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

Jonshagen, Klas LU ; Sammak, Majed LU and Genrup, Magnus LU (2012) In Journal of Engineering for Gas Turbines and Power 134(1).
Abstract
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... (More)
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. [DOI: 10.1115/1.4004146] (Less)
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author
organization
publishing date
type
Contribution to journal
publication status
published
subject
in
Journal of Engineering for Gas Turbines and Power
volume
134
issue
1
publisher
American Society of Mechanical Engineers
external identifiers
  • wos:000296732200009
  • scopus:80555125899
ISSN
1528-8919
DOI
10.1115/1.4004146
language
English
LU publication?
yes
id
48bee7a8-4f8b-4321-bf69-8f91bd92d79b (old id 2279037)
date added to LUP
2012-01-11 14:19:32
date last changed
2017-08-20 03:26:56
@article{48bee7a8-4f8b-4321-bf69-8f91bd92d79b,
  abstract     = {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. [DOI: 10.1115/1.4004146]},
  author       = {Jonshagen, Klas and Sammak, Majed and Genrup, Magnus},
  issn         = {1528-8919},
  language     = {eng},
  number       = {1},
  publisher    = {American Society of Mechanical Engineers},
  series       = {Journal of Engineering for Gas Turbines and Power},
  title        = {Postcombustion CO2 Capture for Combined Cycles Utilizing Hot-Water Absorbent Regeneration},
  url          = {http://dx.doi.org/10.1115/1.4004146},
  volume       = {134},
  year         = {2012},
}