Integrated SOx Emission Trend Estimation for the Sustainability Transition

Students

K. Miller, C. Reid, J. Agan, J. Reynolds

Instructor

Rudolf B. HusarWashington University, St. Louis, MO

Sustainable Air Quality - Class Project Report, May 2003 Presented at

NARSTO Workshop on Innovative Methods forEmission-Inventory Development and Evaluation

Austin, TX ; October 14-17, 2003

Sustainable Development NAS: Our Common Journey: A Transition Toward Sustainability

• SD is the process of reconciling society’s developmental needs with the environmental limits over the long term.

• During the ‘journey’, the pathways of a transition to sustainability have to be ‘navigated’ adaptively incorporating differing views on what should be developed, what should be sustained and over what time period.

• Human activities exert pressures, such as burning fossil fuels that alter the state of environment, such air quality. The impaired environmental state, elicits responses, such as regulations.

• Each can be measured using historical data and quantify the causality chain

Sustainable Air Quality Class Project:

Sustainability Transition for Sulfurous Pollution

SOX Emissions Drivers: Linear Causality ModelSOX Emissions Drivers: Linear Causality Model

The driver of SOX emissions is the population, modified by economic, energy and emission factors

Emissions changes can be caused by any of the four key ‘drivers’

Energy, BTU Economy, $SOX

Sox = (Sox/Btu) x (Btu/GDP) x (GDP/P) x (Pop)

Persons, P

Economic VigorEnergy EfficiencyEmissions Factor

US SOX Emission Trend

0

5000

10000

15000

20000

25000

30000

35000

1900 1950 2000 2050

Causality of change?

Trend of Sox Change Drivers1940-2000

Upward drivers: Population & Economy

Downward drivers: Energy Eff., Emiss. Factors

1960s

1970s

1980s

1990s

0

0.5

1

1.5

2

2.5

3

1900 1950 2000 2050GDP(Mill$)/PersonEnergy(Bbtu)/GDP(Mill$)SOx/Energy(Bbtu)PopulationSOX Emiss

Population - Energy/Goods Consumption– Materials Flow - Emissions

Ek = cjk EMj = bij cjk GEi = ai bij cjk P

Industr. Energy

Transp. Energy

ResCom.Engy

Coal

Oil

GasElectric Energy

SOx

NOx

HC

PM

Goods &Energy,(GE) i Fuels&Mater.(FM), j Emission (EM), k

Ind. Chemicals

Industr. Goods

Pop., P

Metals

Mercury

ai

Consump./Person

bij

Fuels/Energy

cjk

Emission/Fuel-

j ji i i jConsumption of Goods and Energy: GE = ai P

Fuels and Materials Flow: FM = ai bij P

Emission of Pollutants: EM = ai bij cjk P

Industrial Prod.

Transportation

ResComercial

EconMeasure(EM)

Problem:

Many causality links are matrixes; matrix elements are adjusted continuously

The SOX emission causality is a dynamic network

Pollutant Transfer Matrixes: Surface and Atmospheric

S Flow Example: Coal Production and S Content

• Western coal production has increased

• Eastern coal has > 1% S• Western coal has < 1% S

Coal Sulfur Flow in 1980 and 1998

• In 1980, a major flow of sulfur in coal originated in Illinois and was transported to Florida

Arrows indicate the flow of coal from the mines to the consumer

• By 1990, the transport of high sulfur coal from the Midwest has bee replaced by low sulfur western coal

SOx Emissions: Where are We Heading?

US Sulfur: Sustainability Transition

Regional Haze: Regulations in place

US Sulfur Scenario: Western Coal

Sulfur Recovery

• Nature recycles the its sulfur, thus reaching a sustainable level for life.• Man has not reached a sustainable level for sulfur, because the amount

recovered has not been good in past years.• The amounts recovered has drastically changed over the year especially in

some sulfur producing processes moving us toward sustainability.

US Industrial Sulfur: Supply and Demand Trend

US S Budget

S Stocks

Exp/Imp

0

2

4

6

8

10

12

14

1900 1950 2000 2050

ExportsImports

0

2

4

6

8

10

12

14

1900 1950 2000 2050

US SupplyConsumption

-2

0

2

4

6

8

10

12

1900 1950 2000 2050

Sulfur Stock

Stock Change

0

2

4

6

8

10

12

14

1900 1950 2000 2050

S RecoveredS Mined

US S Supply US S Demand

Source http://minerals.usgs.gov/minerals/pubs/of01-006/sulfur.xls

US was a leading source of mined sulfur in the world but S mining has diminished

The demand for industrial sulfur was met by the S recovery of from fuels and metals

Total S Mobilized and Recovered

• Most of the S mobilization is driven by fuels, particularly coal (10-15 Mtons/yr)

• Mined elemental sulfur peaked around 1970 but became insignificant by 2000

• Recovered sulfur, especially from petroleum refining, has increased dramatically since 1950

• The overall flow of mobilized sulfur has increased steadily until about 1970 followed by a downturn

0

2

4

6

8

10

12

14

1900 1950 2000 2050

Mill

ion

Ton

s/yr

CoalSMob OilSMob NGasSMobil

0

2

4

6

8

10

12

14

1900 1950 2000 2050

Mill

ion

To

ns/

yr

PetroleumSRec NatGasSRec MetalSRec

0

2

4

6

8

10

12

14

1900 1950 2000 2050

Mill

ion

To

ns/

yr

Pyrites S Mined Frash S Mined MetalsSMob

Mobilized in Fuels

Mobilized in Minerals

Recovered from Fuels &

Min.

0

5

10

15

20

25

30

35

40

1900 1950 2000 2050

S RecoveredTotMobilizedEmitted

Sulfur Flow through Fuels and Minerals

Mineral Mining Production Consumption

AirLandWater

S Stocks Exp/Imp Raw

Fuel Mining Refining Combustion

Minerals Flow for GoodsMetals, Pyrites, Frasch

Fuels Flow for EnergyCoal, Oil, Gas

Exp/Imp Proc

Ex/Im Raw Ex/Im Processed

Exp/Imp AirEx/Im Water

S as Pollution S as Goods

Man-made S drivers: (1) Minerals: mining, byproduct of metals; (2) Energy: coal, oil and gas

Within these sources, there is some recycling and recovery of sulfur

Un-recovered sulfur is then released to the air, water, and soil environment as pollution

Summary

• The changes of sulfur emissions are caused by a set of ‘drivers’ or ‘forces’:– Population and economy have been upward drivers

– Energy efficiency and emission factors are downward drivers

– Since the 1970s, Sox emissions have declined since downward drivers dominate

• The causality links are dynamic transfer matrices– To explain past (e.g. spatial) emission changes one needs to reconstruct the transfers

• The industrial sulfur demand (fertilizer) is met by S recovered from fuels and minerals

• For sulfurous pollution, we are well along the Sustainability Transition