TWO YEARS EXPERIENCE WITH TWO YEARS EXPERIENCE WITH TEN CAPSTONE 30 KW UNITS AT TEN CAPSTONE 30 KW UNITS AT

THE CALABASAS LANDFILLTHE CALABASAS LANDFILL

Mark McDannel

Supervising Engineer

Energy Engineering Section

County Sanitation Districts of Los Angeles CountyWASTEWATER RECLAMATION

SOLID WASTE MANAGEMENT

Presentation OverviewPresentation Overview

Districts energy program overview Description of Calabasas facility Availability Economics Emissions Siloxane removal Conclusions

County Sanitation Districts of County Sanitation Districts of Los Angeles CountyLos 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 ProductionBiogas Power ProductionFACILITY POWER PRODUCTION

TECHNOLOGY/ (FUEL)NET POWER PRODUCED

Joint WPCP CC Gas Turbine(Digester Gas) 22 MW

Valencia WRP IC Engine (Digester Gas) 400 kW

Puente Hills LF Steam Boiler/Turbine (LFG) 46 MW

Palos Verdes LF Steam Boiler/Turbine (LFG) 4 MW

Spadra LF Steam Boiler/Turbine (LFG) 8 MW

Puente Hills LF Gas Turbine (standby) (LFG) 0 MW

Calabasas Landfill Capstone Microturbines (LFG) 250 kW

Lancaster WRP Ingersoll-Rand Microturbine (DG) 225 kW

Palmdale WRP Molten Carbonate Fuel Cell (DG) 225 kW

Puente Hills LF (2005) IC Engine (LFG) 6 MW

TOTAL BIOGAS GENERATION 87 MW

Calabasas Microturbine ProjectCalabasas 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 Calabasas Microturbine Power Plant Design ParametersDesign Parameters

Gross generation 300 kW

Net output 250 kW

No. of units 10

Manufacturer Capstone

Landfill gas flow rate 180 scfm

Methane content 40%

Siloxane removal Sorbent columns-carbon thru 5/04, silica gel since

Electrical efficiency, LLV 25%

CHP efficiency, LLV 25%

Factors Affecting Microturbine Factors Affecting Microturbine PerformancePerformance

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/FeaturesMajor 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

LFG Handling & Treatment SystemLFG Handling & Treatment System

Facility OverviewFacility Overview

Dedicated HeaderDedicated Header

Gas Compression & Clean-up SkidGas Compression & Clean-up Skid

Siloxane Sorbent ColumnsSiloxane Sorbent Columns

Control System-Main ScreenControl System-Main Screen

Pre-Treatment SystemPre-Treatment System

Energy UsageEnergy Usage(Before Startup)(Before Startup)

Energy UsageEnergy Usage(After Startup)(After Startup)

Periodic MaintenancePeriodic 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

Availability and Capacity FactorAvailability and Capacity Factor

Fiscal Year Availability, %

Capacity Factor, %

2002/2003 79% 58%

2003/2004 77% 65%

2004/2005 thru 12/04

90% 69%

Factors Affecting AvailabilityFactors Affecting Availability

Compressor problems Gas line condensate problems-plugging and

surging Siloxane breakthrough SCE power outages

– No monitoring of system on nights and weekends

Factors Affecting Capacity FactorFactors Affecting Capacity Factor

Ambient temperature 9-turbine operation System electrical

demand

Temp, F Output, kW

< 63 30

70 29

80 27

90 25

100 23

Facility EconomicsFacility 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 DetailsPower Production Cost Details(first 27 months of operation)(first 27 months of operation)

Net power produced 3,100,000 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 CostFactors 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 EmissionsAir 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 NOx, CO, NMHC, particulate, trace organics

Full results available from author by request

Key Air Emissions ResultsKey Air Emissions ResultsNOx, ppm @15% O2 3.0

NOx, lb/MW-hr 0.2

CO, ppm @15% O2 12

CO, lb/MW-hr 0.5

NMHC, ppm as hexane @ 3% O2 2.4

NMHC destruction 97.5%

Formaldehyde 15 ppb

Siloxane Sampling Test ProgramSiloxane 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

Activated Carbon ReplacementActivated Carbon Replacement

Siloxane Levels in Landfill GasSiloxane Levels in Landfill Gas

Only compound above detection limit is D4 at 0.145 ppm

55% of D4 is removed across the chiller (0.8 ppm removal)

Siloxane levels at Calabasas are lower than most landfills assessed

Siloxane in Landfill Gas

0

20

40

60

80

100

120

140

160

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S-2 S-3 S4

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D-Spa

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C-Nas

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C-BCU

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D-Pue

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S-6 S-7 S-8

C-Albu

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C-Lop

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C-Prim

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C-Om

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C-Lak

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C-Mod

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C-Kief

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Silo

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g/M

3

Sorbent PerformanceSorbent Performance

Material Date Installed

Days to Breakthrough

Graphite AC 8/15/02 61

Coconut AC 12/18/02 83

Coconut AC 3/26/03 57

Graphite AC 6/4/03 116

Both types AC 10/20/03 23

Silica gel/AC 12/12/03 >130

Silica gel 5/1/04 >271

Sorbent CostSorbent Cost

Sorbent Carbon Silica Gel

Cost, $/lb $0.70 $1.20

Siloxane collected, lb/lb sorbent 0.0021 0.0065

Operating cost, $/kW-hr

$0.0060 $0.0021 to date1

1. Price will decrease with time; could increase if breakthrough seen at outlet of second vessel.

ConclusionsConclusions

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 NOx levels than flares.

The facility meets most of the power needs of the landfill.

Conclusions, continuedConclusions, 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.