Thursday, March 31, 2011

CO2-flue gas separation for a gas fired power plant


Neelakantha Aryal, Udara S.P.R. Arachchige, Prof. Morten C. Melaaen

Abstract
Combustion of fossil fuel and natural gases are the main sources of CO2 emission. The energy requirement, high capital and operating cost are the challenges regarding the CO2 capture. Absorption is the most common and efficient technique for CO2 removal today and one of the viable options for CO2 capturing from power plants. In this paper, comprehensive flow sheet has been developed for post combustion CO2 removal system with Aspen Plus. The CO2 removal from 500MW natural gas-fired power plant flue gas was considered. The parameters and other operating conditions are selected to achieve 85% of CO2 removal.

The rate based Electrolyte NRTL activity coefficient property method is used in the Aspen Plus with 25w/w % MEA solution and 0.25 as lean CO2 loading. CO2 removal efficiency was specified as a design specification option in Aspen Plus with the variation of Distillate rate in the stripper. The sensitivity analysis was performed to check the parameters’ effect on removal efficiency on the CO2 removal process. As a result of sensitivity analysis, the optimum operating conditions and parameters were selected for absorber and stripper. The complete removal process with re-circulating solvent back to the absorber is implemented with the sequential modular method in Aspen Plus. The re-boiler duty requirement on 85% CO2 removal was calculated as 4500 kJ/kg CO2 after several iterations. Parameters’ effect on re-boiler duty was checked to optimize the process. Temperature and concentration profiles as well as CO2 loading were analyzed to check the model behavior.

Key words: Gas fired flue gas, Aspen Plus, Simulation, Re-boiler duty
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5 comments:

  1. udara sampathApril 1, 2011 at 2:58 PM

    This is really nice work.

    ReplyDelete
  2. udaraApril 1, 2011 at 11:04 PM

    What will be the next step?.Why do u consider only MEA. Do you have any plans to do any other solvents?.

    ReplyDelete
  3. Aryal NeelApril 2, 2011 at 12:47 AM

    Yes, We want to proceed with other amines like DEA, TEA and DGA etc. the results will be compared against each other to find best amine along with their optimal parameter values... Soon I will be posting those documents also for your reference..

    ReplyDelete
  4. RoshanApril 3, 2011 at 12:00 AM

    I love doing 'process optimization'... its just awesome to know how calculation of optimal values improves process performance(maximization/minimization, and bla bla...)

    ReplyDelete
  5. udara sampathApril 4, 2011 at 3:31 PM

    Hope you will update with more information related to carbon capture.

    ReplyDelete

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