Aerospace & Ocean Engineering
Chemical Engineering
Biological Systems Engineering
Civil & Environmental Engineering
Mining & Mineral Engineering
GREEN ENGINEERING & ENVIRONMENTAL LIFE CYCLE ANALYSIS
AT VIRGINIA TECH
Environment
Society
Dr. Sean McGinnis
Director – Green Engineering Program
VT College of Engineering
Economics
www.eng.vt.edu
Technology
VIRGINIA TECH GREEN ENGINEERING PROGRAM MISSION:
GREEN ENGINEERING:
(2) To provide students with courses and other educational experiences in which they
learn skills to minimize environmental impacts and to design for sustainability
(3) To facilitate interdisciplinary research and collaboration in areas of green engineering
and sustainability among faculty
(4) To engage the university, local, and global communities in discussions focused on
engineering approaches to sustainability.
•
Green Engineering focuses at the interface between the
environment, technology, economics, and society.
2. Materials Selection
- The mass and production energy of materials used are key factors for
determining life cycle environmental impact
3. Consider waste as a design flaw
- Waste from all life cycle phases should be minimized through the use of
materials which either return to nature or can be recycled indefinitely
4. Look to nature for sustainable designs
- Nature designs materials and systems with high performance, efficient
energy use, and no waste
LIFE CYCLE ANALYSIS (LCA):
- A method based on scientific data for analyzing and quantifying environmental impacts of products, processes, and systems over their entire life cycle
- LCA provides objective environmental data for decision-making on issues that cross political, economic, social, technological, and environmental boundaries
kg
0.0015
0.0001
Bentazon (C10H12N2O3S)
kg
0.0013
0.0001
Electricity
MJ
19
Gasoline (Farm Tractor)
gal
2.1
Bromoxynil (C7H3Br2NO)
kg
0.0017
Lime (quick, CaO)
kg
83
Chlorpyrifos (C9H11Cl3NO3PS)
kg
0.00056
0.00002
Liquified Petroleum Gas (fuel)
MJ
19
Clomazone (C12H14ClNO2)
kg
0.00029
0.00001
Natural Gas (fuel)
MJ
19
Glyphosate (C3H8NO5P)
kg
0.10
0.0043
Nitrogen Fertilizer (NH4NO3 as N)
kg
1.1
Metolachlor (C15H22ClNO2)
kg
0.0029
0.0001
Phosphorous Fertilizer (TSP as P2O5)
kg
3.8
Potash Fertilizer (K2O)
kg
7.7
Transport: Rail (kg.km)
tkm
46
Transport: Road (diesel oil, liter)
gal
0.27
Cropland (Conservation Tillage)
m
2
2278
Cropland (Conventional Tillage)
m
2
956
Cropland (Reduced Tillage)
m2
813
Water Used (total)
gal
10897
Water: River
gal
6887
Water: Well
gal
4010
Manufacturing
recycle
Extraction
Use
reuse
compost
Disposal
Example: Biodiesel Production From Soybeans
SOYBEAN OIL CONVERSION - PROCESS INPUTS
Climate Change
Ozone Depletion
Smog Formation
Acidification
Human Health
1.2
0.0007
0.00003
Pendimethalin (C13H19N3O4)
kg
0.016
0.0007
Hydrosphere
Sulfosate (C12H32NO5PS3)
kg
0.008
0.0004
Trifluralin (C13H16F3N3O4)
kg
0.016
0.0004
Carbon Dioxide (CO2) (biomass uptake)
kg
-1559
Hydrocarbons (unspecified)
kg
0.25
Nitrogen Oxides (NOx as NO2)
kg
0.19
Nitrous Oxide (N2O)
kg
2.47
Eutrophication
Acidification
Aquifer depletion
Ecotoxicity
Human Health
Nitrogenous Matter (unspecified, as N)
kg
0.14
Phosphorous Matter (unspecified, as P)
kg
0.02
Suspended Matter (unspecified)
kg
2812
Soybean Residues
kg
Sodium Hydroxide (NaOH) catalyst
kg
2.3
SOYBEAN OIL CONVERSION - PROCESS OUTPUTS
Methanol (CH3OH)
kg
96
Biodiesel (neat)
kg
1000
Sodium Methoxide (CH3ONa)
kg
24
Crude Glycerin
kg
150
Electricity
MJ
230
Soap stock
kg
0.54
Steam
kg
1030
Process Water (chemically polluted)
liter
380
Process Water
liter
360
Waste (other)
kg
12
Air Emissions (various)
see
graphs
1.08
Petrodiesel Fossil Energy
1.0
Petrodiesel Total Energy
0.8
0.6
0.4
0.311
0.08
0.066 0.003
0.004
0.007
0.0
Comparison of Net CO2 Life Cycle Emissions
for Biodiesel Blends and Petroleum Diesel
Comparison of Total Wastewater Flows for
Biodiesel and Petroleum Diesel Life Cycles
Biosphere
2097
1040
Biodiesel Total Energy
1.2
0.151
kg
kg
1.24
Biodiesel Fossil Energy
0.2
Metribuzin (C8H14N4OS)
Soybean Oil (degummed)
Industrial System Engineering
1.4
Co
nv
er
Bi
sio
od
n
ie
se
lT
ra
ns
po
rt
To
ta
lE
ne
rg
y
Alachlor (C14H2OClNO2)
Atmosphere
Life Cycle Air Emissions for B20 and
B100 Compared to Petroleum Diesel
O
il
0.0001
Tr
an
sp
or
t
0.0021
O
il
kg
So
yb
ea
n
Materials Science & Engineering
2,4 - D (C8H6Cl2O3)
Solid
Cr
us
hi
ng
4.5
Water
So
yb
ea
n
gal
Air
So
yb
ea
n
Diesel (Farm Tractor)
OUTPUTS PER 1000 KG SOYBEAN OUTPUT
Life Cycle Total and Fossil Fuel Production Energies
(including feedstock) for Biodiesel and Petroleum Diesel
Tr
an
sp
or
t
0.41
NREL LCI Database
http://www.nrel.gov/lci
− Use scientifically derived characterization
factors for comparison
re
kg
NREL LCI Database
http://www.nrel.gov/lci
− How should different impact categories be weighted?
− How accurate and sensitive are results to the data?
− LCA provides the data/analysis, not the decision
Engineering Science & Mechanics
Soil depletion
Deforestation
Resource Depletion
Ecotoxicity
Human Health
Electrical & Computer Engineering
Agrochemicals
− Confirm mass balance (inputs = outputs)
within system boundaries
4. Data Interpretation (ISO 14043)
ul
tu
−What system boundaries? Which impact
categories? Which data sources?
INPUTS PER 1000 KG SOYBEAN OUTPUT (1 acre)
3. Translate inventory outputs to
potential environmental impacts
across categories (ISO 14042)
2. Compile a detailed inventory of all
inputs and outputs (ISO 14041)
So
yb
ea
n
1. Define the project scope, boundaries,
and assumptions (ISO 14040)
Ag
ric
•
Since green engineering is multidisciplinary, the program searches for opportunities in
education, outreach, and research across all VT colleges and departments.
- Environmental impacts occur across multiple life cycle phases for
products/processes and are most effectively minimized by good design
Computer Science
Mechanical Engineering
Green Engineering considers life-cycle environmental
impacts as initial design constraints. It recognizes that
environmental impacts are more effectively minimized the
further upstream they are considered.
1. Consider the entire life cycle
Energy (MJ/MJ Fuel)
•
Green Engineering is the design of materials, processes,
devices, and systems with the objective of minimizing
overall environmental impact across the entire life cycle.
GREEN ENGINEERING DESIGN PRINCIPLES:
So
yb
ea
n
•
(1) To increase students’ awareness of the environmental impact of engineering practice
“An Overview of Biodiesel and Petroleum Diesel Life Cycles”
http://www.nrel.gov/docs/legosti/fy98/24772.pdf
Engineering Education
spm 2/17/07