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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: Integrated Gasification Combined Cycle (IGCC) is a technology for power generation in which the feedstock is partially oxidized with oxygen and steam to produce syngas. In a conventional IGCC design without carbon capture, the syngas is purified for dust and hydrogen sulphide removal and then sent to a Combined Cycle Gas Turbine (CCGT) for power production. The hot GT flue gases are sent to Heat Recovery Steam Generator (HRSG) for steam generation. Additional power is produces by expanding the steam generated in a steam turbine. Carbon capture and storage (CCS) technologies are expected to play a significant role in the coming decades for reducing the greenhouse gas emissions. Integrated Gasification Combined Cycle is one of the power generation technologies having the highest potential to capture carbon dioxide with the low penalties in term of plant energy efficiency and cost. The modification of the IGCC design for carbon capture can be done in various plant concepts considering the carbon capture method to be used (e.g. pre- and post-combustion capture, syngas chemical looping etc.). This paper investigates various carbon capture methods suitable to be applied for an IGCC plant for power generation. The coal blended with biomass (sawdust) based IGCC case study investigated in the paper produces around 400–500 MW net electricity with more than 90% carbon capture rate. An important focus of the paper is concentrated on overall energy efficiency optimization of the IGCC plant concepts with various carbon capture options by better heat and power integration of the main plant sub-systems (e.g. steam integration between gasification island, syngas conditioning line and the steam cycle, influence of heat and power demand for Acid Gas Removal unit etc.). A particular attention of the paper is focused on the quality specification for the captured carbon dioxide stream considering various capture options but also the storage options (enhanced oil recovery, storage in depleted oil and gas fields, saline aquifers etc.). [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: This paper presents results from a 30 -month project devoted to taking the chemical-looping combustion (CLC) technology to the next level of development. The project is part of the EU’s Sixth Framework programme with support from the CCP (Carbon Capture Project) and has mainly focused on the critical issues for an up-scaling of the technology. In an earlier project the CLC technology was demonstrated successfully for the first time for 100 h using Ni -based oxyge n carrier particles using natural gas as fuel. The current project has built on these experiences and : i) established industrial-scale NiO particle production with suitab le commercial raw materials. Oxygen carrier particles have been produced with both s pray -drying and impregnation and investigated extensively with respect to parameters important for CLC operation, such as reactivity in batch and continuous operation, strength, defluidization phenomena, operation at high temperatures and effect of imp urities suc h as H 2S in the fuel; ii) extended operational experience in long term tests of particles in the available 10 kW prototype for more than 1000 hours combustion and iii) succesfully scaled -up and operated the process in a 120 kWth combustor using syn gas and natural gas. Further, the project has included extended and verified modelling of the reactor system for scale-up in addition to process and technology scale-up and economic assessment. The paper will present the main results of the project. [Copyright &y& Elsevier]

Abstract: This paper analyzes various aspects of the Zecomix cycle, a novel coal fired power plant, based on various innovative processes to achieve elevated efficiency and zero-emissions. A coal hydro-gasification process, using recycled steam and hydrogen as gasifying agents, converts carbon to CH4, which is then processed by two carbonator reactors where CH4, mixed with steam and contacted with calcium oxide, is converted to an H2/H2O based syngas while CO2 is absorbed by the solid sorbent generating CaCO3. The synthetic fuel produced in the chemical island is burned with oxygen in a semi-closed high temperature steam cycle, with a rather complex supercritical heat recovery steam cycle. The main relevant operating parameters for the chemical island are varied in order to evaluate their effect on plant performance and to optimize the process. In addition, the paper presents a rather detailed analysis of some critical issues, often neglected in previous works from the literature. Net plant efficiency of 44–47% with a virtually complete carbon capture was predicted, a very interesting results with respect to other proposed coal power plants with carbon capture. The high complexity of the chemical island and the importance of a good sorbent performance in the critical conditions typical of this plant should be however taken into account for a fair comparison with other plant concepts. [Copyright &y& Elsevier]

Abstract: This paper presents the results of ASPEN simulations of a carbon-dioxide (CO2) removal and recovery plant that captures CO2 from a 500 MWe (net) conventional coal-fired power plant flue gas stream. At a constant CO2 recovery rate of 86.5% by weight, the performance of aqueous ammonia solution as an alternative to various aqueous amino solvents (MEA, AMP and MDEA) is compared in terms of the process scenarios, solvent loadings and overall energy consumption. The overall mass transfer co-efficient and CO2 loading data generated for aqueous ammonia solutions using a laboratory scale wetted wall gas-liquid contactor are also presented. The ASPEN simulation results in conjunction with the laboratory data show, that capturing CO2 from coal-fired power plant flue gas, using aqueous ammonia solvent, will require ammonia concentration no more than 5% by weight and absorber temperature 10 ∘C or lower, if the vapor phase ammonia losses are to be contained and the precipitation of ammonium bi-carbonate in the absorber is to be avoided. Under such an operating scenario, the aqueous ammonia based CO2 capture process has overall energy requirement comparable to the conventional 30% by weight aqueous MEA based process. The ASPEN results further show that 30% by weight AMP based process has the lowest overall energy requirement among the solvents considered in this paper. [Copyright &y& Elsevier]

Abstract: The potential benefits of precombustion carbon dioxide capture are well documented, and adsorption remains a promising separation process in this area. This paper details work to identify and assess the potential of high temperature adsorbents suitable for precombustion capture. The aim of this paper is to schematically identify adsorbents that are suitable for carbon capture in different temperature ranges. A critical aspect of this work is to assess the materials not only in terms of carbon dioxide isotherms and absolute loading, but to consider the wide range of other properties that are required to achieve an industrially feasible adsorbent - selectivity, cycling capacity, stability, kinetics, high pressure loading, fate of other components (including water, H2S, NH3, CO and N2). It is only when all these requirements are sufficiently met, that an adsorbent can be consider worthy of industrial consideration. A range of analytic screening tests are described to enable a full characterisation of the merit of a specific adsorbent. The adsorbents investigated are zeolites (NaX, calcium chabazite), commercially available hydrotalcite, layered double hydroxides/oxides (LDH/Os), and magnesium double salts. Each operates in a different temperature range and offers potential for integration within an Integrated Gasification and Combined Cycle precombustion process train. Some of the promising and significant conclusions of this work are - [•] Magnesium double salts present very favourable carbon dioxide isotherms and demonstrate significant carbon dioxide loading and the isotherms are suitable for PSA or TSA operation at high temperature. [•] LDHs or their derivatives as layered double oxides can adsorb up to 1.5mol/kg CO2. Water does not affect CO2 sorption, and the material has good recyclability in TSA. [•] The selectivity of hydrotalcite is well documented. However there is no reported literature on the adsorptive behaviour of these materials with respect to trace components - H2S and NH3. These results are reported. [•] Calcium chabazite displays useful CO2 loading potential in a unique temperature range around 200 ∘C. [•] NaX has the potential to replace Selexol at an operating temperate of 130 ∘C. [Copyright &y& Elsevier]

Abstract: Steam demand is increasing for Oil & Gas projects, and in particular oil sands and extra-heavy oils thermal recovery schemes. Use of oil residues and bitumen can be a cost-effective solution for natural gas substitution in SAGD (Steam Assisted Gravity Drainage). However, use of such fuels gives rise to higher specific GHG emissions. Oxy-combustion technology is an elegant solution to this problem since oxygen allows complete combustion of very high viscosity and heavy fuels, and because it provides a concentrated CO2 stream, for easier Carbon Capture and Storage (CCS). Air Liquide has acquired over the last two decades extensive industrial experience of full oxy-combustion for the glass, metals, cement and waste treatment industries. This expertise and extensive scientific knowledge have been used to develop an innovative oxy-burner technology, specific to steam and power production applications. This oxy-burner technology presents novel and differentiating features, which will be described in this paper. In particular, it features a direct oxygen injection into the burner, without external mixing of oxygen with the flue gas recycle, which provides additional flue gas recycle rate flexibility, and enables a safe handling of the oxygen. Air Liquide has demonstrated the performance of this oxy-burner concept through downscaled (1 MW) oxy- combustion tests in a dedicated cold-wall test-rig with flue gas recycle. Total will retrofit the air-fired boiler at its Lacq CO2 Project (SW of France) with an intermediate size of this oxy- burner technology (four 8 MW oxy-burners). The paper presents: [•] the innovative oxy-burner technology, its challenges and novelties, [•] a description of the Air Liquide 1 MW oxy-combustion test rig and the test results obtained over a wide range of flue gas recycle rates, [•] the integration of the oxy-combustion system into Total’s existing 30 MWth boiler. [Copyright &y& Elsevier]

Abstract: Ecofys and ECN conducted a study commissioned by the IEA Greenhouse Gas R&D Programme to identify the most suitable combinations of medium-scale CO2 sources (1–100 MWth) and capture technologies, with respect to potential and costs (see parallel paper by Hendriks et al.). An industrial coal-fired Circulating Fluidized Bed (CFB) boiler with oxyfuel combustion and Oxygen Conducting Membranes (OCM) appeared to be an economically attractive combination to capture CO2. This paper describes the principle and economic evaluation of this combination in comparison with a reference coal boiler without CO2 capture, as well as a coal boiler with CO2 capture based on amine scrubbing. [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: 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: 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: 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: Adding post-combustion capture technology to existing coal-fired power plants is being considered as a near-term option for mitigating CO2 emissions. To supply the thermal energy needed for CO2 capture, much of the literature proposes thermal integration of the existing coal plant’s steam cycle with the capture process’ stripper reboiler. This paper examines the option of using an auxiliary natural gas turbine plant to meet the energetic demands of carbon capture and compression. Three different auxiliary plant technologies were compared to integration for 90% capture from an existing, 500 MW supercritical coal plant. CO2 capture (via a monoethylamine (MEA) absorption process) and compression is simulated using Aspen Plus. Thermoflow software is used to simulate three gas plant technologies. In some circumstances, it is found that using an auxiliary natural gas turbine may make retrofits more attractive compared to using thermal integration. The most important factors affecting desirability of the auxiliary plant retrofit are the cost of natural gas, the full cost of integration, and the potential for sale of excess electricity. [Copyright &y& Elsevier]

Abstract: As part of the development cooperation of RWE Power, BASF and Linde - aiming at an advanced optimised CO2-scrubbing technology for power plant application - the first post-combustion capture pilot plant in Germany was constructed and commissioned at the lignite-fired 1,000 MW Niederaussem power station in 2009. The pre-assembly of the pilot plant started in October 2008 and commissioning took place in July 2009 as planned. 7.2 t of CO2 per day can be captured from a flue gas slipstream of the power plant downstream of the desulphurisation plant (FGD). The pilot plant comprises optimised components such as a flue gas pre-scrubbing direct contact cooler unit as well as a lean liquid cooler and an interstage cooler that both allow returning the solvent at different absorber heights. During a 6-month campaign, all aspects of the optimised process configuration were tested using 30%-weight MEA as benchmark solvent and the performance of a new advanced amine-based solvent developed by BASF was trialled. This paper summarises the operational experience gained and compares some of the results obtained for MEA with those of the new amine-based solvent. [Copyright &y& Elsevier]

Abstract: The oxy-fuel combustion CO2 capture route and post-combustion CO2 capture route involve different energy consumption rates and subsequent environmental impacts. The holistic perspective offered by Life Cycle Assessment (LCA) can help decision makers to compare alternative CO2 capture and storage technologies in a life cycle perspective. This paper, at first, introduces the principles of the dynamic LCA model developed for oxy-fuel combustion and post-combustion power generation with CO2 capture, transport and injection processes. Next, a comparative life cycle assessment of alternative CO2 capture technologies is presented. Results show that, at life-cycle level, the post-combustion and oxy-fuel combustion CCS cases can reduce the life-cycle Global Warming Potential (GWP) by 78.8% and 80.0% respectively compared to conventional power plant without CCS. Other environmental impacts, such as Ecotoxicity, Human toxicity and Acidification, vary significantly with the different CO2 capture routes employed. Finally, by comparing the results obtained with the most recent LCA studies of post-combustion power generation with CO2 capture and storage, it is shown that the plant level, gate-to-gate studies provide significantly variable results and generally overestimate life cycle environmental impacts. [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: Through technical discussion of oxyfuel retrofit of Meri–Pori’s supercritical power plant (565 MWe net), it was recognized that a deep analysis of the risks associated with the retrofit solution would be necessary for learning more about oxycombustion technology and to clarify the actual risks. As the result of the risk analysis, it was concluded that oxyfuel retrofit and oxyfuel operation would only involve low magnitude risks. This paper describes methodology of the risk analysis and major results including mitigation methods of the risks. [Copyright &y& Elsevier]

Abstract: The performance of post-combustion CO2 capture processes depends on the applied solvent as well as on the chosen process configuration and the integration concept with the power plant. Siemens bases its development efforts on an amino-acid salt solution as solvent, which has a negligible environmental impact and provides favourable properties for a low-energy capture process. The solvent features a high chemical and thermal stability and is easy to handle. The capture process is characterized by near-zero emissions. As a first step for validation of the determined solvent and process features on an industrial scale, the implementation of the capture process in a pilot plant is required. For this purpose, Siemens has installed a pilot plant at E.ON’s coal-fired power plant Staudinger in Germany and started the operation in August 2009. The measured pilot plant process data are used to validate the computational process model, which refines the model accuracy and improves the reliability in terms of plant performance. The findings from pilot plant operation confirmed that an overall net plant efficiency penalty of less than six percentage points (without CO2 compression) for a state-of-the-art coal-fired steam power plant can be achieved. The paper also presents experiences from pilot plant measuring campaigns with regard to the impact of trace components such as SOx and NOx. Solvent losses due to related degradation effects can be minimized by an intelligent reclaiming concept. Loss due to oxygen degradation can be estimated to be less than one percent of hold-up per year. Suitable construction materials have been qualified. The results of the pilot plant operation will serve as basis for the implementation of a demonstration plant, which will be the final step before a full-scale commercial carbon capture plant project. Siemens has been selected as technology provider for the Meri-Pori Carbon Capture and Storage project in Finland, which is a potential funding candidate of the European Flagship Programme. The Meri-Pori power plant has an installed capacity of 565 MW and the capture demonstration project is supposed to treat half of the power plant’s flue gas and to capture 90% CO2 from the treated flue gas. In addition to the Siemens capture process, the demonstration project will include ship transportation and geological storage. [Copyright &y& Elsevier]

Abstract: This paper discusses the energy penalty of solvent based post combustion capture for three different power stations and includes a comparison of shockwave CO2 compression versus conventional turbo machinery on the energy penalty associated with carbon capture and storage. This study uses pinch analysis to determine targets for the energy penalty of three different power stations that include a brown coal power plant with no reheat stage, a more efficient brown coal power station and a black coal power station. Heat integration can be used to reduce the energy penalty of all power stations combined with CCS. It is also found that when heat integration is considered, the heat that can be recovered in shockwave compressor inter/after-coolers reduces the amount of steam that needs to be extracted from the steam turbine. Hence, the net power output from the power station will be higher when shockwave compressors are used for CO2 compression compared to conventional turbo-machinery. [Copyright &y& Elsevier]

Abstract: Commissioned in 2009, the CO2CRC/H3 Capture Project is demonstrating post-combustion carbon capture (PCC) on a lignite fired power plant in the Latrobe Valley, Victoria, Australia. The facility is located within International Power’s Hazelwood Power Plant and uses three different CO2 capture technologies — solvent, adsorption and membrane processes. This project, addressing the PCC issues specific for Victorian brown coal fired power stations, was initiated in July 2007 as a three year research project by the Cooperative Research Centre for Greenhouse Gas Technologies (CO2CRC) under the Victorian State Government’s Energy Technology Innovation Strategy (ETIS) program. The project is part of the Latrobe Valley Post Combustion Capture (LVPCC) Project — a multi site, multi scale, multi technology PCC trial. The integrated research and development program includes an evaluation of these technologies for commercial scale application. This paper describes the technologies used, how they have progressed from laboratory to pilot demonstration, the main outcomes, and plans for future developments. [Copyright &y& Elsevier]

Abstract: In May 2007, E.ON Group (E.ON) set an ambitious target for reducing the specific CO2 emissions of the overall group’s electricity generation. By 2030, E.ON will reduce the specific CO2 emissions to 360 grams per kilowatt hour, half the 1990 figure. Thus, besides increasing the share of renewables and maintaining the nuclear share, E.ON identified the need to advance the technology of fossil fuel fired power plants. E.ON pursues a strategy of replacing power stations at the end of their life cycle with new, state-of-the-art power stations which are ready to be equipped with CCS (carbon capture and storage) and therefore “capture ready”. Moreover, E.ON is developing CO2 capture and storage as this technology has the potential to drastically reduce emissions from coal-fired plants. Beginning in 2020, E.ON intends to have large scale CCS technology available. E.ON’s coordinated strategy encompasses research, development and demonstration (RD&D) and is directed towards pre combustion capture, oxyfuel and post combustion capture with a focus on the latter. E.ON is working together with international partners to further develop the existing technologies for capturing of CO2 by testing advanced technologies in several pilot plants at our sites. The goal of the pilot projects is to optimise the downstream capture of CO2 from flue gas (post combustion capture) hence reducing the auxiliary power consumption of the capture process. An update on the pilot projects, suppliers and achievement made will be given. Besides improving the capture process itself the technology needs a significant increase of the treatable flue gas capacity compared to today’s limits known from chemical industry. Therefore E.ON is also involved in the development of demo scale projects proving the feasibility of the full CCS chain (including transport and storage). E.g. our Kingsnorth power station in the UK has entered the next stage of the UK Government’s carbon capture and storage (CCS) competition after developers. We submitted an Outline Solution Bid competition on 9 November 2009. The competition is aiming to deliver the UK’s first fullscale CCS demonstration project. We have come to an agreement with both the European Commission and the Dutch Government on the funding of our ROAD-project. This is our joint project with Electrabel (part of GDF SUEZ) at RotterdamMaasvlakte (NL). The Dutch part of the funding is now before the European Commission for State Aid approval. We will report about the projects and the progress made in our market units. In addition E.ON is engaged in the development of storage sites and transport routes for CO2. Our business unit E.ON Gas Storage is involved in several research and development activities. The paper will highlight E.ON’s main CCS activities. An overview will be given as well as an update on the status of the current projects and available results. [Copyright &y& Elsevier]

Abstract: The aim of the paper is to investigate plant flexibility for a pre-combustion cycle. That is, answering the question: how flexible is the plant to changes in operating conditions? Steady-state off-design simulations was the key component of the plant flexibility analysis. Specifically, part load behavior and dual-fuel operation of the integrated reforming combined cycle (IRCC) were studied. The idea of the plant was to use hydrogen-rich decarbonized fuel as the primary fuel and natural gas as back-up fuel. If a problem would occur in the reforming, water-gas shift, or CO2 capture processes there might be a need to switch to a natural gas feed for the gas turbine. This led to design challenges for the heat recovery steam generator (HRSG). The design of the HRSG for the IRCC process was different from an HRSG design in a natural gas combined cycle (NGCC) plant because of the significant amount of steam production from the heat generated in the reforming process. In addition, preheating (within the HRSG) of some of the process streams could add to the complexity in HRSG design. For the concepts studied it was of importance to maintain a high net plant efficiency on both fuels. Therefore the HRSG design had to be a compromise between NGCC and IRCC operation modes. In the analysis performed, part load behavior was good with efficiency reductions from base load operation comparable to that of the reference combined cycle plant. Based on the analysis performed in the present work, it was possible to operate a complex plant like an IRCC at loads down to 60 gas turbine load while capturing 85% of the CO2. During start-up and operation at lower loads, CO2 would not be captured. The investigation was done by using process simulation tools Aspen Plus by AspenTech and GT PRO/GT MASTER by Thermoflow. [Copyright &y& Elsevier]

Abstract: Carbon Capture and Storage technology (CCS) has the potential to play a key role in reducing CO2 emissions as required by international commitments. CCS must be included in the portfolio of solutions in order to reach the target of world emissions reduction by 50% in 2050. One of the most relevant European initiatives for the deployment of CCS technologies is promoted by the Fundacion Ciudad de la Energia (CIUDEN). CIUDEN has a complete programme focused on the development of CCT and CCS, particularly oxycombustion technology. This paper includes the description of CIUDEN’s Capture Technology Developing Plant, currently under construction in NW Spain. The installation includes a 20 MWth PC boiler, a 30 MWth CFB boiler, a fuel preparation unit, a biomass gasifier, a flue gas cleaning train, and a CO2 processing unit. The commissioning of the TDP is planned for November 2010. This is the only installation in the world with two large pilot oxy boilers capable of burning a wide range of coals, biomass and pet coke under conventional combustion or oxycombustion conditions. Results are expected to significantly contribute to the development and deployment of oxycombustion technologies, particularly valuable as technical support for the OXYCFB300 Compostilla Project which aims to validate this technology at demo scale. The Compostilla OXYCFB300 Project is based on a 300 MWe Circulating Fluidised Bed (CFB) supercritical oxycombustion plant, with CO2 storage in a saline aquifer. The operation of this installation is planned to start in 2015. [Copyright &y& Elsevier]

Abstract: The Dutch Ministry of Spatial Planning and the Environment (VROM) engaged Jacobs Consultancy to develop a definition and measuring tool aimed at quantifying the CO2 Capture Readiness of a combustion plant. The tool developed tests the level and completeness of pre-project execution information. The testing of pre-project information is a standard practice in the refining and petrochemical industry and Jacobs Consultancy has adapted and tailored these practices to develop the Capture Readiness tool. The tool was developed in 2008 and was pilot tested on two already permitted coal fired power plant projects in 2009. The Capture Readiness tool is similar in concept to the well known Project Definition Rating Index originally introduced by the Construction Industry Institute for Major Capital Projects. The tool quantifies the readiness of a project to accommodate future CO2 capture and parallels the phased approached to Major Capital Projects used by the Project Definition Rating Index. A short introduction to the application of the PDRI methodology to test the completeness of the project development information–often also referred to as Front End Loading or FEL, is included in this paper to establish the parallel approach we have used in the development of the Capture Readiness tool. The Jacobs Consultancy Capture Readiness tool is then discussed in more detail. [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: CSIRO and Delta Electricity have developed, commissioned and operated an aqueous ammonia based post combustion capture (PCC) pilot plant at the Munmorah black coal fired power station. The results from the pilot plant trials will be used to address the gap in know-how on application of aqueous ammonia for post combustion capture of CO2 and other pollutants in the flue gas and explore the potential of the aqueous ammonia based capture process for application in the Australia power sector. This paper reports and discusses part of experimental results obtained from the pilot plant trials. [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: This paper presents a study of two integrated processes for power production with CO2 capture : a post-combustion process involving an amine based CO2 capture unit; and an oxyfuel process involving air separation units, O2 combustion boiler and flue gas purification. These two integrated processes have been compared to a base case air-fired CFB boiler using bituminous international coal as fuel. A complete techno-economical study has been carried out, and electricity production costs have been compared to the base case. The results were also expressed in equivalent CO2 penalties (€/ tco2) as an economic limit to allow CCS processes to be economical against CO2 taxes. It has been found out that both zero emissions post-combustion and oxyfuel integrated process have a big impact on the power plant economics. The study showed oxy- and post-combustion processes led to similar CO2 penalty: around 44€/ tco2 for postcombustion capture and 46€/tco2 for the oxyfuel process. [Copyright &y& Elsevier]

Abstract: The capture and sequestration of CO2 will be necessary to mitigate CO2 emissions from fossil fuel (coal, oil, natural gas or biomass) power generation facilities in a carbon constrained world. Post combustion carbon capture is a viable technology alternative to reduce CO2 emissions from power plants in the short term. The CO2 concentration in the exhaust gases of natural fired power plants can be increased through exhaust gas recirculation (EGR). A joint CO2 Capture Project (CCP) and GE study of the Best Integrated Technology (BIT) shows that EGR enables reduced exhaust gas flow to the post combustion capture plant and cost of the CO2 capture. This paper describes the experimental work performed at General Electric Global Research Center in order to better understand the risks of utilizing EGR in combination with dry low NO x (DLN) combustors. A research combustor was developed for exploring the dry low emissions capability of nozzles to operate in low O2 environment. A series of experiments have been conducted at representative gas turbine pressures and temperatures, in an EGR test rig. Exhaust gas generated in a first stage, at pressure, is used to vitiate the fresh air to levels determined by cycle models. Experimental results include the effect of applying EGR on operability, efficiency and emissions performance under conditions of up to 30% EGR (low oxygen). Our findings confirm the feasibility of EGR for enhanced CO2 capture, exceeding the expectations of operability and combustion efficiency predicted by models. In addition, we confirm benefits of NO x reduction while complying with CO emissions in Dry Low NO x Emissions combustors under low oxygen content oxidizer. [Copyright &y& Elsevier]

Abstract: A 25 TPD post-combustion CO2 capture plant for brown coal and a 0.5TPD pre-combustion CO2 capture IGCC process have been designed and are being built in Victoria, Australia to assess developments in solvent absorption capture technologies. In this paper, the flowsheets developed for these processes will be discussed along with the underpinning research in the following areas: [•] New contact equipment — recent work has shown that the SMR packing has enhanced performance over structured packing and standard Pall rings. [•] The influence of promoters to enhance kinetics - using a wetted-wall column, experiments have been conducted with boric acid added to potassium carbonate solvent with results showing an enhancement in CO2 absorption rates. [•] The influence of flue gas impurities - post-combustion impurities, including SO x and NO x , have been studied with potassium carbonate to evaluate their effects on CO2 absorption. [•] Process modeling — ASPEN Plus™ simulations have been developed to predict column performance and the effects of impurities on the equilibrium relationship. [Copyright &y& Elsevier]

Abstract: This paper presents a guideline for qualification of CO2 capture technology. The guideline provides a systematic and transparent procedure for the qualification of natural gas power generation technologies with CO2 capture. For new technology, there is generally a lack of relevant codes and standards. Qualification according to a set of requirements is therefore the only rational approach. The CO2 capture technologies available today need considerable efforts to integrate, optimize, and to scale up the process components to industrially mature processes. To secure the success and minimize the time to commercialisation of research and development projects for new CO2 capture technologies, it is vital that the technology is qualified in a step-wise and systematic manner. The guideline was developed as a joint industry project and was carried out through three phases: (1) Development of a draft guideline, (2) Test of the draft guideline in case studies, (3) Final guideline developed based on feedback from the case studies. The scope has been to develop a guideline that could cover the major routes to CO2 capture, post combustion, pre combustion and oxy-fuel processes. Thus, the qualification work process itself is described in a rather general way to be applicable for all three capture concepts, whereas further specifications are given as specific examples of applications to CO2 capture technologies. [Copyright &y& Elsevier]

Abstract: There exists within the electricity generation sub-sector the potential for substantial GHG reductions through the application of CO2 capture and storage technologies. Many assessments of the cost and performance of power plants with CCS (Carbon Capture and Storage) have been undertaken but these studies almost always omit considering operability: the ability of a process to operate satisfactorily under conditions different than the nominal design conditions. Electricity systems rely upon generators with a high degree of operability in order to meet variations in power demand, ambient conditions, fuel supply, etc. and the need for operability is expected to increase in the future. The operability of CCS technologies could have a major impact on the extent to which CCS is used in the years to come and it could also affect the choice of the optimum CO2 capture technology. The attention given to the operability of power plants with CCS is in sharp contrast to its potential significance; only a handful of the research groups contributing to the sizeable CCS literature are explicitly investigating the operability of these technologies. This paper seeks to correct this oversight and proposes the scope of a comprehensive comprehensive assessment of the leading CO2 capture schemes—pre-combustion, post-combustion, and oxy-combustion— with respect to operability. In the final analysis, a layered approach is suggested with four major study areas: [•] flexibility [•] controllability [•] start-up/shutdown characteristics [•] assessment of trade-offs between operability and cost While the proposed undertaking is ambitious, it is believed that by building upon the existing process modelling and simulation expertise that exists with the CCS community, the work could be completed within a reasonable amount of time. [Copyright &y& Elsevier]

Abstract: The paper describes the development of a novel reactor concept for natural gas fueled chemical looping combustion (CLC). The reactor is best described as a rotating bed reactor in which a doughnut shaped fixed bed containing an oxygen carrier material is rotated between different sectors where air and methane are fed. The gases are fed radially outwards through the fixed bed. Between the air and methane sectors are sectors where an inert gas is fed to avoid uncontrolled mixing of air and methane. The rationale for the choice of reactor is discussed and a CuO/Al2O3 based oxygen carrier has been selected for the initial reactor evaluation. A major challenge with the proposed reactor setup is to avoid mixing between the air and methane side caused by the unavoidable insufficient sealing between the moving parts. Initial testing show that mixing is only partly avoided, and a degree of separation corresponding to around 80% is observed at ambient temperature for the first reactor prototype. Further work will be to improve the design in order to reduce gas mixing further and to demonstrate real CLC operation utilizing the reactor. [Copyright &y& Elsevier]

Abstract: Carbonate Looping is a promising post-combustion capture process involving the separation of CO2 from the flue gas of a coalfired power plant at high temperatures (600–700 ∘C) using the reversible exothermic CaO carbonation reaction and the endothermic calcination reaction of CaCO3. The core of the carbonate looping process is a dual fluidized bed reactor in which the CO2 acceptor material (CaO) is transported between the carbonator (CO2 absorption) and regenerator (CO2 desorption). Due to the heat requirements for the regenerator, the carbonate looping acts as a CO2 separation unit and an add-on power plant, thereby offering the opportunity for increasing the site electricity production while inflicting only a low electric efficiency penalty on the total power plant. However, the quantity and quality of the Carbonate Looping heat sources differ significantly from a conventional coal-fired power plant. This paper presents the design and simulation of the carbonate looping steam cycle for a large coal-fired plant. The simulation involves the coupling of the carbonate looping reactor model from Aspen Plus with the steam cycle in EBSILON Professional code which is a mass and energy balance cycle calculation program specifically tailored for steam cycle calculations. The resulting simulation includes penalty deduction for the Air Separation Unit and the CO2 conditioning unit, resulting in a net efficiency of 39.2% and while increasing the net power input from 1052 MWe to 1533 MWe, an addition of 481 MWe for the retrofitted power plant. [Copyright &y& Elsevier]

Abstract: Post combustion absorption technologies represent one of the most commercially ready technologies for CO2 capture. Solvent selection is the critical consideration in post-combustion absorption capture technology. In order to compare the performance of different solvents, it is necessary to perform simulations on a consistent basis and perform a process analysis of the system. The focus of this work was to develop consistent simulations for MEA and K2CO3 systems in ASPEN. The simulations have been developed within the ASPEN RateSep framework and are valid for both natural gas and coal fired power plants. This paper describes the methodology of the simulations and some results from the two systems. The MEA base case was validated with reported values in literature. Potassium carbonate was found to be particularly useful for pressurized combustion and for CO2 removal from product gases of reforming of natural gas or coal. [Copyright &y& Elsevier]

Abstract: A series of different amines was immobilized on a silica support by grafting or impregnation and tested for CO2 adsorption in simulated flue gases. This paper compares the adsorption isotherms and the cyclic adsorption capacities of these materials. Furthermore, we estimate the diffusion rate of CO2 from simulations of the breakthrough curves and discuss some aspects of the design of a potential adsorption process for CO2 capture. [Copyright &y& Elsevier]

Abstract: There is strong world-wide interest in developing new and improved processes for post-combustion capture of CO2, usually using chemical absorption. Developers of new processes make positive claims for their proposals in terms of low energy consumption, but these are usually difficult to validate. This paper demonstrates that rigorous application of thermodynamic analysis and process simulation provides a powerful way to quantitatively evaluate the energy requirements of CO2-capture processes by applying this methodology to the analysis of the chilled-ammonia process. [Copyright &y& Elsevier]

Abstract: In the plant configuration discussed in this paper, CO2 rich flue gas from an air fired coal boiler is contacted with CaO in a fluidized bed reactor (carbonator) generating CaCO3 and capturing more than 90% of the CO2 generated. Sorbent is regenerated in a second fluidized bed (calciner) via oxyfuel combustion of coal, generating a CO2 rich stream ready for compression and sequestration. Kunii–Levenspiel model, together with correlations for the estimation of sorbent performance after a number of carbonation–calcination cycles were used, in order to estimate carbonator dimensions and pressure losses. A net LHV efficiency of 37.4% was predicted for the selected reference case, with 97% of CO2 captured. As a comparison, for full oxy-combustion and amine based plants, net efficiency of 36.3% and 32.6% were obtained respectively. [Copyright &y& Elsevier]

Abstract: Post-combustion capture of CO2 is a key technology for the reduction of greenhouse gas emissions from Australian coal fired power stations. It is an emerging technology, which still faces significant challenges in scaling up to full commercial scale suitable for power station applications. To increase adoption by the power industry significant cost reductions in capital and operating cost must be realised. CSIRO has developed an integrated post-combustion capture R&D and pilot plant program aimed at bringing down the barriers for commercial deployment. This paper provides an overview of the program and its status. [Copyright &y& Elsevier]

Abstract: Post combustion CO2 capture with chemical solvents is performed in packed columns operating in the counter current mode. Good predictions of the pressure drop and of the mass transfer characteristics is critical for their design. Many experimental works are dedicated to characterization of packings. However, experiments are carried out at a laboratory intermediate scale, with almost no possibility to bring information neither at small scale nor at very large scale. It is shown in this paper how CFD, via an original multi scale approach from the liquid film thickness to the industrial column dimensions, can help in complementing experimental data. [Copyright &y& Elsevier]

Abstract: As part of the EU project CASTOR, a 1 t/h CO2 absorption pilot plant has been erected at Esbjergværket (Esbjerg power station) in Denmark. The main purpose of the pilot plant is to demonstrate the post combustion capture technology in conjunction with a coal-fired power station. Additionally, the pilot plant has been used to test the performance of new energy efficient solvents and to validate modelling work. The pilot plant operates on a slipstream of flue gas from the power plant without any further pre- treatment. During the CASTOR project, four 1000-hours test campaigns have been conducted at the facility using conventional solvent, 30%-weight MEA as well as two novel amine-based solvents, CASTOR 1 and CASTOR 2. Among others, the test campaigns consisted of parameter variation tests and longer periods of continuous operation. This paper summarises the operation experience and some of the results obtained during the CASTOR project. [Copyright &y& Elsevier]

Abstract: This paper presents the results of gas turbine simulations that were conducted to compare state-of-the-art and re-designed gas turbines operated on syngas, in Integrated Gasification Combined Cycles (IGCC) with pre-combustion CO2 capture. The effects of the desired carbon capture ratio on efficiency and power output were evaluated, for retrofit applications both with and without capacity building. The results indicate that re-designed gas turbines for syngas applications can achieve higher efficiencies than natural gas turbines that were modified for syngas applications. [Copyright &y& Elsevier]

Abstract: This paper presents the results of system assessments that were conducted to compare conventional and advanced water-gas shift reaction section in Integrated Gasification Combined Cycles (IGCC) with pre-combustion CO2 capture. The advanced shift reaction section comprises four staged reactors with distributed feeds of syngas and quench water in between the reactors. This configuration reduces the steam requirement of the shift reaction up to 70% in comparison with conventional configurations, at carbon capture ratios of approximately 85%. The specific lost work per amount of CO2 was used to determine the optimum carbon capture ratio for each case. [Copyright &y& Elsevier]

Abstract: The second pre-combustion decarbonisation technology Sorption Enhanced Water-Gas Shift (SEWGS) combines the WGS reaction with simultaneous CO2 capture by using a mixture of WGS catalyst and CO2 sorbent. Accordingly, the WGS catalyst is exposed to all conditions encountered in the cyclic SEWGS process, such as exposure to steam in the regeneration step. This paper shows that commercial precious metal, FeCr, and CoMo WGS catalysts are robust towards periodic exposure to these atypical conditions. Catalyst behavior is reported to periodic exposure to these atypical conditions at a temperature of 400 ∘C, pressures up to 5 bara and H2S contents from 1 ppm to 2,000 ppm. Although additional experiments need to be performed at increased pressure, it appears that all catalysts can potentially be used in the SEWGS process. [Copyright &y& Elsevier]

Abstract: There is considerable interest in identifying carbon dioxide capture processes that can be incorporated within Integrated Gasification and Combined Cycle (IGCC) systems. In this paper, two novel adsorption based process configurations are proposed to operate in the temperature window (250–500 ∘C) suitable for an IGCC process after the water gas shift reactor. These process configurations are numerically simulated with an in-house simulator MINSA (Monash Integrated Numerical Simulator for Adsorption), and the simulation results indicate that good performance can be achieved with low operating cost. Carbon dioxide purity of greater than 95% and carbon dioxide recovery of greater than 90% can be obtained by both process options. [Copyright &y& Elsevier]

Abstract: This paper describes the development of carbon-based adsorbents for CO2 separation in integrated gasification combined cycle (IGCC) processes for energy generation and hydrogen production. The research presented forms part of a Research Fund for Coal and Steel funded project “Hydrogen separation in advanced gasification processes” (HYDROSEP) with the ultimate aim of developing technologies to reduce the costs for the capture of CO2 when compared to existing absorption processes. A range of carbon adsorbents were developed by MAST Carbon. They present significant microporosity and in some cases also meso or macroporosity. CO2 adsorption isotherms have been determined using a dual limb differential pressure apparatus under realistic operating conditions. CO2 and H2 high pressure adsorption isotherms at room temperature have also been evaluated in a high pressure adsorption balance. Maxima CO2 uptakes of 58 wt.% at 3 MPa and H2 uptakes of 0.3 wt.% at 4 MPa were obtained. The significant differences observed in CO2 and H2 adsorption at high pressures showed the high selectivity for CO2 of the tested MAST Carbon adsorbents. [Copyright &y& Elsevier]

Abstract: Doosan Babcock is aiming to develop a competitive oxyfuel firing technology suitable for full plant application post 2010, and is taking a phased approach to the development and demonstration of oxyfuel technology. Doosan Babcock is leading a number of UK Government supported collaborative projects that are developing oxyfuel combustion technology. The “Fundamentals and Underpinning Technologies” project aims to develop a competitive oxyfuel firing process based on the integration of well proven and innovative power plant design components, addressing critical technology gaps such as combustion fundamentals, furnace design and operation, novel flue gas purification technologies and generic process issues. The “Demonstration of an Oxyfuel Combustion System” project aims to demonstrate an oxyfuel combustion system of a type and size (40MWt) applicable to new build and retrofit advanced supercritical boiler plant. These two projects are discussed in the paper and preliminary results from pilot-scale testing undertaken in the first of these are presented. [Copyright &y& Elsevier]

Abstract: Chemical-looping with oxygen uncoupling (CLOU) is a novel method to burn solid fuels in gas-phase oxygen without the need for an energy intensive air separation unit. This paper presents batch laboratory fluidized bed CLOU tests where six different solid fuels are used with a Cu-based oxygen carrier. The results show that CLOU results in a factor 3 to 15 faster fuel conversions than conversional chemical-looping combustion. [Copyright &y& Elsevier]

Abstract: This paper describes a detailed process optimization of the mass and energy balances for multi-stage membrane systems used in coal-fired power plants. Based on the recovery rate of 50% or 90% CO2 with 95 mol% CO2 purity, different concepts using recirculation of flue gas and variation of feed gas compressor and vacuum pump on the permeate side were developed and optimized to obtain minimum energy consumption. Simultaneously, a cost model was developed to make a further analysis of the optimized concept in view of the tradeoff balance between material and energy consumption. [Copyright &y& Elsevier]