Life cycle-based air quality modelling for technology assessment and policy applications: the concept and technical considerations

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Dec 2, 2013 (3 years and 9 months ago)

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Life cycle
-
based air quality modelling


for technology assessment and policy applications:
the concept and technical considerations

Weimin Jiang, Steven C. Smyth, Qiangliang Li


CMAS Conference, Chapel Hill

2

Oct 16
-
18, 2006

Outline


Introduction


Two current approaches in analysing air
quality impact of technologies


The concept of life cycle
-
based air quality
modelling (lcAQM) for technology assessment
and policy applications


Technical considerations for conducting
lcAQM


Summary and discussions

CMAS Conference, Chapel Hill

3

Oct 16
-
18, 2006

Introduction


A crucial and pressing issue facing human civilization:


Rapidly expanding human material needs/desire


vs. Availability and sustainable use of natural resources


The three pillars of sustainable development:


Social, economic, and environmental


Possible civilized solution:


New and emerging technologies, e.g., biofuels


Key question: Which technologies are
really

“sustainable”?


What can we (air quality modellers) contribute?


Understand potential impact of the technologies on air quality


Who need the answers?



Policy community


Industry

Anyone who breathes


CMAS Conference, Chapel Hill

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Oct 16
-
18, 2006


LCA = life cycle assessment


Definition by ISO 14040:


“the compilation and evaluation of the inputs, outputs, and potential
environmental impacts of a product system
throughout its life cycle



Life cycle: from cradle to grave; individual stages or as a whole


e.g. from biomass feedstock production to biofuel combustion


ISO 14042: standard on life cycle impact assessment



ISO 14042



GaBi

(a LCA software)

impact category


photo
-
oxidant formation

category indicator


tropospheric ozone formation

characterization factor

photochemical ozone creation potential





(POCP)


Current approach:

LCA (1)


Emissions and impact assessment are based on a functional unit:


e.g., 1 vehicle
-
km travelled (VKT), 1 liter of fuel, 1 MJ energy, ...

Species

Emissions

POCP

Tropos. O
3

formation

(g/VKT)

(g C
2
H
4
-
eq/g emis)

(g C
2
H
4
-
eq/VKT)

Diesel

SD100



Diesel

SD100

Carbon monoxide

1.14E+00

2.28E+00

2.70E
-
02

3.08E
-
02

6.16E
-
02

Nitrogen dioxide

5.31E
-
01

4.01E
-
01

2.80E
-
02

1.49E
-
02

1.12E
-
02

Nitrogen oxides

2.33E+00

2.60E+00

2.80E
-
02

6.53E
-
02

7.28E
-
02

Alkene (unspecified)

2.49E
-
05

8.90E
-
05

1.00E+00

2.49E
-
05

8.90E
-
05

Benzene

7.58E
-
05

5.41E
-
05

2.18E
-
01

1.65E
-
05

1.18E
-
05

Butane

7.29E
-
03

7.95E
-
04

3.52E
-
01

2.56E
-
03

2.80E
-
04

• • •

• • •

• • •

• • •

• • •

• • •

Xylene

1.03E
-
04

3.67E
-
04

1.06E+00

1.09E
-
04

3.89E
-
04

VOC (unspecified)

2.03E
-
09

1.04E
-
04

1.13E
-
01

2.30E
-
10

1.18E
-
05

TOTAL

11.516

7.535



1.809

0.535

Current approach:

LCA (2)

CMAS Conference, Chapel Hill

6

Oct 16
-
18, 2006

Current approach:


3
-
D AQM


Use a
3
-
D air quality model, such as CMAQ, CAMx,
CALGRID, ...


Detailed atmospheric chemical and physical processes


Spatially, temporally, and chemically resolved


Technology scales considered


Impact on atmospheric pollutant concentrations


Most (if not all) focused on certain life cycle stage(s), e.g.,
emissions from vehicle engine combustion

CMAS Conference, Chapel Hill

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Oct 16
-
18, 2006

The lcAQM concept


lcAQM: life cycle
-
based Air Quality Modelling


a natural advance of the current AQM practice with life
cycle thinking


integrate the LCA framework defined by ISO 14040 with
the current AQM approach


Example to illustrate the concept and considerations


The potential impact of large scale production and application
of SunDiesel as a transportation fuel on air quality in Canada
and the U.S. from a whole life cycle perspective. The results
are to be used to support policy decisions regarding biofuel
development.

An operational lcAQM framework

Goal definition
System boundary and modelling scenario
definition/design
Emissions data collection,
estimation, and analysis
3-D air quality modelling,
including input file preparation
Air quality impact analysis: ambient
pollutant levels, location, and time
Result interpretation and presentation
Sensitivity test:
emissions of life cycle stages
Sensitivity test:
modelling scenario design
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Technical consideration:

System boundary definition


Chemical, physical, and engineering processes in different
life cycle stages to be included in the analysis


SunDiesel:


Introduced by Choren Industries in Germany


Can be used directly to replace petroleum diesel


Made from
cellulose, hemicellulose, and lignin, which are
major components

of a wide variety of biomasses



Produced through two major chemical processes


biomass gasification


syngas (CO, H
2
, CO
2
, etc)


Fisher
-
Tropsch synthesis: syngas


SunDiesel

CMAS Conference, Chapel Hill

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Oct 16
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18, 2006


Life cycle of SunDiesel

as a transportation fuel

Biomass
production
SunDiesel
production
SunDiesel
transportation
SunDiesel
storage
SunDiesel
dispensing
Vehicle
operation
CMAS Conference, Chapel Hill

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Oct 16
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The biomass
production stage

Fertilizer/herbicide production and transportation
Fertilizer/herbicide application
Biomass cultivation and harvesting
Biomass transportation
The SunDiesel production stage

Pyrolysis 400
-
500
o
C
Char
Tar
-
Rich Volatiles
O
2
Ash
FT Reactor
Steam
Dust Remover
H
2
O
HCl
H
2
S
NH
3
+
H
2
O
Ash
Steam
Compressor
Washing Lye
KHCO
3
Ultrafiltration
H
2
O
H
2
O
Sundiesel
Recuperator
1500
o
C
870
o
C
200
-
240
o
C
Scrubber II
Scrubber
I
Flash Gas
Gasifier
Electricity
Condenser
Electricity
H
2
O
Biomass
Regenerator
Steam
H
2
O
Air + CO
2
Air
Gasification System
Clean System
FT Reaction
Feeding System
Electricity
Steam
H
2
O
N
2
Wax
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,
2006


SunDiesel production:

an energy self
-
sufficient model

Feedstock
preparation
and feeding
Biomass
gasification
Syngas
cleaning
FT Synthesis
Steam
generation
Power
generation
Oxygen
generation
heat
flash gas
steam
Biomass
SunDiesel
electricity
oxygen
nitrogen
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,
2006


Technical consideration:
Modelling scenario
definition/design (1)


Possible locations and timing of industrial and agricultural
operations in different life cycle stages


Technology application scales and penetration levels


Uncertainties in assumptions: sensitivity tests


SunDiesel:


Canada and continental US


Full year of 2050: substantial displacement of petroleum oil
by bio
-
fuels (?)

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Biomass
-
growing locations:


Land
-
use coverage in Canada and US


Forest logging site


logging wood residues


Agriculture and other suitable land


energy crops


Energy crop yields


Conversion efficiencies of biomass


SunDiesel


Needs of food crops, animal feed, and energy crops


SunDiesel production plant locations:


Close to the biomass growth or collection sites


Competing factors of plant sizes and distances from the biomass
sites


Technical consideration:
Modelling scenario
definition/design (2)

CMAS Conference, Chapel Hill

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-
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Technical consideration:

Emissions (1)


Life cycle emissions data:


scarce, a major barrier, and require significant efforts


Life cycle thinking in E.I. development:


Cross
-
checking emissions between different life cycle stages


Ensure completeness and self
-
consistency among life cycle
stages


E.I. used in AQM + LCI (life cycle inventory) used in LCA:


emissions data in GaBi, SimaPro, EcoInvent, etc.


Spatial surrogate/ratios, temporal factors:


based on scenario definition/design assumptions and to be
studied through sensitivity tests

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Removal of old
-
technology emissions:



analysis of SIC & SCC codes, and emis. source descriptions



SunDiesel:


Emissions from some life cycle stages can be assembled or
derived:


GaBi: Functional unit
-
based NOx, VOC, SO
2
, PM, and heavy
metal emissions for various processes related to different
fertilizers, fuels, and power


Analysis of fertilizer and energy needs for biomass growth, and
transportation, storage, and dispensing


Speciated VOC emissions


VOC speciation profiles for some life
cycle stages





Technical consideration:

Emissions (2)

CMAS Conference, Chapel Hill

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Measured emissions from SunDiesel production not publicly
available


a major challenge for the SunDiesel lcAQM.


Effort in estimating the emissions with great uncertainties


Need emissions data: Choren or other FT processes, flash gas
combustion


Spatial surrogate ratios: reflect assumed spatial distributions of
agricultural & industrial sources within life cycle stages


Temporal factors: reflect seasonality of agriculture and
industrial operational schedules


Emissions from petroleum diesel life cycle: to be partially
removed to reflect displacement of the fuel by SunDiesel

Technical consideration:

Emissions (3)

CMAS Conference, Chapel Hill

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Technical consideration:
Model implementation
and result analysis


Emissions grouped by major life cycle stages:


e.g., feedstock generation, fuel production, fuel
transportation, storage, and dispensing, and fuel usage for
transportation purposes, etc.


Model runs with all the emissions, and sensitivity runs with
or without emissions from certain life cycle stages







the air quality impact of individual life cycle



stages or whole life cycle

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Summary and discussions


lcAQM =

3
-
D AQM practice with life cycle thinking for



analysing technology impact on air quality.


Special considerations:


System boundary definition: lcAQM foundation


Modelling scenario design: lcAQM foundation


Emissions data collection, estimation, and analysis:


Data availability


Life cycle thinking in E.I. development for AQM


AQM E.I. + LCI


Spatial and temporal information associated with life cycle stages


Model runs and analysis:


Based on the whole life cycle or individual life cycle stages


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Acknowledgements


Helmut Roth and Albert Chan, ICPET/NRC:




Review and comments



Natural Resources Canada:



Funding for SunDiesel analysis


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