Polyethylene furanoate (PEF) is a
bioplastic that can potentially
replace its fossil-fuel counterpart, polyethylene terephthalate (PET),
to reduce greenhouse gas (GHG) emissions. A life-cycle GHG, water,
and fossil-fuel consumption analysis is conducted for a potential
bioplastic alternative for a fossil-based PET resin, or PEF on a kg-resin
basis. PEF is assumed to be produced from a lignocellulosic feedstock
(i.e., wheat straw) via furanics conversion reactions through three
different pathways. The system boundary includes cradle-to-gate processes
including feedstock farming, pretreatment, hydrolysis, conversion
into furanics, recovery, polymerization into PEF, and on-site combined
heat and power (CHP) generation. While electricity export from the
CHP plant is assumed to displace the U. S. grid electricity, other
coproducts of PEF are assumed to distribute the emissions and energy
burdens on a mass basis. The results showed that all three PEF routes
achieved significant GHG reduction relative to its fossil-based counterpart
(i.e., PET): 134, 139, and 163% reduction for routes 1, 2, and 3,
respectively. While fossil-fuel consumptions for all three pathways
were also significantly reduced (i.e., 79, 57, and 53% reduction for
routes 1, 2, and 3), water consumptions for routes 1 and 2 were increased
by 168 and 79%, respectively, while route 3 only achieved reduction
(by 77%) relative to fossil-PET. Different sensitivity analyses were
conducted, and the results showed that coproduct allocation methods
and wheat straw management assumption were the most important. A preliminary
analysis on the farmland area and cost required to reduce unit mass
of GHGs using PEF to replace PET is also conducted, showing a promising
result for both metrics: (i) 3 metric tons of GHGs reduced/ha for
all three PEF pathways and (ii) affordable cost of GHG abatement for
routes 1 and 2, while route 3 even generated profits.
