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Abstract Carbon sequestration is an important measure to reduce greenhouse gas emissions. This paper introduces a new method of carbon sequestration using CO 2 waterless fracturing technology. Based on the supporting technology system with independent intellectual property rights, waterless fracturing field tests were carried out on 19 wells in Jilin oilfield. The on-site monitoring data shows that CO 2 stays in a supercritical state for a long time in the process of waterless fracturing, soaking and flowback, which is favourable for carbon sequestration. The geological model of H87 test area was established to simulate and evaluate CO 2 recovery after fracturing. The results show that the storage ratio of CO 2 waterless fracturing is 76.46%. Meanwhile, the production after waterless fracturing is 2.4 times that after water-based fracturing with the same scale, and the average single well operation saves 1512 m3 water. It can be seen that CO 2 waterless fracturing is a new type of carbon sequestration technology with high storage efficiency, good stimulation effect, significantly reduction of water consumption during oil and gas reservoir development and has broad market prospects. [ABSTRACT FROM AUTHOR]

Defining the ideal suite of monitoring technologies to be deployed at a carbon capture and storage (CCS) site presents a challenge to project developers, financers, insurers, regulators and other stakeholders. The monitoring, verification, and accounting (MVA) toolkit offers a suite of technologies to monitor an extensive range of parameters across a wide span of spatial and temporal resolutions, each with their own degree of sensitivity to changes in the parameter being monitored. Understanding how best to optimize MVA budgets to minimize the time to leak detection could help to address issues around project risks, and in turn help support broad CCS deployment. This paper presents a case study demonstrating an application of the Designs for Risk Evaluation and Management (DREAM) tool using an ensemble of CO 2 leakage scenarios taken from a previous study on leakage impacts to groundwater. Impacts were assessed and monitored as a function of pH, total dissolved solids (TDS), and trace metal concentrations of arsenic (As), cadmium (Cd), chromium (Cr), and lead (Pb). Using output from the previous study, the DREAM tool was used to optimize monitoring system designs based on variable sampling locations and parameters. The algorithm requires the user to define a finite budget to limit the number of monitoring wells and technologies deployed, and then iterates well placement, sensor type and location until it converges on the configuration with the lowest time to first detection of the leak averaged across all scenarios. To facilitate an understanding of the optimal number of sampling wells, DREAM was used to assess the marginal utility of additional sampling locations. Based on assumptions about monitoring costs and replacement costs of degraded water, the incremental cost of each additional sampling well can be compared against its marginal value in terms of avoided aquifer degradation. Applying this method, DREAM identified the most cost-effective ensemble with 14 monitoring locations. While this preliminary study applied relatively simplistic cost and technology assumptions, it provides an exciting proof-of-concept for the application of DREAM to questions of cost-optimized MVA system design that are informed not only by site-specific costs and technology options, but also by reservoir simulation results developed during site characterization and operation. [ABSTRACT FROM AUTHOR]

The Midwest Regional Carbon Sequestration Partnership (MRCSP) is implementing a commercial-scale carbon capture and storage (CCS) project in multiple Silurian carbonate pinnacle reefs in northern Michigan that are in various phases of enhanced oil recovery. This paper presents analyses of five pressure fall-off tests performed sequentially during the injection of 166,000 tonnes of CO 2 into a Type-1 (depleted) reef which has undergone primary and secondary production. Bottom-hole pressures were monitored in the injection well and in two observation wells to record progressively increasing reservoir pressure during the injection period, which also included five fall-off tests. Pressure data were analyzed using combined history-matching and pressure derivative matching techniques implemented with a commercial well-test interpretation program, FAST WellTest™. The paper illustrates the challenges of consistently interpreting CO 2 injection fall-off tests under multi-phase flow with varying pressure conditions using a single-phase analytical model. This work is relevant to CO 2 sequestration in depleted oil reservoirs because regular fall-off testing is required under the U.S. Environmental Protection Agency's Underground Injection Control (UIC) Program for CO 2 geologic sequestration (75 FR 77230). [ABSTRACT FROM AUTHOR]

Large-scale pressure increases resulting from carbon dioxide (CO 2 ) injection in the subsurface can potentially impact caprock integrity, induce reactivation of critically stressed faults, and drive CO 2 or brine through conductive features into shallow groundwater. Pressure management involving the extraction of native fluids from storage formations can be used to minimize pressure increases while maximizing CO 2 storage. However, brine extraction requires pumping, transportation, possibly treatment, and disposal of substantial volumes of extracted brackish or saline water, all of which can be technically challenging and expensive. This paper describes a constrained differential evolution (CDE) algorithm for optimal well placement and injection/extraction control with the goal of minimizing brine extraction while achieving predefined pressure contraints. The CDE methodology was tested for a simple optimization problem whose solution can be partially obtained with a gradient-based optimization methodology. The CDE successfully estimated the true global optimum for both extraction well location and extraction rate, needed for the test problem. A more complex example application of the developed strategy was also presented for a hypothetical CO 2 storage scenario in a heterogeneous reservoir consisting of a critically stressed fault nearby an injection zone. Through the CDE optimization algorithm coupled to a numerical vertically-averaged reservoir model, we successfully estimated optimal rates and locations for CO 2 injection and brine extraction wells while simultaneously satisfying multiple pressure buildup constraints to avoid fault activation and caprock fracturing. The study shows that the CDE methodology is a very promising tool to solve also other optimization problems related to GCS, such as reducing ‘Area of Review’, monitoring design, reducing risk of leakage and increasing storage capacity and trapping. [ABSTRACT FROM AUTHOR]

Natural gas is considered a cleaner and lower-emission fuel than coal, and its high abundance from advanced drilling techniques has positioned natural gas as a major alternative energy source for the U.S. However, each ton of CO 2 emitted from any type of fossil fuel combustion will continue to increase global atmospheric concentrations. One unique approach to reducing anthropogenic CO 2 emissions involves coupling CO 2 based enhanced gas recovery (EGR) operations in depleted shale gas reservoirs with long-term CO 2 storage operations. In this paper, we report unique findings about the interactions between important shale minerals and sorbing gases (CH4 and CO 2 ) and associated economic consequences. Where enhanced condensation of CO 2 followed by desorption on clay surface is observed under supercritical conditions, a linear sorption profile emerges for CH4. Volumetric changes to montmorillonites occur during exposure to CO 2 . Theory-based simulations identify interactions with interlayer cations as energetically favorable for CO 2 intercalation. In contrast, experimental evidence suggests CH4 does not occupy the interlayer and has only the propensity for surface adsorption. Mixed CH4:CO 2 gas systems, where CH4 concentrations prevail, indicate preferential CO 2 sorption as determined by in situ infrared spectroscopy and X-ray diffraction techniques. Collectively, these laboratory studies combined with a cost-based economic analysis provide a basis for identifying favorable CO 2 -EOR opportunities in previously fractured shale gas reservoirs approaching final stages of primary gas production. Moreover, utilization of site-specific laboratory measurements in reservoir simulators provides insight into optimum injection strategies for maximizing CH4/CO 2 exchange rates to obtain peak natural gas production. [ABSTRACT FROM AUTHOR]

Numerical simulation is an invaluable analytical tool for scientists and engineers in making predictions about of the fate of carbon dioxide injected into deep geologic formations for long-term storage. Current numerical simulators for assessing storage in deep saline formations have capabilities for modeling strongly coupled processes involving multifluid flow, heat transfer, chemistry, and rock mechanics in geologic media. Except for moderate pressure conditions, numerical simulators for deep saline formations only require the tracking of two immiscible phases and a limited number of phase components, beyond those comprising the geochemical reactive system. The requirements for numerically simulating the utilization and storage of carbon dioxide in partially depleted petroleum reservoirs are more numerous than those for deep saline formations. The minimum number of immiscible phases increases to three, the number of phase components may easily increase fourfold, and the coupled processes of heat transfer, geochemistry, and geomechanics remain. Public and scientific confidence in the ability of numerical simulators used for carbon dioxide sequestration in deep saline formations has advanced via a natural progression of the simulators being proven against benchmark problems, code comparisons, laboratory-scale experiments, pilot-scale injections, and commercial-scale injections. This paper describes a new numerical simulator for the scientific investigation of carbon dioxide utilization and storage in partially depleted petroleum reservoirs, with an emphasis on its unique features for scientific investigations. The mathematical foundations of this new simulator for enhanced oil recovery are those of the simulators developed for carbon sequestration in deep saline reservoirs, altered to consider the increased number of potential phases and compositional aspects by considering the oil in the system. As a demonstration of the simulator, a numerical simulation of carbon dioxide utilization for enhanced oil recovery in the western section of the Farnsworth Unit, representing an early stage in the progression of numerical simulators for carbon utilization and storage in depleted oil reservoirs. [ABSTRACT FROM AUTHOR]

This paper is inspired by theory related to the water-food-energy-climate nexus and suggests a novel model, suited for analysing carbon sequestration in dry land agriculture using irrigation. The model is applied specifically to photovoltaic water pumping (PVWP) systems for irrigation of grasslands in China. We argue against the narrow approaches to analysing the water issue often found in literature and propose that carbon sequestration, energy security, food security together with local moisture recycling patterns should be included within the system boundary in order to make analyses of dry land agricultural activities more relevant and accurate. [ABSTRACT FROM AUTHOR]

Abstract: The eddy covariance method is a micrometeorological technique for direct measurements of gas transport between the surface and the atmosphere. It is widely used for quantifying CO2 emission rates from natural, urban and agricultural ecosystems, including areas of agricultural carbon sequestration. In geological carbon capture, utilization and sequestration, emerging projects utilize eddy covariance to monitor large areas where CO2 may escape from the subsurface, to detect and quantify CO2 leakage, and to improve CO2 storage efficiency. This paper describes key principles of the method, main requirements, typical instrumentation and software, and educational resources particularly useful for carbon sequestration research. [Copyright &y& Elsevier]

Abstract: Packing is widely used in post-combustion CO2 capture. This paper is focused on the measurement of three fundamental packing characteristics: effective gas-liquid contact area (ae), gas phase and liquid phase film mass transfer coefficient (kG) and (kL). Results show that contact area initially increases with liquid flow rate before it asymptotes to a value nearly equivalent to the nominal surface area. Initial attempts at constructing new mechanistic models have shown that existing kG and kL models can be improved. Both gas and liquid phase film mass transfer coefficients can be described as a power function of superficial gas or liquid velocity. [Copyright &y& Elsevier]

Abstract: The recent years have seen growing attention towards the study of dynamic behavior in post-combustion CO2 capture plants using amines, albeit, apparently contesting yet without comparison or critique. This paper reviews what has been reported in literature concerning issues pertinent to transient behavior of CO2 capture including interaction with power plants. Details of models used, their validation and modeling tools as well as an attempt to piece-out convergent points from the various conclusions are given. Knowledge gaps and areas that still need more attention are emphasized. [Copyright &y& Elsevier]

Abstract: This paper describes an operability analysis and control structure design for handling membrane leakage in a hydrogen membrane reactor (HMR) as used in an integrated reforming combined power cycle (IRCC) based on natural gas as fuel. For this type of reforming to be competitive to power generation with carbon capture, low costs and emission of CO2 and NOx is required. Further, high operability and robustness is also required. This is achieved through an understanding of the system dynamics and robust control structure design. The overall aim of the work is to improve the operability of such gas power plants under membrane leakage, which may cause detrimental hot areas in the reactor. Good operability means essentially that a plant can be operated easily, i.e. it can cope with disturbances, offsets and other uncertainties with the smallest possible profit loss and without frequent shutdowns. This is obtained both through design of the process itself and design of the control system. An important ingredient is the use of a dynamic, control relevant simulation model. The paper presents an analysis of how the control objective affects the choice of control structure for the HMR process and the control performance under membrane leakage. Also, the effect on CO2 capture is shown. [Copyright &y& Elsevier]

Abstract: Transport is an important feature of the CCS process as the CO2 quality requested by pipelines may influence the choice of the capture technology and its limit performance requirements. So, the knowledge of the thermodynamic properties of CO2-mixtures has an important role, however a suitable equation of state under the appropriate conditions for pipeline transport has not been clearly defined yet. In this paper different equations of state for predicting densities of CO2 and CO2 mixtures have been analyzed and compared with experimental data found in literature or obtained by authors performing specific laboratory p-ρ-T measurements. [Copyright &y& Elsevier]

Abstract: In 2007, the Norwegian prime minister made the promise that a ‘lunar landing’ was due at Mongstad Refining in 2014, involving full-scale cleaning of CO2. This was the prelude to a long and heated debate on Carbon Capture and Storage (CCS) in Norwegian media. Through a discourse analysis we have identified two main media discourses related to the announced lunar landing; including important participants and arguments, as well as the positions taken by the actors of the discourses. The paper outlines the underlying structures of the public debate about CCS, and argues that the discourse is not really about CCS but politics in the form of narratives on promises, alliances and emotions caused by political actions. The paper shows the importance of media discourses for the legitimacy and willingness to finance CCS R&D. [Copyright &y& Elsevier]

Abstract: Recently, the Norwegian authorities have established a number of Centres for Environment-friendly Energy Research (CEER), intended to develop new knowledge, foster breakthrough technology and promote innovation in order to solve specific challenges in the field of energy and environment. The expectation is that these heterogeneous, multipartner research consortia will lead to excellent academic performance and at the same time, that the new knowledge is of such nature that it can be exploited for practical and commercial purposes. This paper suggests that the adoption of two concepts of knowledge production, denoting knowledge produced in an academic context and in a context of application, respectively. These concepts, referred to as Mode 1 and Mode 2 knowledge production, open up for insight and implications about the challenges inherent in the CEER scheme. Our key argument is that in order to move our understanding of innovation in heterogeneous research collaborations, research efforts should be seen as concurrent processes of problem solving around scientific and practical problems. The main management challenge identified is the need to perform well as a manager of basic research and at the same time, lay the groundwork for innovation, that is, to lead according to differing expectations. Our claims are based on an empirical example, drawn on the CEER Centre BIGCCS. [Copyright &y& Elsevier]

Abstract: The BIGCO2 R&D (BIGCO2) Platform is an international collaborative research project aiming at developing several enabling technologies and innovative solutions supporting a large-scale deployment of CO2 capture from power generation and underground storage of CO2. All main routes for CO2 capture are investigated. The project is coordinated by SINTEF Energy Research and the budget of the current project period (2007-2011) is 16 M€. BIGCO2 builds knowledge and technology underpinning demonstration of power generation with carbon capture and storage (CCS) at industrial scale. The project aims at closing critical knowledge gaps in the CO2 chain to enable sustainable power generation from fossil fuels based on carbon capture and underground storage of CO2. BIGCO2 is unique in terms size, diversity, and the fact that it comprises the whole CO2 chain. The project includes extensive international collaborative effort bringing together expertise and research infrastructure of competent research institutes and universities, supported by leading vendors, energy companies, and oil and gas companies. This paper presents the structure, the original objectives and the achievements of BIGCO2. Further, for each research task, the results are analyzed in light of the objectives. Each task leader has analyzed the results in the following context of: originally stated objectives, results, and if the results meet the objectives. The purpose of BIGCO2 is to develop new knowledge to enable power generation with CCS. Tangible objectives are: 90% CO2 capture rate, 50% cost reduction, and a fuel-to-electricity penalty less than 7% compared with state-of-the-art power generation. Partners of the Consortium are: Statoil, GE Global Research, Statkraft, Aker Clean Carbon, Shell, TOTAL, ConocoPhillips, ALSTOM, DLR, TUM, NTNU, CICERO, SINTEF Materials and Chemistry, SINTEF Petroleum Research, and SINTEF Energy Research. The University of Oslo is a subcontractor to the project. Further, BIGCO2 benefits from a strong collaboration between the combustion research facility at Sandia National Laboratories (USA) and SINTEF Energy Research. The main sponsor of BIGCO2 is the Research Council of Norway, with considerable co-funding from the industry partners and Gassnova. The research challenges and approach are extensively presented in . [Copyright &y& Elsevier]

Abstract: CCS will play an important role in reducing greenhouse gas emissions in order to limit global warming to 2° Celsius by 2050. Amongst other things, both the costs and the technologies associated with CCS are subject to uncertainties. Cost estimations in the literature vary significantly. Some analyses provide cost estimation for CCS as a generic value, giving only a few distinctive technical options and only a few attempts to investigate the costs separately for each technology. The objective of this paper is therefore to analyze the cost spectrum for CCS provided by different studies and to determine realistic cost estimations for carbon dioxide capture and storage, as well as to investigate the impact of costs on the economic maturity of CCS. Results show that costs of CCS vary significantly along the CCS process chain. Furthermore, it becomes apparent that further efforts need to be taken, both in technology development and in terms of the willingness of an economy to pay high prices for mitigating CO2 emissions, before CCS may be referred to as economic feasible. [Copyright &y& Elsevier]

Abstract: Coupling flexible power generation with Carbon Capture and Sequestration (CCS) technology may be important for substantial reductions in CO2 emissions. In this paper we consider some of the implications of flexible power plant operation on the CCS process. Specifically, we consider the CCS chain capacity selection decision, by which we mean the choice of the optimal plant size, to understand what determines the amount of CO2 that is efficient to capture and how the decision to invest in CCS chain capacity is affected by price volatility of CO2 emissions quotas. We found that the plant''s emissions profile determined a range of CCS capacities that could be efficient with the tradeoff between the price of CO2 emissions quotas and the cost of CCS technology determining the specific optimal chain capacity. Secondly, investment into CCS technology for a flexible load power plant was more likely to be delayed in a multiple time point investment decision tree model as a result of price volatility, compared to investment in CCS technology on a base load power plant. [Copyright &y& Elsevier]

Abstract: The present renewed interest on CO2 EOR/EGR is led by an environmental concern. The consequence is that, today, we are urgently asked for considering the new CO2 EOR projects in association with CO2 storage. This implies an appropriate production well management allowing for delaying the CO2 breakthrough, while one has to keep a great concern on the safety issues related to the social acceptance, and to ensure a full economical viability of the CO2 injection projects. The picture becomes even more complex when it is planned to link various CO2 emission sites to various remote CO2 injection sites (typically already produced hydrocarbon reservoirs) through a large CO2 transportation infrastructure. In such a situation, it will be needed to harmonize in real time the rate fluctuations of the CO2 sources and the evolution of the CO2 sink injectivities (closely related to the reservoir pressure), while avoiding to meet the surface/transportation equipment limitations. The optimization of such a large system being not solvable rigorously, there is a particular interest towards methodologies allowing for a simplified reservoir modeling of the CO2 sinks (hydrocarbon field or aquifer). This point has been addressed in the work presented hereafter, which has been completed within the frame of the European ECCO project, aiming at providing a techno-economical tool for the CO2 value chain analysis. After a review of possible methods of reservoir conceptual modeling, the paper is presenting the approach followed for modeling reservoir CO2 EOR/EGR candidates in Central Europe. What is emphasized is the quantification of the impact of production constraints on hydrocarbon recovery and CO2 storage, in particular by means of an experimental design based tool. In addition, it is shown how some uncertainty on fluid miscible behavior can influence the hydrocarbon production. [Copyright &y& Elsevier]

Abstract: The application of Carbon Capture and Storage (CCS) in the power industry is important for reducing man-made CO2 emissions. This paper proposes new ways to categorize the options for mitigation of man-made CO2 emissions and CO2 capture. A detailed description on the ways to capture, transport and store CO2 has been presented. The power penalties and cost can be big challenges to apply CCS to the power industry, while a lot of opportunities exist, such as value added CO2 storage, industrial utilization of CO2 and the development of the carbon trade market. [Copyright &y& Elsevier]

Abstract: Biofixation of CO2 by microalgae has become an effective carbon dioxide capture and storage (CCS) technology and it has the potential for large-scale application in decreasing CO2 emission from combustion flue gases. In general, the production of the microalgae under flue gas CO2 carbon sequestration is closely related with the algae species, culture methods, biological conditions, gas conditions and the CO2 concentration. In this paper, the production parameter (biomass) for microalgae chlorella under flue gas was predicted using response surface methodology. It was found that the model agreed well with the experimental data. Further, the interacted analysis indicated that the carbon source, nitrogen source, cell inoculation density and light intensity had important effect on microalgae production. [Copyright &y& Elsevier]

Abstract: CO2 emission from combustion flue gases has become the primary factor in global warming. Chemical methods of absorbing CO2 from combustion flue gases have been widely used in engineering, because of its simple and convenient operation, high absorption efficiency and economic value. This paper analyses the domestic and foreign researches on chemical methods of absorbing CO2 from combustion flue gases, and summaries the effect of the reactors structure, absorbent type and operating conditions on absorption efficiency. This article also forecasts present developmental directions, and expects to have a certain reference to later research and development. [Copyright &y& Elsevier]

Abstract: Carbon capture and storage (CCS) technology is one of the most effective way of reducing emission. In this paper, we present a carbon capture investment model of power producer under carbon price and CCS technology uncertainties with real option theory. Then the investment t iming of CCS is explored by numerical simulation, the results indicate that the carbon price volatility and technological improvement of carbon capture will both delay carbon capture investment, and power producers will choose not to invest if the volatility is big enough. [Copyright &y& Elsevier]

Abstract: In this paper we report a laboratory scale evaluation test of MEA degradation associated with analysis of degradation products and an evaluation of different oxidation inhibitors. Control of oxidation with inhibitors selected among conventional antioxidants was found to be unsuccessful. New classes of chemicals were investigated and MEA oxidative degradation was considerably reduced using specific inhibitors. The inhibition was found to be effective with 40% MEA and was successfully extended to others amines such as DEA, MDEA and AMP. [Copyright &y& Elsevier]

Abstract: Tens of millions of tons per year of CO2 are being captured from raw feed gas by natural gas plants using solvent-based technologies comprising a pair of absorber and regenerator, and this CO2 is then being released to the environment. As interest in reducing CO2 emissions from natural gas plants has increased in recent years, CO2 capture and storage (CCS) has gained in importance. However, if a natural gas plant is provided with a CCS system, additional energy is required to compress the captured CO2. Therefore, JGC Corporation and BASF SE have started joint development of a new solvent-based CO2 capture technology, called HiPACT (High Pressure Acid gas Capture Technology), which improves the energy efficiency of the CO2 capture and compression units in a natural gas plant. HiPACT solvent is robust against the high temperatures associated with solvent regeneration at high pressures. Therefore, the regeneration process used in HiPACT can be operated well above atmospheric pressure, which significantly reduces the energy consumption of the CO2 compression unit. Further, HiPACT solvent absorbs a larger amount of CO2 per volume unit than other solvents, thus resulting in lower energy consumption for pumping and regeneration of the solvent. When compared to conventional technology, it is estimated that HiPACT can yield cost reductions of more than 25 percent. A recent pilot test has validated the key features of the HiPACT solvent, its thermal stability and CO2 absorption performance, and it has been decided to carry out a large-scale demonstration test. This paper presents the results of a batch test and a pilot test, both of which validated the key features of HiPACT, and presents the results of a case study which shows HiPACT’s advantages over state-of-the-art technology currently used worldwide. [Copyright &y& Elsevier]

Abstract: Power generation is one of the biggest sources of man-made carbon dioxide (CO2) emissions, the main anthropologic greenhouse gas. As the combustion of fossil fuels generates CO2 emissions, new technologies are required to enable the power sector to continue to meet the global demand for electric power, while controlling the CO2 emissions that contribute to global warming. To achieve meaningful reductions, it will be necessary to develop technologies that can be applied to both greenfield projects and to the existing fleet through cost effective retrofits. Among those technologies under development, Post-Combustion Carbon Capture and Storage (CCS) using the Chilled Ammonia Process (CAP) technology is one of the more promising solutions. Testing and technology development for CAP has been completed at the We Energies Field Pilot and is underway at the E.ON Karlshamn and AEP Mountaineer facilities. This paper will report on the progress being made at those three facilities and describe how the data being generated is contributing to the commercial scale-up of the technology. The current status of these facilities is as follows: [•] The We Energies Field Pilot, designed to capture over 15,000 metric tonnes/year of CO2, commenced operations in June 2008 and was operated through October 2009. This first of a kind Proof of Concept unit demonstrated that CAP could be applied to coal fired applications. [•] The E.ON Karlshamn Field Pilot, designed to capture over 15,000 metric tonnes/year of CO2, was commissioned in April of 2009 and captures CO2 emissions from a boiler combusting a high sulfur fuel oil. [•] The Product Validation Facility (PVF) at American Electric Power (AEP)’s coal-fired Mountaineer Power Plant, inaugurated in September 2009, is designed to capture and store 100,000 metric tonnes/year of CO2. The Chilled Ammonia Product Validation Facility treats a flue gas slipstream taken from a location downstream of Mountaineer’s existing selective catalytic reduction (SCR), electrostatic precipitator (ESP), and wet flue gas desulfurization (WFGD) systems. Deployment of a CAP facility in this configuration represents a significant step in the technology scale-up process. This project scope includes CO2 capture, compression, and storage in two geologic reservoirs with injection wellheads located on the plant property. AEP worked with Battelle to develop the geologic storage system. This paper describes the Chilled Ammonia Process Development Program and provides an update on the CO2 capture pilot plants status including the AEP Mountaineer Product Validation Facility. [Copyright &y& Elsevier]

Abstract: Global climate warming caused by emission of greenhouse gas including CO2 is one of serious problems nowadays. In an effort to mitigate CO2 emissions, one of most effectively clean energy plan is to produce power from coal using the integrated gasification combined cycle (IGCC). However, the cost of existing CO2 capture technologies is still too high. Utilization of large-solubility and low-cost absorbent for CO2 capture in IGCC can effectively reduce the electricity price increase caused by addition of CO2 removal unit. As it needs to trap CO2 before combustion under high pressure in IGCC absorption is considered to be a better choice. HPP (Hot Potash Process) uses aqueous solution of potassium carbonate as the absorbent. Compared to physical solvent absorption method Rectisol and Selexol, HPP has relatively low investment and relatively high CO2 recovery. Even in comparison with other chemical absorbent amine method HPP still has advantages as good chemical stability and low vapor pressure. In this paper several activators piperidine, piperozine, pyrazine, morpholine, imidazole, N-hydroxyethyl piperozine, Naminoethyl piperozine, AMP was tested respectively at 70 °C. As a result, piperidine activation works best, followed by N-(2-hydroxyethyl)piperazine, N-(2-aminoethyl) piperazine, 2-amino-2-methyl-1 -propanol and piperazine, pyrazine and imidazole is at its worst. Among them, N-(2-hydroxyethyl)piperazine is less volatile, more stable and suitable as the activator. Absorbing capacity and absorbing rate of CO2 in carbonate aqueous solution with HPZ increases by 5% or more than those with PZ. An improved HPP process is presented adopting the new activator. In this process two de-absorption two columns is designed operating at different pressure. This makes it possible to reuse the heat of condensation during high pressure de-sorption in reboiler of low pressure de-sorption. By preliminary calculating the novel process can save energy consumption obviously. The steam consumption, cooling water consumption and power consumption declines by 43.30%, 31.81% and 10.57%, respectively. It is expected to develop a low-cost technology for capture CO2 from IGCC in the future. [Copyright &y& Elsevier]

Abstract: In-situ CO2 capture in coal utilization captures CO2 during coal combustion or gasification such as Oxygen fuel combustion or HyPr-RING. coal gasification processes. Regarding Oxufuel combustion, Callide Oxyfuel Project has been being conducted as the world first project to apply the technology to an existing power plant, Callide A Power Station #4 unit (30MWe) with injection of captured CO2 into the underground. This is a Japan-Australia collaboration project and JCOAL participates in it as a supporting collaborator. JCOAL also proposed a novel coal gasification method-,HyPr-RING (Hydrogen Production by Reaction-Integrated Novel Gasification). HyPr-RING method utilizes a chemical looping with the calcium cycle, in which CaO (or Ca(OH)2) captures CO2 during coal gasification completely to form CaCO3 and release heat for gasification to produce near pure hydrogen in one gasifier. This paper introduces the current developing status of the HyPr-RING method, mainly including the experimental examination of the transition of sorbent particle size distribution, ash and sulfur concentration of materials at several locations of gasification and calcination system for the HyPr-RING process. And the plant cold gas efficiency which should be affected by ash separation was also analyzed. As the results, it was found that coal ash and sulfur concentrated highly in the process of calcination after cyclone. If it is possible, separate and remove ash and sulfur by applying devices like filter or/and cyclone separator, the plant coal gas efficiency may raise 2 points than that in the previous study in which a part of recycled sorbent was rejected without separation. One method for reducing CO2, the green house gas emissions is to capture CO2 before it releases into the atmosphere and then sequestrate it. Active lime (main component, CaO) can be used to capture CO2 in the exhaust gas or in the reactor from fossil fuels utilization effectively. That is calcium oxide (CaO) absorbs CO2 to yield calcium carbonate (CaCO3) (Eq.(1)), then the CaCO3 is thermally decomposed to CaO again and release nearly pure CO2 (Eq. (2)) for sequestration. To obtain a nearly pure CO2 stream from CaCO3 decomposition, the heat for decomposing CaCO3 can be supplied by combusting fossil fuels, such as coal and natural gas, in a calciner with oxygen fuel combustion. The oxygen diluted by CO2 (CO2 cycle) or H2O (steam cycle), in order to obtain near pure CO2 stream from CaCO3 decomposition. In our previous studies4−6, it was clarified that calcinations of limestone (main component, CaCO3) in a fluidized bed calciner can be performed in CO2 cycle atmosphere when the bed temperature was raised above 1293 K, whereas with 60% steam cycle in atmosphere, limestone can be decomposed at comparatively lower temperature, such as 1173 K. The decomposition conversions of the limestone were about 95% and 98%, in CO2 cycle and in steam cycle atmospheres, respectively. Reducing the calcinations temperature of limestone was helpful to produce more than 30% active CaO as shown in previous study4−6. In this study, the energy of CaCO3 calcination process by H2O (steam) cycle was analyzed and compared with CaCO3 calcination process by CO2 cycle. For process calculations, the mass and energy flows were calculated iteratively, based on the input and output balances, until err [(input-output)/input] was <0.01. Analysis showed that, although H2O (steam) cycle calcination had calcination energy more about 3.6% than CO2 cycle due to water evaporation latent heat loss, however, the calcination energy per active CaO was lowest for H2O (steam) cycle. [Copyright &y& Elsevier]

Abstract: Chemical-looping combustion (CLC) is a combustion concept with inherent separation of CO2. The process uses a solid oxygen carrier, which consists of metal oxide, to transfer the oxygen from air to fuel. This paper presents findings from batch tests performed in a 10 kWth CLC pilot for solid fuels. The pilot, which is the world’s first chemical-looping combustor for solid fuels, is based on interconnected fluidized-bed technology and features a fuel reactor (FR) and an air reactor (AR) as the principal reaction chambers. In the FR, fuel is gasified with steam whereupon gasification products react with the oxygen carrier to form, ideally, CO2, H2O and SO2. Oxygen-carrier particles exit the FR through a weir and are led to the AR, where they are regenerated to their oxidized state. The pilot has been operated using a natural iron-titanium ore called ilmenite as oxygen carrier. Previous continuous tests have demonstrated a need for batch tests in order to obtain complementary information on system performance. In this study, five fuels were fed to the fuel reactor in batches of 20–25 g at four temperatures; 940 °C, 970 °C, 1000 °C and 1030 °C. By using devolatilized fuel, it was possible to determine (a) oxygen demand associated with syngas from char gasification as well as (b) kinetics of char conversion to gas. Rates of char conversion were found to be temperature dependent, as expected, whereas no temperature dependence was found for the oxygen demand. Activation energies for conversion of char to gas were calculated using Arrhenius plots. The minimum oxygen demand for char was found to be around 5%. [Copyright &y& Elsevier]

Abstract: The Calcium Looping (CaL) process using CaO as sorbent for capturing CO2 from flue gases is a promising postcombustion CO2-capture technology that is economically competitive with other capture technologies with an overall increased output in electric power and a low electric efficiency penalty associated with CO2 capture. The process can be realized in a Dual Fluidized Bed (DFB) system utilizing a Circulating Fluidized Bed (CFB) reactor as carbonator operating at 600–700 °C and a second CFB as regenerator operating at temperatures between 850–950 °C. The separation of CO2 from the flue gas takes place through the carbonation reaction (CaO+CO2→CaCO3). The regeneration of the sorbent is realized via the reverse reaction in the regenerator at higher temperatures. The feasibility of the CaL process has already been shown at IFK, University of Stuttgart on a lab-scale size. In order to investigate the calcium looping process using real combustion flue gas and to evaluate the process on a long-term basis, a 200 kWth pilot plant has been built at IFK. This paper delineates the design of the pilot plant to capture over 90% CO2 and provides an overview of the main components and the control philosophy. First results from the successful commissioning of the pilot plant are also shown. [Copyright &y& Elsevier]

Abstract: Climate change mitigation is a dynamic area that, as it is addressed, brings new challenges to other environmental aspects. Carbon capture and storage (CCS) plants are the latest development in a series of environmental controls and have some distinctive features that could potentially lead to other wider environmental problems. Whilst CCS represents a significant step towards cutting greenhouse gas emissions, consideration needs to be given to the potential wider environmental consequences especially in terms of pollutant emissions and local air quality impacts. Challenges remain for existing plants which will need to consider the most cost-effective strategies for installation of CCS plant balanced against managing air quality impacts as dispersion characteristics change. In the case of post-combustion carbon dioxide (CO2) capture technology, which is the focus of this paper, removal of CO2 from the main flue gas stream requires diversion of the flue gas through the CCS process, before it arrives at the exhaust stack. This flue gas stream may be all or part of the total plant flow or for multi-unit plants may be diverted from specific power generation units into the CCS plant before exhausting to atmosphere, either through returning back to the existing stack or through a new dedicated stack. This diversion and subsequent emission in itself poses an engineering challenge. In particular, the integration of the CCS process with the existing plant must also ensure that the diverted flue gas still achieves adequate dispersion as it contains residual levels of pollutants such as nitrogen oxides (NOx) and sulphur dioxide (SO2), despite the fact that the CCS process itself may reduce some of these pollutant levels further as a process by-product. Power plants which incorporate CCS will still be required to adhere to the appropriate pollutant emission limits and ensure effective dispersion to minimise the risk of breaching local air quality standards. This paper draws on experience gained through post-combustion CCS projects and addresses the potential effects of CCS on air quality, in the case of carbon capture retrofits. The findings of this paper are relevant to project developers, power generators and policymakers globally who have an interest in the potential for CCS to provide an emissions abatement option for existing thermal assets in the short and long term. [Copyright &y& Elsevier]

Abstract: The most promising process for Post Combustion Carbon Capture (PCC) is reactive absorption. For the design and scale-up of this process, reliable process models are needed. To achieve this, the models need to not only reliably describe the physical and chemical equilibria in the reacting systems but also to account for both mass transfer and reaction kinetics. Consequently, the models are complex and contain a large number of input parameters for describing fluid dynamics and physico-chemical properties. In order to assess the required quality of the input, the sensitivity of the simulation results to the parameters has to be known. This paper presents results from such a sensitivity study for a typical operating point of a PCC pilot plant with 0.3 g/g monoethanolamine (MEA) in water as the solvent. A rate-based model and its input parameters are introduced and describe the pilot plant results well. The most relevant input parameters of the model are systematically varied and the influence of that variation on the simulation results is monitored. Absorber and desorber are considered separately. The results are sensitive to most of the studied parameters. High sensitivities are found for the interfacial area, the Henry’s law constant and the enthalpy of absorption as well as for the parameters describing the equilibrium and kinetics of the carbamate formation and the amine protonation equilibrium. [Copyright &y& Elsevier]

Abstract: Packed towers are common as gas/liquid contacting units for separation processes. Several studies have been performed to measure and model pressure drop, liquid hold-up and effective mass transfer area. However, most investigations have concentrated on distillation operation and the correlations obtained may not be directly applicable to reactive absorption. The present work presents a study of hydrodynamics and mass transfer properties of Sulzer structured packing Mellapak 2X using both an inorganic and an amine solvent. The pilot plant has an absorber column with packing height of 5 m and diameter 0.5 m. In this paper results for absorption studies and pressure drop, liquid hold-up and effective mass transfer area are presented. Dependencies of liquid flow, gas flow and viscosity were in agreement with correlations found in literature. New correlations for the hydrodynamic characteristics will be implemented in an in-house software as a basis for absorber and desorber design. [Copyright &y& Elsevier]

Abstract: This paper describes an investigation for multi-stage systems used in coal-fired power plant. The whole work was divided into two steps: energetic and economic analyses. In the first step: on the basis of a serial concept, through varying the position of compressors and vacuum pumps, recycling the retentate of the 2nd membrane to the feed side of the 1st membrane, a cascade variant was developed and analysed. In the second step: an economic model was developed to calculate the capture cost of the cascade system. The total cost is composed of investment cost, operation and maintenance (O&M) cost and electricity cost. A correlation between the membrane parameters: selectivity & permeability and capture performance: energy consumption & capture cost was built up. Using Polyactive® membrane developed by GKSS with CO2 permeance of 3 Nm3/m2hbar and CO2/N2 selectivity of 50, under the separation target of 70% degree of CO2 separation and 95 mol% CO2 purity, adopting the cascade membrane system in the 600 MW NRW-reference power plant, the specific energy consumption including CO2 compression (110 bar, 30 °C) is 256 kWh/tseparatedCO2 with 6.4%-pts efficiency loss. The capture cost is 31 euro/tseparatedCO2 , which could be a promising solution as a retrofit for the existing power plants. [Copyright &y& Elsevier]

Abstract: IGCC power plants seem to represent one of the most appealing options to produce electric energy from coal and low grade solid fuels with interesting plant efficiency and low environmental impact. As a matter of fact the majority of gasification-based power plants are equipped with oxygen-blown gasifiers which have two main advantages with respect to air-blown reactors: high values of cold gas efficiency and an N2 deprived syngas. The aim of this paper is to compare two different oxygen production technologies for oxidant supply to the gasification island. An IGCC power plant with pre-combustion CO2 capture has been modelled considering: (i) a cryogenic distillation ASU based on a pumped liquid oxygen cycle; (ii) an innovative OTM-based oxygen production technology integrated in the power island. An overall heat and material balance has been estimated to evaluate plant performances and compare the two options; our thermodynamic analysis shows a promising improvement of the overall plant performance for the OTM-based IGCC nonetheless several key issues deserve a more in depth analysis to asses the real potentialities of membrane-based oxygen production technology. [Copyright &y& Elsevier]

Abstract: To make the deployment of carbon capture possible, it is highly needed to develop original solutions that induce low energy penalty and that are easy to operate. This paper aims at presenting the DMX™ process developed at IFP Energies nouvelles based on special solvents which are characterized by the formation of two immiscible phases for given temperature and CO2 loading conditions. The concept of demixtion is briefly described in terms of physico-chemical properties, its interest and all required steps for appropriate process development are discussed. The corresponding process is presented and a technico-economic analysis is given. It is shown than one can reach a reboiler duty as low as 2.1 GJ/t CO2 which is significantly lower than the 3.7 GJ/t CO2 of the 30wt.% MEA reference process. It is also discussed that the energy consumption at reboiler cannot be the only parameter to consider for comparison with other processes and some further information about the DMX™ process are given. Operational issues are particularly discussed. In that sense, the performances of the DMX-1TM solvent in terms of degradation and corrosion are shown. Similarly a particular focus is made on the liquid/liquid separation which is a key aspect of the DMX™ process. [Copyright &y& Elsevier]

Abstract: The oxygen requirements for oxycoal combustion in a coal-fired power station are unusual in several respects. The amount of oxygen required is large, for instance a 500  MWe power plant will require around 10,000 tonnes per day of oxygen. The oxygen purity is low and the pressure required is essentially atmospheric pressure. There is no demand for any significant quantity of co-products, such as argon or nitrogen. The parasitic nature of the power means that high efficiency is important but the large scale means that capital cost should also be minimised. These factors open up new possibilities to optimise the process cycle and machinery configuration to minimise the power consumption of the air separation unit without compromising the requirement for low cost. This paper presents the results of a study to develop Air Products’ air separation unit (ASU) offerings for oxycoal CO2 capture projects. A scalable “reference plant” concept is described to match particular sizes of power generation equipment, taking into account factors such as safety, reliability, operating flexibility, efficiency, and of course low capital cost. We describe the selection of a process cycle to exploit the low purity requirements as well as the options for compression machinery and drivers as the scale of the plant increases and the sizes of referenced equipment limit the possibilities. We also explore integration with other elements of the oxycoal system, such as preheating condensate or heating and expanding pressurised nitrogen. Finally, the advantages and disadvantages of different execution strategies for air separation unit projects are discussed, as well as alternative commercial models for the supply of oxygen. [Copyright &y& Elsevier]

Abstract: Coal-fired power stations under oxyfuel combustion produce a raw CO2 product which contains impurities such as water, oxygen, nitrogen and argon from excess oxygen and air leakages. There are also acid gases present, such as SO3, SO2, HCl and NOX produced as by-products of combustion. These acidic impurities will need to be removed from the CO2 stream before it is introduced into the pipeline to prevent corrosion and comply with possible regulations. There may also be stringent requirements on purity, particularly for applications such as enhanced oil recovery. A novel compression method of producing NO x -free, SO2free CO2 was proposed in GHGT-8 where SO2 and NO x are removed as H2SO4 and HNO3respectively by compression and water contact of the flue gas. At GHGT-9, initial experimental results were presented using actual fluegas via a sidestream from Doosan Babcock’s 160 kW coal-fired oxyfuel rig, showing the feasibility of the process eliminating 99% SO x and 90% NO x compounds. In this paper, we report on the effects of pressure, temperature, residence time and presence of water in a laboratory scale apparatus using synthetic flue gas. [Copyright &y& Elsevier]

Abstract: Alstom is developing a portfolio of solutions to address CO2 emission reductions. Among them is CO2 Capture and Storage (CCS) for which Alstom is developing several CO2 capture systems based on post-combustion and oxycombustion processes. This paper will be oriented to utility and industrial companies that would like to be prepared to CCS challenges and understand the key features of the CO2 capture technologies, in this article focus will be on oxy-combustion. This paper is also oriented to “oxy-experts” community for an update coming from pilots operation. It will describe key features of the different pilot projects with Alstom’s involvement and will describe the work performed in there. The development of CO2 capture technologies are being pursued by European and US suppliers in collaboration with utility companies, academia, the US DOE, the European Union, and universities. The first part of this article will address the work of Alstom and corresponding results in three major oxy pilots: • Vattenfall Schwarze Pumpe Oxy-combustion pilot plant (30 MWth, coal)) and corresponding results (pilot is in operation since September 2008, a full PC oxy-combustion chain has been under evaluation there). • An oxy tangentially fired boiler development project (coal) with co-funding from the US DOE and other organizations, which includes pilot testing at the 15 MWth scale, conducted in Windsor CT (US). This pilot has started operation in September 2009. • The TOTAL Lacq Oxy-combustion pilot plant (30 MWth, natural gas) where Alstom did the retrofit of a conventional boiler for its conversion into oxy-combustion. Considerable knowledge has been gained with these pilots through different considerations, both on boiler components but also on the integrated oxy chain. All these positive outcomes confirm the expectations of the community in oxy-development and open the door to the next development step of ∼250 MWel large scale oxy-fired carbon capture and storage (CCS) demonstration plants. This paper provides an update about the CO2 capture pilot plant operation and also present the technical challenges expected to be demonstrated during large scale demonstration plants. [Copyright &y& Elsevier]

Abstract: Doosan Power Systems has adopted an evolutionary approach to the design and implementation of OxyCoal™ technology combining well proven and commercially available components with state-of-the-art advances in technology, and is leading a number of UK Government supported collaborative projects that are developing oxyfuel combustion technology. The “Demonstration of an Oxyfuel Combustion System” OxyCoal 2 project aimed to demonstrate an oxyfuel combustion system of a type and size (40MWt) applicable to new build and retrofit advanced supercritical oxyfuel plant. Following conversion to oxyfuel firing, the Clean Combustion Test Facility (CCTF) became the world’s largest demonstration facility of an oxyfuel combustion system, and since the official opening on 24th July 2009 a test programme has been successfully undertaken to demonstrate the full-scale Doosan Power Systems first generation 40MWt OxyCoal™ burner on air and oxyfuel firing, achieving safe and stable operation across a wide operational envelope and CO2 flue gas concentrations in excess of 75% v/v dry, and up to 85% v/v dry. The OxyCoal 2 project is discussed in the paper and results from testing the full-scale 40MWt OxyCoal™ burner firing bituminous coal in both air and oxyfuel firing operation are presented. [Copyright &y& Elsevier]

Abstract: Oxyfuel combustion CO2 capture technology presents an excellent opportunity for achieving near zero emissions from the coal-fired power plants. In the oxyfuel technology, the volume of flue gas is reduced by a factor of four to five (on a dry basis) due to elimination/reduction of nitrogen from combustion. This reduced volume of CO2-rich flue gas has to be compressed to 25 to 35 bar (a) for purification, thus further reducing the actual volume of flue gas by a factor of 25 to 35. If the equipment for removing trace impurities (SOx, NOx and Hg) is installed downstream of the flue gas compressor, the capital investment could be significantly reduced compared to that for the air-fired operation. Furthermore, by processing the entire volume of flue gas in the CO2 purification unit, it is possible to remove and concentrate the trace impurities in the solid and liquid waste streams and to produce a vent stream with near zero emissions and a high purity CO2 relatively free of trace impurities. Praxair is developing an oxy-combustion flue gas purification technology that will leverage these synergies. This technology will reduce emissions of CO2, SOx and Hg by >99% and NOx emissions by >95% compared to an air-fired pulverized coal power plant. The benefits of the technology include management of air ingress problems, capital and operating cost savings for SOx and NOx removal, reduction in CO2 capture cost and production of high purity CO2 stream for sequestration. These benefits will translate to lower cost of electricity for power plants with CO2 capture. This paper presents the experimental data for the SOx/NOx removal and high CO2 recovery processes and the results of the commercial viability assessment. [Copyright &y& Elsevier]

Abstract: Oxy-fuel combustion of fossil fuels produces a CO2-rich gas stream with some impurities, such as nitrogen, argon, oxygen, nitrogen oxides, heavy metals and sulphur oxides, whose concentrations vary based on the type of fuel, combustion conditions, plant configuration, and other process related parameters. To control the greenhouse gas (GHG) emissions from these plants and sustain their operational competitiveness in a carbon constrained world, the CO2 in the flue gas stream has to be captured, cleaned up and compressed to make it suitable for pipeline transport and permanent storage in geological formations. The flue gas CO2 capture and processing, including integrated multi-pollutant control, provides a feasible and viable technological pathway towards this goal. For oxy-fuel combustion systems, the CO2 capture is best achieved by physical gas separation through a series of compression and cooling stages to liquefy and separate CO2 from non-condensable gases in the flue gas stream. The effectiveness of the CO2 capture and compression system depends on the process design and assessed using removal efficiency, level of purification and energy demand for a unit of captured CO2. If the CO2 capture process can also simultaneously remove other pollutants in the gas stream, then the whole process becomes more efficient and cost-effective. In this case, implementing an elaborate flue gas pre-treatment system will not be necessary. Hence, CO2 capture technologies that are capable of simultaneously controlling emissions of multiple pollutants offer the potential to achieve emissions reduction at lower cost and reduced footprint, when compared to conventional emission control systems. For the new oxy-coal fired power plants, multi-pollutant control technologies can help designers of these plants select effective and less expensive compliance strategies, compared with compliance choices made when the requirements are addressed individually. CanmetENERGY has developed and successfully implemented an advanced and proprietary CO2 capture and compression unit (CO2CCU) that is capable of capturing and generating a relatively pure CO2 product stream, while simultaneously removing the pollutants such as nitrogen oxides, sulphur oxides and mercury in the process condensate streams. The pilot-scale unit is currently integrated with the existing 0.3 MWth oxy-fuel Vertical Combustor Research Facility. This advanced CO2 capture system represents an integrated approach to oxy-fuel combustion with multi-pollutant and CO2 capture and provides a unique test platform for CO2 processing. In this paper, we present and discuss the recent pilot-scale test results of CanmetENERGY’s CO2CCU. The unit was used to conduct experiments with a broad range of flue gas compositions, including different levels of CO2 concentrations and a host of impurities in the flue gas stream. The real-time measurements of CO2 product and vent stream gas compositions as well as the analysis of condensate streams provide insight into the type of chemical reactions that are taking place under different pressure, temperature, and moisture levels. The experimental results help to explain some of the chemical reactions involved in the CO2 capture and compression for better optimizing the capture process. [Copyright &y& Elsevier]

Abstract: Studies have been carried out to show that there could be benefits in employing a hybrid of the post combustion capture and oxyfuel processes. The former is suited for retrofit purposes but involves an energy intensive solvent regeneration process. The oxyfuel process would result in high partial pressures of CO2 in the flue gas making separation easier. However, the Air Separation Unit is also energy intensive and significant modifications would have to be made on the power generation process. An enhanced- O2 coal power plant with post combustion CO2 capture would produce flue gas with reduced mass flow and higher CO2 partial pressures. The dynamic response of the downstream CO2 capture plant was studied in this paper. [Copyright &y& Elsevier]

Abstract: In conjunction with John Zink Co., LLC, the Chevron Energy Technology Company conducted a three part study evaluating potential issues with switching refinery process heaters from fuel gas to hydrogen fuel for the purpose of greenhouse gas emissions reduction via CO2 capture and storage. The focus was on the following areas: • Heater performance • Burner performance and robustness • Fuel gas system retrofit requirements This paper will summarize the findings of the study. [Copyright &y& Elsevier]

Abstract: CO2 emission control is significant issue as a countermeasure for a global warming problem. Utility companies are required to reduce CO2 emission from thermal power stations and make various efforts to improve thermal efficiency and to utilize carbon neutral fuels such as biomass fuels. CCS (CO2 capture and storage) technology is regarded as one method to reduce CO2 emission, but CCS required great decrease of thermal efficiency. As amount of fossil fuel on the globe is so restricted, it is important to keep high thermal efficiency as high as possible, in order to utilize valuable fossil fuel effectively. This project plans to develop innovative gasification technology with CO2 capture, which can keep thermal efficiency as high as state of the art IGCC plant, namely more than 40%. This is to gasify coal with mixed gas of O2 and recycled CO2 flue gas, just like oxy-fuel combustion system. We expect following two merits. First merit is to simplify the system. As the CO2 concentration in exhaust gas is almost 100%, this system doesn’t require CO2 separation unit. So no steam is required to bleed from steam cycle in order to maintain absorber for CO2, therefore thermal efficiency is kept high even after capturing CO2. We expect another merit in this system. Generally speaking, CO2 gas works as gasifying agent for coal, so high CO2 concentration improves gasification performance of gasifier. This paper is to report the status of the project executed by CRIEPI. [Copyright &y& Elsevier]

Abstract: After 3 years and over one thousand person-months of effort, the FP6 CACHET project was successfully concluded in the first half of 2009. CACHET focussed on pre-combustion capture of carbon dioxide (CO2) from natural gas fuelled power generation and hydrogen (H2) production. Through a combination of experimental and paper studies, CACHET developed, optimised and evaluated four promising capture technologies: Advanced steam methane reforming (HyGenSys), Redox technologies (chemical looping), Metal membranes and Sorption enhanced water gas shift (SEWGS). This paper reports the technical and economic conclusions of the project and provides a look ahead to the future for each of the technologies and the challenges for full scale deployment. All technologies showed the potential to reduce CO2 emissions by more than 90% and the opportunity to improve the energy efficiency compared to the state-of-the-art technology. [Copyright &y& Elsevier]

Abstract: This paper investigates the performance of SEWGS (Sorption Enhanced Water Gas Shift), an innovative reactor for CO2 capture, applied to Integrated Gasification Combined Cycle (IGCC). Firstly, two IGCC reference cases based on dry feed slagging Shell gasifier, with and without CO2 capture, are defined. Then, two different integrations of SEWGS are investigated. The first assumes a conventional low-temperature acid gas removal process adopted upstream the SEWGS; this solution shows slight thermodynamic advantages towards the reference case with CO2 capture (higher efficiency of 1% point), but not from lay-out simplification and equipment savings. The second solution assumes a simultaneous CO2 and sulphur separation from the syngas; this results in a net electric efficiency gain over the reference case of about 2 percentage points. Moreover, this solution allows a significant plant simplification and equipment reduction with further advantages from economic point of view, which is not evaluated in this work. This activity is carried out under the FP7 project CAESAR financed by the EU community. [Copyright &y& Elsevier]

Abstract: The sorption enhanced water-gas shift technology is attractive for pre-combustion decarbonisation of power production based on IGCC, but only when the SEWGS technology can be applied for sour syngas. To this extend, it was recently demonstrated that 2000 ppm of H2S did not influence the CO2 sorption behaviour of a potassium promoted hydrotalcite material at a relatively low pressure of 5 bar. This paper highlights ongoing sorbent testing at pressure swing operation between 30 bar adsorption and 2 bar regeneration, crucial for the successful development of the technology. The sorbent has good catalytic activity for the water-gas shift reaction during SEWGS conditions. At 30 bar pressure and 400 °C feed temperature, a CO, CO2 and H2S free H2-product is obtained when feeding a syngas containing 200 ppm H2S. This implies that mixing in a separate WGS catalyst is not needed, which significantly simplifies the technology. Moreover, multi-cyclic testing at 30 bar and 400 °C for 110 cycles shows good sorbent stability in the presence of 200 ppm H2S. Deliberately induced slips of CO2 and H2S stabilize within a limited number of cycles. By simply reducing the adsorption period, the mass-transfer zones for both CO2 and H2S are readily pushed back into the column, again producing a product free of CO2 and H2S. These observations suggest that reversibility of sorption processes on the material that have been tested is fully appropriate for the further development of the long-term operation of sour-SEWGS technology. [Copyright &y& Elsevier]

Abstract: Sorption Enhanced-Steam Methane Reforming (SE-SMR) is a promising process which allows producing in a single reactor a hydrogen-rich syngas from natural gas, while capturing the CO2 by reaction with a solid sorbent. Scope of this paper is to investigate the potentiality of the SE-SMR process coupled to a combined cycle, by estimating the plant performance and by discussing the main issues related to plant layout and reactors characteristics. The calculated net efficiency and carbon capture ratio are comparable with that obtained for a competitive technology based on Auto-thermal Reforming (ATR), but advantages could result from the higher plant simplicity and lower plant cost. [Copyright &y& Elsevier]

Abstract: In this paper, a new synthesis method to obtain mixed CaO/Ca12Al14O33 solids for high temperature CO2 capture is presented. The modification of a pure phase Ca3Al2O6 solid through a thermal treatment under controlled conditions leads to a high CO2 absorption capacity material, with very promising long term stability during absorption/desorption cycles. The influence of the calcination temperature during the synthesis of the Ca3Al2O6 powders, and the temperature and atmosphere applied during the thermal treatment was studied. Therefore, optimum conditions for high stabilization rate and high final CO2 absorption capacity of the sorbent could be determined. Comparison with a natural sorbent (dolomite) over 150 carbonation/calcination cycles is also included, showing a substantial improvement of the synthetic solid CO2-uptake at long term use, compared to that of natural sorbents. [Copyright &y& Elsevier]

Abstract: N.V. Nuon (part of the Vattenfall Group) operates an IGCC in Buggenum and is developing a multi-fuel IGCC with CO2 capture and storage (Nuon Magnum) in Eemshaven, the Netherlands. In order to prepare for large-scale application of CO2 capture and storage, a CO2 capture pilot plant is constructed at the Buggenum IGCC plant and will be ready for testing in January 2010. The overall objective of the CO2 Catch-up project is to demonstrate pre-combustion CO2 capture and to generate knowledge in the form of useful data and operational experience. In parallel with the development, realisation and operation of the pilot plant, a test and R&D programme has been initiated together with Delft University of Technology, ECN and KEMA. In this paper, the technology is described in more detail and the test and R&D programme is outlined. [Copyright &y& Elsevier]