Evaluation of Reclaimer

Sludge Disposal from Post-

Combustion CO2 Capture

Prachi Singh,

IEA Greenhouse Gas R&D Programme, UK

Paul Nielsen,

University of Texas at Austin

Trimeric Corporation, University of Texas at Austin

and URS Corporation

Capacity (MWe) CO2 Concentration (mole%)

Coal 900 11.8%

Natural Gas 810 4.1%

Reference Cases

Solvent Flue Gas

Lean Loading (mole CO2 / mole total alkalinity)

Rich Loading

(mole CO2 / mole total alkalinity)

Solvent Circulation

Rate (standard

m3/h) 7m MEA (120 °C)

Coal 0.12 0.51 10,719

Natural Gas 0.12 0.49 5,083

8m PZ (150 °C)

Coal 0.31 0.41 21,641

Natural Gas 0.28 0.37 10,818

7/2m MDEA/PZ (135 °C)

Coal 0.11 0.25 26,707

Natural Gas 0.11 0.25 12,105

Solvent inventory: 30 minutes total holdup

Amine Losses

• Thermal Degradation

• 10 min residence time in stripper packing, sump, & reboiler

• MEA: 120 °C, PZ: 150 °C, MDEA/PZ: 135 °C

• Oxidation

• Function of O2, Thot of cross exchanger (30 second residence

time), catalyzed by metal ions

• 5 mol% O2 (11% for NGCC)

• Nitrosation

• 1.5 ppmv NO2

• Volatile amine loss/aerosols

• 1 ppmv after water wash

• Loss in reclaimer sludge

• 1 – 5 % of amine fed to reclaimer

Containment Removed by

Amine Absorber

Contaminant Unit Coal

(min – max range)

Coal Base case

NGCC Base case

% Removal from gas

SO3 ppmv 10 10 0 0%

SO2 ppmv 1 – 10 5 0.5 90%

NO2 ppmv 1 – 5.5 1.5 0.5 100%

Other NOX ppmv 19 – 104.5 45 15 10%

HCl ppmv 0.2 – 1.85 1.85 0 90%

HF ppmv 0.075 0.075 0 90%

Fly ash mg/Nm3 1.5 – 45 6 0 50%

Hg μg/Nm3 0.135 – 6 1.8 0 50%

Se μg/Nm3 0.3 – 30 2.3 0 50%

Other metals μg/Nm3 3 – 150 5.5 0 50%

Conservatively high

Thermal Reclaiming

• 95% amine recovery

• 100% removal of HSS’s and metals

Bleed to

Reclaimer

Purified Amine

(95% recovery)

1 mol NaOH/

1 mol HSS Impurities

(5% Amine loss)

Reboiler

154oC/1 bar

,

Stripping

Still

Condenser

CO2 to

stripper

Hot lean

solvent

Lean solvent

to exchanger

1.5 wt% HSS

Ion Exchange &

Electrodialysis

Ion Exchange

• 99% amine recovery

• 90% removal of HSS’s

• No metals removal

Electrodialysis

• 97% amine recovery

• 92% removal of HSS’s

• No metals removal

Lean Amine

Reclaimer

Feed

Anion

Exchange

Resin

Caustic for Regeneration

(Distilled, deionized water)

Aqueous Brine to

Wastewater

Treatment Plant

Purified Amine

(99% recovered)

Cation

Exchange

Resin

Caustic

Pretreatment

Sulfuric Acid for

Regeneration

(Distilled, deionized water)

1 mol NaOH/

1 mol HSS

Aqueous Brine to

Wastewater

Treatment Plant

Particulate

Filter

CO2

Pretreatment

Rates of amine loss (coal)

0

0,05

0,1

0,15

0,2

0,25

0,3

0,35

0,4

0,45

0,5

MEA PZ MDEA/PZ Thermal Ion exchange

mM

/hr

Thermal Deg Oxidation Nitrosation Volatility Reclaiming Loss

NGCC: 2x oxidation rate

0.1 % drawoff

120 °C

150 °C

135 °C

95% amine recovery

0.1% slipstream

99% recovery

5 vol% O2 1.5 ppm NO2

Rates of contaminant

accumulation (coal)

0

0,02

0,04

0,06

0,08

0,1

0,12

0,14

0,16

0,18

MEA PZ MDEA/PZ

mM

/hr

DEA + 1-MPZ

HEEDA,HEIA/AEP, HEPHeGly/Bicine

HEI/EDA, 2-imid

Formate,HEF/FPZ

Sulfate: 0.162 0.080 0.065 [90% of 5 ppm SO2]

Nitrate: 0.165 0.080 0.065 [10% of 45 ppm NOx]

Not harmful to solvent

Polishing scrubber to reduce SO2 highly recommended

Economics: MEA Coal

Base Case

0

0,5

1

1,5

2

2,5

3

3,5

4

4,5

5

Thermalreclaiming

Ion Exchange Electrodialysis

Op

era

tin

g C

os

t ($

MM

/yr)

Energy

Mebrane/ResinReplacement

Other Consumables

Solvent Losses

Fixed O&M

PEC: 3.7 5.4 3.7 $MM

Total: 1.11 1.2 1.1 $/tonne CO2

Alternative case 1.5% HSS reduces cost e.g. MDEA/Pz

Thermal reclaiming, Coal:1.33$/tonneCO2 & NGCC:

0.9$/tonneCO2

Estimated Normalized Cost:

Coal & NGCC, 0.1% slipstream Coal NGCC

Sensitivity Analyses

(MEA/Coal/Thermal Reclaiming)

-15

-10

-5

0

5

10

15

20

25

30

35

% C

hange in E

conom

ics

105 °C

135 °C 10 %

2.5 %

2x

2/3x

+/- 2x fly ash

Low metals

(no ox. catalysis)

Base Case: Stripper:

120 °C

5.5 mol% O2 5 ppm SO2

45 ppm NOx

6 mg/Nm3

50% cap.

Waste Disposal Options

~10x cost

Conclusions

For MEA thermal reclaiming was found to be least expensive, whereas for MDEA/Pz and Pz ion exchange and electrodialysis was found to be least expensive. [All within uncertainties of assumptions]

For NGCC case Ion exchange followed by electrodialysis was found to be least expensive

Solvent reclaiming will be 0.6-1.3% of total electricity cost for coal and 0.3-0.4% for NGCC case

Metal and mercury content will trigger Reclaimer waste Classification as Hazardous in US, increasing disposal cost

Polishing scrubber to reduce SO2 in coal flue gas to <1 ppmv highly recommended

Acknowledgements

• IEAGHG: Prachi Singh

• Trimeric: Andrew Sexton, Kevin Fisher,

Anne Ryan

• UT: Paul Nielsen, Nathan Fine, Steven

Fulk, Eric Chen, Gary Rochelle

• URS: Katherine Dombrowski, Jean

Youngerman, William Steen, Douglas Orr

This presentation contains the expression of the professional opinion of Trimeric Corporation (Trimeric), URS Corporation (URS), and the

University of Texas (UT) as to the matters set out herein and it was prepared pursuant to an agreement dated November 9, 2012 between Trimeric

Corporation and IEA Environmental Projects Ltd. Greenhouse Gas R&D Programme (IEAGHG) and the methodologies, assumptions and

procedures stated therein. This presentation is written solely for the purpose stated in the agreement, and for the sole and exclusive benefit of

IEAGHG, whose remedies are limited to those set out in the agreement. This presentation is not intended for the use of anyone other than

IEAGHG, and anyone other than IEAGHG who elects to use and/or rely on this agreement, does so at its own risk.

Waste Characterization

Characterization was performed based on US and EU regulation by evaluating the characteristics of the solvent, metals content, nitrosamine content from model

In US waste hazardous classification would be based on the metals content and mercury for coal-fired thermal reclaimer waste

In EU thermal reclaiming waste from coal and NGCC will be hazardous

Waste from ion exchange and electrodialysis 95% water; No or very low metal content

Piperazine (Pz) is a sensitizing agent, so Pz and MDEA/Pz containing waste stream from ion exchange and electrodialysis may be hazardous in EU

Recommendations Oxidative degradation rate of the amine and oxidation products are least understood phenomenon that impact impurity accumulation and reclaimer design

Amine Degradation

Developing methods for selective removal of metals; Atmospheric reclaiming of non-volatiles; Development of volatiles reclaiming to minimize air emissions of ammonia, aldehydes and other volatile degradation products etc.

Solvent Reclaiming

Analysis of amine waste composition from plant, Estimation of Chemical Oxygen Demand for WWT, Evaluation of waste disposal cost, Firing in HRSG require further investigation, Effect on emission

Waste Disposal Options

Amine solvents tend to degrade in presence of heat/O2 and accumulate impurities from flue gas

Degradation compounds increases solvent viscosity affecting mass/heat transfer, enhances corrosion and foaming, increases toxicity

Solvent reclaiming removes build up impurities

Reclaiming reduces solvent makeup cost and concentrates degradation products to reduce the waste disposal cost

Why Solvent Reclaiming ?

Degradation products

MEA

Product

mole produced /mole

amine lost

Thermal Degradation

HEIA 0.2

triHEIA 0.05

HEEDA in equilibrium w/ HEIA

MEA trimer in equilibrium w/ triHEIA

Oxidative Degradation

Ammonia 0.67

Formate/HEF 0.12

Oxalate +

oxylamide (HEO)

0.01

Nitrate 0.01

Nitrite 0.002

HEI 0.06

HeGly 0.05

Amides

HEI

HeGly

Continuous slipstream ratio of 0.1% to reclaimer unit

(equivalent to 1% slipstream batch mode operating 10%

of plant operation time)

100% recovery of water and CO2

1 mol NaOH added/mol HSS

Reclaimer Assumptions

Economic Evaluation

• Capital costs (PEC)

• Reference capital costs from thermal reclaiming

vendors

• Reference ion exchange, electrodialysis costs from

1988 LRGCC

• Compared to cost estimates from Aspen In-Plant Cost

Estimator

• 4 parallel units

• 0.6 scale-up factor

• Lang Factor = 3

• 8% discount rate

Waste Handling

In Wiped Film Evaporator Thermal Reclaimer sludge removed without water addition

Other thermal reclaiming 50%+ water will be added for dilution. Required to be dried/solidified prior to landfill

For Cement kiln waste must be analysed, stabilized blend of waste will be used for constant composition

For Co-firing at Power Plant a sludge handling system is required (dilution, pumping, storage tank etc.)

Waste management plan (monitoring, testing, record keeping, reporting) and operator training will be required

Landfill and Waste Incineration In US Non-Hazardous (NGCC) and Hazardous (Coal) waste

can be disposed in commercial landfill

In EU wastes do not meet the criteria not suitable for

landfill

For Incineration, profile of waste is required on the energy

generated and water content in US

Waste Streams NGCC Power Plant Coal Power Plant

Non-hazardous Waste

Landfill ($/year)

Hazardous Waste

Disposal, Landfill/

Incinerator ($/year)

MEA 208,000 2,531,000

MEA + 50% Water 567,000 6,395,000

PZ 369,000 3,963,000

PZ + 50% Water 981,000 10,103,000

10x – 12x

Addition of amine sludge may

require additional testing and

monitoring

Cement Kiln dust waste need to

be evaluated for metal and

chlorine content

1% Chlorine in waste will not

affect overall Chlorine content

0.5-3% Ash in coal amine

sludge no effect

Sulfate and NaOH range <1% -

18.5%; may require bypass to

remove sulfate to avoid effect

on clinker quality

Cement Kiln

Rotary Kiln

Coal case of

MDEA/Pz Thermal

reclaimer waste

can provide up to

15% Thermal Input

to rotary kiln

Prior testing is required to identify the waste characteristics

Reclaimer waste co-fired using exiting oil gun/with an

alternative fuel

Co-firing waste is subject to regulation for commercial and

industrial solid waste incinerator

Co-firing at NGCC HRSG is possible with additional

considerations e.g. temperature, residence time, corrosion,

emission (SOx, NOx, particulates)

Projected MDEA/Pz thermal reclaimer waste flow rate of

406-1902 kg/hr for 900MWe SCPC plant:

Co-firing at Power plant

Coal / Waste Stream Flow rate,

kg/hr

Heat Input,

GJ/hr

Base Case Coal 293,300 7,815

Undiluted Reclaimer waste 951 8.4

Effect on SCPC Emission

Parameter

Concentration of

Constituent in Stream

Mass Flow rate, kg/hr

Coal, MDEA/PZ Thermal

reclaimer sludge

Ratio of

Sludge Flow

rate to Coal

Flow rate Coal Undiluted

Sludge Coal

Undiluted

Sludge

Flowrate - - 293,300 951 0.32%

Moisture 9.5% 0% 27,864 0 0.0%

Sulfur 0.9% 2.6% 2,640 25 0.95%

Chloride 0.3% 1.1% 88 10.5 11.9%

Nitrogen 1.4% 9.3% 4,106 89 2.2%

Mercury (Hg) 0.04 ppm 3.7 ppm 0.0123 0.0035 28.6%

Selenium (Se) 0.05 ppm 4.7 ppm 0.0147 0.0045 30.5%

Arsenic (As) 1.26 ppm 0.8 ppm 0.3696 0.0008 0.21%

Cadmium

(Cd)

0.07 ppm 0.3 ppm 0.0197 0.0003 1.45%

Chromium

(Cr)

0.47 ppm 9.2 ppm 4.6635 0.0087 0.19%

Lead (Pb) 6.8 ppm 0.9 ppm 1.9944 0.0009 0.04%

Fly ash 13.5% 1.2% 39,595 11.4 0.03%

35-70% amine in sludge, possibly converted to NH3 in

SCR

Could replace half of SNCR reagent (900 MWe SCPC)

Consideration needed for residence time, corrosion,

consistency in reclaimer waste, heavy metals, NOx

Use as SNCR/SCR Reagent

Ion exchange and Electrodialysis

amine waste is more suitable to

be treated in WWT

In US currently there is no

specific regulations for amine

sludge

In EU reclaimer waste is subject

to additional regulations

Additional onsite waste water

treatment system (Advanced

oxidative / Denitrification system)

is required to treat waste

containing MEA, MDEA and Pz

Waste Water Treatment Plant

Cost of different waste

water treatment will be

dependent on waste

characteristics

Sensitivity Analysis

MEA Thermal Reclaiming,

Parameters

Overall

HSS Conc.

(wt%)

$/ton

CO2

% Change in

Economics

from Base

Case

Base Case 1.48 0.9 0.00%

105°C Regeneration Temp. 1.45 0.88 -1.70%

135°C Regeneration Temp. 1.51 0.91 1.70%

10% Inlet O2 1.54 0.93 3.40%

2.5% Inlet O2 1.44 0.88 -2.30%

90 ppm NOX

(3 ppm NO2) 2.04 1.18 32.20%

30 ppm NOX

(1 ppm NO2) 1.31 0.81 -9.80%

10 mg/Nm3 fly ash

(6mg/Nm3) 1.48 0.9 0.00%

3 mg/Nm3 fly ash 1.48 0.9 0.00%

0 ppm corrosion metals

(100 ppmv dissolved iron) 1.41 0.86 -4.00%

Electrodialysis

• 97% amine recovery

• 92% removal of HSS’s

• No metals removal