Heat recovery – efficiency at any price? Sebastian Brechtel Product & Strategy Manager
Heat recovery – efficiency at any price?Sebastian Brechtel
Product & Strategy Manager
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Agenda
• Efficiency – General terms• Automotive fuel consumption – „Clean diesel“• Thermal efficiency in acid plants• Financial efficiency - ROI• Facing real life• Take care of your cash cows• HEROS heat recovery system design• Getting digital support
05/01/20232
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Efficiency – General terms
05/01/20233
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Removal or conversion efficiency
Operational efficiency
Energy efficiency
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Efficiency – Automotive fuel consumption
05/01/20234
Standard operation
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05/01/20235
Standard operation
Efficiency – Automotive fuel consumption
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05/01/20236
loss
Best operation
Standard operation
Efficiency – Automotive fuel consumption
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05/01/20237
loss
Standard operation
Best operation
Efficiency – Automotive fuel consumption
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05/01/20238
loss
Standard operation
Best operation
Too small particle filter
Efficiency – Automotive fuel consumption
DEADLOCK
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Thermal efficiency – Waste heat recovery in sulfuric acid plants (sulfur burner)
05/01/20239
SulphurMelting1% 34%
10%IntermediateHeat Exchanger
EvaporatorEconomizer
Final Absorber
Acid Coolers
Tail Gas3%
11%3%
Sulphur98%
ElectricEnergy2%
Blower
DryingTower
Air
Acid Coolers
6%
23% 9%1%
Steam57.5%
Acid Cooling 39%
IntermediateAbsorber
Waste HeatBoiler
ConverterTray No.1
ConverterTray No.2
ConverterTray No.3
ConverterTray No.4
SulphurCombustionFurnace
ProductionAcid0.5%
SteamSuperheater
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Thermal efficiency – Waste heat recovery in sulfuric acid plants (sulfur burner)
05/01/202310
SulphurMelting1% 34%
10%IntermediateHeat Exchanger
EvaporatorEconomizer
Final Absorber
Acid Coolers
Tail Gas3%
11%3%
Sulphur98%
ElectricEnergy2%
Blower
DryingTower
Air
Acid Coolers
6%
23% 9%1%
Steam57.5%
Acid Cooling 39%
IntermediateAbsorber
Waste HeatBoiler
ConverterTray No.1
ConverterTray No.2
ConverterTray No.3
ConverterTray No.4
SulphurCombustionFurnace
ProductionAcid0.5%
SteamSuperheater
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05/01/202311
Financial efficiency – Return on Investment (ROI)
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05/01/202312
?
Financial efficiency – Return on Investment (ROI)
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Financial efficiency – Return on Investment (ROI)
05/01/202313
Design basis for a financial efficiency calculation
Plant capacity 4500 mtpd H2SO4 (as 100wt%)
Plant location Europe
Plant type Sulphur burning, 3+1
Utility concept “Over the fence” – purchase of electricity, cooling water, demin water and LP steam. Sale of HP and LP steam.
Financial concept Plant cost fully financed by a commercial loan: interest rate 6%, depreciation based on a 20 year period.
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ROI – HEROS heat recovery system
05/01/202314
0 0.5 1 1.5 2 2.5 3 3.5 40
0.2
0.4
0.6
0.8
1
1.2
1.4
HEROS
Operational years
Cum
uala
tive
RO
I
$$
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ROI - SAP and HEROS™
05/01/202315
0 2 4 6 8 10 12 140
0.20.40.60.8
11.21.4
SAPHEROS
Operational years
Cum
uala
tive
RO
I
$$
$$
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Facing real live – Failure scenarios
05/01/202316
Heat recovery (HR) failure scenarios
Short term failure Long term failure
Failure mode Acid pump failure Boiler leakage with weak acid scenario
HR shutdown duration 3 days 3 months
Additional cost[% of initial investment]
3% 20%
$$
$$
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Interdependency of Acid plant & Heat recovery system
05/01/202317
loss loss
One way option
Twoway option
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05/01/202318
lossloss
Plant down time & production
loss
Fall back to standard operation
One way option
Twoway option
Interdependency of Acid plant & Heat recovery system
Shut down of heat recovery system
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ROI - Heat recovery system (failure)
05/01/202319
0 0.5 1 1.5 2 2.5 3 3.5 40
0.20.40.60.8
11.21.4
HR short term failureHR long term failure
Operational years
Cum
uala
tive
RO
I
$$
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ROI - Heat recovery system (failure)
05/01/202320
0 0.5 1 1.5 2 2.5 3 3.5 40
0.20.40.60.8
11.21.4
HR short term failureHR long term failure
Operational years
Cum
uala
tive
RO
I
$$??
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ROI - Sulphuric acid plant (failure)
05/01/202321
0 2 4 6 8 10 12 140
0.20.40.60.8
11.21.4
HR short term failure
HR long term failure
Operational years
Cum
uala
tive
RO
I
$$
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ROI - Sulphuric acid plant (failure)
05/01/202322
0 2 4 6 8 10 12 140
0.20.40.60.8
11.21.4
HR short term failure
HR long term failure
Operational years
Cum
uala
tive
RO
I
DEADLOCK
?
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HEROS design aspect: Plant Availability
05/01/202323
AdvantageAcid and HP steam production guaranteed
even if HEROS ís not in operation.
Features
Separation of hot acid circuit from system possible
IAT design for 100 % capacity
Target
Failure of hot circuit must not lead to plant shutdown
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HEROS design aspect: Safety precaution 1
05/01/202324
AdvantageWide operational window & minimized
corrosion under off-set conditions
Feature
Material selection: stainless steel & acid resistant bricklining (indicated in red)
Target
Limit hazard potential
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HEROS design aspect: Safety precaution 2
05/01/202325
AdvantageMinimized corrosion in case of
heat exchanger failure and emergency stop
Features
Heat exchanger outside of acid tank
Fast isolation of acid and water circuit
Target
Limit hazard potential
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Getting digital support
• The PORS (Plant Operability Reliability and Safety) system is a virtual process expert - it is our online know-how at plant site
• Analysis of plant operation for potentially hazardous situations
• Guidance and support for plant operators
Plant Operability Reliability and Safety System
05/01/202326
PORS
Operational Data
Process know-how
Awareness of key
operational trend / upset
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05/01/202327
PORS system – virtual process expert
Benefits
Value proposition
Improved process safety and plant availability
Features
Operator support and guidance
Process know-how delivered to site in black box “traffic light” system
Permanent systemic process monitoring and analysis of plant status
Risk mitigation - early detection of developing hazards and reduction of response time to upset conditions
Improved awareness of operators for plant mal-operation
Improved plant availability
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05/01/202328
Risk mitigations for heat recovery systems
HEROS™ feature
Availability Flow Sheet Fundamental principle is that HR plant failure will not lead to SAP plant shutdown. The hot acid circuit is completely separated from rest of the acid plant. Intermediate absorption tower is designed for complete SO3 absorption at 100% plant load.
✔
Availability Material of Construction
All vessels are acid-brick lined to minimize corrosion. Use of Alloy 3033, which allows for wide operational window where no brick lining is possible ✔
Safety Flow SheetMaterial of ConstructionAutomation
In fail-safe mode, automatic draining of hot acid by gravity into brick lined equipment, reducing corrosion to minimum levels. ✔
Operability Support tools PORS system for additional high level trending/critical process information requiring operator action to safeguard operating plant integrity. Operator training simulator as optional training measure.
✔
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Thank you for your attention ...