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New Generation Strategy

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Presentation on theme: "New Generation Strategy"— Presentation transcript:

1 New Generation Strategy
IGCC Technology Presented by: Mary Zando, Manager Chemical Systems, New Generation Projects Dan Duellman, Manager Mechanical & Balance of Plant, Monty Jasper, Manager New Plant Development Projects APP Site Visit October 30 – November 4, 2006

2 The American Electric Power System
100 years in operation 36,000 MW generation capacity – more than 70% coal Largest generator of electricity in US Largest coal purchaser and consumer – over 70 million short tons (64 million metric tons) per year 39,000 miles (62,000 km) transmission 7,900 miles (12,600 km) 230 – 765 kV 200,000 miles (320,000 km) distribution 5 million customers in 11 states $11.9 billion annual revenue $36.2 billion assets Source: AEP 2005 Annual Report Revenues: $14.5 billion Assets: $37 billion US customers: million US employees: ,000 Source: AEP 2003 Annual Report Monty AEP feels the obligation to be a leader in developing the next generation of technology to serve our customers We have the financial strength to advance technology without unreasonable risk to our company

3 The American Electric Power System
Monty AEP feels the obligation to be a leader in developing the next generation of technology to serve our customers We have the financial strength to advance technology without unreasonable risk to our company

4 AEP Today: The Need for New Generation
AEP is committed to providing reliable, affordable, and sustainable electricity to our 5 million customers. AEP has not added base load capacity since 1991 (Zimmer conversion) AEP will need approximately 1200 MW of additional generating capacity in our Eastern region by 2010 AEP believes that Integrated Gasification Combined Cycle (IGCC) technology is the best choice for capacity additions in the East Revenues: $14.5 billion Assets: $37 billion US customers: million US employees: ,000 Source: AEP 2003 Annual Report Monty

5 Site Selection & Evaluation Process
Where is the best site to build a new IGCC Power Plant in AEP East? Site Study Team Established Representatives from AEP Third Party Consultant retained for study Potential Sites Identified AEP existing plants sites AEP owned/controlled property Fatal Flaw Analysis to narrow list 15 sites identified for evaluation Developed Ranking Criteria Established Design Basis Dan Almost 3 years ago New Generation Development was asked, “Where is the best site in the AEP East System territory to build an IGCC Power Plant?” We reviewed some previous siting studies, which were several years old; Decided it was time to redo the studies. Team made up of Engineering disciplines Commercial operations, Land Management, Legal Sites were evaluated for available land … fatal flaw Reduced list from 25+ to 15 Developed 25 evaluation criteria Third party consultant and a core group of Team members traveled to the sites.

6 Design Basis - Key Siting Parameters
600 MW IGCC Unit (with option to expand to 1200 MW) 2 x 2 x 2 x 1 Configuration 2 Operating Gasifiers / Gas Cleanup Systems 2 Combustion Turbines 2 Heat Recovery Steam Generators 1 Steam Turbine 600 MW 1200 MW Fuel Consumption 2 million (1.8 million) 4 million (3.6 million) short tons per year (metric tons per year) Heat Rate HHV 8,500 (2,142) Btu/kWh (kcal/kWh) Make-up water flow 5,500 (347) 11,000 (693) gallons per minute (liters per second) Land Requirements: power block 30 (12) 45 (18) acres (hectares) gasification island 60 (24) 105 (43) rail loop 150 (60) coal yard 40 (16) acres (hectares) inside rail loop solid waste disposal 300 (121) Total (rail delivery) 390 (158) 600 (243) Total (barge delivery) 280 (113) 490 (198) Operating staff 125 200 full time equivalent employees Dan The siting Team used this design basis for the evaluation of the sites.

7 Site Selection Ranking Criteria
Site Topography Topography and Size Expandability Distance from Waste Disposal Flood Potential Constructability Air & Water – Environmental Distance from Class I Areas Dispersion Conditions Existing Air Quality Air Quality Non-Attainment Area CO2 Sequestration - Third Party Desktop Study Transmission Distance from Transmission Transmission Stability Feasibility of 2 Unit Transmission plan Fuel Delivery Distance from Rail or Barge Alternate Transportation Distance from Natural Gas Pipeline Delivered Coal Cost Differential Cooling Water Distance from Adequate Water Source Adequacy of Cooling Water Source Land Use Designated Parks & Recreation Areas Existing Land Use Existing Residences Nearby Land Use Habitat Wetlands Impact Potential Other Natural Habitats Impact Potential Documented Presence of Threatened and Endangered Species Dan Here are 26 ranking criteria presented in 7 general categories. These were developed from a very detailed list of about 57 criteria. These were picked for use in our study as those that could be easily researched and evaluated for each site in a period of 2 – 3 months. Each of the criteria was defined with a a list of musts and wants. Those musts were minimum requirements for the evaluation and scoring; wants are desired but not required. Example Topography – Must Sufficient land must be available for the plant footprint and associated facilities. Ground slope across the site, including material storage but excluding solid waste disposal, must not be more than 5% or less than 0.5%. Topography – Want Minimize average ground slope (beyond 0.5%) and fill requirements in order to minimize costs for earthwork, retaining walls, erosion control, drainage, roadwork, and track work. Expandability – Must None Expandability- Want Site should have room for expansion with at least one unit beyond base capacity (1,000 MW).

8 Site Selection Ranking Criteria
Weighting Factors Scale of Rating Factors Scale of 1 – 5 Example below Criteria Description Weighting Factor Evaluation Criteria Rating Factor Plant Site Topography and Size 8 0.5 to 1.0 percent slope and less than 100,000 c.y. (76,000 cubic meters) fill 5 1.0 to 2.0 percent slope or 100,000 to 300,000 c.y. (76,000 to 228,000 cubic meters) fill 4 2.0 to 3.0 percent slope or 300,000 to 600,000 c.y. (228,000 to 456,000 cubic meters) fill 3 3.0 to 4.0 percent slope or 600,000 to 1,000,000 c.y. (456,000 to 760,000 cubic meters) fill 2 4.0 to 5.0 percent slope or more than 1,000,000 c.y. (760,000 cubic meters) fill 1 Expandability for Future Units 7 Three or more units can fit on site Only two units can fit on site Only one unit can fit on site Dan Each ranking criteria is assigned Weighting Factor relative to all of the other criteria. This is a 1 – 10 scale with 10 being the most important Each criteria has evaluation parameters in order to assign a Rating Factor Here are two examples: Topography

9 Results Top Sites by State Mountaineer – West Virginia
Great Bend – Ohio Carrs - Kentucky

10 Generating Technology Options: Integrated Gasification Combined Cycle (IGCC) Plants
Monty

11 Gasification Technology Options
Business Models of Various Technology Suppliers Syngas over the fence Technology owner provides capital investment and operating services Cost of syngas may be tied to fuel cost, escalation, other factors Also oxygen over the fence Licensing Technology owner provides equipment design and performance guarantees for equipment Owner assumes risk of integrated unit performance Turn key EPC with performance guarantees Technology owner provides engineering and design of integrated unit and all components Technology owner also assumes cost and schedule risk Guaranty of total unit performance: inputs vs. outputs Monty

12 Gasification Technology Options
Commercial Technology Choices Slurry fed – Conoco, GE Slurry fed technologies suited to high rank fuels Dry fed – Shell Better heat rate, longer injector life Technology suited for lower rank subituminous coals as well as high rank fuels Heat Recovery/Integration Quench – GE Chemical production applications Radiant syngas cooler – GE, Conoco, Shell Heat recovery for power generation in steam turbine Convective syngas cooler – GE Availability impact due to plugging – not selected for reference plant Mary

13 Current Configuration – AEP East IGCC
Net output 621 MW, Heat Rate 8,890 Btu/kWh (2,240 kcal/kWh) Target turndown to 40% of full load, and load following operation Broad fuel specification (eastern bituminous coal, petcoke) GE (formerly Texaco) Gasifiers Two radiant + quench gasifiers – no spare Operating pressure 625 psi (43 bar) Turbine-Generators Two GE 7FB combustion turbines MW each Evaporative inlet cooling Single steam turbine – 300 MW Emissions Control Systems Selexol acid gas removal system for sulfur (H2S) removal w/COS reactor Activated carbon bed for mercury removal Syngas moisturization, nitrogen diluent for NOx control Space provisions for future polygeneration and CO2 capture Mary

14 Gasifier/Radiant Syngas Cooler (RSC)
The gasifier operates at approximately 625 psi (43 bar) and 2550oF (1400oC) Gasifier volume 1800 cubic ft (50.4 cubic meters) The RSC generates high pressure steam by cooling the hot syngas from the gasifier from 2550oF to 1250oF (1400oC to 700oC). The RSC vessel is lined with waterwall panels along the inside perimeter of the vessel as well as some in the radial direction. The steam is generated in the RSC and circulated to the external steam drum. The RSC concept has been demonstrated at plants in Germany as well as Coolwater and Polk Power in the USA. The vessel is about 6 m in diameter and m long. The AEP RSC design is different than the Polk Power design because it has an internal water quench section at the vessel bottom which further cools the syngas at about 450oF (230oC). Mary

15 Gasifier/Radiant Syngas Cooler (RSC)
When the gasifier load changes the oxygen to slurry ratio remains constant because the oxygen to carbon ratio is part of the control system. The gasifier is connected to the RSC through a flange connection. The vessel heads and flanges are protected by the refractory lined transfer line. The molten slag from the gasifier solidifies as it cools inside the RSC, and is collected in a water quench section at the bottom of the RSC. The slag and fines are removed through a lockhopper (LH) system which is automatically cycled to collect the slag at high pressure. The LH is then isolated and depressurized, and slag is dumped. The LH is re-pressurized and returned to collection mode. There will be 2 to 3 LH cycles per hour, depending on the fuel ash content. Mary

16 Gasifier/Radiant Syngas Cooler (RSC)
The velocity from the gasifier to the RSC decelerates from feet per second (5-6 meters per second) to less than 3 feet per second (1 meter per second). The velocity profile of the syngas from the gasifier to the RSC is based upon jet flow calculations. The jet velocity when it hits the waterwall cannot be so high that it causes erosion and cannot be low enough to allow ash deposition. Mary

17 Air Separation Unit 95% oxygen purity for oxygen to gasifier – 98% other uses Economy, ability to maintain design composition when changing loads ASU will consume ~110 MW depending on fuel and ambient conditions Air integration Approximately 25-30% of flow to main air compressor supplied by extraction air from CT at design point (ISO) Lessons learned from Polk Unit output curtailed due to lack of ASU capacity ASU Turndown Compressor limited to approximately 85% Can adjust air extraction to extend range No plans to produce other gases for sale Storage capacity 8 hours full load oxygen use Nitrogen for purge, transfer CT to natural gas in case of ASU trip Dan

18 Gasification Fuel Options
Fuel Flexibility The gasification process can utilize any fuel containing hydrocarbons Coal Biomass Petroleum Byproducts Petcoke The AEP East IGCC design fuels include Northern Appalachian and Illinois Basin bituminous coals and the ability to blend petcoke with coal Technology selection is dependant on fuel Eastern Coal – Low moisture content, high heating value Many eastern coals have high ash fusion temperatures, requiring the use of fluxant Some eastern coals have high chloride content Lignite & PRB coals – High moisture content, high ash content, not currently suited for slurry fed gasifiers, due to ability to achieve desired slurry concentration. Dan

19 Impact of coal specifications
Coal ash fusion temperature - This is a slagging gasifier design which requires a less than 2500oF (1370oC) reducing ash fusion temperature. Coals with this low fusion temperatures are found in the Northern Appalachian and Illinois Basin. Coal in the Central and Southern Appalachian basin have high fusion temperatures and would require the addition of fluxant to suppress the ash fusion temperature. A fluxing system is currently not part of the AEP IGCC design. Sulfur content range - The design sulfur content of the fuel effects the sizing of the Acid Gas Removal (AGR) and Sulfur Recovery Unit (SRU) systems. Coals from the Northern Appalachian and Illinois Basin have high sulfur content coals. The AEP coal specification allows for coals with sulfur content up to 7.5 lb SO2/mmBtu (5.26% wt. sulfur dry basis). Dan

20 Impact of coal specifications (cont.)
Chloride content Coals from the Illinois Basin have high levels of chlorides. For IGCC technology, the chlorides are removed in the syngas cleaning systems. High chlorides may require the selection of higher alloys in certain systems, and may increase water usage. The AEP design provides for coal chlorides up to 3500 ppm (0.35% wt.). Coal ash percentage Nearly all of the ash is removed from the gasifier as slag. The ash content of the fuel determines the size of the slag handling systems. The AEP specification allows for ash content in the fuel up to 12%. This allows the use of many run-of-mine coals, with no coal washing needed. Dan

21 Coal Prep System Rod mills are used to mix and pulverize the coal. Dry coal and processes water is added to the rod mills. Coal slurry is then pumped into the gasifier at operating pressure. Dan

22 Power Block There are two syngas/natural gas fired combustion turbines. The combustion turbine selected is the GE 7FB designed for syngas. Each turbine can generate 232 MW, utilizes air inlet cooling, and uses a hydrogen cooled generator. Nitrogen from the ASU and steam will be added to the syngas to increase mass flow and reduce the flame temperature. This feature enhances the output of the turbine, and allows for lower NOx operation. The HRSG is a two pressure design, which converts the heat from the exhaust of each combustion turbine into superheated steam. The HRSGs also receive steam from the gasification process. The steam turbine used is a GE D-111 with 40 inch (1 m) last stage blades. Steam in condensed by a water tube condenser. The steam turbine output is 310 MW, and uses a hydrogen cooled generator. The cooling tower provides circulating water for both the steam turbine condenser, and cooling loads from the ASU. The cooling tower is a mechanical draft type. Dan

23 Air Emissions NOx 15 ppm NOx in exhaust gas (15% O2 ref) on syngas
25 ppm NOx in exhaust gas (15% O2 ref) on natural gas SO2 >99.5% removal 40 ppm total sulfur in syngas (H2S + COS) 0.02 lb SO2/mmBtu ~4 ppm total sulfur in exhaust gas (10% O2 ref) Particulates (PM10 and PM2.5) Mercury Activated carbon bed for mercury removal Expect 90% of mercury in syngas Other Hazardous Air Pollutants Startup considerations Environmental performance without CO2 removal comparable to supercritical PC equipped with state of the art emissions controls Mary

24 Sulfur Removal Acid gas technology choice
MDEA – amine technology – chemical solvent Selexol – allows for deeper sulfur removal – physical solvent Rectisol – methanol solvent Cost vs. effectiveness Depends on gas composition, sulfur removal desired Capital O&M Effect on output COS Hydrolysis Effects on total emissions COS removal in AGR varies from <10% (MDEA) to 100% (Rectisol) COS reactor required to cost effectively meet 99% sulfur removal in MDEA and Selexol systems Mary

25 NOx Control Diluent injection
Nitrogen – from ASU – increase CT mass flow/output CO2 – maximize slip in AGR – increase CT mass flow/output Steam – impact on steam cycle output SCR Cost Uncertainty of catalyst formulation for coal derived syngas Interaction with sulfur Ammonia salts produce particulate emissions, may deposit in HRSG Other Air Emissions Particulate – salts, H2SO4 Ammonia – 5 ppm slip (ref 15% O2) Mary

26 Flare Options Flare used to destroy raw or combustible gases during startup, shutdown, and transient events Flare emissions result in elevated ground level concentrations of SO2 Operational and hardware modifications to reduce duration of flare events Visibility low during daylight hours Elevated Flare (AEP plant) Flare height 200 ft (60 m) Mary

27 Flare Options Ground Level Flare Enclosed Flare Mary

28 Grey Water Cool Water IGCC Discharge Target Average/Max
Wastewater Effluents Current plan to discharge wastewater to Ohio River The discharge permits and their associated limits are set by the state where the plant is sited The Ohio River Valley Water Sanitation Commission (ORSANCO) is an organization that tries to address inconsistencies between states and proposes pollution control standards ( ORSANCO discharge targets are set to protect the users of the water and avoid water quality degradation The target values for some elements are very low Mary Parameter River Max Dissolved River Max Total Grey Water Cool Water IGCC Discharge Target Average/Max Mercury, ppt 1.93 13.1 630 10/20 Beryllium, ppb <0.2 230 0.1/0.2

29 Wastewater Treatment Challenges
Uncertainty of grey water composition Samples not available for jar tests Potential interferences in treatment Uncertainty on levels achievable level of treatment Detection Limits Historic data Toxicity Chlorides in the effluent Daphnia survivability Temperature Mary

30 Wastewater Treatment Process
Grey Water Pretreatment Final Effluent Sump Ammonia stripping Holding Tank Metals Removal Biological treatment Retention Pond Filter Lime Sulfide Phosphoric acid Aeration Makeup water sludge Filter Belt Presses Sludge Thickening Sludge to landfill Mary

31 Wastewater Effluents Zero liquid discharge system currently under evaluation Reduced effluent to river Capital cost still to be determined Uncertainties in grey water composition would also affect this design Potentially higher auxiliary power consumption for this system Possibility of recovering metals for sale Mary

32 Solid Effluents Byproduct disposition (Primarily Slag and Sulfur)
Slag is the primary waste product produced by the IGCC process The carbon content of the slag is the key parameter that effects the ability to market the product. Slag is sold as roofing materials, grit blasting materials, and concrete additive. The acceptable carbon content for each of these applications is critical to its marketability. The AEP plant will be designed with landfill capacity for disposal of slag. Sulfur is a byproduct of the AGR system/sulfur recovery system. Sulfur can be produced as sulfuric acid, molten sulfur, or pelletized or prilled sulfur. Local market condition will dictate the form of sulfur produced. The AEP plant will be designed to produce molten sulfur. Landfill capacity will include space for sulfur disposal. Dan

33 Admin Building/ Control Room River Water Intake House
Great Bend IGCC Plant Scope of Work Landfill Storage Pile Visitors Center Truck Unloading Future AEP Work Scope 345 KV Switchyard 345 KV Switchyard Maintenance Building/ Warehouse Admin Building/ Control Room Slag Handling & Storage Coal Unloading Coal Storage Water Intake Future Polygen SRU Coal Storage CO2 ASU TGT UNIT 1 COOLING TOWER AGR GE/Bechtel Work Scope PB SRU – Sulfur Recovery Unit Flare GS TGT – Tail Gas Treating Unit Unit 1 AGR – Acid Gas Removal ASU – Air Separation Unit PB – Power Block GS - Gasifier Fluxing System Future CO2 -Future CO2 Capture TOWER FUTURE UNIT 2 COOLING Equipment Flare Future Dan PB Unit 2 Future Future Polygen Barge Unloader #1 Future River Water Intake House Barge Unloader #2 Smathers Ohio River

34 Great Bend - Site with Landfill & Property Lines
Dan

35 Mountaineer IGCC Plant

36 Great Bend IGCC Plant

37 Operational Considerations
Startup Fuel Natural gas to warm gasifier, electric demand for ASU Emissions Time to place sulfur systems in service Time to start up Over 70 hours for cold startup Turndown Target to 40% net Availability Target 85% Maintenance requirements Refractory replacements Hot gas path turbine inspections Production costs On par with conventional PC Dan

38 Economic Considerations
Evaluate capital cost for design features vs. benefits Screening Valuations Capacity $1.5 million/MW Heat rate $5.0 million/100 Btu/kWh ($5.0 million/25.2 kcal/kWh) Availability $3.5 million/percentage point of availability 1st quarter 2005 – based on operating characteristics of similar sized plant in Ohio River Valley Critical assumptions – fuel cost, capacity factor, production cost Mary

39 Generating Technology Options: Cost of Electricity without CO2 Capture
PC Supercritical IGCC NGCC Capacity, MW net 600 500 Fuel cost, $/mmBtu 1.50 6.00 Full Load Heat Rate, Btu/kWh 8,691 8,500 7,040 EPC Cost, $/kW 1,192 1,450 455 Total Project Cost, $/kW 1,442 1,737 550 Operations and Maintenance, $/MWh 8.49 9.63 6.66 Cost of Electricity, $/MWh 53.11 60.33 88.25 Mary Value of emissions credits is not included. Assumes 80% capacity factor for PC and IGCC, 25% for NGCC. EPC is overnight engineer, procure, construct 4Q2004. Total project cost includes owner’s costs and AFUDC. Transmission upgrades not included. Results of AEP analysis based on EPRI studies.

40 CO2 Capture Carbon capture (CO2) in IGCC system (syngas fuel) is proven and inexpensive: Convert CO in syngas to CO2 using water-gas shift reaction CO + H2O  CO2 + H2 Remove CO2 before the fuel is burned in the CT Lower volume of gases for processing Higher concentration of CO2 Either chemical (amine) or physical solvents IGCC stands out due to lower cost of CO2 removal Commercial application depends on H2 burning CT technology CO2 capture in flue gas (PC & NGCC application) more difficult: Flue gas volumes larger – lower pressure, combustion air Low CO2 partial pressure – physical solvents are impractical Amines (MEA or MDEA) applicable – but overall system becomes expensive More work is needed on CO2 capture technology & cost from flue gas in PC & NGCC applications Mary

41 CO2 Capture Recent work indicates significant impact on cost of electricity to implement CO2 capture and sequestration: Price adder will depend on the extent of CO2 capture Cost of electricity for IGCC plants with CO2 capture expected to be lower than PC with CO2 capture Mary

42 Generating Technology Options: Cost of Electricity with CO2 Capture
PC Supercritical IGCC Capacity, MW net 425 501 Fuel cost, $/mmBtu 1.50 Full Load Heat Rate, Btu/kWh 12,100 10,700 Cost of Electricity, $/MWh 94 85 CO2 Removal Cost, $/ton 22 16 Mary Value of emissions credits is not included. Assumes 80% capacity factor for PC and IGCC. Results of AEP analysis based on EPRI studies.

43 Carbon Capture from Syngas
No pre-investment for carbon capture Space in plot plan to be left for retrofit systems Clean shift will result in greater impact to steam cycle Mary

44 Polygeneration Options
Maintaining full load on gasifier at all times Synergies with other stakeholders Syngas contains H2, CO, CO2 Important building blocks in chemical manufacturing Potential to replace natural gas, petroleum in chemical processes Polygeneration – production of power and chemicals at an IGCC plant Gases from air plant Argon Nitrogen Oxygen Mary

45 Polygeneration Options
Screening Study considered production of hydrogen, methanol, urea Methanol selected for further consideration Ease of storage/transport Possible in-plant use Start up fuel AGR solvent Study assumptions Need to cycle daily Produce fuel grade product Conventional process Capacity factor Mary


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