Life Cycle Assessment of Waste Conversion Technologies

Life Cycle Assessment of Waste Conversion Technologies

April 15, 2004

Outline

• Background and goals

• Overall approach

• CT material and energy balance models

• CT life cycle inventory models

• Scenario analysis

• Key findings

Background

• AB 2770 included the requirement that the CIWMB’s report on CTs “describe and evaluate the life cycle environmental and public health impacts of CTs and compare them with impacts from existing solid waste management.”

Goals

• What are the life cycle environmental impacts of CTs and how do these compare to existing MSW management practices? – Landfill

– Waste-to-energy

– Compost

Overall Approach

• Define CTs:– Acid hydrolysis

– Gasification

– Catalytic Cracking

• Develop material and energy balance for CTs• Develop life cycle inventories for CTs• Utilize CT inventories and RTI’s solid waste

model to analyze future scenarios

Overall Boundaries

Pre-processing (if needed)

Conversion technology(e.g., gasification)

Land Disposal

Waste Generated

Energy

Conversion Technology Subsystem

Collection Up-front MRF

Land Disposal

EmissionsEmissions

Emissions

Conversion Technology(e.g., gasification)

Recyclables

Electricity or Fuel Offset

Recycling Offset

Waste Collection

Energy and Materials Input

CT Byproducts

Beneficial Use Offset

Energy and Materials

Production

Energy and Materials Input

Energy and Materials

ProductionFuel and Electricity Production

Energy Input

Fuel and Electricity Production

Energy Input

Material and Energy Balance Models

• Developed using ASPEN Plus

• Used publicly available information– Patent applications

– Responses to UC questionnaire

• Communicated with CT vendors

• Employed conservative assumptions

Acid Hydrolysis

Sulfuric acid

Sorted MSW

Lime Water

Water Gypsum

VOC Emissions

Water CO2, VOC

Emissions Nutrients (CSL) Cooling Tower

Losses Ammonia

Biogas Air Emissions Steam for

Electricity for Internal Use Internal Use

WWT Air

Air Ash Electricity WWT Chemicals Treated water VOC Emissions Air Catalysts Emissions Spent to Grid

to POTW (Criteria, toxics Catalyst Denaturant and metals)

Ethanol Product

Air Pollution Control

Feed Handling

Mixer Hydrolysis Reactor Filter Press Washer

Separator Acid/Sugar Separation Evaporation Neutrali-

zation Filtering

Fermentation Distillation

Ethanol Storage

Boiler Steam Turbine

Wastewater Treatment

Reverse Osmosis

GasificationCombustion Emissions

50 psi steamto MRF

Pre-processed MSW

BrineReformer CombustionAir

ResidualHydrocarbons

Boiler Feedwater

SpentChar

Mix TankWater

Steam CombustionHot Water Emissions

Electricity for Internal Use

Spent CatalystCatalysts

Electricity Feedwater Ammonia

CombustionAir

Air Pollution

Control

Gasifier/

Reformer Cyclone Gas

Scrubbing

Waste heat

recovery

Engine Gen-set

Gas CoolerMix TankCentrifugeDe-

emulsifier

Water Cooler/

Treatment

Catalytic CrackingVOC

Emissions

Water Wastewater Catalyst

Baled Plastic Spent Catalyst &

Contaminants

Combustion

Emissions

VOC

Emissions

Electricity

for Internal

Use

VOC

Emissions

Electricity

Catalysts Spent Catalyst

Diesel Product

Ammonia Combustion

Air

Feed

Shredding

Feed

Cleaning

Melting Cracker

Distillation

Diesel

Storage

Air Pollution

Control GasTurbine

Scenario Analysis

• Analyzed future CT scenarios as defined by the Board in the RfP:2003: three 500 tpd acid hydrolysis plants,

four 500 tpd gasification plants, one 50 tpd catalytic cracking plant

2005: one additional 500 tpd gasification plant

2007: two additional 500 tpd acid hydrolysis plants

2010: one additional 500 tpd gasification plant

Waste Management Scenarios Compared

• Landfill:– Gas venting (worst case)

– Gas collection and flare (average case)

– Gas collection and energy recovery (best case)

• Waste-to-energy

• Compost (organics only)

• Conversion technologies

Mixed WasteCollection

Mixed Waste Transfer Station Landfill

50% direct hauled

50%

Landfill Scenario

ElectricityProduction

with landfill gas-to-energy


Waste-to-Energy Ash Landfill50% Mixed Waste Transfer Station

50% direct hauled


Steel Recycling

WTE Scenario

Mixed WasteResiduals

Mixed Waste Transfer Station

Landfill with Gas Collection and Flaring

50% direct hauled

50%

Organic Wastes OrganicsComposting

Compost Scenario


Upfront-MRF(95% sep. efficiency)

Gasification

RecoveredMaterials toRecycling


Co-Located MRF/CT Facilities

50% Glass70% Metals

45% Glass25% Metals

Landfill with Gas Collection and Flaring

MRF Residuals

Gasification Scenario


Up-Front MRF(95% sep. efficiency)

Acid Hydrolysis Landfill with Gas Collection and Flaring


EthanolProduction


50% Glass50% Plastic70% Metals

45% Glass45% Plastic25% Metals

MRF Residuals

GypsumByproduct

Acid Hydrolysis Scenario



Catalytic Cracking Landfill with Gas Collection and Flaring


DieselProduction


50% Glass50% Paper70% Metals


CommercialCollection

(presorted plastic only)

MRF Residuals

50%

50%

Catalytic Cracking Scenario

Example Mass Balance Datato LCI for Catalytic Cracking



Catalytic Cracking Landfill with Gas Collection and Flaring


DieselProduction




CommercialCollection

(presorted plastic only)

MRF Residuals

50%

50%

Materials and Energy Inputs

Baled Plastic Water

Cracking Catalyst

Turbine Combustion

Air

Heater Combustio

n Air AmmoniaSCR

CatalystBoiler Water

IN/OUT IN IN IN IN IN IN IN IN

BFD Stream No. 1 2 3 4a 4b 5 6 7ASPEN Stream 1001 1002 2007 3203 4001 NA NA NA

Component (lb/hr) (lb/hr) (lb/hr) (lb/hr) (lb/hr) (lb/hr) (ft3/hr) (lb/hr)Total Flow 4,386 625 2 41,649 458 2 1 61

Components BUTANE 0.00 0.00 0.00 0.00 0.00 CO2 0.00 0.00 0.00 21.04 0.00 CO 0.00 0.00 0.00 0.00 0.00 O2 0.00 0.00 0.00 9613.56 106.77 N2 0.00 0.00 0.00 31749.80 351.64 H2 0.00 0.00 0.00 0.00 0.00 AR 0.00 0.00 0.00 0.00 0.00 NO2 0.00 0.00 0.00 0.00 0.00 SO2 0.00 0.00 0.00 0.00 0.00 VOC 0.00 0.00 0.00 0.00 0.00 H2O 219.30 625.05 0.00 264.96 0.00 GASOLINE 0.00 0.00 0.00 0.00 0.00 60.64 DIESEL 0.00 0.00 0.00 0.00 0.00 PE 3793.28 0.00 0.00 0.00 0.00 PP 121.06 0.00 0.00 0.00 0.00 PS 121.06 0.00 0.00 0.00 0.00 PE-L 0.00 0.00 0.00 0.00 0.00 PP-L 0.00 0.00 0.00 0.00 0.00 PS-L 0.00 0.00 0.00 0.00 0.00 0.63 FE-SI 0.00 0.00 1.67 0.00 0.00 1.52 S 0.00 0.00 0.00 0.00 0.00 ASH 131.59 0.00 0.00 0.00 0.00 AL 0.00E+00 0.00E+00 0.00E+00 0.00E+00 0.00E+00 AS 0.00E+00 0.00E+00 0.00E+00 0.00E+00 0.00E+00 B 0.00E+00 0.00E+00 0.00E+00 0.00E+00 0.00E+00 BA 0.00E+00 0.00E+00 0.00E+00 0.00E+00 0.00E+00 BE 0.00E+00 0.00E+00 0.00E+00 0.00E+00 0.00E+00 CD 0.00E+00 0.00E+00 0.00E+00 0.00E+00 0.00E+00 CR 0.00E+00 0.00E+00 0.00E+00 0.00E+00 0.00E+00 CU 0.00E+00 0.00E+00 0.00E+00 0.00E+00 0.00E+00 FE 0.00E+00 0.00E+00 0.00E+00 0.00E+00 0.00E+00 HG 0.00E+00 0.00E+00 0.00E+00 0.00E+00 0.00E+00 MN 0.00E+00 0.00E+00 0.00E+00 0.00E+00 0.00E+00 NI 0.00E+00 0.00E+00 0.00E+00 0.00E+00 0.00E+00 PB 0.00E+00 0.00E+00 0.00E+00 0.00E+00 0.00E+00 SB 0.00E+00 0.00E+00 0.00E+00 0.00E+00 0.00E+00 SE 0.00E+00 0.00E+00 0.00E+00 0.00E+00 0.00E+00 SN 0.00E+00 0.00E+00 0.00E+00 0.00E+00 0.00E+00 ZN 0.00E+00 0.00E+00 0.00E+00 0.00E+00 0.00E+00

Materials and Energy Outputs

Combustion Emissions Wastewater

Spent Catalyst Distillation Storage

Diesel Product Electricity

Spent SCR Catalyst

Boiler Blowdown

Compressor Losses

IN/OUT OUT OUT OUT OUT OUT OUT OUT OUT OUT OUT

BFD Stream No. 8 9 10 11 12 13 14 15 16

ASPEN Stream 4003 1006 2004 NA NA 3005 WGTPOWER NA NA 3215

Component (lb/hr) (lb/hr) (lb/hr) (lb/hr) (lb/hr) (lb/hr) (kW) (lb/hr) (lb/hr) (lb/hr)

Total Flow 40,780 967 121 0 0.02 3,260 94 1 61 1,994

Components

BUTANE 0.00 0.00 0.00 0.00 0.00

CO2 2046.03 0.00 0.00 0.00 0.00

CO 1.29 0.00 0.00 0.00 0.00

O2 6954.62 0.00 0.00 0.00 0.00

N2 30588.76 0.00 0.00 0.00

H2 0.00 0.00 0.00 0.00 0.00

AR 0.00 0.00 0.00 0.00 1.01

NO2 0.28 0.00 0.00 0.00 0.00

SO2 0.00 460.32

VOC 0.34 0.00 0.00 0.00 1520.25

H2O 1188.22 84.43 0.00 0.00 0.00

GASOLINE 0.00 0.00 0.00 0.47 60.64 0.00

DIESEL 0.28 0.00 0.00 0.02 3258.13 0.00

PE 0.00 0.00 0.00 0.00 0.00

PP 0.00 0.00 0.00 0.00 0.00

PS 0.00 0.00 0.00 0.00 0.00

PE-L 0.00 0.00 0.00 0.00 0.00

PP-L 0.00 0.00 0.00 0.00 0.00

PS-L 0.00 0.00 0.00 0.00 0.63 0.00

FE-SI 0.00 0.00 1.67 0.00 0.00

S 0.00 0.00 0.00 0.00 0.00

ASH 0.00 1.32 98.19 0.99 0.00

AL 0.00E+00 0.00E+00 6.32 6.38E-02 0.00

AS 0.00E+00 0.00E+00 0.00 1.64E-05 0.00

B 0.00E+00 0.00E+00 0.09 9.18E-04 0.00

BA 0.00E+00 0.00E+00 0.23 2.29E-03 0.00

BE 0.00E+00 0.00E+00 0.01 1.33E-04 0.00

CD 0.00E+00 0.00E+00 0.03 3.03E-04 0.00

CR 0.00E+00 0.00E+00 0.10 1.02E-03 0.00

CU 0.00E+00 0.00E+00 0.10 9.83E-04 0.00

FE 0.00E+00 0.00E+00 9.72 9.82E-02 0.00

HG 0.00E+00 0.00E+00 0.00 0.00E+00 0.00

MN 0.00E+00 0.00E+00 0.16 1.58E-03 0.00

NI 0.00E+00 0.00E+00 0.03 3.06E-04 0.00

PB 0.00E+00 0.00E+00 0.26 2.61E-03 0.00

SB 0.00E+00 0.00E+00 0.17 1.74E-03 0.00

SE 0.00E+00 0.00E+00 0.00 1.76E-06 0.00

SN 0.00E+00 0.00E+00 0.04 4.53E-04 0.00

ZN 0.00E+00 0.00E+00 0.57 5.72E-03 0.00

Life Cycle Inventory For Catalytic Cracking Process

Parameter Units Offsets Net TotalInput Output

Ammonia DieselEnergy Consumption MBTU 2.17E+02 1.71E+05 -1.70E+05

Air EmissionsTotal Particulate Matter lb 5.93E+00 1.34E+03 -1.34E+03Nitrogen Oxides lb 3.19E+01 2.08E+03 6.03E+03 -3.92E+03Sulfur Oxides lb 1.14E+01 1.25E+04 -1.24E+04Carbon Monoxide lb 5.70E-01 9.68E+03 1.47E+03 8.21E+03Carbon Dioxide Biomass lb 0.00E+00 0.00E+00 0.00E+00Carbon Dioxide Fossil lb 2.39E+04 1.53E+07 2.39E+06 1.30E+07Green House Equivalents MTCE 3.82E+00 2.09E+03 4.38E+02 1.66E+03Hydrocarbons (non CH4) lb 5.36E-01 0.00E+00 5.37E+04 -5.37E+04Lead lb 5.70E-03 0.00E+00 5.37E-01 -5.31E-01Ammonia lb 1.14E-02 8.86E-01 -8.74E-01Methane lb 1.94E+02 3.91E+04 -3.89E+04Hydrochloric Acid lb 1.48E-01 2.51E+01 -2.50E+01 O2 lb 5.22E+07 5.22E+07 N2 lb 2.29E+08 2.29E+08

Total Solid Waste lb 7.58E+01 6.23E+04 -6.22E+04

Water EmissionsDissolved Solids lb 5.70E-03 4.00E+02 -4.00E+02Suspended Solids lb 7.98E-01 2.92E+02 -2.91E+02BOD lb 5.70E-03 3.62E+01 -3.62E+01COD lb 5.70E-03 1.19E+03 -1.19E+03Oil lb 5.70E-03 6.75E+02 -6.75E+02Sulfuric Acid lb 0.00E+00 0.00E+00 0.00E+00Iron lb 5.70E-03 0.00E+00 1.06E+02 -1.06E+02Ammonia lb 5.70E-03 6.73E+02 -6.73E+02Copper lb 0.00E+00 0.00E+00 1.12E+00 -1.12E+00Cadmium lb 0.00E+00 0.00E+00 5.69E-01 -5.69E-01Arsenic lb 0.00E+00 0.00E+00 3.31E-01 -3.31E-01Mercury lb 0.00E+00 0.00E+00 3.28E-03 -3.28E-03Phosphate lb 0.00E+00 7.22E-01 -7.22E-01Selenium lb 0.00E+00 0.00E+00 3.28E-01 -3.28E-01Chromium lb 0.00E+00 0.00E+00 1.92E+00 -1.92E+00Lead lb 5.70E-03 0.00E+00 3.48E-01 -3.42E-01Zinc lb 0.00E+00 0.00E+00 3.34E+00 -3.34E+00

Burdens

Life Cycle Inventory For Entire Catalytic Cracking Waste

Management System

Parameter Units Net Total Collection MRF Ccracking Landfill Transport Remfg.

Energy Consumption MBTU -1,392,401 341,080 174,677 -170,294 456,235 51,282 -2,245,380

Air EmissionsTotal Particulate Matter lb -143,922 8,045 49,974 -1,335 113,647 10,192 -324,443Nitrogen Oxides lb 564,604 621,495 207,340 -3,920 275,888 70,774 -606,974Sulfur Oxides lb -607,286 55,823 322,301 -12,440 78,380 20,085 -1,071,435Carbon Monoxide lb 2,061,352 102,889 63,766 8,211 3,148,759 69,766 -1,332,039Carbon Dioxide Biomass lb 4,480,280,702 13,558 474,584 0 4,329,650,286 1,976 150,140,298Carbon Dioxide Fossil lb 6,074,606 15,317,027 49,472,287 12,976,704 9,241,190 8,249,446 -89,182,047Green House Equivalents MTCE 643,355 2,114 7,001 1,658 644,100 1,129 -12,646Hydrocarbons (non CH4) lb 15,178 118,396 59,044 -53,689 25,786 28,475 -162,833Lead lb -48 0 2 -1 0 0 -50Ammonia lb -3,711 0 192 -1 21 13 -3,936Methane lb 224,374,468 8,798 88,964 -38,880 224,483,658 1,312 -169,384Hydrochloric Acid lb 36,778 56 2,614 -25 41,636 8 -7,511

Total Solid Waste lb -13,143,781 292,340 6,712,109 -62,227 2,507,821 43,086 -22,636,909

Water EmissionsDissolved Solids lb -225,247 75,070 176,806 -400 19,164 11,274 -507,159Suspended Solids lb 129,722 1,723 25,287 -291 2,154 256 100,593BOD lb 666,724 280 209 -36 493,400 42 172,830COD lb 1,291,348 1,875 2,616 -1,191 1,373,009 282 -85,243Oil lb 170,822 1,746 3,173 -675 166,562 262 -247Sulfuric Acid lb 41 15 323 0 20 2 -319Iron lb 9,311 43 1,923 -106 114 6 7,332Ammonia lb 13,256 30 24 -673 15,743 5 -1,874Copper lb -1 0 0 -1 0 0 0Cadmium lb -14 3 8 -1 1 0 -25Arsenic lb 0 0 0 0 0 0 0Mercury lb 0 0 0 0 0 0 0Phosphate lb 136 8 161 -1 111 1 -145Selenium lb 0 0 0 0 0 0 0Chromium lb -15 3 8 -2 2 0 -25Lead lb 0 0 0 0 0 0 0Zinc lb 116 1 3 -3 0 0 114

Key Findings

1. The amount of energy produced by the CTs is significant. 2. For criteria air pollutants, the CTs are not necessarily

better than existing options. 3. From a climate change perspective, CTs are generally

better than existing management options except for WTE. 4. Inadequate data to assess the potential for CTs to produce

emissions of dioxins/furans and other hazardous and toxic pollutants.

5. Similar to recycling, CTs will likely result in greater local environmental burdens and a potential reduction in regional or global burdens.

Key Findings (cont.)

6. It is important for CT facilities to achieve high levels of conversion efficiencies and materials recycling.

7. CTs can decrease the amount of waste disposed of in landfills.

8. CTs can increase materials recovery and recycling with large associated benefits.

9. CTs are not equal in terms of life cycle environmental performance.

10. No CT facilities exist in the U.S. for MSW and therefore there is a high level of uncertainty regarding their environmental performance.

Limitations

• CT facilities don’t exist in the U.S.:– Limited data

– Uncertain feedstock composition

– Uncertain pollution control requirements

• An LCA is not a risk assessment: – Pollutants are totaled across time and locations

– Concentrations of pollutants at a given time and location are not captured by a life cycle study

Sensitivity

• Feedstock composition

• Conversion efficiency

• Level of additional recycling achieved versus pass through of inert materials to landfill

• Pollution control devices and required inputs

Documents

Life Cycle Assessment of Waste Conversion Technologies