Presentation on theme: "TWO YEARS EXPERIENCE WITH TEN CAPSTONE 30 KW UNITS AT THE CALABASAS LANDFILL Mark McDannel Supervising Engineer Energy Engineering Section County Sanitation."— Presentation transcript:
TWO YEARS EXPERIENCE WITH TEN CAPSTONE 30 KW UNITS AT THE CALABASAS LANDFILL Mark McDannel Supervising Engineer Energy Engineering Section County Sanitation Districts of Los Angeles County WASTEWATER RECLAMATION SOLID WASTE MANAGEMENT
Presentation Overview Districts energy program overview Description of Calabasas facility Availability Economics Emissions Siloxane removal Conclusions
County Sanitation Districts of Los Angeles County Confederation of 25 Independent Special Interest Districts Operate and Maintain Regional Wastewater Treatment and Solid Waste Management Systems since 1920s Service for 5 Million People and 78 Cities in Los Angeles County
Districts Solid Waste Management Facilities Facilities –3 Active Sanitary Landfills –3 Inactive Sanitary Landfills –2 Recycle Centers –1 Transfer Station – 1 Materials Recycling Facility –4 Gas-to-Energy Facilities –2 Refuse-to-Energy Plants Capacity –Disposal of approximately 20,000 tons of trash per day (approximately half the County- wide disposal needs)
Biogas Power Production FACILITYPOWER PRODUCTION TECHNOLOGY/ (FUEL) NET POWER PRODUCED Joint WPCPCC Gas Turbine(Digester Gas)22 MW Valencia WRPIC Engine (Digester Gas)400 kW Puente Hills LFSteam Boiler/Turbine (LFG)46 MW Palos Verdes LFSteam Boiler/Turbine (LFG)4 MW Spadra LFSteam Boiler/Turbine (LFG)8 MW Puente Hills LFGas Turbine (standby) (LFG)0 MW Calabasas LandfillCapstone Microturbines (LFG)250 kW Lancaster WRPIngersoll-Rand Microturbine (DG)225 kW Palmdale WRPMolten Carbonate Fuel Cell (DG)225 kW Puente Hills LF (2005)IC Engine (LFG)6 MW TOTAL BIOGAS GENERATION87 MW
Calabasas Microturbine Project First Power Plant at Calabasas Landfill due to poor LFG Quality (8000 cfm @ 20 to 25% Methane is Flared) Minimum Level for Optimum Microturbine Performance is 35% Methane Selective LFG Collection System Designed to Collect better quality LFG (150 cfm @ 40 to 45% Methane) Power Produced is Sufficient to meet On-site Demands
Calabasas Microturbine Power Plant Design Parameters Gross generation300 kW Net output250 kW No. of units10 ManufacturerCapstone Landfill gas flow rate180 scfm Methane content40% Siloxane removalSorbent columns-carbon thru 5/04, silica gel since Electrical efficiency, LLV25% CHP efficiency, LLV25%
Factors Affecting Microturbine Performance GAS HANDLING AND CLEANUP –Moisture Removal –Industrial Compressor and Packaged Chiller –Treatment of Organics and Siloxanes CONTROL SYSTEM –Ability to Load-Follow DEDICATED LFG HEADER AND WELLS –Importance of Stable Fuel Flow and Quality
Major Equipment/Features 10 Capstone C-30 Microturbines Dedicated Header and LFG Wells EM Inlet Moisture Separator Davey 50 hp Compressor Schreiber 10 ton Chiller Elanco Gas/Gas and Gas/Water Heat Exchangers Siloxane Sorbent Columns Switchgear and Utility Equipment Power Plant is integrated with Flaring Station and Condensate Collection System
Periodic Maintenance Change Air Filters every 4000 hrs (Capstone recommended interval is 8000 hrs) Chiller Service (Clean Screens and Fins to Prevent Plugging) Service Compressor (Oil Change) Sorbent Media Replacement
Facility Economics Capital cost$705,500 PUC subsidy$221,600 SCAQMD subsidy$300,000 Net cost to Districts$183,900 Annual power savings$78,500 Subsidized production cost$0.079/kW-hr Operation and maintenance$0.063/kW-hr
Power Production Cost Details (first 27 months of operation) Net power produced3,100,000 kW-hr Avoided power purchases$358,451 O&M costs$145,061 Capstone extended warranty$22,500 Gross operating margin$190,890 Cost of plant$183,900 Capital cost of plant fully recovered in 27 months
Factors Impacting O&M Cost For reference, Ingersoll-Rand has offered fixed price O&M at 1.8¢/kW-hr for our Lancaster facility Manufacturer does not offer turnkey O&M Turbine service providers do not offer service for balance of plant Consulting/service companies have had difficulties being cost-effective and responsive
Air Emissions Units operate under Permit and Rules of South Coast Air Quality Management District Subject to Rule 1150.1, similar to USEPA Subpart WWW Source test one unit every 1-5 years for NO x, CO, NMHC, particulate, trace organics Full results available from author by request
Key Air Emissions Results NO x, ppm @15% O 2 3.0 NO x, lb/MW-hr0.2 CO, ppm @15% O 2 12 CO, lb/MW-hr0.5 NMHC, ppm as hexane @ 3% O 2 2.4 NMHC destruction97.5% Formaldehyde15 ppb
Siloxane Sampling Test Program Different types of sorbent were evaluated –Coconut Shell-Based Activated Carbon –Graphite-Based Activated Carbon –Silica Gel Siloxanes are difficult to quantify, since the levels are often below the detection limit Initial difficulty in detecting break-through has been resolved by improved analytical methods
Siloxane Levels in Landfill Gas Only compound above detection limit is D 4 at 0.145 ppm 55% of D 4 is removed across the chiller (0.8 ppm removal) Siloxane levels at Calabasas are lower than most landfills assessed
Sorbent Performance MaterialDate Installed Days to Breakthrough Graphite AC8/15/0261 Coconut AC12/18/0283 Coconut AC3/26/0357 Graphite AC6/4/03116 Both types AC10/20/0323 Silica gel/AC12/12/03>130 Silica gel5/1/04>271
Sorbent Cost SorbentCarbonSilica Gel Cost, $/lb$0.70$1.20 Siloxane collected, lb/lb sorbent 0.00210.0065 Operating cost, $/kW-hr $0.0060$0.0021 to date 1 1. Price will decrease with time; could increase if breakthrough seen at outlet of second vessel.
Conclusions Microturbines can be effectively operated on LFG with careful consideration to handling and treatment of LFG. With subsidies, the plant was paid off in 27 months. The facility operates at lower NO x levels than flares. The facility meets most of the power needs of the landfill.
Conclusions, continued Removal of moisture and LFG contaminants was the single-most important factor in yielding a stable operation. Silica gel is more effective and more cost- effective than activated carbon at removing siloxanes. O&M costs remain relatively high compared to the Districts other microturbine. Plant availability continues to increase as operating experience is gained.