Ecodata: Values,
sources, precision
Data Accuracy
Engineering properties are well characterized.
Environmental properties are not.
Embodied energy
Carbon footprint
Embodied Energy
Energy to product a unit of mass of material
ISO 14040 gives guidelines, but they are vague.
How much can we trust the presented values?
Studies suggest 10% variance is optimistic.
To what end?
Although the lack of accuracy is a problem, it
depends on the ultimate goals.
We can only make conclusions if differences are
significant (much more than 10%).
Often we see ranges to account for lack of accuracy
(200-240 MJ/kg, e.g.)
Geo-Economic Data
Information about the resource base from which
material is draw, and the rate of exploitation.
Annual World Production is the mass of material
extracted annually from ores/feedstock
Reserve, as we know, is current economical
sources
Ecoproperties: Material Production
The embodied energy (Hm) is the energy committed
to create 1kg of usable material.
CO2 footprint is the release of CO2 into the
atmosphere - kg of CO2 for each kg of material
produced.
Embodied Energy
this is not done by pure thermodynamics, due to inefficiencies
in actual processes and scrap waste, and other things
The Input/Output Analysis is used.
The total energy input to the production plant over some
period of time is measured; including that already invested in
feedstock.
The total output (mass of material) over that same time period
is recorded.
The ratio of these two is the MJ/kg Embodied Energy.
Aluminum + Alloys
Geo-Economic Data
Annual World Production
33-35 M-tonnes/Yr
Reserve
2.0-2.2 G-tonnes
Eco-properties: material production
Embodied Energy (primary prod)
200-240 MJ/kg
CO2 footprint (primary prod)
11-13 kg/kg
Water usage
125-375 l/kg
Eco-indicator
740-820 mPoints/kg
Eco-properties: material production
Casting Energy
2.4-2.9 MJ/kg
Casting CO2 footprint
0.14-0.17 kg/kg
Deformation process energy
2.4-2.9 MJ/kg
Deformation process CO2
0.19-0.23 kg/kg
Recycling
Embodied energy accounting
Must include the feedstock and its embodied energy
in your calculations to get a robust understanding.
Suppose we want to study bottles of soda. First we
figure out the feedstock by looking at the energy
entering the plant per hour and dividing by the mass
of PET produced per hour.
Energy of PET production
Tracking Carbon
Carbon tracking is done similar to energy.
Carbon emissions come from transport, energy
generation, feedstocks, and fuels.
Usually expressed as kg of CO2 per kg of material
Tracking Carbon
Plants grow by absorbing CO2 and H2O and
converting it to cellulose and lignin etc.
Wood sequesters carbon
Some say the carbon footprint of wood is negative
(it removes carbon from atmosphere without
releasing it)
Coal
Thinking about sequestering, coal is dervied from
plant life. The carbon in the coal was once in the
atmosphere.
It does not get a negative footprint because we
don’t replace it after use.
A credit is only real if it gets replaced.
Kenaf
Kenaf can be grown without fertilizer, and grows
fast. It can grow fast enough to convert the carbon
used in processes - sometimes over 1 inch per day
Wood
Is wood more like kenaf or coal?
Forests are being removed faster than they are
replaced world-wide.
Until stocks are replaced as fast as they are
consumed, wood should be viewed more like coal
than kenaf.
Data Precision (Al)
Data Precision
The mean value of the previous Aluminum chart is
204 MJ/kg.
The standard deviation is 58 MJ/kg (c. 25%)
If we design on allowables, we include several
standard deviations.
e.g. Al embodied energy is 100-300 MJ/kg
Eco-Indicators
Attempts are made to combine energy, water, and
emissions into a single ECO-INDICATOR value.
EcoProperties
Materials are processed and finished. This adds
energy to the product.
Polymers are molded or extruded
Metals are cast, forged, machined
Ceramics are shaped (sintering)
There is energy with each
More steps
We’ve made PET pellets, now we need to make
bottles...
Energy for PET Bottle Production
Recylcing and End-of-Life
Now that we’ve made bottles, we can still track
them.
They go to the bottling factory, get filled, used, and
possibly recycled.
Recycling and End of Life
Recycling
Often (not always) recycled materials result in
reduced embodied energy in a produced object.
This is because some of the embodied energy from
first life is retained.
Energy for Recycling
Special cases: Precious metals
and electronics
Precious metals used in small quantities, but have a
high embodied energy, carbon, and cost.
Generally have exception conductivity, resistance to
corrosion and thus make good electronics parts.
Same is true of electronics themselves
Electronics & Precious Metals
(approx energy)
Component
Embodied energy
(MJ per...)
Carbon Footprint (kg
per...)
Small electronic devices
(per kg)
2,000-4,000
200-400
Displays, per sq. m.
3,000-3,750
300-375
120-140
12-14
180-220
18-22
Assembling of printed
wiring boards (per kg)
Batteries (Ni-Cd
rechargeable) (per kg)
Energy Intensities
Fuel
kg OE
MJ/liter
MJ/kg
CO2,
kg/liter
CO2,
kg/MJ
CO2,
kg/kg
Coal, lignite
0.45
--
18-22
--
0.08
1.6
Coal,
anthracite
0.72
--
30-34
--
0.088
2.9
Crude oil
1.0
38
44
3.1
0.07
3.0
Diesel
1.0
38
44
3.1
0.071
3.2
Gasoline
1.05
35
45
2.9
0.065
2.89
Kerosene
1.0
35
43.8
3.0
0.068
3.0
Ethanol
0.71
23
31
2.8
0.083
2.6
Liquid natural
gas
1.2
25
55
3.03
0.055
3.03
Electricity Generation
MJ
CO2
Efficiency OE/kw-hr kg/kW-hr
Fossil fuel
Country
Fossil
Nuclear
Renewables
Australia
92
0
8
33
10.0
0.71
China
83
2
15
32
9.3
0.66
France
10
78
12
40
0.9
0.06
India
81
2.5
16.5
27
10.8
0.77
Japan
61
27
12
41
5.4
0.38
Norway
1
0
99
--
0
0
United
Kingdom
75
19
6
40
6.6
0.47
United States
71
19
10
36
7.1
0.54
Transport
Products are made in cheapest location and then
transported to customer
We express energy of transport as energy per tonkm, and CO2 in kg/ton-km
Transport Energy
Energy
Fuel and vehicle type
Diesel - ocean shipping
Diesel - coastal shipping
Diesel - rail
Diesel - 32 ton truck
Diesel - 14 ton truck
Diesel - light goods vehicle
Gas - family car
Diesel - family car
LPG - family car
Gas-Hybrid family car
Gas - super sports/SUV
Kerosene - long haul aircraft
Carbon
(MJ/ton-km) (kg/ton-km)
0.16
0.27
0.31
0.46
0.90
1.36
2.06
1.60
3.87
1.55
4.76
8.30
0.015
0.019
0.022
0.033
0.064
0.097
0.14
0.11
0.18
0.10
0.31
0.55
Exploring the data
Bar charts vs Bubble Charts
Bar charts show a value for each item
Range of bar shows range of values
Bubble charts show ranges for a material that
have two different properties
Watch for logarithmic axes!
Material Property Charts
Give an overview of physical, mechanical,
functional properties in a compact way
Reveal aspects of physical origins of properties
Tool for optimized selection of materials to given
design requirements
Allow properties of new materials to be displayed
and compared with conventional materials
Tensile Modulus of typical
materials
Modulus and Density
Metal recycling in current supply
(%)
Polymer recycling in current supply
(%)
Ceramic recycling in current
supply (%)
Natural and Hybrid