The presentation delas with a comparison between plastic bags and plastic bags. I have taken into consideration the economic as well as environmental effects of the use of both. The tool used was life cycle assessment through softwares like CES and EIO-LCA.

1. ME 5645 Group Project
Life Cycle Assessment of Carry Bags
Group 14 :
Amey Patil
Anirudh Punganur
Yishi Liu

2. Introduction
 We selected carry bags
as our topic for the life
cycle assessment. Our
focus was on the
energy requirements
and CO2 footprint of
the manufacturing
process of polythene
bags and paper bags.
 This is a cradle to gate
approach.

3. Introduction
 Pros
Throw away price: CHEAP
Abundant resin supply
Toughness to thickness ratio: HIGH
 Cons
Non- biodegradable
Environmental degradation during
production
 Pros
Environment friendly
Easily recyclable
 Cons
Cost of production: HIGH
Scarcity of raw materials

4. Functional Unit
 To allow a fair comparison
among the alternatives, we
need to define a functional
unit. We initially decide to
define the functional unit as:
carrying 223L (weekly
supply) of shopping items
home from supermarket. And
the reference flow is the
number of shopping bags
required to fulfil the
functional unit.

5. Methodology and Results
 Functional unit is defined as: carrying 223 liter-item home from
supermarket.
 Reference flow is the number of shopping bags required to fulfil the
functional unit
Bag type
Volume per
bag (liters)
Retail price
per bag ($)
Ref.flow –
No. bags
Weight per
bag (g)
Paper Bag 25.35 0.4 8.8 59.87
Plastic Bag 24.73 0.042 9.02 5.60

6. EIO-LCA Result
Bag type Measure Industry 1 Industry 2 Total
Paper Bag
Embodied
energy (TJ)
103 39.6 142.6
CO2
Emission (T)
2600 1930 4530
Plastic Bag
Embodied
energy (TJ)
6.30 4.99 11.29
CO2
Emission (T)
376 297 673
Bag type Industry 1 Industry 2
Paper Bag Pulp mills
All other paper bag and
coated and treated
paper manufacturing
Plastic Bag
Plastics material and
resin manufacturing
Plastics packaging
materials, film and sheet

7. ECO-Audit Results
Inputs
 Material of paper bag: paper (cellulose based)
 Material of plastic bag: PET (unfilled, amorphous)
 Recycled Content in Material: 0%
 Amount of material removed from secondary process:
10%
 End of life: Combust
 Amount of components recovered at end of life: 30%

8. ECO-Audit Results
Paper Bag Plastic Bag
Relative contribution of life phase

9. ECO-Audit Results
Comparison

10. ECO-Audit Results
Changing the Recycled Content in Material
2850
2540
2230
1920
1610
1300
434 369 324 269 213 155
0
500
1000
1500
2000
2500
3000
0% 20% 40% 60% 80% 100%
Energy(MJ)
Recycled Content in Material
Paper Bag
Plastic Bag

11. ECO-Audit Results
68.8 69 69.2 69.4 69.6 69.8
23.6 20.6 17.4 14.6 11.6 8.56
0
10
20
30
40
50
60
70
80
0% 20% 40% 60% 80% 100%
CO2(kg)
Recycled Content in Material
Paper Bag
Plastic Bag
Changing the Recycled Content in Material

12. ECO-Audit Results
Paper bag – EoL potential change
-78
-465
-854 -806
17.8 0.317
-20.6 -17.3
-900
-800
-700
-600
-500
-400
-300
-200
-100
0
100
Combust Recycle Reuse Re-manufacturing
EoL Potential
Energy (MJ) CO2 (kg)

13. ECO-Audit Results
-8.93
-82.9
-130 -126
2.85
-4.5 -7.07 -6.75
-140
-120
-100
-80
-60
-40
-20
0
20
Combust Recycle Reuse Re-manufacturing
EoL Potential
Energy (MJ) CO2 (kg)
Plastic bag – EoL potential change

14. EIO-LCA Limitations
 It was surprising to find a vast difference between the values of CO2 footprint
and embodied energy generated by both the software.
 There were a few limitations in the EIO-LCA software. The results are based
on old data (2002) and it takes the whole supply chain into consideration
whereas CES is updated yearly.
 Number of parameters assumed are more in the case of EIO-LCA than CES
Software making the calculated values more erroneous.
 The breakdown of the supply chain, right from material selection to manner
of recycling is possible only in CES while a fixed set of defined supply chains
are available in EIO-LCA ,making it a significant erroneous. This tailor made
approach makes CES a more lucrative option to consider.

15. EPA TRI results
 EPA TRI is a government agency that keeps a check on the amount of toxic
chemicals being released in the environment.
 We checked for the report submitted by Solutia Inc. for the chemicals
released by the plastic industry. We found that a total of 34 chemicals are
released during the production of plastic bags. The prominent ones being
acetone, trichloro-ethane, benzene, toluene, methanol etc.
 In case of the paper industry, the company that we checked for was Ideal
tape Co. There are just three chemicals released by the paper industry which
are toluene, xylene and n-hexane.

16. Summary
 It was surprising to find a vast difference between the values of CO2 footprint and
embodied energy generated by both the software.
 From our life cycle assessment analysis we were able to come to a conclusion that
paper bags have an advantage over plastic only when it comes to amount of emissions
and degree of harm to the environment when disposed wrongly (70% of the time).
 The manufacturing phase of paper bags is minimal as compared to plastic bags when it
comes to relative contribution in life phase.
 On recycling (from 0% to 100%) in the life phase of the material, the energy
consumption drop for paper is 54% while it is 64.9% in the case of plastic.
 On recycling (from 0% to 100%) in the life phase of the material, the CO2 production
rises for paper by 1.54% while it is reduces by 63.72% in the case of plastic.
 The results from EPA TRI were in the favor of paper bags. The complete process of
producing paper releases very few chemicals in comparison to plastic bags.
 Plastic bags are better than paper bags in every other aspect like the cost of
production, CO2 footprint, Embodied energy etc.