combat climate change ( IEA-GHG, 2013 ). As such, an extensive transportation infrastructure will be required to transport captured CO 2 from different sources to the available sinks. Several studies in the literature suggest that shared oversized pipeline networks may be the most efficient long term option compared to single source to sink pipelines, based on increased CCS deployment over the years and therefore increased CO 2 flowrate to the transport network. However, what is neglected in this vision is that the deployment of intermittent renewable energy tends to displace thermal power generation. This directly reduces the amount of fossil fuel burned, CO 2 produced, captured and transported through the network. This paper presents an optimisation methodology to “right-size” CO 2 transport infrastructure, explicitly accounting for the transient flow of CO 2 arising from the co-deployment of intermittent renewable energy generators. By application of this methodology, we demonstrate that capital cost reductions of up to 28% are possible relative to a business-as-usual design case. [ABSTRACT FROM AUTHOR]

In order to mitigate CO 2 emissions while continuing to use fossil fuels as an energy source, CO 2 emissions from large point sources such as power stations can be captured and stored in suitable subsurface sedimentary formations. However, concerns have been raised that the injection of pressurized CO 2 may alter the subsurface stress state, leading to the re-activation of faults and generating induced seismic activity. Southeast Saskatchewan has seen extensive oil and gas activity since the 1950s. This activity includes, in recent years, a boom in shale oil production entailing hydraulic fracturing. It is also home to two world-leading CCS projects, the Weyburn-Midale CO 2 Monitoring and Storage Project, and the Boundary Dam/Aquistore Project. The aim of this paper is to assess whether any of the conventional oilfield operations, shale oil activity or CCS has caused induced seismicity in southeast Saskatchewan. We find that the region has a very low rate of natural seismicity, and that there is no evidence to suggest that any kind of oilfield activity has caused induced events. However, seismicity has been associated with potash mining activities in the region. It is not clear whether the potash mining-induced events are triggered by subsidence above the mined zones, or by re-injection of waste brines. It is of interest to compare the situation in southeast Saskatchewan with other areas that have seen substantial increases in the amount of injection-induced seismic activity. It is notable that in many areas that have seen injection-induced seismicity, fluid injection is into basal aquifers that are hydraulically connected to the crystalline Precambrian basement. In contrast, most oilfield activities in southeast Saskatchewan are in Carboniferous formations, while the only units to have experienced a net volume increase are of Cretaceous age. It is tentatively suggested that the lack of induced seismic activity is due to the fact that injection is hydraulically isolated from the basement rocks, although it is also possible that stress conditions in the region are less conducive to induced seismicity. [ABSTRACT FROM AUTHOR]

[Display omitted] • Various robust AI methods were implemented for predicting IFT of CO 2 -brine system. • A comprehensive database including more than 2184 experiment samples was employed for implementing the AI study. • The newly proposed random forest model for predicting IF outperforms the other AI models. Given the current global climate change, renewable energy sources, carbon capture, utilization, and storage (CCUS) are being considered as a potential solutions to this critical global issue. Structural and capillary processes can be used to store carbon dioxide (CO 2) in deep saline aquifers in a way that is safe and does not harm the environment. Due to this fact, the interfacial tension (IFT) of the CO 2 -brine system is an important factor influencing the capacity of storage formations to sequester CO 2. As a result, IFT is essential for conducting a thorough and accurate evaluation in order to determine the optimal strategy for CO 2 storage projects. This paper used intelligent models such as Gaussian Process Regression (GPR), Radial Basis Function (RBF), and Random Forest (RF) to forecast IFT in the CO 2 -brine system with high precision and substantial time saving. The results reveal that the constructed RF model could deliver excellent performance in predicting IFT with the lowest average absolute percent relative error (AAPRE = 1.9156 percent), highest coefficient of determination (R2 = 0.9907), and lowest root mean squared error (RMSE = 0.7279). Furthermore, a sensitivity analysis was performed to ascertain the most critical parameters in the RF model to be considered. The parametric analysis found that both pure and non-pure CO 2 systems had a significant impact on IFT prediction. Also, the RF model was used to assess the structural trapping capacity of a storage location in the Cuu Long Basin. The estimation results obtained in this study agreed perfectly with the previous ones. The findings of this study can aid in a better understanding of how machine learning models can be applied to predict IFT values for the evaluation of the structural CO 2 storage capacity. [ABSTRACT FROM AUTHOR]

Abstract: This paper presents initial findings from focus groups with the general public, conducted as part of the European (FP7) NearCO 2 project on public perceptions and understanding of CCS in six European countries. The research design specifically enabled the evolution of opinion to be observed in a relatively naturalistic setting. Each focus group was exposed to a specially-commissioned DVD that provided an overview of CCS, its rationale and arguments for and against CCS. Exposure was phased and a pre- and post-questionnaire was applied. The results concurred with much of the preceding work on CCS perceptions, namely a strong preference for renewable energy and a high level concern about the safety implications of CO2 leakage. There were few strong differences between groups, with the exception of a higher level of concern about climate change in Spain, related to experience of drought. In all groups, concerns about safety quickly amplified and information on the difficulty in rapidly installing very high levels of renewable energy supply infrastructure had little influence on opinion. We conclude that the case for CCS, and reassurance on the risks posed by CO2 leakage, will need to be made more convincingly and overtly, particularly for affected European publics. Moreover, in so far as the focus groups simulated the consequences of exposure to information on CCS without expert-moderation, they illustrate the importance of involving trusted parties in CCS communication processes, with the objective of moderating and responding to concerns as they arise. [Copyright &y& Elsevier]

Abstract: Consistent with other published studies, the modelling presented here reveals that baseload power plants are the first aspects of the electricity sector to decarbonize and are essentially decarbonized once CO2 permit prices exceed a certain threshold ($90/ton CO2 in this study). The decarbonization of baseload electricity is met by significant expansions of nuclear power and renewable energy generation technologies as well as the application of carbon dioxide capture and storage (CCS) technologies applied to both coal and natural gas fired power plants. Relatively little attention has been paid thus far to whether intermediate and peaking units would respond the same way to a climate policy given the very different operational and economic context that these kinds of electricity generation units operate under. In this paper, the authors discuss key aspects of the load segmentation methodology used to imbed a varying electricity demand within the GCAM (a state-of-the-art Integrated Assessment Model) energy and economic modelling framework and present key results on the role CCS technologies could play in decarbonizng subpeak and peak generation (encompassing only the top 10% of the load) and under what conditions. To do this, the authors have modelled two hypothetical climate policies that require 50% and 80% reductions in US emissions from business as usual by the middle of this century. Intermediate electricity generation is virtually decarbonized once carbon prices exceed approximately $150/ton CO2. When CO2 permit prices exceed $160/ton CO2, natural gas power plants with CCS have roughly the same marketshare as conventional gas plants in serving subpeak loads. The penetration of CCS into peak load (upper 6% here) is minimal under the scenarios modeled here suggesting that CO2 emissions from this aspect of the U.S. electricity sector would persist well into the future even with stringent CO2 emission control policies in place. [Copyright &y& Elsevier]

Abstract: In this paper, different electricity demand scenarios for Spain are presented. Population, income per capita, energy intensity and the contribution of electricity to the total energy demand have been taken into account in the calculations. Technological role of different generation technologies, i.e. coal, nuclear, renewable, combined cycle (CC), combined heat and power (CHP) and carbon capture and storage (CCS), are examined in the form of scenarios up to 2050. Nine future scenarios corresponding to three electrical demands and three options for new capacity: minimum cost of electricity, minimum CO2 emissions and a criterion with a compromise between CO2 and cost (CO2-cost criterion) have been proposed. Calculations show reduction in CO2 emissions from 2020 to 2030, reaching a maximum CO2 emission reduction of 90% in 2050 in an efficiency scenario with CCS and renewables. The contribution of CCS from 2030 is important with percentage values of electricity production around 22–28% in 2050. The cost of electricity (COE) increases up to 25% in 2030, and then this value remains approximately constant or decreases slightly. [Copyright &y& Elsevier]

Abstract: The EU electricity market is changing. Electricity demand in Europe is on the rise, the power plant fleet is aging, and a large share of the capacity will need to be replaced in the coming decades. An ambitious target has been formulated for the share of renewable energy, and CO2 prices are anticipated to increase. On top of this, CO2 Capture and Storage (CCS) has appeared as an important technology in the transition to a long term sustainable energy supply. This paper discusses the implications all of the above developments for the EU electricity market, with an emphasis on the market North Western Europe. On the whole electricity prices in North Western Europe until 2020 are anticipated to increase, but this may only partly be ascribed to the pending introduction of CCS. [Copyright &y& Elsevier]

• Developed life cycle assessment model for biomass co-firing power plants with CCS. • Given detailed process-level input-output table based on mass and energy balances. • Co-firing of 25% biomass with coal can achieve near-zero emissions in CCS plants. • Environmental burden shifts significantly as the co-firing ratio. • Uncertainty analysis was carried out for the environmental burden shift. As a carbon-neutral renewable energy source, biomass co-firing with coal contributes to reducing the carbon intensity of pulverized coal power plants with CO 2 capture and storage; thus, this process significantly reduces the greenhouse gas emissions of the power industry. However, various types of environmental impacts caused by co-firing have hindered the large-scale deployment of this technology. In this study, ten life cycle assessment models were developed based on the Integrated Environmental Control Model and GaBi software to quantify the performance parameters of different power plants and the influence of the co-firing ratio on various environmental impact categories. The system boundaries included raw material acquisition, raw material transport, energy conversion of power plants, CCS and brine treatment. The results indicated that a pulverized biomass/coal co-firing power plant with CCS can achieve near-zero emissions at a co-firing ratio of 25% and negative emissions of 877 kg CO 2 -e/MWh from a life-cycle perspective when coal is totally replaced. Co-firing biomass and coal in power plants has a passive impact on seven environmental categories, such as the eutrophication potential and toxicity potential, rather than on the global warming potential, abiotic resource depletion potential and acidification potential. The major causes of environmental burden shifting are energy penalties and indirect emissions from high-energy-consumption processes, especially emissions of N 2 O, NH 3 and ethylene oxide released during biomass extraction and solvent preparation. The conclusions and recommendations presented in this paper may have implications for deep decarbonization in other industrial sectors. [ABSTRACT FROM AUTHOR]