economic analysis of advanced ultra supercritical pulverized coal power

Economic Analysis of Advanced Ultra-supercritical Pulverized Coal Power Plants

Dr. Jeffrey N. Phillips Senior Program ManagerJohn WheeldonTechnical Executive6th Int’l Conference on Advances in Materials for Fossil Power PlantsAugust 31, 2010

2© 2009 Electric Power Research Institute, Inc. All rights reserved.

Acknowledgements

• This analysis was paid for by EPRI’s CoalFleet for Tomorrow® program.

• EPRI would like to thank its CoalFleet members for their support of this project

• CoalFleet member include more than 50 organizations including power generators, coal companies, technology suppliers and government energy R&D units located on 6 continents


Outline

• Background for EPRI’s UltraGen concept• Design Premises for Case Study• Case Study Results• Implications for Future Research


What Is the UltraGen Initiative?

• A program to advance pulverized coal technology to achieve near-zero emissions and cost-effective CO2 capture and storage

– Conceived by EPRI’s CoalFleet for Tomorrow program in 2007

• This objective cannot be achieved with a single project; thus, a series of demonstration projects were proposed that advance the technology progressively

– UltraGen I, II, and III, with a component test facility, ComTes-1400

– Staged approach manages technical and financial risk


UltraGen I

Demonstration Post-Comb. CO2 Capture

Unit (90% capture)

800 MWElectricity

Stack

1 million tons of CO2per year to pipeline for

storage or EOR

75% Gas Flow

25%Gas Flow

Ultra-Clean Emission Controls

0.03 lb/MBtuSOX, NOX

850 MW USC

1110°F+ (600°C+)Ferritic alloys

39% HHV (before capture)

PRB Coal(or low-S, low-Cl

alternate)

DemonstrationPost-Comb.CO2 Capture

Unit (90%capture)

90% Hg Capture

Use today’s best technology for the boiler, steam turbine and emission controls while demonstrating CO2 Capture & Storage at large scale


UltraGen II

>90% Hg Capture

600-MWElectricity

0–50% Gas Flow

50–100% Gas Flow

650–700 MW Advanced USC

1290°F (700°C)Nickel-base alloys

42– 44% HHV (before capture)

PRB Coal (or low-S, low-Cl

alternate)

(NZE)Stack

Up to 3.8 million tons CO2 per year to

pipeline for storage or EOR


0.03 lb/MBtuSOX, NOX

Commercial Post-Comb. CO2 Capture

Unit (90% capture)

Boiler & Steam Turbine similar to European AD 700 design with CO2 emissions comparable to a Natural Gas Combined Cycle


UltraGen III

600 MWElectricity

100% Gas Flow

630–670 MW Advanced USC

1400°F (760°C)Nickel-base alloys

45–48% HHV (before capture)

PRB Coal (or low-S, low-Cl

alternate)

(NZE)Stack

~3.5 million tons of CO2 per year to

pipeline for storage or EOR


0.01 lb/MBtuSOX , NOX

Commercial CO2 Capture

Unit (90% capture)

>90% HgCapture

Boiler & Steam Turbine Design Takes Full Advantage of On-going US DOE/OCDO Advanced Materials Program

Could use oxy-combustion

boiler or post-combustion

capture


Purpose of the Study

• Wanted to understand the economics of the UltraGen II concept– Would it make sense to build a coal plant in the US

with a 700ºC steam cycle?– Would the increased cost of the high temperature

materials be offset by the reduction in fuel use?


Design Basis for Study

• Analyzed the cost and performance of four new coal power plants – Each with progressively higher steam conditions

• All cases based on 750 MW PC• WorleyParsons designed BOP and environmental controls,

Doosan Babcock designed the boiler, and Siemens provided steam turbine design data

• State-of-the-art emission controls for SOx, NOx, PM and Hg

• No CO2 capture equipment


Design Coal – Powder River Basin

Ultimate Analysis, %wt• Carbon 48.18• Hydrogen 3.31• Nitrogen 0.70• Chlorine 0.01• Sulfur 0.37• Oxygen 11.87• Ash 5.32• Moisture 30.24

Delivered cost = $1.71/GJ


Air Emission Control Systems and Targets

SOx Controls• Wet Flue Gas Desulphurization (FGD)

– 30 mg/Nm3 (0.03 lb/MMBtu)NOx Controls• Low NOx burners with Over-Fired Air (OFA) and Selective Catalytic

Reduction (SCR) unit– 30 mg/Nm3 (0.03 lb/MMBtu)

Particulate Matter (PM) Controls• Electrostatic Precipitator (ESP) and Wet FGD

– PM2.5 13 mg/Nm3 (0.013 lb/MMBtu) – PM10 10 mg/Nm3 (0.01 lb/MMBtu)

Mercury Controls• CaBr2 injection into furnace to promote oxidation across the SCR

followed by co-capture in the wet FGD– 90% mercury removal


Design Steam Conditions for Case Study

Sub-critical Supercritical Current USC Advanced-USC

Superheat Temperature 541 ºC 582 ºC 604 ºC 680 ºC

Superheat Pressure 179 bar 262 bar 276 bar 352 bar

Reheat Temperature 541 ºC 582 ºC 604 ºC 700 ºC

Reheat pressure 35.9 bar 57.9 bar 65.5 bar 73.5 bar


Materials Used in Advanced-USC Boiler

Material Pressure bar Steam temp, °C

Final superheater Inconel 740Inconel 617

363.0 to 364.0364.0 to 364.7

657 to 682627 to 657

Secondary superheater Inconel 617 366.1 to 371.3 546 to 657

Primary superheaterTP 347H

T91T12 – T23

371.3 to 376.8 502 to 557

Final reheater Inconel 617TP 310H 76.9 to 77.9 666 to 702

607 to 666

Primary reheaterTP 347HTP 310H

T92

77.6 to 77.976.9 to 78.378.3 to 78.6

543 to 610482 to 543416 to 482

Furnace walls T23 368.5 to 376.8 316 to 482Economizer SA 210C 376.8 to 392.0 260 to 343


High-Energy Piping Wall Thicknesses

Lowest-cost design uses 740 for both superheat and hot reheat lines

Main SteamID = 9.8 inches or

24.0 cm

ReheatID = 18.4 inches or

46.7 cm

Ni/Cr ratios45/22 45/22 57/22 52/25 50/20

Creep rupture stress, psi

102 127 102 255 171

617 CCA617 230 740 263

stress, 105 psi


Performance Results from Case Study

Sub-critical Supercritical Current USC

Advanced-USC

Thermal efficiency, %(HHV) 36.2 38.5 39.2 42.7

Net heat rate, Btu/kWh (HHV) 9,430 8,860 8,700 7,990

Coal feed rate, kg/hr 384,000 361,000 355,000 326,000

Flue gas mass flow, kg/hr 3,420,000 3,151,000 3,098,000 2,827,000

Volume at boiler outlet, actual m3/min

66,700 61,400 60,400 55,100

NOX and SO2, kg/MWh 0.127 0.121 0.118 0.109

PM2.5, kg/MWh 0.0535 0.0508 0.0499 0.0458

CO2, kg/MWh 900 851 836 763

15% less coal than

sub-critical

15% less CO2 than

sub-critical

Advanced USC will have smaller coal handling, cooling water & emission control systems


Quantity Sub-critical

Super-critical

1100 USC

700 A-USC

760 A-USC

Coal Cost, $/GJ 1.71 1.71 1.71 1.71 1.71

Main Steam Temperature, °C 541 582 604 680 (3) 732 (4)

Main Steam Pressure, bar 179 262 276 352 352

Efficiency, % HHV 35.5 38.5 39.2 42.7 44.7

LCOE, $/MWh (1) 54.3 53.3 53.7 55.3 55.3 (2)

CO2, kg/MWh from plant 900 851 836 763 729

CO2 avoided cost, $/ton vs Subcritical Baseline -12.5 -6.0 5.7 4.6

CO2 avoided cost, $/ton vs Supercritical - Baseline 20.0 21.1 14.8

Relative CO2 emissions vs Subcritical 100 94.5 92.9 84.8 81.0

Economics – US Coal Price

(See background slides for footnote details)

NETL Baseline Studies showed current CCS technology has CO2 avoided costs of ~$50-70/ton – A-USC technology may achieve CO2 reductions at 1/3rd that cost

EPRI Report 1015699

Lower fuel costs do not offset

higher capital cost


Quantity Sub-critical

Super-critical

1100 USC

700 A-USC

760 A-USC

Coal Cost, $/GJ 3.42 3.42 3.42 3.42 3.42

Main Steam Temperature, °C 541 582 604 680 (3) 732 (4)

Main Steam Pressure, bar 179 262 276 352 352

Efficiency, % HHV 35.5 38.5 39.2 42.7 44.7

LCOE, $/MWh (1) 71.0 69.2 69.4 69.7 69.7

CO2, kg/MWh from plant 900 851 836 763 729

CO2 avoided cost, $/ton vs Subcritical Baseline -36.7 -25.0 -9.5 -7.6

CO2 avoided cost, $/ton vs Supercritical - Baseline 13.3 5.7 4.1

Relative CO2 emissions vs Subcritical 100 94.5 92.9 84.8 81.0

Economics at 2 x US Coal Price

Advanced USC designs are more competitive in locations with higher priced coal

EPRI Report 1015699


Impact of Carbon Capture on Cost of Electricity Higher PC Efficiency = Less Impact

No costs included for transportation and storage – that would magnify the impact of improved efficiency

110%

120%

130%

140%

150%

30 35 40 45 50Efficiency of PC plant without CO2 capture, % (HHV)

CO

E R

elat

ive

to N

on-C

CS

Cas

e

Pittsburgh #8 PRB

Increase in Levelized Cost of Electricity due to CCS is

Significantly Decreased with Increased Efficiency

DOE Target of 35% Increase

EPRI Report 1011402


Other Points to Consider

• Capital costs were based on prices in 2007• Raw materials for 740 alloy assumed to cost $39/kg

which was average price in 2007– But price fluctuated between $27 and $50/kg during

2007!!!– Nickel price is now around $22/kg

• Cost to fabricate heavy wall pipe from 740 was assumed to be $22/kg (excludes cost of materials) – twice that of ferritic steel pipe– Estimate, not based on vendor quotes

• Labor to install nickel alloy pipe estimated to be 3 times that of ferritic steel pipe


Summary

• Economic analysis showed that for US coal prices and 2007 construction costs the fuel savings of a 700ºC USC would not offset the increased cost of using nickel alloy material– Piping fabrication & installation costs need better

quantification• However, the increase in levelized cost of electricity was

modest (4% higher than a 582ºC SCPC) while the CO2 emission reductions were significant (10% less than SCPC)

• The reduction in CO2 emissions from building an advanced USC compared to a 582ºC SCPC comes at a cost of circa $20/ton of avoided CO2 – far less than the cost of capturing and storing CO2.


Background slides


Background for Slide 5 (COE table)

• Source: Engineering and Economic Evaluation of 1300F Series Ultra-Supercritical Pulverized Coal Power Plants: Phase 1. EPRI Report 1015699, Palo Alto, CA: September 2008.

• Footnotes:1. Mid-2007 dollars, 30-year book life, carrying charge = 0.121,

capacity factor = 85%, no CO2 emissions cost2. LCOE assumed to be same as for 1290°F design3. EPRI study reduced main steam temperature because of

turbine material limitations. 60 Hz operation imposes more stress than European 50 Hz operation. DOE program expects to identify how this limitation can be lifted to raise efficiency by 0.7% points.

4. Conditions chosen to match current US DOE/OCDO Consortium designs with 1350°F main steam and 1400°F reheat


Together…Shaping the Future of Electricity

economic analysis of advanced ultra supercritical pulverized coal power

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