advancement of co2 compression and purification plant in

R. Ritter, N. SchödelCCT 2009 Conference Dresden, May 2009

Advancement of CO2 Compression and Purification Plant in the Integration with the Oxyfuel

Technology

2 N. Schödel / 0901 / LE-Presentation_E.pptLinde AG Engineering Division

Table of Contents

New Process

Developments

for

NOx and SOx

Removal

Catalytic

DeNOx

Alkali-based

Scrubbing

Unit


Contents

New Process

Developments

for

NOx and SOx

Removal

Catalytic

DeNOx

Alkali-based

Scrubbing

Unit


New Process Development for NOx

and SOx

Removal Background

Background

—

The flue gas of oxyfuel

power plants with CSS has to be purified before transportation and storage.

—

There are several common technologies for flue gas purification for:

— DeNOx

— DeSOx

—

Simultaneous removal

—

The purification steps are cost intensive. Due to this, an optimization is desirable.

—

There is a high operation pressure available in the CO2-stream.

⇒ new process ideas


New Process Development Selected concepts

Self induced homogeneous

OxidationNO

N2 (Linde-

Patent)

Fast SCR

+Reduction media

AbsorptionNO+N

O2

NO+N

O2

Alkali based scrubber

Reduction N2

Fertilizer(Linde-Patent)

Simultaneous removal of SOx

and NOx

possible

Elevated

Pressure

Selected

Linde R&D concepts: Catalytic

DeNOx

and Alkali-based

Scrubbin


Contents

New Process

Developments

for

NOx and SOx

Removal

Catalytic

DeNOx

Alkali-based

Scrubbing

Unit


Catalytic DeNOx

State of the Art Technology

Boiler SCR Filter FGD CO2 Com-pression

State of the art arrangement

Boiler Filter SCR FGD CO2 Com-pression

High dust

Low

dust

Tail

end

NH3-DeNOx: vanadium-titanium-oxide catalyst, 300 –

450°C, approx. atmospheric pressure


Catalytic DeNOx

Linde Concept

Pressure 2 –

100 bar ⇒ preferred: 5 –

50 bar

Reaction 4NO + 4NH3

+ O2

→ 4N2

+ 6H2

O2NO + 2H2

→ N2

+ 2H2

OCatalyst vanadium-titanium-oxide or other, e.g. noble metal

Temperature 100 –

350 °C ⇒ preferred: 120 –

250 °C


1 barg 10 barg

0

20

40

60

80

100N

Ox

conv

erio

n [%

]

Catalytic DeNOx

“Proof of Principle”

Tests

TE-(1-6)

PI

PI 1

TI

PI 2

TI

TE-(7-12)

Abgas

MultiportventilAnalytik

Abgas

MultiportventilAnalytik PI 3

TI

Te-(13-18)

Abgas


Wasserdampferzeugung

Waage

TI

Kohlen-wasser-stoffe

O2CO2Stickstoff

F1 F2 F3 F4 F5

FICFICFICFICFIC

PI


PI

Tests performed:— reduction medium NH3 or H2

— pressure up to 25 bar

— GHSV up to 100 000 h-1

— temperature down to 150°C

— NOx

content up to 0,07%

— O2 content up to 6%

— in CO2/N2 matrix (~ 85/10)

Example NH3-DeNOx:

V2O5/TiO2 catalyst

≈

0.04% NOx

T ≈

250°C

GHSV ≈

70 000 h-1

Results:— Conversion under pressure

possible

— Positive effect of the pressure on the performance

⇒ Patent application prepared


Catalytic DeNOx

Technology Comparison

State of the Art Linde fast DeNOx

Concept

low pressure high pressure

NH3 as reduction medium reduction medium e.g. NH3, H2

V2O5-TiO2-(WO3)catalyst V2O5-TiO2 or other, e.g. noble metal catalyst

(low temperature types possible)

temperature 300 –

450°C

(heat integrated)

temperature 100 -350°C, preferred: 120 –

250°C

(use of compression heat)

highly contaminated stream relatively pure stream

large stream reduced stream (1/3 to CO2 plant, pressure)

positive effect on reaction rate due to, e.g., NO2 formation, increased NOx

concentration, pressure

Salts formation (sulfate/nitrate) possible

Depending on reduction media no or limited salt formation (nitrate) possible


Contents

New Process

Developments

for

NOx and SOx

Removal

Catalytic

DeNOx

Alkali-based

Scrubbing

Unit


Alkali-based Scrubbing Unit State of the Art Technology

NO Oxidationflue gas

Gas Scrubber

Oxidation media

ProductWashing media

Cleaned flue gasFGD

NO Oxidation:

NO+H2

O2 NO2 + H2O or

NO+O3 NO2 + O2

Water Scrubber for Nitric Acid Production:

3NO2

+ H2

O 2HNO3 + NO

Alkaline Scrubber for Fertilizer Production:

NO + NO2

+ 2NH3

+ H2

O 2NH4NO2

2NO2

+ 2NH3

+ H2

O NH4NO2 + NH4NO3

NH4

NO2 + 1/2 O2 NH4NO3

Fertilizer is produced

in several processes using O3

or H2

O2

for NO oxidation and subsequent alkaline scrubbing. (e.g. Walter-Process)

Nitric acid

produced from NO rich gas needs a continuous oxidation of the released NO. This increases the amount of oxidation media in the washing media or decreases the NO removal.

alternative


Alkali-based Scrubbing Unit Linde Concept

NO and SO2

Oxidation:

NO+1/2O2 NO2

SO2 + NO2 SO3 + NO

Alkaline Scrubber:

SO2

+ 2NH3

+ H2

O (NH4)2 SO3

SO3

+ 2NH3

+ H2

O (NH4)2 SO4

NO + NO2

+ 2NH3

+ H2

O 2NH4NO2

2NO2

+ 2NH3

+ H2

O NH4NO2 + NH4NO3

Regeneration: NH4NO2 N2 + 2H20 (decomposition > 50°C)

Ammonia solution washing media is also able to…

—

remove NO2

—

remove water-insoluble NO in presence of NO2

—

remove SO2 and SO3

The resulting nitrites and nitrates can be…

—

oxidized to a mixed sulfur/nitrogen fertilizer

—

decomposed to N2

and H2

O (Denitrification)

flue gasGas Scrubber

Product (Fertilizer)Alkaline washing media

Cleaned flue gasFGD

alternativeRegeneration


Alkali-based Scrubbing Unit


Tests

— Test conditions: NOx

removal rate depending on washing media

NOx

removal rate (p/T/t)

Nitrate, Nitrite formation depending on NO/NO2

Nitrite decomposition (regeneration)

Simultaneous removal tests

— ResultsNOx

removal possible

Removal improved at higher pressure

Simultaneous SOx

and NOx

removal possible

Nitrite selectivity > 90% achievable

— Patent application prepared

Pressure: 10-20 bar

Temperature : 20 -

30°C

Gas composition: CO2 70 mol%

O2 1,5-

6 mol% NO 300-1600 Vppm

SO2 0 –

2000 Vppm

N2

balance


1 0 b a r ; 3 ,0 v o l% O 2 ; 7 0 v o l% C O 2

0

5 0

1 0 0

1 5 0

2 0 0

2 5 0

3 0 0

0 2 0 4 0 6 0t im e in s e c .

NO

vpp

m

Probable Mechanism: [NO] >> [NO2

]

2NO + O2 2NO2

NO+NO2

+2NH3

+H2

O 2NH4NO2

4NO + O2

+ 4NH3

+2H2

O 4NH4NO2

U

p

p

e

r

s

e

c

t

i

o

n

l

o

w

e

r

s

e

c

t

i

o

n

— NO removal in alkaline washers is two times faster than NO oxidation itself

Example: NOx

Removal

Example: Simultaneous SOx

and NOx

Removal

— Mechanism of NO removal is understood

⇒ simultaneous removal feasible



Tests

0

500

1000

1500

2000

2500

Feed Bottom 0 sec 13 sec 25 sec 39 sec.

Sample

SO

2 in

vppm

0

100

200

300

400

500

600

NO

in v

ppm

SO2 conversionNO conversion SO2 NO

Conversio

n

99.5% 85%11 bar; 23 °C; 3,0 vol% O2

t =0 sec.



Technology Comparison

Washing media

Oxidation requiremen

t

Product Benefits Disadvantage

Water —100% NO Oxidation

—100% SO2 Oxidation required

—Acids —Only water as washing media

—Material handling (corrosion)

—For high NOx

removal sufficient residence time in the scrubber is needed

—Acid mixture in case of simultaneous SOx

and NOx

removal

NH3 in water

—Only

50% NO2

in NOx

required

—No SO2 Oxidation required

—Fertilizer

—or N2

—No corrosion issue

—Increased NOx

removal rate

—Lower residence time is needed (smaller process units)

—Reduction to N2

possible

—Defined product

—Ammonia consumption


Feasibility of Concepts Gate Process

LINDE Phase Gate Criteria for R&D projects:

e.g.

— Technology ownership / patent situation

— Implementation concept

— Time schedule / time to market

— Technical feasibility

— Process economics

Commercial

ScaleR&D Idea Prefeasibility Feasibility Lab Scale Pilot Scale

Gate 1Gate 2 Gate

3Gate 4 Gate 5

Final Gate


Feasibility of Concepts Economics –

Comparison to State of the Art Technology

Preliminary Cost EstimateCommercial

NH3

-SCRHigh Dust

fast-SCR 10 -

20 bar

Alkaline Wash Unit 10

bar

Conversion Up to 90% Up to 90% 80 -

95%Invest costs total % High Dust

NH3-DeNOx 100 140 -

170 65 -

70Utilities total % High Dust

NH3-DeNOx 100 80 -

140 20

Overall cost (10% depreciation/a) % High Dust

NH3-DeNOx 100 120 -

140 40 -

50

Reference Case:250 MW (electrical) oxyfuel power plant

CO2-content:

~75 vol%

High dust conventional NH3-DeNOx with 90% NOx

conversion

Thanks for your attention.


New Process Development Common DeNOx

Technology in Gas Processing Units

NO

Oxidation Absorption

catalytic Reduction

non catalytic Reduction

selective

not selective

ReductionNO2

N2

Nitric acid, Nitrates, Nitrites, Fertilizer

+Reduction media

e.g.+H2

O/NH3

/(NH4

)2

SO3

+Oxidation media or Radical formation or catalytically via

O2

N2

N2

SCR and SNCR units

Walther process, Electron beam process

Absorption ReductionN2

+Absorption media for NO

EDTA -

process

Principles of NOx

Reduction Chemistry

+Reduction media

Catalytic DecompositionN2


DeSOx-

process

regenerative

not regenerative

wet

wet

dry

dry

semi -dry

DESONOX

Activated carbon processSOLINOX

Sorbent injection process

Spray dryer absorption

Lime (stone) scrubbing

Sodium(hydroxide) scrubbingAmmonia scrubbing (Walther)

Hydrogen peroxide scrubbing Seawater scrubbing

Wellman-Lord

New Process Development Common DeSOx

Technology in Gas Processing Units

Principle:

Sorption –

Desorption

Product:

Products are mainly SO2

rich gas

streams or sulfuric acids,

Principle:

Chemical Absorption

Product:

In general, the final product is gypsum. Special applications are producing sulfuric acid, Ammonia sulfates (fertilizer)


New Process Development Simultaneous Removal Technology in Gas Processing Units

Sorption / Desorption

Reduction

N2

Gypsum or Fertilizer

SOx

NOx

Oxidation

Oxidation“Walther –Simultan”

-

process

SOx

NOx

CuO

process

Activated

carbon

process

AbsorptionFertilizer

Absorption

Reduction

SOx

NOxEDTA Process

N2

SOx

rich process gas

—Simultaneous removal rates of NOx

and SOx

are generally lower compared to the selective processes

—Removal rates are depending on SOx/NOx

–Ratio

+ Oxidation media

advancement of co2 compression and purification plant in

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