5 research outputs found
Exploring Comparative Energy and Environmental Benefits of Virgin, Recycled, and Bio-Derived PET Bottles
Polyethylene terephthalate (PET)
is a common plastic resin used
to produce packaging, notably plastic bottles. Most PET bottles are
produced from fossil fuel-derived feedstocks. Bio-derived and recycling-based
pathways to PET bottles, however, could offer lower greenhouse gas
(GHG) emissions than the conventional route. In this paper, we use
life-cycle analysis to evaluate the GHG emissions, fossil fuel consumption,
and water consumption of producing one PET bottle from virgin fossil
resources, recycled plastic, and biomass, considering each supply
chain stage. We considered two routes to produce bottles from biomass:
one in which all PET precursors (ethylene glycol and teraphthalic
acid) are bio-derived and one in which only ethylene glycol is bio-derived.
Bio-derived and recycled PET bottles offer both GHG emissions and
fossil fuel consumption reductions ranging from 12% to 82% and 13%
to 56%, respectively, on a cradle-to-grave basis compared to fossil
fuel-derived PET bottles assuming PET bottles are landfilled. However,
water consumption is lower in the conventional pathway to PET bottles.
Water demand is high during feedstock production and conversion in
the case of biomass-derived PET and during recycling in the case of
bottles made from recycled PET
MOESM1 of Succinic acid production on xylose-enriched biorefinery streams by Actinobacillus succinogenes in batch fermentation
Additional file 1. Supporting information
Techno-Economic Analysis and Life-Cycle Analysis of Two Light-Duty Bioblendstocks: Isobutanol and Aromatic-Rich Hydrocarbons
Isobutanol
and aromatic-rich hydrocarbons (ARHC) are two biomass-derived
high-octane blendstocks that could be blended with petroleum gasoline
for use in optimized spark-ignition engines in light-duty vehicles,
potentially increasing engine efficiency. To evaluate technology readiness,
economic viability, and environmental impacts of these technologies,
we use detailed techno-economic analysis (TEA) and life-cycle analysis
(LCA). We assumed isobutanol is produced via biochemical conversion
of an herbaceous feedstock blend while ARHC is produced via thermochemical
conversion of a woody feedstock blend. The minimum estimated fuel
selling price (MFSP) of isobutanol ranged from 0.045/MJ) based on today’s technology to
0.034/MJ) with technology advancements. The MFSP of ARHC
could decline from 0.042/MJ) based on today’s technology
to 0.034/MJ) as technology improves. Both isobutanol and
ARHC offer about 73% greenhouse gas (GHG) emission reduction relative
to petroleum gasoline per LCA of these two bioblendstocks. On the
other hand, water consumption in the production of both bioblendstocks
exceeds that of conventional gasoline although process engineering
offers routes to cutting water consumption. Over their life-cycles,
both isobutanol and ARHC emit more NO<sub><i>x</i></sub> and PM<sub>2.5</sub> than petroleum gasoline. Improving the energy
efficiency and lowering air emissions from agricultural equipment
will reduce the life-cycle air pollutant emissions of these bioblendstocks
Current and Future United States Light-Duty Vehicle Pathways: Cradle-to-Grave Lifecycle Greenhouse Gas Emissions and Economic Assessment
This
article presents a cradle-to-grave (C2G) assessment of greenhouse
gas (GHG) emissions and costs for current (2015) and future (2025–2030)
light-duty vehicles. The analysis addressed both fuel cycle and vehicle
manufacturing cycle for the following vehicle types: gasoline and
diesel internal combustion engine vehicles (ICEVs), flex fuel vehicles,
compressed natural gas (CNG) vehicles, hybrid electric vehicles (HEVs),
hydrogen fuel cell electric vehicles (FCEVs), battery electric vehicles
(BEVs), and plug-in hybrid electric vehicles (PHEVs). Gasoline ICEVs
using current technology have C2G emissions of ∼450 gCO<sub>2</sub>e/mi (grams of carbon dioxide equivalents per mile), while
C2G emissions from HEVs, PHEVs, H<sub>2</sub> FCEVs, and BEVs range
from 300–350 gCO<sub>2</sub>e/mi. Future vehicle efficiency
gains are expected to reduce emissions to ∼350 gCO<sub>2</sub>/mi for ICEVs and ∼250 gCO<sub>2e</sub>/mi for HEVs, PHEVs,
FCEVs, and BEVs. Utilizing low-carbon fuel pathways yields GHG reductions
more than double those achieved by vehicle efficiency gains alone.
Levelized costs of driving (LCDs) are in the range 1.00/mi
depending on time frame and vehicle-fuel technology. In all cases,
vehicle cost represents the major (60–90%) contribution to
LCDs. Currently, HEV and PHEV petroleum-fueled vehicles provide the
most attractive cost in terms of avoided carbon emissions, although
they offer lower potential GHG reductions. The ranges of LCD and cost
of avoided carbon are narrower for the future technology pathways,
reflecting the expected economic competitiveness of these alternative
vehicles and fuels
Environmental, Economic, and Scalability Considerations and Trends of Selected Fuel Economy-Enhancing Biomass-Derived Blendstocks
Twenty-four
biomass-derived compounds and mixtures, identified
based on their physical properties, which could be blended into fuels
to improve spark ignition engine fuel economy, were assessed for their
economic, technology readiness, and environmental viability. These
bio-blendstocks were modeled to be produced biochemically, thermochemically,
or through hybrid processes. To carry out the assessment, 17 metrics
were developed for which each bio-blendstock was determined to be
favorable, neutral, or unfavorable. Cellulosic ethanol was included
as a reference case. Overall economic and, to some extent, environmental
viability is driven by projected yields for each of these processes.
The metrics used in this analysis methodology highlight the near-term
potential to achieve these targeted yield estimates when considering
data quality and current technical readiness for these conversion
strategies. Key knowledge gaps included the degree of purity needed
for use as a bio-blendstock. Less stringent purification requirements
for fuels could cut processing costs and environmental impacts. Additionally,
more information is needed on the blending behavior of many of these
bio-blendstocks with gasoline to support the technology readiness
evaluation. Overall, the technology to produce many of these blendstocks
from biomass is emerging, and as it matures, these assessments must
be revisited. Importantly, considering economic, environmental, and
technology readiness factors, in addition to physical properties of
blendstocks that could be used to boost engine efficiency and fuel
economy, in the early stages of project research and development can
help spotlight those most likely to be viable in the near term