Environmental Assessment of Green Chemicals
LCA of bio-based chemicals produced using biocatalysis
LIFE CYCLE
ASSESSMENT
Linda Tufvesson
Environmental and Energy System Studies
Lund University
What is ”green”?
Q1: Are chemicals based on renewable resources
better than their fossil counterparts?
Q2: Are biocatalytic processes better than
conventional chemical processes?
Q3: What defines a “green” chemicals?
The LCA method
Raw material extraction
Inflow
Outflow
Raw material preparation
Material
Energy
Manufacturing
Transportation
Use
Recycling/Reuse
Disposal
The life-cycle
of the product
Emissions to air
Emissions to water
Waste
Other emissions
What defines a green chemical?
Methodological aspects and
key parameters
!
Methodological aspects
Functional unit
State-of-the-art or future technology
Choice
of environmental parameters
Optimisation
Allocation method
Mature
Mature
conventional
technology
alternative
technology
Emerging
alternative
technology
Time
Methodological aspects - Allocation
More than one product is produced in the same
production process.
Coal
Transport
Heat and power
plant
Heat
Electricity
The environmental impact from the processes (half-green boxes) then
must be shared (allocated) to the two products (electricity and heat).
Methodological aspects - Allocation
Physical or economic allocation
Crop
Products
Rapeseed
Oil
Rape meal
Physical allocation %
Economical allocation %
40
60
67
33
System expansion
Rape seed cultivation
Oil
Meal
Soybean cultivation
Resulting system
Soybean meal
Rape seed oil
+ More accurate result, recommended by ISO
- More LCI data needed
Raw material production – key parameters
Type of biomass and removal of crop residues
N2O emissions from fertiliser production
Biogenic N2O emissions from soil
CO2 emissions from the se of fossil fuels
CO2 emissions due to land use change
Raw material production - key parameters
!
Allocation method
Type of biomass
Removal of crop
residues
N2O emissions
Land use change
Reference: Börjesson and Tufvesson (2010) J. Clean. Prod., doi:10.1016/j.jclepro.2010.01.001
Process – key parameters
Yield
Process energy demand and primary energy source
Use of solvent
Toxicity
Environmental impact of enzymes
Process - key parameters
Fatty acid esters for cosmetic applications
Enzymatic vs. conventional production process
–
–
–
–
–
Superior quality
34-62% less energy
80% less waste
Less hazardous solvents and toxic materials
Less reaction steps
References:
Hills (2003) Eur. J. Lipid Sci. Technol., 105:601-607.
Petersson et al. (2005) Green Chem., 7:837-843.
Thum and Oxenbøll (2006) IFCCC Congress, Osaka, Japan.
Process - key parameters
!
Yield
Reference: Tufvesson and Börjesson (2008) Int. J. of LCA, 13(4):328-338.
Process - key parameters
!
Primary energy source
Reference: Börjesson and Tufvesson (2010) J. Clean. Prod., doi:10.1016/j.jclepro.2010.01.001
Conclusions
• Renewable often better than fossil-based
chemicals regarding contribution to climate
change, higher for AP and EP
• Biocatalysis often better than conventional
chemical processes
• Bulk chemicals – raw material production
• Fine chemicals and pharmaceuticals – process
• A few key parameters have high impact on the
overall environmental performance of chemicals
Success factors
Cooperation along the whole supply chain
Materials
Manufacturing
Use
Cooperation with several
disciplines
- Environmental engineers
- Process engineers
- Toxicologists
Transport
Disposal
Thank you for your attention!
linda.tufvesson@miljo.lth.se