Seneca Landfill: Landfill Gas to Energy Project

Presented by: Marty Siebert2006 EGSA Spring Conference

Agenda

• Landfill Gas 101• Seneca Landfill • Landfill Gas

– LFG Collection– LFG Treatment

• Power Generation• Heat Recovery• Emissions• Benefits

• Landfill gas (LFG) is a by-product of the decomposition of municipal solid waste (MSW).

• LFG:– ~ 50% methane (CH4).

– ~ 50% carbon dioxide (CO2).– <1% non-methane organic compounds (NMOCs).

• For every 1 million tons of MSW:– ~ 1.0 MW of electricity– ~ 550,000 cubic feet per day of landfill gas.

• If uncontrolled, LFG contributes to smog and global warming, and may cause health and safety concerns.

Landfill Gas 101

Modern Municipal Solid Waste Landfill

1 ton domestic waste => 530,00 – 880,00 ft³ Landfill gas over a period of 15 - 25 years

LHV = approx. 430 - 500 Btu/scf 40 - 50% collectable from a covered landfill

Source: Biogasvolume and Properties; U. Loll,“ATV Seminar 2/99 Essen”; Germany

Landfill gas production

Seneca Landfill Project

• Butler County, PA just North of Pittsburgh

• State Funded Project

• Combined Heat and Power (CHP) Landfill Gas to Energy Plant– Electricity used to offset grid power– Thermal used to offset natural gas boiler

• Plant is over 80% efficient

• Renewable/Green power source

Landfill Gas Site

Utilization of Landfill Gas

Wellhead

• A system of horizontal or vertical wells are constructed across a landfill.

• These wells are connected to a header system.

• A blower provides vacuum to the header system to collect gas from the wells.

• The blower sends the landfill gas to a treatment and control system

• The control system sends gas to the flare and genset as required

LFG Collection

LFG treatment, blower, and flare station

LFG Conditioning and Treatment

• Packaged skid downstream of LFG collection system and flare

• Required LFG treatment prior to use in genset• Blower/Compressor

– Increase pressure

• Chillers– Knock out moisture and contaminants

• Filters– Filter out contaminants

• Active Carbon Vessel– Cleaning and removal of Siloxanes– Siloxanes and Hydrocarbons damage engine

life and performance– Critical Issue in Project Success

LFG Conditioning and Treatment cont.

Gas Quality Control - Sample Data

0

10

20

30

40

50

60

70

80

Jun 94 Jan 95 Jul 95 Feb 96 Aug 96 Mrz 97 Sep 97 Apr 98Si-

con

ten

t in

en

gin

e o

il (a

pp

rox.

1.0

00 B

h)

[mg/

kg]

start gas pretreatment

Si-limit new oil

The following adverse affects are prevented by gas cleaning:

•Engine damage from siloxane buildup

•Damage/Fouling to oxidation catalyst

•Emissions level increases over time

•Decrease in maintenance intervals

Examples of Si Buildup

Examples of Si Buildup

Examples of Si Buildup

Power Generation Equip.

Power Generation

• 330kW Recip. Jenbacher Gas Engine • Prime Power > 8,000 hrs/yr• Low NOx Emissions < 0.6 g/bhp-hr• Dual fuel capable

– Natural Gas site over

• Designed to Burn Low-Btu gas• Follows fluctuation in gas energy content• Tolerate of gas contaminants• Low Maintenance

Electrical Operation and Interconnect

• Utility parallel switchgear and controls• Generate electricity for site use with excess

power exported to the grid• Base load application driven of thermal demand• Black start, island mode capability with load

shed controls • Interconnect through Penn Power• Consolidation of site distribution

Heat Recovery

Heat Recovery

• Engine’s jacket water and exhaust heat recovered

• Hot water used to process LF’s Leachate– Leachate heated to 95degF to kill bacteria– Must be treated

• Increase system efficiency

• Offsets natural gas boiler

LF Gas Treatment

Skid

Utility Paralleled

Electric Output: 335kW at 480V, 60Hz, 3 Phase

Rem

ote

Du

mp

Rad

iato

rs

P

Exhaust Heat Recovery Unit

Low Temp Loop - Dumped

P

Raw LFG From Flare Skid

Clean LFG to Engine

Natural Gas Secondary Fuel Source

Site Loads

Utility

Exhaust Out

Hot Water Recovery Loop

Hot Water to Leachate Process

Project Overview

LFG Politics and Challenges

• Gas Rights

• Power Purchase Agreements (PPAs)

• Utility Interconnect

• Emissions Permitting

• Destroys methane and other organic compounds in LFG– Each 1 MW of generation =

• planting ~11,300 acres of trees per year, • removing the emissions of ~8,400 cars per year, • preventing the use of ~89,000 barrels of oil per year

• Offsets use of nonrenewable resources (coal, oil, gas) reducing emissions of:– SO2 - contributes to acid rain

– NOx - contributes to ozone formation and smog

– PM - respiratory health concern

– CO2 - global warming gas

LFGE Project Benefits

Emission Reduction Benefits (lbs/MWh)

Emission Type (LFG from AP-42; others from eGRID)

NOx

SO2

Mercury

Weighted Average for all LFG Electricity Generating Technologies

2.05

0.17 3.4 x 10-6

National Grid Average – Emitting Sources Only

4.09 8.48

37.0 x 10-6

National Grid Average – All Sources 2.96

6.04 27.2 x 10-6

Methane Emissions

Sources of Anthropogenic Methane Emissions in the US

Coal Mining 17%

Domestic Livestock21%

Landfills 36%

LivestockManure10%

Natural Gas Systems10%

Other Systems 6%

• Estimated Annual Benefits for all LFGE:– Planting over 19,000,000 acres of forest,

– Preventing the use of over 150,000,000 barrels of oil,

– Removing emissions equivalent to over 14,000,000 vehicles, or

– Offsetting the use of 325,000 railcars of coal.

Environmental Benefits

• Methane is a potent heat-trapping gas.

• Landfills are the largest human-made source of methane in the US.

• There are many cost effective options for reducing methane emissions while generating energy.

• Projects reduce local air pollution, create jobs, revenues, and cost savings.

Why Should We Care About LFG?

396 operational projects (January 2006) ~9.7 billion kWh of electricity produced and

~82 billion cubic feet of gas delivered in ‘05 Numerous projects under construction Over 600 candidate landfills with 1,500 MW of

potential capacity, or 280 billion cubic feet/yr of LFG for direct use, and ~17 MMTCE potential emissions reductions

State of the LFGE Industry

• LFGE is a recognized renewable energy resource (Green-e, EPA Green Power Partnership).

• LFG is generated 24/7 and available over 90% of the time.

• Serves as the “baseload renewable” for many green power projects.

• LFG is among the most cost competitive renewable resources available ($0.04 - 0.06/kW).

• LFG can act as a long-term price and volatility hedge against fossil fuels.

• Utilities are already using LFGE.

Landfill Gas and Green PowerA Winning Combination

Questions?

Contact Information:Marty SiebertEmail: msiebert@nixonpower.comPh: 901-751-3634