biosolids and carbon footrpint - c.ymcdn.com · us targeted at 7% reduction ... fertilizer offset,...

Biosolids and CarbonBiosolids and CarbonFootprintFootprint

Patricia Scanlan

Andrew Shaw, Steve Tarallo

November 3, 2009

November 3, 2009Page - 2

� The Buzz About CarbonFootprints

� International, national, andregional initiatives and drivers


The Buzz…Why are we inventorying GHG emissions anddeveloping carbon footprints?

� GHG emissions vs. carbon footprint

� Means for auditing, measuring GHG emissions

� Global warming potential (GWP)

� Useful if carbon trading programs are implemented orcarbon caps are imposed in the future

� Important component of a sustainability assessment

� Strategic planning and process selection


International Initiatives and Drivers

� Kyoto Protocol (1997)

� By 2012, reduce GHG emissions to 5% below 1990levels

� Reduction requirements vary by country

� Only 37 countries required to reduce emissions

� US targeted at 7% reduction

� US did NOT ratify Kyoto

� Expires in 2012. UN Climate Change Conference (Dec2009)


National Initiatives� Conference of Mayors Climate

Protection Agreement

� Includes 1,012 cities

� Meet or beat Kyoto Protocoltargets (7% reduction by 2012)

� Local implementation

� Arizona cities include:

� Apache Junction

� Bisbee

� Buckeye

� Bullhead City

� Flagstaff

� Gilbert

� Goodyear

� Mesa

� Oro Valley

� Phoenix

� Tucson

� Winslow


National Initiatives - Legislation


National Initiatives - Legislation

� American Clean Energy and Security Act of 2009 (ACES) (H.R. 2454)

� Reduce GHG emissions by 17% by 2020

� Applies to emitters of 10,000 tonne/yr CO2e (for specific categoriesof emitters)

� Establishes federal GHG registry

� Includes Cap-and-Trade provisions

� Addresses barriers to carbon sequestration and capture

� Provides for trading, banking, borrowing credits and offsets

� Senate hearings this week


National Initiatives - Rules� USEPA 40 CFR Part 98

� Mandatory reporting of GHG emissions forspecific industries

� Triggered at 25,000 tonne/year CO2 equiv

�Based on actual, direct emissions

�Does not include electricity purchase

�Biogenic emissions reported separately

�30 mmBtu/hr comparison


Regional Initiatives� Northeast, midwest, and western

initiatives

� Western Climate Initiative (WCI)

� Reduce GHG emissions to 15%below 2005 levels by 2020(beginning in 2012). POTWsincluded starting 2015. Measured atpoint of emission

� Reporting begins at 10,000 tonne/yrCO2e

� Compliance at 25,000 tonne/yrCO2e

� Triggers based on stationarycombustion emissions

� Includes reporting of emissionsfrom biomass combustion

� Offsets limited to 49% of reductions WCI Partners


� Carbon footprint of biosolidsmanagement

� Options to reduce emissions


What are the WW Treatment Carbon Footprint Boundaries?

Treatment System

DecommissioningOperationConstruction


Inventory Operational Boundaries

Source:WRI/WBCSD


Scope Definitions

Contracted services

Supply chainsources

Waste disposal

Employee travel

Purchasedelectricity

Direct processemissions

Direct fugitiveemissions

Stationarycombustion

Vehicle fleet fuelcombustion

Scope 3(Optional)

Scope 2Scope 1


Scope 1 Sources – Wastewater treatment� CO2

� Stationary combustion,vehicle use

� CH4

� stationary combustion,fugitive emissions, vehicleuse, lagoons

� N2O

� stationary combustion,N/DN, vehicle use,incineration, plant effluent


Scope 2 Purchased Electricity - eGRID

AZNM: 1,316 lb/MWh

National Average: 1,329 lb/MWh

The Emissions & Generation Resource IntegratedDatabase for 2007

(eGRID2007) Technical Support Document


Scope 3 Sources – Wastewater treatment

� “Embodied” carbon from supply chain

� Equipment

� Chemicals

� Consumables for maintenance

� Solids disposal/final use

� Contractor hauling (mobile combustion)

� Landfill gas production (w/ or w/o LFG collection system)

� Land application

� Fertilizer offset, carbon sequestration, N2O emissions


Developing the Carbon Footprint for BiosolidsProcesses

� Build GHG emissions from “ground up”

� Identify evaluated processes

� Identify emissions associated with each process

�Use measurement or emission factors

�May be difficult to identify actual energy useassociated with specific processes

� Remember impacts of sidestream treatment


Carbon Footprint of Thickening and Dewatering

�Polymer use

�Equipmentmanufacture andconstruction

�Transportation forstaff

�Purchasedelectricity

�None

Scope 3(Optional)

Scope 2Scope 1


Carbon Footprint of Aerobic Digestion

�Polymer use


�Transportation forstaff

�Purchasedelectricity

�N2O emissions

Scope 3(Optional)

Scope 2Scope 1


Carbon Footprint of Anaerobic Digestion

�Chemicals for biogascleaning

�Offsets for biogas use“outside the fence”


�Transportation for staff

�Purchased electricity

�Electricity offset(shown as reduction inpurchased electricity)

�Natural gas use

�Fugitive CH4

emissions

�Flare combustion orcogeneration emissions(N2O and CH4)

Scope 3(Optional)

Scope 2Scope 1


Carbon Footprint of Thermal Processes


�Transportation for staff

�Purchased electricity

�Electricity offset frompower generation(shown as reduction inpurchased electricity)

�Combustionemissions (incinerators– N2O)

�Natural gas use(incineration/heatdrying)

Scope 3(Optional)

Scope 2Scope 1


Carbon Footprint for Final Use Options

�Contracted hauling

�Landfill emissions

�Land application N2Oemissions

�Chemical use (alkalinestabilization)

�Offsets for energy use“outside the fence”

�Offsets for fertilizerreplacement

�Offsets for carbonsequestration

�Purchased electricity�Utility-owned hauling

Scope 3(Optional)

Scope 2Scope 1


Reducing Carbon Footprint

� First, determine your objectives

� Scope 1 and 2 only?

� For reporting reasons or totalsystem sustainability decisions? Drying Beds

� Choose technologies with lower energy requirements

� Minimize options that require aeration

� Consider impact of thickening and dewatering

� Heat drying and incineration have high energyrequirements

� Solar drying has low energy requirements


What Portion of Total is Purchased Energy?

Purchased Elec.92%

Mobile2%

Stationary0%

FugitiveEmissions

2%Polymer

4%

Mobile

Purchased Elec.

Stationary

Polymer

Fugitive Emissions

Centrifuge Dewatering

21,000 tonne/yr CO2e

Scope 1 and Scope 2

Converting to BFP dewatering reduces GHG by 11%


What is the Impact of Technology Choice onGHG?

GHG EmissionsBy Emissions Source

0

5,000

10,000

15,000

20,000

25,000

30,000

35,000

40,000

Cent. BFP Cent w / ER BFP w /ER Drying Incineration

To

nn

e/ye

ar

Fugitive Emissions

Incineration

Polymer

Stationary

Purchased Elec.

Mobile


Environmental Product Declarations (EPD)

� EPD describes the environmentalimpact of producing and using aproduct based on verified Life CycleAssessments (LCA) in accordance withISO 14025

� Good Example: Flygt Pumpshttp://int.flygt.com/1000251.asp

� Climate Declaration is a simplifiedEPD just for green-house gases,expressed as CO2-equivalents for aproduct's life cycle.

� Tools where customers can comparedifferent products' environmentalperformance.

CO2e kg per kW ofPumping Power

Used over 5yr Life

Production Use Total

Consider Impacts of Equipment Choice


Reducing Carbon Footprint (continued)

� Maximize use of energy recovery

� Use biogas for power generation, process orbuilding heating/cooling

� Consider biogas augmentation processes

�Co-digestion with FOG

�WAS pretreatment (OpenCEL, Crown Biogest,thermal hydrolysis)


Reducing Carbon Footprint – Scope 3

� In general, final use options using land applicationhave the lowest GHG emissions

� Landfill disposal has high GHG emission

� Landfill gas systems may not capture methanegenerated by biosolids (3-5 year delay)


Putting Biosolids in Perspective

� Western Australia (42 mgd / 62 dtpd)

� SBR treatment

� Rotary screw thickeners

� Anaerobic digestion

� Centrifuge dewatering

� Co-generation

1.3 tonne/tonne total

� Co-generation decreased totalby 1.1 tonne/tonne (46%)

29%

71%

Plant Total Solids Treatment

biosolids and carbon footrpint - c.ymcdn.com · us targeted at 7% reduction ... fertilizer offset,...

Documents