Environmental Engineering Reference
In-Depth Information
sugarcane, feedstock a hectare of land yields about three tons of bio-PE.
Coupled with fossil fuel resource conservation, the use of bio-based
feedstock also results in substantial reductions in carbon emissions. For
instance, sugarcane-derived PP has a net negative carbon emission (or a
sequestration) of 2.3 kg of CO
2
/kg of bio-PP produced. This compares with
the emission of 3 kg/kg of PP produced, resulting in a net approximately
5 kg carbon emission avoided per kg bio-PP (Godall, 2011). Reliance on
agricultural biomass as a raw material is the main limiting factor for this
technology. However, improving the process to use lignocellulosic waste
materials can address this problem.
4.6.2.2 Bio-PET
Popularity ofbio-PETisduetoitssuccessfulapplication inbeveragebottles.
Polyester is made by polycondensation of EG with terephthalic acid [TPA].
Bio-based EG is made from molasses, sugarcane, switchgrass, and bagasse
via their fermentation into ethanol. Using this bio-EG with fossil fuel-based
TPA, a PET that is partially bio-based is obtained. The “PlantBottle” by
Coca-Cola in 2009 is made using this partly (22.5%) bio-based resin. The
Bio-PET is recyclable, can be processed without variance from regular PET,
performs the same in products and reduces carbon emissions of 8-11%
as well, according to the manufacturer, compared to the fossil fuel-based
PET.
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