Publications Database - List of capture publications |
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Vol 1 Chapter 26: The Oxyfuel Baseline: Revamping Heaters and Boilers to Oxyfiring by Cryogenic Air Separation and Flue Gas RecycleRodney Allam, Vince White, Neil Ivens and Mark Simmonds Abstract: This feasibility study involves the potential application of oxyfuel technology on a refinery-wide basis at the BP Grangemouth unit in Scotland. A total of seven boilers and 13 process heaters of various types, burning a mixture of refinery fuel gas and fuel oil resulting in the production of approximately 2.0 million tonnes per annum of CO2, form the basis of this study. This work considers the issues involved in modifying the process heaters and boilers for oxyfuel combustion and locating two world scale air separation plants totalling up to 7400 tonne/day of oxygen plus a CO2 compression and purification system on a congested site. In addition, we present the scheme for distributing the oxygen around the site and collecting the CO2-rich effluent from the combustion processes for purification, final compression, and delivery into a pipeline for enhanced oil recovery. The basic case, Case 1, is presented and costed involves the supply of the complete oxyfuel system with installation and start-up and includes all required utilities. The electrical energy required for the system is provided by a GE 6FA gas turbine combined cycle cogeneration unit with 10.7 MW of excess power available as surplus. Two further cases are also presented. The first uses a GE 7EA gas turbine plus heat recovery steam generator producing steam primarily at the refinery condition of 127 barg 518℃ together with some additional supplies at 13.7 barg. The steam production from the existing boilers is reduced by a corresponding amount. The third case uses a similar 7EA gas turbine plus heat recovery steam generator, but in this case the fuel is hydrogen produced from an oxygen autothermal reformer with product steam generation and CO2 removed using a methyl diethanolamine (MDEA) system. In each of these three cases the total quantity of CO2 emission avoided and the quantity of CO2 available for pipeline delivery is calculated, costed and presented in Table 1. Carbon Dioxide Capture for Storage in Deep Geologic Formations – Results from the CO2 Capture Project Capture and Separation of Carbon Dioxide from Combustion Sources - Volume 1 |
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Vol 1 Chapter 27: Zero Recycle Oxyfuel Boiler Plant with CO2 CaptureMark Simmonds and Graeme Walker Abstract: The Carbon Capture Project has been established by eight leading energy companies to develop novel technologies that significantly reduce the cost of capturing CO2 for long-term storage. One area considered by the CCP is the use of oxygen in combustion systems (oxyfuel combustion). This is attractive to the CCP as it produces a flue gas essentially containing only CO2 and water, from which CO2 can be easily captured. This study reviews two oxyfuel schemes, one that incorporates a recycle of some of the flue gas and one that does not. Recycling a proportion of the flue gas helps to mitigate the combustion temperatures in the furnace and thereby permit the use of conventional boiler designs. Eliminating the flue gas recycle and burning fuel gas in a near-pure oxygen environment is beneficial as it leads to a more thermally efficient and thereby compact boiler design, and has a lower volumetric throughput, thus reducing the size of all equipment and ducting. Very high temperatures are reached in the zero recycle case and novel boiler design are required. This study evaluates the technical feasibility of the zero recycle case and assesses the justification for developing new boiler designs as part of the CCP. The study concludes that the zero recycle scheme is technically feasible. A boiler design is proposed that is capable of withstanding the high combustion temperatures but, although such a design has been tested in a pilot study, it is not currently commercially proven. The zero recycle case is an attractive option for raising steam and generating electrical power. It is cheaper than the alternative scheme that does recycle part of the flue gas and, for identical feed conditions, generates more electrical power. However, both cost- and thermal-efficiency benefits are only marginal and it is concluded that there is insufficient justification to warrant the development of boiler designs suited to fuel gas combustion in a near-pure oxygen environment within the CCP. Carbon Dioxide Capture for Storage in Deep Geologic Formations – Results from the CO2 Capture Project Capture and Separation of Carbon Dioxide from Combustion Sources - Volume 1 |
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Vol 1 Chapter 28: Zero or Low Recycle In-Duct Burner Oxyfuel Boiler Feasibility StudyMark Simmonds and Graeme Walker The CO2 Capture Project (CCP) has been established by eight leading energy companies to develop novel technologies that significantly reduce the cost of capturing CO2 for long-term storage. One area considered by the CCP is the use of oxygen in combustion systems (oxyfuel combustion). This is attractive to the CCP as it produces a flue gas essentially containing only CO2 and water, from which CO2 can be easily captured. This study evaluates the potential benefits of a novel oxyfuel boiler design that splits the fuel gas between a number of in-line burners. The adiabatic flame temperature is limited to a maximum of 850 8C by cooling the flue gas between each successive burner and thereby permitting conventional stainless steel construction. Steam is raised in these inter-stage coolers and superheated in the exhaust stream exiting the boiler. The design intent is to use this inter-stage cooling to control the combustion temperature rather than the more conventional alternative of recycling flue gas. Therefore, the objective is to eliminate, or at least minimise, flue gas recycle. The study concludes that a zero recycle case is technically feasible. However, in order to deliver the required amount of steam to the specified superheated conditions, either a large number of burner stages are required (.14), or the oxygen stream needs to be over-supplied to help suppress the flame temperature. Both of these factors will add to the cost and complexity of the system considerably and the zero recycle case is not pursued further in this study on the grounds that it is not considered to be the most economic configuration. A second case incorporating flue gas recycle is then considered. In order to limit the number of burner stages required, a substantial flue gas recycle is required. This study shows that by recycling 75% of the flue gas, a 3-stage burner design will deliver the required steam production to the required superheated conditions. Even though this case has a large recycle, it is considered to offer the lowest cost option of incorporating the in-duct oxyfuel boiler concept for the steam generation design basis. The installed cost of the in-duct oxyfuel boiler design with flue gas recycle, including the associated air separation and CO2 capture/compression units, is estimated to be £30 million ($52.5million), equating to a CO2 capture cost of £90.80($158.90) per tonne of CO2 captured per year. The installed capital expense is roughly 10% cheaper than an alternative oxyfuel boiler design based on conventional boiler technology and incorporating flue gas recycle. The footprint required by the in-duct oxyfuel boiler is also assessed and is estimated to be about twice the size of a conventional oxygen-fired boiler. Based on the cost and footprint evaluation, it is considered that there is insufficient justification to develop the in-duct oxyfuel boiler concept within the CCP framework. Although the installed cost is slightly lower than a more conventional boiler design, it still represents a high cost of CO2 capture and does not offer a sufficiently large enough prize to warrant further development. Carbon Dioxide Capture for Storage in Deep Geologic Formations – Results from the CO2 Capture Project Capture and Separation of Carbon Dioxide from Combustion Sources - Volume 1 |
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Vol 1 Chapter 29: A Comparison of the Efficiences of the Oxy-fuel Power Cycles Water-cycle, Graz-cycle and Matiant-cycleOlav Bolland, Hanne M. Kvamsdal and John C. Boden Abstract: One of the technology areas targeted in the CO2 Capture Project (CCP) has been oxy-fuel combustion. This process generates a flue gas consisting largely of carbon dioxide and water from which carbon dioxide is easily separated. The use of oxy-fuel combustion in gas turbine-based power generation will require new equipment, but also provides an opportunity to develop new cycles which may offer higher efficiencies than current air-based combined cycle systems, thus partially offsetting the additional cost of oxygen production. Three oxy-fuel power generation concepts (Water-cycle, Graz-cycle and Matiant-cycle), based on direct stoichiometric combustion with oxygen, are evaluated in the present study. Considering cycle efficiency and given similar computational assumptions, the Graz-cycle and the latest versions of the Matiant-cycle seem to give rather similar net plant efficiencies (around 45%), while the Water-cycle is 3–5% points behind. When comparing the three cycles with the well-known oxy-fuel gas turbine combined cycle (similar to CC-Matiant-cycle), for which efficiencies in the range 44–48% have been reported, there is no obvious advantage for the three. A challenge for all oxy-fuel cycles is the combustion. Both the fuel and the oxidant are supposed to be consumed simultaneously in the combustion process. This requires very good mixing and sufficient residence time. Incomplete combustion with CO formation may result, or a surplus of oxygen to the combustion process may need to be supplied. Another challenge is the development of turbo machinery capable of working with CO2/H2O mixtures at high temperatures and pressures. In general, one can say that oxy-fuel cycles do not exhibit significantly better efficiency compared to postand pre-combustion CO2 capture methods. One can also question what other advantages oxy-fuel cycles offer compared to other options. A disadvantage with oxy-fuel cycles is that this technology only can be used in plants where CO2 is to be captured. This means that equipment developed for this purpose may, as it seems today, have a limited market potential, and the motivation for technology development is not that evident. The future for oxy-fuel cycles depends on:
Carbon Dioxide Capture for Storage in Deep Geologic Formations – Results from the CO2 Capture Project Capture and Separation of Carbon Dioxide from Combustion Sources - Volume 1 |
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Vol 1 Chapter 30: Revamping Heaters and Boilers to Oxyfiring-producing Oxygen by ITM TechnologyRodney Allam, Vince White, VanEric Stein, Colin McDonald, Neil Ivens and Mark Simmonds Abstract: The work reported in Chapter 30 considered the issues involved in modifying the process heaters and boilers for oxyfuel combustion and locating two world scale air separation plants totalling up to 7400 tonnes/day of oxygen plus a CO2 compression and purification system on a congested site. In addition we presented the scheme for distributing the oxygen around the site and collecting the CO2-rich effluent from the combustion processes for purification, final compression, and delivery into a pipeline for enhanced oil recovery (EOR). In this Chapter, we will look at an alternative oxygen generation technology that would replace the two cryogenic air separation units (ASUs). This technology utilises ion transport membranes (ITMs) to produce the oxygen. The ITM oxygen process is based on ceramic membranes that selectively transport oxygen ions when operated at high temperatures. Under the influence of an oxygen partial pressure driving force, the ITM achieves a high flux, high purity (99þ mol%) separation of oxygen from a compressed-air stream. By integrating the non-permeate stream with a gas turbine system, the overall process co-produces high purity oxygen, power, and steam if desired. The base case, Case 1, is presented and costed and involves the supply of the complete oxyfuel system with installation and startup and includes all required utilities. In order to provide the hot air for the ITM oxygen process, two Siemens V94.2 combined cycle gas turbines are used and excess power is exported to the local electricity grid. Two further cases are also presented. Case 2 also uses two Siemens V94.2 gas turbines plus a heat recovery steam generator (HRSG) producing steam primarily at the refinery condition of 127 barg 518 8C together with some additional supplies at 13.7 barg and some boiler feed water. The steam production from the existing boilers is reduced by a corresponding amount. The turndown of the steam boilers results in a reduction in the oxygen requirement from 6626 to 3828 tonnes/day. Case 3 uses one Siemens V94.3 gas turbine plus a HRSG, but in this case the fuel is hydrogen produced from an oxygen autothermal reformer (ATR) with product steam generation and CO2 removed using an methyl diethanolamine (MDEA) system. The gas turbine waste heat boiler produces steam at the refinery conditions as in Case 2. In this case, the use of hydrogen fuel gas allows operation of the gas turbine combustor at a much lower oxygen inlet concentration compared to Cases 1 and 2 which use natural gas fuel. This feature allows for greater oxygen recovery, which allows the entire oxygen requirement to be met with a single gas turbine, thereby minimising export power and decreasing capital cost. In each of these three cases the total quantity of CO2 emission avoided and the quantity of CO2 available for pipeline delivery is calculated, costed and presented in Table 1. Carbon Dioxide Capture for Storage in Deep Geologic Formations – Results from the CO2 Capture Project Capture and Separation of Carbon Dioxide from Combustion Sources - Volume 1 |
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Vol 1 Chapter 31: Techno-economic Evaluation of an Oxyfuel Power Plant Using Mixed Conducting MembranesDominikus Bucker, Daniel Holmberg and Timothy Griffin Abstract: The techno-economic performance of gas turbine power plants with zero or low CO2 emission has been evaluated. The plant concepts make use of “Mixed Conducting Membranes” (MCMs) to extract oxygen from the inlet air and thus enable combustion of gaseous hydrocarbon fuels in a nitrogen-free environment. This technology is being developed in the ongoing EU FP5 Integrated Research Project “AZEP” (see www.azep.org). Unlike the combined cycle processes investigated in the AZEP project, the concepts considered here are simple cycle configurations. The scenario is based on the CCP Scenario D, a BP gas gathering and processing installation in Prudhoe Bay, Alaska. Three different base configurations were identified, each run in two different modes (with and without supplementary firing). These six cases were compared to a conventional non-capture, gas turbine plant. The thermodynamic process simulations showed penalties in terms of the net electrical efficiency between 2.4 and 6.8%-points for the different configurations. These penalties include the capture, purification and compression of the carbon dioxide. The economic evaluation revealed very promising figures, estimating costs of CO2 avoided from 17.3 US$/ton to as low as 7.3 US$/ton, if a value of 20 US$/ton produced CO2 (as suggested by CCP) is considered. Carbon Dioxide Capture for Storage in Deep Geologic Formations – Results from the CO2 Capture Project Capture and Separation of Carbon Dioxide from Combustion Sources - Volume 1 |
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Vol 1 Chapter 33: Chemical Looping Combustion (CLC) Oxyfuel Technology SummaryPaul Hurst and Ivano Miracca Abstract: This chapter provides a general overview of the Chemical Looping Combustion Technology Research and Development Program, carried out with EU and CCP funding by a Partnership composed by BP, Alstom Power, Chalmers University of Technology, Instituto de Carboquimica (CSIC) and Vienna University of Technology. The contribution of the Partners will be discussed in detail in the following chapters. Carbon Dioxide Capture for Storage in Deep Geologic Formations – Results from the CO2 Capture Project Capture and Separation of Carbon Dioxide from Combustion Sources - Volume 1 |
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Vol 1 Chapter 34: Development of Oxygen Carriers for Chemical-looping CombustionJuan Ada´nez, Francisco Garcı´a-Labiano, Luis F. de Diego, Pilar Gaya´n, Alberto Abad and Javier Celaya Abstract: The objective of this work was to develop oxygen carriers with enough reduction and oxidation rates, resistant to the attrition and with high durability, maintaining the chemical, structural and mechanical properties in a high number of reduction–oxidation cycles, to be used in a chemical-looping combustion (CLC) system. A significant number of oxygen carriers, composed up to 80% of Cu, Fe, Mn or Ni oxides on Al2O3, sepiolite, SiO2, TiO2 or ZrO2, were prepared by different methods, and tested in a thermogravimetric analyser (TGA) and in a fluidized bed. Based on data of rushing strength, reactivity, attrition, and agglomeration of the carriers and its variation during successive reduction–oxidation cycles, the three most promising oxygen carriers based on Cu, Fe, and Ni were selected and prepared to be tested in a pilot plant. The effect of the main operating variables, such as temperature, gas composition, gas concentration, etc. on the reduction and oxidation reaction rates were analysed in a TGA to determine the kinetic parameters of the selected carriers. A heat balance in the particle showed that the particles can be considered isothermal when using small particle sizes, as it would be normal in a CLC process. The reduction reaction rate of the oxygen carriers with CH4 was controlled by the chemical reaction, meanwhile the oxidation reaction rate was controlled by the chemical reaction and the diffusion in the product layer. Finally, the kinetic parameters obtained for the selected oxygen carriers were included into a mathematical model to describe the behaviour of these particles in the fuel reactor of a CLC system. Carbon Dioxide Capture for Storage in Deep Geologic Formations – Results from the CO2 Capture Project Capture and Separation of Carbon Dioxide from Combustion Sources - Volume 1 |
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Vol 1 Chapter 35: Chemical-looping Combustion-reactor Fluidization Studies and Scale-up CriteriaBernhard Kronberger, Gerhard Loffler and Hermann Hofbauer Abstract: This chapter is aimed to report the results of the work package of Vienna University of Technology in the GRangemouth Advanced CO2 CapturE Project (GRACE). The GRACE project is an EU founded research project under the specific programme for research on “energy, environment and sustainable development”. The work of Vienna University of Technology is concerned with the design and scale-up of a CLC reactor concept by investigations of the fluidization conditions. Detailed modelling was carried out experimentally in cold flow models at different scales. The experimental findings were integrated into mathematical models on the kinetics and hydrodynamics. The derivation of scale-up guidelines of the CLC process was carried out and recommendations are given. Clearly, the dual fluidized bed reactor concept coupled by the solid flow is well suitable for chemical-looping combustion. Scale-up issues can be overcome and a demonstration of the technology is recommended. Carbon Dioxide Capture for Storage in Deep Geologic Formations – Results from the CO2 Capture Project Capture and Separation of Carbon Dioxide from Combustion Sources - Volume 1 |
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Vol 1 Chapter 36: Construction and 100 h of Operational Experience of a 10-kw Chemical-looping CombustorAnders Lyngfelt and Hilmer Thunman Abstract: Chemical-looping combustion (CLC) is a new technology for burning gaseous fuels, with inherent separation of CO2. Metal oxide particles are used for the transfer of oxygen from the combustion air to the fuel, thus the combustion products CO2 and H2O are obtained in a separate stream. A 10-kW prototype for CLC has been designed, built and run with nickel-based oxygen-carrier particles. A total operation time of more than 100 h was accomplished with the same batch of particles, i.e. without adding fresh, unused material. A high conversion of the fuel was reached, with approximately 0.5% CO, 1% H2 and 0.1% methane in the exit stream, corresponding to a fuel conversion efficiency of 99.5% based on fuel heating value. The best way to treat the unconverted fuel is not clear, although it is believed that it can be separated from the liquefied CO2 at a reasonable cost and recycled to the process. There was no detectable leakage between the two reactor systems. Firstly, no CO2 escapes from the system via the air reactor. Thus, 100% of the CO2 is captured in the process. Secondly, it should be possible to achieve an almost pure stream of CO2 from the fuel reactor, with the possible exception of unconverted fuel, or inert compounds associated with the fuel, e.g. N2. No decrease in reactivity or particle strength was seen during the test period. The loss of fines was small and decreased continuously during the test period. At the end of the period the loss of fines, i.e. particles smaller than 45 mm was 0.0023% per hour. If this can be assumed to be a relevant measure of the steady-state attrition, it corresponds to a lifetime of the particles of 40,000 h. Assuming a lifetime of the particles one order of magnitude lower, i.e. 4000 h, the cost of particles in the process is estimated to be below e1 per ton of CO2 captured. Carbon Dioxide Capture for Storage in Deep Geologic Formations – Results from the CO2 Capture Project Capture and Separation of Carbon Dioxide from Combustion Sources - Volume 1 |
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