tailor-made catalyst solutions to meet the demands for lower so2 emissions - haldor topsoe - cobras...
TRANSCRIPT
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Presented by Osman Chaudhry, Haldor Topsøe A/S
Tailor-made catalyst solutions to meet the demands for lower SO2 emissions
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Haldor TopsoeIn brief
• Established in 1940 by Dr. Haldor Topsøe.
• Market leader in heterogeneous catalysis and surface science for over 70 years.
• 2,800 employees, 11 countries, five continents.
• Buenos Aires – main office in South America
• VK catalyst production in USA and Denmark.
• Private 100% family owned company.• Spend more than 10% of revenue on
R&D.
PelletsFirstwith Daisy
VK-WSA
VK69VK59
25 mmVK-701 LEAP5
VK-WSX
Firstwith Rings
Firstwith Cs
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Low Emissions During Start-up02
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Reaction rate: Standard catalyst
SO2(g) + ½ O2(g) SO3(g) + Heat
Reac
tion
rate
Depth in bed
10% SO2, 11% O2, inlet temperature 390°C
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Reaction rate: Too cool? – Too hot!
Equilibrium limitedCatalyst limited?
SO2(g) + ½ O2(g) SO3(g) + Heat
Reac
tion
rate
Depth in bed
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Temperature profile: Standard catalyst VK38
380
430
480
530
580
SO2(g) + ½ O2(g) SO3(g) + Heat
Tem
pera
ture
Depth in bed390°C
10% SO2, 11% O2, inlet temperature 390°C
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Effect of Inlet Temperature – 390°C vs 420°C
380
430
480
530
580
Tem
pera
ture
Depth in bed
10% SO2, 11% O2, inlet temperatures 390°C and 420°C
390°C420°C
Faster Activation of the Catalyst Bed and Reduced Catalyst Needs
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Going from 390°C inlet 420°C inlet?
Higher inlet temperature = Lower total bed
conversion
Time consuming preheating
Cost of heating oil, natural gas, etc.
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Handling 390°C inlet - Use of Cesium Ignition Layer
Cesium ignition layer - VK59
Standard catalyst - VK38Bed 1
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Effect of Ignition Layer
380
430
480
530
580
Reac
tion
rate
Depth in bed
10% SO2, 11% O2, inlet temperature 390°C
VK38VK59 and VK38
Maintain Maximum Conversion with Low Catalyst VolumeDramatic Increase in Ignition Capability
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Handling 370°C inlet - Use of Cesium Catalyst in last bed (after IAT)
Cesium promoted last bed – VK69Bed 4
Accommodates faster & cleaner start-ups
Less preheating time
Savings in ”preheating fuel”
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Low emissions during Steady State Operation
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Low temperature catalyst options – VK59
10-15%reduction in SO2 emission
Single adsorption
VK38
VK38
VK48
VK48VK59
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Low temperature catalyst options – VK69
50%reduction in SO2 emission
Double adsorption
VK38
VK38
VK48
VK38VK69
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VK-701 LEAP5™
Boosting the conversion further• Achieving remarkably low emission
Key application areas:• Lower passes in single-absorption plants• 3rd pass in 3+1 or 3+2 double-absorption plants
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SO 3
SO 3
(V O ) O (S O ) OV -42 4 4
2V O S O (s)IV4
(V O ) O (S O ) S OV2 4 4 3
-4
(V O ) O (S O )V2 4 4
-4
(V O ) O (S O ) OV2 4 4 2
-4
2V O (SO )IV4 2
-2
2S O 4-2SO 2
O 2
2
1
3
4
SO 2 SO 3
SO 2
Source: O.B. Lapina et al (1999). Catalysis Today, 469-479.
V5+ is the active oxidation state
Mechanism of catalytic SO2 oxidation
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60
0380 400 420 440
Temperature, °C
Content of vanadium compounds (relative)
70
80
50
40
30
20
10
VK-701 LEAP5
VK48
Bed 3 ConditionsV5+
VK59
V5+
V5+
VK-701 LEAP5™ operates with a higher content of Vanadium +5
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1000
100
1380 390 400 410 420 430 440 450 460
Temperature°C
Relative activity
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VK-701 LEAP5
VK59
VK48
Bed 3 Conditions
Superior activity of VK-701 LEAP5™
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Performance of VK 701 LEAP5™ - Case Study…
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Case study – VK-701 LEAP5™
• Layout : 3+1 double-absorption plant
• SO2 source : S-burning
• Feed gas : 11% SO2, 10% O2
• Catalysts in beds ½ : VK38 / VK38
• Conversion outlet bed 2: 88.5%
Reduced emissions from a double-absorption plant
Double adsorption
VK38
VK38
VK48
VK38VK69
VK-701
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Case study – VK-701 LEAP5™Reduced emissions from a double-absorption plant
Catalyst in bed 3 VK48 VK48 VK-701 LEAP5
Inlet temperature, °C 440 440 423
Conversion outlet bed 3, % 95.45 95.45 96.43
Catalyst in bed 4 VK38 VK69 VK69
Intlet temperature, °C 425 395 395
Overall conversion, % 99.85 99.92 99.96
SO2 in the stack, ppm 200 100 64
Relative SO2 emission 100 50 32
36% SO2 reduction compared to VK48/VK6968% SO2 reduction compared to VK48/VK38
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Performance of VK-701 LEAP5™ - In operation…
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Case story – VK-701 LEAP5™Example from North America:
Double adsorption• Emission had to be reduced in the 3x1 plant from 350 ppm to approx. 165 ppm.
• Solution; to revamp and install VK69 and VK-701 LEAP5™
Plant and feed gas specification:• 3+1 double absorption• 2000 MTPD • 11.7% SO2
• 9.3% O2
VK38
VK38
VK-701
VK69
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Case story – VK-701 LEAP5™
• Start up June 2012
• After 2 years the activity of VK-701 LEAP5™ was still so high that Bed 3 ran into equilibrium.
* During this TOPGUN a leak was detected in one of the re-heat exchangers
Prior to loading Predicted Start of
run 1 year* 2 years
Production 2085 MTPD 2085 MTPD 2085
MTPD 2065 MTPD 2060 MTPD
SO2 11.50% 11.7% 11.80% 11.78% 11.95%Conversion 99.75% 99.89% 99.92% 99.89% 99.89%
Emission 350 ppm 160 ppm 118 ppm 159 ppm 160 ppm
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Conclusions
Lowering SO2 emissions
• Start-up• Low ignition temperature cesium catalyst for
faster and cleaner start-ups.
• Steady operation• High active cesium catalyst for significant
reduction in SO2 emission.• VK-701 LEAP5™ for unmatched activity in SO3
rich process gas.
