Green Chemistry and Engineering

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• Green Chemistry and Engineering
• Justin Barone
• jbarone_at_vt.edu
• http//renewablemat.bse.vt.edu

ENGR 3124 Introduction to Green Engineering
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Why go green?

• It was simply the right thing to do because
  environmental pollution became hazardous to our
  health!
• If there was not a saleable component, industry
  did not care.
• Until what happened?

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It became costly to not be green
The Bisphenol-A Debate A Suspect Chemical in
Plastic Bottles and Cans
Phthalates From Toys to Body Lotion the
Everywhere Chemical Found in urine samples from
10 of 10 Washingtonians in the Pollution in
People study
Formaldehyde has been classified as a known
carcinogen by the State of California (Prop 65)
and the World Health Organization (International
Agency for Research on Cancer). It also has a
range of other heatlh effects including being a
bronchial irritant and asthma trigger and is
connected to multiple chemical sensitivity.
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and the price of petroleum sky-rocketed
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There are many ways to be green

• Increase energy efficiency a few percent
• Completely rid yourself of petroleum
• Completely rid yourself of fossil fuel feedstocks
• What else can we use?

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What do we have in biomass? Large Molecules!
This is what we will separate in our biorefinery
and process into products
Polysaccharides M105-106 Proteins
M104-105 Fats M102-103
Plastics M105-106 Chemicals M103 Fuels
M101-102
gtEnergy
Examples Lactic Acid from corn or use starch as
is.
Given molecular weights (M g/mol) and amounts
much more than other molecules!
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sugars
fats
N-terminal
C-terminal

peptide bond
proteins
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Rules

• Bio-based sources that are not food or fuel or
  else you are out
• 25-37oC and H2O no heat, pressure, or solvents
• Biological processing
• Biodegrade to CO2 and other small molecules

I view the rules as the ultimate in green,
sustainable engineering!
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Back to our first examples

• Phthalates
• Phenol-formaldehyde
• Bisphenol-A

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PLA Polylactic Acid
An aliphatic polyester made with a combination of
biotechnology (fermentation) and chemical
technology (polymerization)!
Polyethylene terephthalate (PETE) is an aromatic
polyester
which is what your soda bottle and polyester
fibers are made of!
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PHA Polyhydroxyalkanoates
The ultimate in green materials produced
naturally by organisms or genetically engineer to
give custom properties known since 1920s Most
common PHA is PHB or poly (?-hydroxybutyrate,
RC1 below) b/c it is produced naturally by
organisms It is used as an energy storage
material like fat in animals or starch in plants.
Just like starch exists as discrete granules in
the cell cytoplasm in a completely amorphous (no
order or xtals) form (readily available for
biosynthesis)
What will happen as R??
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Epoxies from Fats
oxidation rxn
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Protein-Based Materials
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Fibers
D1-10 mm
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PLA vs. Petroleum-based Polymers
Year 1 is 1st commercial PLA plant Year 5 is
improved PLA plant Long-term takes into
account advances in fermentation and renewable
energy use eutrophication is not taken into
account here and is a big (-) for the PLA.
from Handbook of Biodegradable Polymers, ed.
Bastioli, 2005