Postcombustion CO2 Capture for Combined Cycles Utilizing Hot-Water Absorbent Regeneration

2011 ◽  
Vol 134 (1) ◽  
Author(s):  
Klas Jonshagen ◽  
Majed Sammak ◽  
Magnus Genrup
Keyword(s):  
Power Plant ◽  
Temperature Difference ◽  
Co2 Capture ◽  
Steam Pressure ◽  
Low Pressure ◽  
Pressure Level ◽  
Combined Cycle ◽  
Hot Water ◽  
Combined Cycle Power Plant ◽  
Pressure Plant

The partly hot-water driven CO2 capture plant offers a significant potential for improvement in performance when implemented in a combined-cycle power plant (CCPP). It is possible to achieve the same performance with a dual-pressure steam cycle as in a triple-pressure unit. Even a single-pressure plant can attain an efficiency competitive with that achievable with a triple-pressure plant without the hot-water reboiler. The underlying reasons are better heat utilization in the heat recovery unit and less steam extraction to the absorbent regenerating unit(s). In this paper, the design criteria for a combined cycle power plant utilizing hot-water absorbent regeneration will be examined and presented. The results show that the most suitable plant is one with two steam pressure levels. The low-pressure level should be much higher than in a conventional combined cycle in order to increase the amount of heat available in the economizer. The external heat required in the CO2 capture plant is partly supplied by the economizer, allowing temperature optimization in the unit. The maximum value of the low-pressure level is determined by the reboiler, as too great a temperature difference is unfavorable. This work evaluates the benefits of coupling the economizer and the reboiler in a specially designed CCPP. In the CO2 separation plant both monoethanolamine (MEA) and ammonia are evaluated as absorbents. Higher regeneration temperatures can be tolerated in ammonia-based plants than in MEA-based plants. When using a liquid heat carrier the reboiler temperature is not constant on the hot side, which results in greater temperature differences. The temperature difference can be greatly reduced by dividing the regeneration process into two units operating at different pressures. The possibility of extracting more energy from the economizer to replace part of the extracted steam increases the plant efficiency. The results show that very high efficiencies can be achieved without using multiple pressure-levels.

Post Combustion CO2 Capture for Combined Cycles Utilizing Hot-Water for Absorbent Regeneration

2011 ◽  
Author(s):  
Klas Jonshagen ◽  
Majed Sammak ◽  
Magnus Genrup
Keyword(s):  
Power Plant ◽  
Temperature Difference ◽  
Co2 Capture ◽  
Steam Pressure ◽  
Low Pressure ◽  
Pressure Level ◽  
Combined Cycle ◽  
Hot Water ◽  
Combined Cycle Power Plant ◽  
Pressure Plant

The partly hot-water driven CO2 capture plant offers a significant potential for improvement in performance when implemented in a combined-cycle power plant (CCPP). It is possible to achieve the same performance with a dual-pressure steam cycle as in a triple-pressure unit. Even a single-pressure plant can attain an efficiency competitive with that achievable with a triple-pressure plant without the hot-water reboiler. The underlying reasons are better heat utilization in the heat recovery unit and less steam extraction to the absorbent regenerating unit(s). In this paper, the design criteria for a combined cycle power plant utilizing hot-water absorbent regeneration will be examined and presented. The results show that the most suitable plant is one with two steam pressure levels. The low-pressure level should be much higher than in a conventional combined cycle in order to increase the amount of heat available in the economizer. The external heat required in the CO2 capture plant is partly supplied by the economizer, allowing temperature optimization in the unit. The maximum value of the low-pressure level is determined by the reboiler, as too great a temperature difference is unfavourable. This work evaluates the benefits of coupling the economizer and the reboiler in a specially designed CCPP. In the CO2 separation plant both monoethanolamine (MEA) and ammonia are evaluated as absorbents. Higher regeneration temperatures can be tolerated in ammonia-based plants than in MEA-based plants. When using a liquid heat carrier the reboiler temperature is not constant on the hot side, which results in greater temperature differences. The temperature difference can be greatly reduced by dividing the regeneration process into two units operating at different pressures. The possibility of extracting more energy from the economizer to replace part of the extracted steam increases the plant efficiency. The results show that very high efficiencies can be achieved without using multiple pressure-levels.

scholarly journals Solvent Screening and Feasible Study of Retrofitting CO2 Capture System for Natural Gas Combined Cycle Power Plant

2014 ◽  
Vol 63 ◽  
pp. 2394-2401
Author(s):  
Satoshi Saito ◽  
Norihide Egami ◽  
Toshihisa Kiyokuni ◽  
Mitsuru Udatsu ◽  
Hideo Kitamura ◽  
...  
Keyword(s):  
Power Plant ◽  
Natural Gas ◽  
Co2 Capture ◽  
Combined Cycle ◽  
Combined Cycle Power Plant ◽  
Natural Gas Combined Cycle ◽  
Feasible Study

Failure Analysis of Low Pressure Evaporator Tubes in a Typical Combined Cycle Power Plant

2011 ◽  
Vol 110-116 ◽  
pp. 4607-4614
Author(s):  
M. Nematollahi ◽  
M. Rezaeian
Keyword(s):  
Power Plant ◽  
Steam Generator ◽  
Power Plants ◽  
Fluid Dynamic ◽  
Flow Distribution ◽  
Low Pressure ◽  
Combined Cycle ◽  
Two Phase ◽  
Combined Cycle Power Plant ◽  
Suitable Material

Flow-induced corrosion is one of the most prevalent tube damage mechanisms in steam generators of power plants. In this study, tube failure of a steam generator in Fars Combined Cycle Power Plant is evaluated. In addition to analysis of the measured tube thicknesses and the failure statistics data, computational fluid dynamic (CFD) methods are used to simulate flow distribution inside and outside of the tubes in one header of the low pressure circuit of the plant steam generator. The results show that regarding the created two-phase flow pattern inside the tubes, the droplet impingement erosion is the main source of tube failures in the bending areas where the extrados surface of the tubes are partially prone to the droplets. The results are useful for modifying the design of the steam generator from different viewpoints such as, optimal design for appropriate configuration of downcomer, header and footer and tube bending. Also, selecting suitable material for the steam generator tubes and implementation of protective coating in risky areas would benefit from the present results.

Novel CO2 Emissions Reduction Technique for IGCC Plants

2005 ◽  
Author(s):  
E. Kakaras ◽  
A. Koumanakos ◽  
A. Doukelis ◽  
D. Giannakopoulos ◽  
Ch. Hatzilau ◽  
...  
Keyword(s):  
Power Plant ◽  
Co2 Capture ◽  
Power Plants ◽  
State Of The Art ◽  
Combined Cycle ◽  
The Novel ◽  
Operating Characteristics ◽  
Calcination Process ◽  
Combined Cycle Power Plant ◽  
Novel Concept

Scope of the work presented is to examine and evaluate the state of the art in technological concepts towards the capture and sequestration of CO2 from coal-fired power plants. The discussion is based on the evaluation of a novel concept dealing with the carbonation-calcination process of lime for CO2 capture from coal fired power plants compared to integration of CO2 capture in an Integrated Gasification Combined Cycle power plant. In the novel concept, coal is gasified with steam in the presence of lime. Lime absorbs the CO2 released from the coal, producing limestone. The produced gas can be a low-carbon or even zero-carbon (H2) gas, depending on the ratio of lime added to the process. The produced gas can be used in state-of-the-art combined cycles for electricity generation, producing almost no CO2 emissions or other harmful pollutants. The limestone is regenerated in a second reactor, where pure CO2 is produced, which can be either marketed to industry or sequestered in long term disposal areas. The simulation model of a Combined Cycle power plant, integrating the novel carbonation-calcination process, is based on available data from a typical natural gas fired Combined Cycle power plant. The natural gas fired power plant was adopted to firing with the low-C fuel, maintaining the basic operating characteristics. The performance of the novel concept power plant is compared to that of an IGCC with CO2 removal by means of Selexol absorption. Results from thermodynamic simulation, dealing with the most important features for CO2 reduction, are presented. The operating characteristics, as well as the main figures of the plant energy balances are included. A preliminary economic comparison is also provided, taking into account investment and operating costs, in order to estimate the electricity cost related to the two different technological approaches and the economic constrains towards the potentials for applications are examined. The cycle calculations were performed using the thermodynamic cycle calculation software ENBIPRO (ENergie-BIllanz-PROgram). ENBIPRO is a powerful tool for heat and mass balance calculations, solving complex thermodynamic circuits, calculating the efficiency, and allowing 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 [1]. 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.

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