scholarly journals Pilot testing of CO2 capture from a coal-fired power plant—Part 2: Results from 1-MWe pilot tests

Clean Energy ◽  
2020 ◽  
Vol 4 (1) ◽  
pp. 12-25 ◽  
Author(s):  
Sharon Sjostrom ◽  
Constance Senior

Abstract Using a 1-MWe slipstream pilot plant, solid-sorbent-based post-combustion CO2 capture was tested at a coal-fired power plant. Results from pilot testing were used to develop a preliminary full-scale commercial design. The sorbent selected for pilot-scale evaluation during this project consisted of an ion-exchange resin that incorporated amines covalently bonded to the substrate. A unique temperature-swing-absorption (TSA) process was developed that incorporated a three-stage fluidized-bed adsorber integrated with a single-stage fluidized-bed regenerator. Overall, following start-up and commissioning challenges that are often associated with first-of-a-kind pilots, the pilot plant operated as designed and expected, with a few key exceptions. The two primary exceptions were associated with: (i) handling characteristics of the sorbent, which were sufficiently different at operating temperature than at ambient temperature when design specifications were established with lab-scale testing; and (ii) CO2 adsorption in the transport line between the regenerator and adsorber that preloaded the sorbent with CO2 prior to entering the adsorber. Results from the pilot programme demonstrate that solid-sorbent-based post-combustion capture can be utilized to achieve 90% CO2 capture from coal-fired power plants.

Author(s):  
Qin Chen ◽  
Ashok Rao ◽  
Scott Samuelsen

Existing coal fired power plants are expected to continue providing a significant portion of power generation and a majority of these are subcritical pulverized coal (PC) units which have higher CO2 emissions on a MWe basis due to their higher heat rates, while CO2 emissions are an increasing concern due to global pressure on limiting greenhouse gas accumulation in the atmosphere. Current state-of-the-art CO2 capture technology uses an aqueous amine solution to chemically absorb the CO2 from the flue gas and thus requires a large amount of energy for solvent regeneration. Novel solid sorbent based CO2 capture technologies are under development to capture the CO2 via physical adsorption and desorption, thereby consuming far less energy for the sorbent regeneration process. This present work is focused on retrofitting a subcritical PC power plant with solid sorbent post combustion CO2 capture technology. Thermal performance and costs are compared with an amine based CO2 capture plant as well as the plant with no CO2 capture. The design of the solid sorbent based CO2 capture system is optimized for integration to minimize plant modifications and the associated downtime. In an existing PC plant with a net power efficiency of 36.57%, use of the amine based capture reduces the net efficiency to 26.01% while with the solid sorbent based capture, the reduction in net efficiency is far less at 28.67% when 90% of the CO2 is captured. As a consequence, the increase in plant cooling duty is significantly lower for the solid sorbent CO2 capture case, with the water usage on a per MW basis being almost 17% lower than the amine based PC plant. The calculated levelized cost of electricity is increased from $60.5/MWh without CO2 capture to $124.3/MWh for amine based capture while that with the solid sorbent based capture is much lower at $115.8/MWh.


2019 ◽  
Author(s):  
Gerhard Schöny ◽  
Johannes Fuchs ◽  
Melina Infantino ◽  
Sander Van Paasen ◽  
Jolinde van de Graaf ◽  
...  

2016 ◽  
Vol 139 (3) ◽  
Author(s):  
Bilal Hassan ◽  
Oghare Victor Ogidiama ◽  
Mohammed N. Khan ◽  
Tariq Shamim

A thermodynamic model and parametric analysis of a natural gas-fired power plant with carbon dioxide (CO2) capture using multistage chemical looping combustion (CLC) are presented. CLC is an innovative concept and an attractive option to capture CO2 with a significantly lower energy penalty than other carbon-capture technologies. The principal idea behind CLC is to split the combustion process into two separate steps (redox reactions) carried out in two separate reactors: an oxidation reaction and a reduction reaction, by introducing a suitable metal oxide which acts as an oxygen carrier (OC) that circulates between the two reactors. In this study, an Aspen Plus model was developed by employing the conservation of mass and energy for all components of the CLC system. In the analysis, equilibrium-based thermodynamic reactions with no OC deactivation were considered. The model was employed to investigate the effect of various key operating parameters such as air, fuel, and OC mass flow rates, operating pressure, and waste heat recovery on the performance of a natural gas-fired power plant with multistage CLC. The results of these parameters on the plant's thermal and exergetic efficiencies are presented. Based on the lower heating value, the analysis shows a thermal efficiency gain of more than 6 percentage points for CLC-integrated natural gas power plants compared to similar power plants with pre- or post-combustion CO2 capture technologies.


Author(s):  
W. J. Thayer ◽  
R. T. Taussig

Applications of energy exchangers, a type of gasdynamic wave machine, were evaluated in power plants fired by pressurized, fluidized bed combustors (PFBCs). Comparative analyses of overall power plant efficiency indicate that the use of energy exchangers as hot gas expanders may provide a 0.5 to 1.5 efficiency point increase relative to gas turbines. In addition, the unique operating characteristics of these machines are expected to reduce rotating component wear by a factor of 50 to 300 relative to conventional gas turbines operating in the particulate laden PFBC effluent stream.


Author(s):  
Stuart M. Cohen ◽  
John Fyffe ◽  
Gary T. Rochelle ◽  
Michael E. Webber

Coal consumption for electricity generation produces over 30% of U.S. carbon dioxide (CO2) emissions, but coal is also an available, secure, and low cost fuel that is currently utilized to meet roughly half of America’s electricity demand. While the world transitions from the existing fossil fuel-based energy infrastructure to a sustainable energy system, carbon dioxide capture and sequestration (CCS) will be a critical technology that will allow continued use of coal in an environmentally acceptable manner. Techno-economic analyses are useful in understanding the costs and benefits of CCS. However, typical techno-economic analyses of post-combustion CO2 capture systems assume continuous operation at a high CO2 removal, which could use 30% of pre-capture electricity output and require new capacity installation to replace the output lost to CO2 capture energy requirements. This study, however, considers the inherent flexibility in post-combustion CO2 capture systems by modeling power plants that vary CO2 capture energy requirements in order to increase electricity output when economical under electricity market conditions. A first-order model of electricity dispatch and a competitive electricity market is used to investigate flexible CO2 capture in response to hourly electricity demand variations. The Electric Reliability Council of Texas (ERCOT) electric grid is used as a case study to compare plant and grid performance, economics, and CO2 emissions in scenarios without CO2 capture to those with flexible or inflexible CO2 capture systems. Flexible CO2 capture systems can choose how much CO2 to capture based on the competition between CO2 and electricity prices and a desire to either minimize operating costs or maximize operating profits. Coal and natural gas prices have varying degrees of predictability and volatility, and the relative prices of these fuels have a major impact on power plant operating costs and the resulting plant dispatch sequence. Because the chosen operating point in a flexible CO2 capture system affects net power plant efficiency, fuel prices also influence which CO2 capture operating point may be the most economical and the resulting dispatch of power plants with CO2 capture. Several coal and natural gas price combinations are investigated to determine their impact on flexible CO2 capture operation and the resulting economic and environmental impacts at the power plant and electric grid levels. This study investigates the costs and benefits of flexible CO2 capture in a framework of a carbon-constrained future where the effects of major energy infrastructure changes on fuel prices are not entirely clear.


Fuel ◽  
2015 ◽  
Vol 151 ◽  
pp. 50-56 ◽  
Author(s):  
Marcin Stec ◽  
Adam Tatarczuk ◽  
Lucyna Więcław-Solny ◽  
Aleksander Krótki ◽  
Marek Ściążko ◽  
...  

Author(s):  
Soumya Jyoti Chatterjee ◽  
Goutam Khankari ◽  
Sujit Karmakar

The comparative performance study is carried out for 500 MW Supercritical (SupC) Oxy-Coal Combustion (OCC) and Air-Coal Combustion (ACC) power plants with membrane-based CO2 capture at the fixed furnace temperature. The proposed configurations are modelled using a computer-based analysis software 'Cycle-Tempo' at different operating conditions, and the detailed thermodynamic study is done by considering Energy, Exergy, and Environmental (3-E) analysis. The result shows that the net energy and exergy efficiencies of ACC power plants with CO2 capture are about 35.07 % and 30.88 %, respectively, which are about 6.44 % and 5.77 % points, respectively higher than that of OCC power plant. Auxiliary power consumption of OCC based power plant is almost 1.97 times more than that of the ACC based plant due to huge energy utilization in the Air Separation Unit (ASU) of OCC plant which leads to performance reduction in OCC plant. However, environmental benefit of OCC based power plant is more than that of ACC based power plant with respect to CO2 emission. OCC plant emits about 0.164 kg/kWh of CO2 which is approximately 16.75 times lower than the CO2 emission in ACC based power plant. It is also analyzed that the performance of the CO2 Capture Unit (CCU) for the OCC based plant is about 3.65 times higher than the ACC based power plant due to higher concentration of CO2 (nearly 80.63%) in the flue gas emitting from OCC plant. The study also reveals that the auxiliary power consumption per kg of CO2 capture of the OCC based plant is about 0.142 kWh/kg, which is approximately 0.06 times lower than the ACC based plant. The higher performance of the OCC based power plant is found at lower value of flue gas recirculation due to the fact that reduction in exergy destruction at the mixing zone of the combustor is higher than the increase in exergy destruction of the heat exchangers at higher furnace exit temperature. But the metallurgical temperature limit of boiler tube materials restricts the use of the higher value of furnace temperature. OCC based power plant with CO2 capture can be preferred over ACC based plant with CO2 capture due to higher environmental benefits towards mitigating CO2, the key greenhouse gas on earth in spite of exhibiting lesser energy and exergy efficiencies.


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