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1.
This work focuses on the techno-economic assessment of bituminous coal fired sub- and super-critical pulverised fuel boilers from an oxyfuel based CO2 capture point of view. At the initial stage, two conventional power plants with a nominal power output of above 600 MWe based on the above steam cycles are designed, simulated and optimised. Built upon these technologies, CO2 capture facilities are incorporated within the base plants resulting in a nominal power output of 500 MWe. In this manner, some sensible heat generated in the air separation unit and the CO2 capture train can be redirected to the steam cycle resulting in a higher plant efficiency. The simulation results of conventional sub- and super-critical plants are compared with their CO2 capture counterparts to disclose the effect of sequestration on the overall system performance attributes. This systematic approach allows the investigation of the effects of the CO2 capture on both cycles. In the literature, super-critical plants are often considered for a CO2 capture option. These, however, are not based on a systematic evaluation of these technologies and concentrate mainly on one or two key features. In this work several techno-economic plant attributes such as the fuel consumptions, the utility usages, the plant performance parameters as well as the specific CO2 generation and capture rates are calculated and weighed against each other. Finally, an economic evaluation of the system is conducted along with sensitivity analyses in connection with some key features such as discounted cash flow rates, capital investments and plant efficiencies as well as fuel and operating costs.  相似文献   

2.
The current studies on power plant technologies suggest that Integrated Gasification Combined Cycle (IGCC) systems are an effective and economic CO2 capture technology pathway. In addition, the system in conventional configuration has the advantage of being more “CO2 capture ready” than other technologies. Pulverized coal boilers (PC) have, however, proven high technical performance attributes and are economically often most practical technologies. To highlight the pros and cons of both technologies in connection with an integrated CO2 capture, a comparative analysis of ultrasupercritical PC and IGCC is carried out in this paper. The technical design, the mass and energy balance and the system optimizations are implemented by using the ECLIPSE chemical plant simulation software package. Built upon these technologies, the CO2 capture facilities are incorporated within the system. The most appropriate CO2 capture systems for the PC system selected for this work are the oxy-fuel system and the postcombustion scheme using Monoethanolamine solvent scrubber column (MEA). The IGCC systems are designed in two configurations: Water gas shift reactor and Selexol-based separation. Both options generate CO2-rich and hydrogen rich-gas streams. Following the comparative analysis of the technical performance attributes of the above cycles, the economic assessment is carried out using the economic toolbox of ECLIPSE is seamlessly connected to the results of the mass and energy balance as well as the utility usages. The total cost assessment is implemented according to the step-count exponential costing method using the dominant factors and/or a combination of parameters. Subsequently, based on a set of assumptions, the net present value estimation is implemented to calculate the breakeven electricity selling prices and the CO2 avoidance cost.  相似文献   

3.
The current studies on power plant technologies suggest that Integrated Gasification Combined Cycle (IGCC) systems are an effective and economic CO2 capture technology pathway. In addition, the system in conventional configuration has the advantage of being more “CO2 capture ready” than other technologies. Pulverized coal boilers (PC) have, however, proven high technical performance attributes and are economically often most practical technologies. To highlight the pros and cons of both technologies in connection with an integrated CO2 capture, a comparative analysis of ultrasupercritical PC and IGCC is carried out in this paper. The technical design, the mass and energy balance and the system optimizations are implemented by using the ECLIPSE chemical plant simulation software package. Built upon these technologies, the CO2 capture facilities are incorporated within the system. The most appropriate CO2 capture systems for the PC system selected for this work are the oxy-fuel system and the postcombustion scheme using Monoethanolamine solvent scrubber column (MEA). The IGCC systems are designed in two configurations: Water gas shift reactor and Selexol-based separation. Both options generate CO2-rich and hydrogen rich-gas streams. Following the comparative analysis of the technical performance attributes of the above cycles, the economic assessment is carried out using the economic toolbox of ECLIPSE is seamlessly connected to the results of the mass and energy balance as well as the utility usages. The total cost assessment is implemented according to the step-count exponential costing method using the dominant factors and/or a combination of parameters. Subsequently, based on a set of assumptions, the net present value estimation is implemented to calculate the breakeven electricity selling prices and the CO2 avoidance cost.  相似文献   

4.
CO2 capture from power plants, combined with CO2 storage, is a potential means for limiting the impact of fossil fuel use on the climate. In this paper, three oxy-fuel plants with incorporated CO2 capture are evaluated from an economic and environmental perspective. The oxy-fuel plants, a plant with chemical looping combustion with near 100% CO2 capture and two advanced zero emission plants with 100% and 85% CO2 capture are evaluated and compared to a similarly structured reference plant without CO2 capture. To complete the comparison, the reference plant is also considered with CO2 capture incorporating chemical absorption with monoethanolamine. Two exergy-based methods, the exergoeconomic and the exergoenvironmental analyses, are used to determine the cost-related and the environmental impacts of the plants, respectively, and to reveal options for improving their overall effectiveness.For the considered oxy-fuel plants, the investment cost is estimated to be almost double that of the reference plant, mainly due to the equipment used for oxygen production and CO2 compression. Furthermore, the exergoeconomic analysis reveals an increase in the cost of electricity with respect to the reference plant by more than 20%, with the advanced zero emission plant with 85% CO2 capture being the most economical choice. On the other hand, a life cycle assessment reveals a decrease in the environmental impact of the plants with CO2 capture, due to the CO2 and NOx emission control. This leads to a reduction in the overall environmental impact of the plants by more than 20% with respect to the reference plant. The most environmentally friendly concept is the plant with chemical looping combustion.  相似文献   

5.
The techno-economic evaluation of four novel integrated gasification combined cycle (IGCC) power plants fuelled with low rank lignite coal with CO2 capture facility has been investigated using ECLIPSE process simulator. The performance of the proposed plants was compared with two conventional IGCC plants with and without CO2 capture. The proposed plants include an advanced CO2 capturing process based on the Absorption Enhanced Reforming (AER) reaction and the regeneration of sorbent materials avoiding the need for sulphur removal component, shift reactor and/or a high temperature gas cleaning process. The results show that the proposed CO2 capture plants efficiencies were 18.5–21% higher than the conventional IGCC CO2 capture plant. For the proposed plants, the CO2 capture efficiencies were found to be within 95.8–97%. The CO2 capture efficiency for the conventional IGCC plant was 87.7%. The specific investment costs for the proposed plants were between 1207 and 1479 €/kWe and 1620 €/kWe and 1134 €/kWe for the conventional plants with and without CO2 capture respectively. Overall the proposed IGCC plants are cleaner, more efficient and produce electricity at cheaper price than the conventional IGCC process.  相似文献   

6.
In the work presented in this paper, an alternative process concept that can be applied as retrofitting option in coal-fired power plants for CO2 capture is examined. The proposed concept is based on the combination of two fundamental CO2 capture technologies, the partial oxyfuel mode in the furnace and the post-combustion solvent scrubbing. A 330 MWel Greek lignite-fired power plant and a typical 600 MWel hard coal plant have been examined for the process simulations. In a retrofit application of the ECO-Scrub technology, the existing power plant modifications are dominated by techno-economic restrictions regarding the boiler and the steam turbine islands. Heat integration from processes (air separation, CO2 compression and purification and the flue gas treatment) can result in reduced energy and efficiency penalties. In the context of this work, heat integration options are illustrated and main results from thermodynamic simulations dealing with the most important features of the power plant with CO2 capture are presented for both reference and retrofit case, providing a comparative view on the power plant net efficiency and energy consumptions for CO2 capture. The operational characteristics as well as the main figures and diagrams of the plant’s heat balances are included.  相似文献   

7.
A CO2 capture process for an integrated gasification combined cycle (IGCC) power plant using the calcium looping cycle was proposed. The CO2 capture process using natural and modified limestone was simulated and investigated with the software package Aspen Plus. It incorporated a fresh feed of sorbent to compensate for the decay in CO2 capture activity during long‐term cycles. The sorbent flow ratios have significant effect on the CO2 capture efficiency and net efficiency of the CO2 capture system. The IGCC power plant, using the modified limestone, exhibits higher CO2 capture efficiency than that using the natural limetone at the same sorbent flow ratios. The system net efficiency using the natural and modified limestones achieves 41.7 % and 43.1 %, respectively, at the CO2 capture efficiency of 90 % without the effect of sulfation.  相似文献   

8.
This paper presents the results of the cost of energy (COE) analysis of an integrated gasification combined cycle (IGCC) power plant with respect to CO2 capture ratio under the climate change scenarios. To obtain process data for a COE analysis, simulation models of IGCC power plants and an IGCC with carbon capture and sequestration (CCS) power plant, developed by the United States Department of Energy (DOE) and National Energy Technology Laboratory (NETL), have been adopted and simulated using Aspen Plus. The concept of 20-year levelized cost of energy (LCOE), and the climate change scenarios suggested by International Energy Agency (IEA) are also adopted to compare the COE of IGCC power plants with respect to CO2 capture ratio more realistically. Since previous studies did not consider fuel price and CO2 price changes, the reliability of previous results of LCOE is not good enough to be accepted for an economic comparison of IGCC power plants with respect to CO2 capture ratio. In this study, LCOEs which consider price changes of fuel and CO2 with respect to the climate change scenarios are proposed in order to increase the reliability of an economic comparison. And the results of proposed LCOEs of an IGCC without CCS power plant and IGCC with CCS (30%, 50%, 70% and 90% capture-mole basis- of CO2 in syngas stream) power plants are presented.  相似文献   

9.
The 2007 IEA's World Energy Outlook report predicts that the world's energy needs will grow by 55% between 2005 and 2030, with fossil fuels accounting for 84% of this massive projected increase in energy demand. An undesired side effect of burning fossil fuels is carbon dioxide (CO2) emission which is now widely believed to be responsible for the problem of global warming. Various strategies are being considered for addressing the increase in demand for energy and at the same time developing technologies to make energy greener by reducing CO2 emissions.One of these strategies is to ‘capture’ produced CO2 instead of releasing it into the atmosphere. Capturing CO2 and its injection in oil reservoirs can lead to improved oil recovery as well as CO2 retention and storage in these reservoirs. The technology is referred to as CCS (carbon capture and storage). Large point sources of CO2 (e.g., coal-fired power plants) are particularly good candidates for capturing large volumes of CO2. However, CO2 capture from power plants is currently very expensive. In addition to high costs of CO2 capture, the very low pressure of the flue gas (1 atm) and its low CO2 content (typically 10-15%) contribute to the high cost of CO2 capture from power plants and the subsequent compression. This makes conventional CO2 flooding (which requires very large volumes of CO2) uneconomical in many oil reservoirs around the world which would otherwise be suitable candidates for CO2 injection. Alternative strategies are therefore needed to utilize smaller sources of CO2 that are usually available around oil and gas fields and can be captured at lower costs (due to their higher pressure and higher CO2 concentration).We investigate the potential of carbonated (CO2-enriched) water injection (CWI) as an injection strategy for improving recovery from oil reservoirs with the added benefit of safe storage of CO2. The performance of CWI was investigated by conducting high-pressure flow visualization as well as coreflood experiments at reservoir conditions. The results show that CWI significantly improves oil recovery from water flooded porous media. A relatively large fraction of the injected CO2 was retained (stored) in the porous medium in the form of dissolved CO2 in water and oil. The results clearly demonstrate the huge potential of CWI as a productive way of utilizing CO2 for improving oil recovery and safe storage of potentially large cumulative quantities of CO2.  相似文献   

10.
In this work, we present a model of a super-critical coal-fired power plant integrated with an amine-based CO2 capture process. We use this model to solve a multi-period dynamic optimisation problem aimed at decoupling the operation of the power plant from the efficiency penalty imposed by the CO2 capture plant, thus providing the power plant sufficient flexibility to exploit price variation within an electricity market. We evaluate four distinct scenarios: load following, solvent storage, exhaust gas by-pass and time-varying solvent regeneration. The objective is to maximise the decarbonised power plant's short run marginal cost profitability. It is found that while the solvent storage option provides a marginal improvement of 4% in comparison to the load following scenario, the exhaust gas bypass scenario results in a profit reduction of 17% whereas the time-varying solvent regeneration option increases the profitability of the power plant by 16% in comparison to the reference scenario.  相似文献   

11.
Scope of the work presented in this paper is to examine and evaluate the application of the oxyfuel combustion CO2 capture technology in a lignite-fired power plant from an economic point of view. Results from simulations dealing with the most important features for CO2 reduction are performed. The operational characteristics, the efficiency penalties as well as the net efficiency reduction emerging from the Greenfield application of the oxyfuel technology are presented.CO2 capture costs and the energy requirements associated with the oxyfuel method affect significantly the cost of electricity. This paper focuses on the analysis of the techno-economic factors that result in the increase of the cost of electricity in comparison with the conventional air-fired power plant. For this reason a typical Greek lignite power plant is used as a reference case. Any technical, economic and financial assumptions applied provide a common basis for both power plants (i.e., conventional and oxyfuel) for the assessment of the change of the cost of electricity and the CO2 capture cost. The oxyfuel simulations are performed by taking into account the adoption of measures for the exploitation of heat that would otherwise be wasted. Such measures concern both the water/steam cycle and the gas flows (e.g., the oxygen flow). Heat integration from processes - such as the air separation, the CO2 compression and purification and the flue gas treatment - is adopted in order to lower as much as possible the efficiency penalty.The cycle calculations have been performed using the thermodynamic cycle calculation software ENBIPRO (ENergie-BIllanz-PROgram). ENBIPRO is a powerful tool for heat and mass balance solving of complex thermodynamic circuits, calculation of efficiency, exergetic and exergoeconomic analysis of power plants. The software code models all pieces of equipment that usually appear in power plant installations and can accurately calculate all thermodynamic properties (temperature, pressure, enthalpy) at each node of the thermodynamic circuit, power consumption of each component, flue gas composition, etc. The code has proven its validity by accurately simulating a large number of power plants and through comparison of the results with other commercial software (Stamatelopoulos GN. Calculation and optimisation of power plant thermodynamic cycles. VDI-Regulations. Series 6, No. 340. Braunchweig, Mechanical Engineering Department; 1996 [in German]).  相似文献   

12.
This article presents a fleet‐wide model for energy planning that can be used to determine the optimal structure necessary to meet a given CO2 reduction target while maintaining or enhancing power to the grid. The model incorporates power generation as well as CO2 emissions from a fleet of generating stations (hydroelectric, fossil fuel, nuclear, and wind). The model is formulated as a mixed integer program and is used to optimize an existing fleet as well as recommend new additional generating stations, carbon capture and storage, and retrofit actions to meet a CO2 reduction target and electricity demand at a minimum overall cost. The model was applied to the energy supply system operated by Ontario power generation (OPG) for the province of Ontario, Canada. In 2002, OPG operated 79 electricity generating stations; 5 are fueled with coal (with a total of 23 boilers), 1 by natural gas (4 boilers), 3 nuclear, 69 hydroelectric and 1 wind turbine generating a total of 115.8 TWh. No CO2 capture process existed at any OPG power plant; about 36.7 million tonnes of CO2 was emitted in 2002, mainly from fossil fuel power plants. Four electricity demand scenarios were considered over a span of 10 years and for each case the size of new power generation capacity with and without capture was obtained. Six supplemental electricity generating technologies have been allowed for: subcritical pulverized coal‐fired (PC), PC with carbon capture (PC+CCS), integrated gasification combined cycle (IGCC), IGCC with carbon capture (IGCC+CCS), natural gas combined cycle (NGCC), and NGCC with carbon capture (NGCC+CCS). The optimization results showed that fuel balancing alone can contribute to the reduction of CO2 emissions by only 3% and a slight, 1.6%, reduction in the cost of electricity compared to a calculated base case. It was found that a 20% CO2 reduction at current electricity demand could be achieved by implementing fuel balancing and switching 8 out of 23 coal‐fired boilers to natural gas. However, as demand increases, more coal‐fired boilers needed to be switched to natural gas as well as the building of new NGCC and NGCC+CCS for replacing the aging coal‐fired power plants. To achieve a 40% CO2 reduction at 1.0% demand growth rate, four new plants (2 NGCC, 2 NGCC+CCS) as well as carbon capture processes needed to be built. If greater than 60% CO2 reductions are required, NGCC, NGCC+CCS, and IGCC+CCS power plants needed to be put online in addition to carbon capture processes on coal‐fired power plants. The volatility of natural gas prices was found to have a significant impact on the optimal CO2 mitigation strategy and on the cost of electricity generation. Increasing the natural gas prices resulted in early aggressive CO2 mitigation strategies especially at higher growth rate demands. © 2009 American Institute of Chemical Engineers AIChE J, 2009  相似文献   

13.
Calcium looping is a CO2 capture scheme using solid CaO-based sorbents to remove CO2 from flue gases, e.g., from a power plant, producing a concentrated stream of CO2 (∼95%) suitable for storage. The scheme exploits the reversible gas-solid reaction between CO2 and CaO(s) to form CaCO3(s). Calcium looping has a number of advantages compared to closer-to-market capture schemes, including: the use of circulating fluidised bed reactors—a mature technology at large scale; sorbent derived from cheap, abundant and environmentally benign limestone and dolomite precursors; and the relatively small efficiency penalty that it imposes on the power/industrial process (i.e., estimated at 6-8 percentage points, compared to 9.5-12.5 from amine-based post-combustion capture). A further advantage is the synergy with cement manufacture, which potentially allows for decarbonisation of both cement manufacture and power production. In addition, a number of advanced applications offer the potential for significant cost reductions in the production of hydrogen from fossil fuels coupled with CO2 capture. The range of applications of calcium looping are discussed here, including the progress made towards demonstrating this technology as a viable post-combustion capture technology using small-pilot scale rigs, and the early progress towards a 2 MW scale demonstrator.  相似文献   

14.
About 20% power output penalties will be incurred for implementing CO2 capture from power plant. This loss can be partially compensated by flexible operation of capture plant. However, daily large variations of liquid and gas flows may cause operation problems to packed columns. Control schemes were proposed to improve the flexibility of power output without causing substantial hydraulic disturbances in capture plant is presented. Simulations were implemented using ASPEN Plus. In varying lean solvent flow strategy, the flow rate of recycling solvent was manipulated to control the CO2 capture rate. The liquid flow of the absorber and gas flow of the stripper will vary substantially. In an alternative strategy, the lean solvent loading will be varied. Variation of gas throughput in the stripper is avoided by recycling part of CO2 vapor to stripper. This strategy provided more stable hydraulics condition in both columns and is recommended for flexible operation. © 2011 American Institute of Chemical Engineers AIChE J, 2012  相似文献   

15.
Post‐combustion CO2 capture was studied in the favorable context where the captured CO2 can be reused in a neighboring industrial process. Three technologies for CO2 capture, absorption by amines, adsorption on activated carbon, and separation using polymer membranes, were considered, modeled and compared. The three capture processes were designed for achieving the same performances. The models were integrated in a commercial flowsheeting software. The results show that, for a targeted CO2 purity of 95 %, the membrane process appears to be the least energy consuming. A next step will be to quantify the environmental benefits using life cycle assessment.  相似文献   

16.
Carbon capture and storage (CCS) technologies are expected to play a significant role in the coming decades for curbing the greenhouse gas emissions and to ensure a sustainable development of power generation and other energy-intensive industrial sectors. Chemical looping systems are very promising options for intrinsically capture CO2 with lower cost and energy penalties. Gasification offers significant advantages compared with other technologies in term of lower energy and cost penalties for carbon capture, utilization of wide range of fuels, poly-generation capability, plant flexibility, lower environmental impact, etc.  相似文献   

17.
A. Lawal  P. Stephenson  H. Yeung 《Fuel》2010,89(10):2791-2801
Post-combustion capture by chemical absorption using MEA solvent remains the only commercial technology for large scale CO2 capture for coal-fired power plants. This paper presents a study of the dynamic responses of a post-combustion CO2 capture plant by modelling and simulation. Such a plant consists mainly of the absorber (where CO2 is chemically absorbed) and the regenerator (where the chemical solvent is regenerated). Model development and validation are described followed by dynamic analysis of the absorber and regenerator columns linked together with recycle. The gPROMS (Process Systems Enterprise Ltd.) advanced process modelling environment has been used to implement the proposed work. The study gives insights into the operation of the absorber-regenerator combination with possible disturbances arising from integrated operation with a power generation plant. It is shown that the performance of the absorber is more sensitive to the molar L/G ratio than the actual flow rates of the liquid solvent and flue gas. In addition, the importance of appropriate water balance in the absorber column is shown. A step change of the reboiler duty indicates a slow response. A case involving the combination of two fundamental CO2 capture technologies (the partial oxyfuel mode in the furnace and the post-combustion solvent scrubbing) is studied. The flue gas composition was altered to mimic that observed with the combination. There was an initial sharp decrease in CO2 absorption level which may not be observed in steady-state simulations.  相似文献   

18.
The world will need greatly increased energy supply in the future for sustained economic growth, but the related CO2 emissions and the resulting climate changes are becoming major concerns. CO2 is one of the most important greenhouse gases that is said to be responsible for approximately 60% of the global warming. Along with improvement of energy efficiency and increased use of renewable energy sources, carbon capture and sequestration (CCS) is expected to play a major role in curbing the greenhouse gas emissions on a global scale. This article reviews the various options and technologies for CO2 capture, specifically for stationary power generation sources. Many options exist for carbon dioxide capture from such sources, which vary with power plant types, and include post-combustion capture, pre-combustion capture, oxy fuel combustion capture, and chemical looping combustion capture. Various carbon dioxide separation technologies can be utilized with these options, such as chemical absorption, physical absorption, adsorption, and membrane separation. Most of these capture technologies are still at early stages of development. Recent progress and remaining challenges for the various CO2 capture options and technologies are reviewed in terms of capacity, selectivity, stability, energy requirements, etc. Hybrid and modified systems hold huge future potentials, but significant progress is required in materials synthesis and stability, and implementations of these systems on demonstration plants are needed. Improvements and progress made through applications of process systems engineering concepts and tools are highlighted and current gaps in the knowledge are also mentioned. Finally, some recommendations are made for future research directions.  相似文献   

19.
Hannah Chalmers  Jon Gibbins 《Fuel》2007,86(14):2109-2123
Pulverised coal-fired plants often play an important role in electricity grids as mid-merit plants that can operate flexibly in response to changes in supply and demand. As a consequence, these plants are required to operate over a wide output range. This paper presents an initial evaluation of some potential impacts of adding post-combustion CO2 capture on the part load performance of pulverised coal-fired plants. Preliminary results for ideal cases analysed using a simple high-level model indicate that post-combustion CO2 capture could increase the options available to power plant operators. In particular, solvent storage could allow higher effective plant load factors to be achieved to assist with capital recovery while still permitting flexible operation for grid support. A number of areas for more detailed analysis are identified.  相似文献   

20.
Post-combustion is considered among the different options for CO2 capture as the most mature available technology. All major components of the CO2 absorption/desorption process are commercially available but at a smaller scale, and they are not integrated and optimized for the application in power plants. Therefore, it is still to be demonstrated that this process is a viable option for the capture of CO2 at power plants. The amine scrubbing process with standard solvents is highly energy demanding due to solvent regeneration and CO2 compression. This is a significant energy sink for the power plant and efficiency can be reduced up to 16%-points. In order to minimise the energy penalty, complete integration and optimization of the capture and the power plant processes are necessary.Simulations of the power plant cycle and the amine scrubbing system have been performed with specialized software. The results of the integration are discussed.  相似文献   

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