co2 absorption from ccpp pakistan

8/10/2019 CO2 Absorption from CCPP Pakistan

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Absorption by using aqueousblended solution ofMEA/AMP

Presented By : Hafiz Muhammad AtifStudent ID # : 2 319942

Course title: Advanced Gas ProcessingCourse code: ENIN 831

CO2absorption from

Gas Turbine


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Gas u b e

Introduction of Combine Cycle

Power Plant

Student ID number : 200319942

Major Equipments

Gas TurbineHRSG / OTSG

Steam TurbineCondenser

Cooling TowersPumps


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Gas Turbine


Air Intake (Compressor)Fuel IntakeIgnitionCombustion Chamber


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Why CO2is Alarming?? Greenhouse gases

Water vapor (H2O)

Carbon dioxide (CO2)Methane (CH4)

Nitrous oxide (N2O)

Chlorofluorocarbon (CFCs)

Contributing to

Global warming

Climate change



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Mass transfer technologies for

CO2 capturingAdsorption

Cryogenics

Membrane technologies

Absorption



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CO2capturing

technologiesPre

CombustionPost

CombustionOxy

Combustion


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Post Combustion



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Absorption Absorption, or gas absorption, is a unit operation used inthe chemical industry to separate gases by washing orscrubbing a gas mixture with a suitable liquid

The fundamental physical principles underlying theprocess of gas absorption are the solubility of the absorbedgas and the rate of mass transfer. One or more of theconstituents of the gas mixture dissolves or is absorbed in

the liquid and can thus be removed from the mixture. Insome systems, this gaseous constituent forms a physicalsolution with the liquid or the solvent, and in other cases ,it reacts with the liquid chemically.



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The absorber may be a packed column , plate column ,spray column , venturi scrubbers , bubble column ,falling films , wet scrubbers ,stirred tanks usually Plate

and Packed column are used.



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Reaction mechanism Following reactions occurs according to zwitterion

mechanism

Bcan be base which could be amine, OH-or H2O

Resulting Carbamate of reaction (1) is quite stable forMEA



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Cont Hindered aminescarbamate is not stable resulting

Resulting improvement of primary aminesstoichiometry restriction.



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Issues in CO2absorption Solvent Selection??

Major industrially chemical absorbents for CO2are MEA, DEA,MDEA, DIPA

Most commonly used amine is MEA, limited by following factors Stoichiometry limitation up to 0.5 mol CO2/mol amine (kg

CO2 absorbed per kg solvent). Solvent degradation due to SO2 and O2 in flue gas.High equipment corrosion rate. High energy consumption MDEA shows lower reactivity with CO2,

AMP limited by higher precipitation rate Recently, the use of blends of alkanolamines, a solution of two or

more amines in varying concentrations, has been shown toproduce absorbents with excellent absorption characteristics as

well as savings in energy requirements



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Cont..


CO2removal efficiency of MEA and AMP

In the beginning MEA

System shows high

Efficiency up to almost40 min but than due to

limit of stoichiometry

to 0.5 mol CO2/mol aminethis decreases sharply


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Reeducation of Regeneration

Energy reduction of the energy requirement for solvent

regeneration



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Cont



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Re boiler heat duty


Ratio of the power supplied by the heating fluid at the re boiler and the massrate of CO2 released from the regeneration column.

The power supplied was determined by the following equation:

mfCP

tin,ftout,f

Mass flow rate of heating fluidHeat capacity of heating fluid

Temperature of heating fluid enteringTemperature of heating fluid going out

The CO2 mass rate is defined as

amine

CO2

CO2

Heat capacity of heating fluid

Heat capacity of heating fluid

molar flow rate of amine


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Re boiler heat duty



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Regeneration efficiency Vs Repeated

regeneration times



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Optimum Concentration of amine

solution Rule of thumb

Corrosion rate

Viscosity Economic ally feasible



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Present research focus


Selection of new optimum Solvents

Make some blend of known amines

Systematic modification of the structure of thesolvents to make them efficient


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Following different blend ratio of aqueous amine 30 %


MEA AMP

30 0

24 6

18 1212 18

6 24

0 30


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Results and discussion The performances will be evaluated under various

operating conditions to investigate the absorptioncharacteristic of absorbents by studying followings

using absorption/regeneration process

The absorption rate of CO2

CO2 removal efficiency

Absorption amountCO2loading for blended aqueous MEA + AMP.

The optimum blending ratio of MEA and AMP



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The absorption rate of CO2Kov=overall reaction rate constant =

HA = Henrys constantDa = Diffusivity



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Effect of gas flow rate and absorbent concentration

Removal efficiency=

% removal decrease with increase in gasflow rate

Removal efficiency of MEA is more thanAMP



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Cont.

Optimum concentration 30 %



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Cont. The CO2removal efficiency of AMP was maintained

highly for a long time due to the additional reaction byzwitterions mechanism. Therefore, the use of blended

solution of the MEA and AMP for CO2removal couldbe more useful to enhance absorption characteristicsthan a single absorbent. Meanwhile, CO2absorptionamount of aqueous 30 wt.% MEA and 30 wt.% AMP

solutions were 0.46 and 0.84 mol CO2/mol amine,respectively



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Effect of blending with MEA and AMP MEA has higher removal efficiency and fast reaction

rate with CO2 while AMP has higher capability toabsorb more CO2than MEA so blending is nice option.

The CO2 removal of

30/0 > 0/30 of MEA/AMP for

single aq amine solution

Removal decreases withIncrease in AMP concentration



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ContWhile absorption amount of CO2 increases with

increase in AMP concentration.

So rectangular area looks efficient point

Thus performance of the blended solution looksbetter.



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Effect of regenerator temperatureExperimental conditions

Absorber temperature 40C

Gas flow rate 7.5 L/min

CO2 inlet concentration 12.% by vol

Liquid flow rate 90 mL/min



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Cont.Addition of AMP provides

better results than alone MEA

Best temperature found

to be 110 oC



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Cont



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ConclusionsAfter comparative study we can conclude

In absorption process MEA was superior to AMP in theCO

2removal efficiency but AMP was better than MEA

in CO2absorption amount.


G ki


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Groups working .



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Major References Evaluation of natural gas combined cycle power plant for

post-combustion CO2capture integration (InternationalJournal of Greenhouse Gas Control 19 (2013) 396405 ) Carbon capture and storages (Energy Policy 36 2008 4317

4322) Advances in CO2 capture technology The U.S. Department

of Energys Carbon Sequestration Programs Mass Transfer Performance of CO2 Absorption into

Aqueous Solutions of 4-Diethylamino-2-butanol, Monoethanolamine and N-Methyl di ethanolamine

Carbon Capture: A Technology Assessment July 19, 2010

Pre-combustion, post-combustion and oxy-combustion inthermal power plant for CO2 capture Applied ThermalEngineering 30 (2010) 5362



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co2 absorption from ccpp pakistan

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