LCA of Gasoline and Diesel
April 6, 2011
SEAC analyst David Hsu
recently published the report "Life Cycle Assessment of Gasoline and Diesel Produced via Fast Pyrolysis and Hydroprocessing."
In this work, a life cycle assessment (LCA) estimating greenhouse gas (GHG) emissions
and net energy value (NEV) of the production of gasoline and diesel from forest residues
via fast pyrolysis and hydroprocessing, from production of the feedstock to end use
of the fuel in a vehicle, is performed. The fast pyrolysis and hydrotreating and hydrocracking
processes are based on a Pacific Northwest National Laboratory (PNNL) design report.
The LCA results show GHG emissions of 0.142 kg CO2-equiv. per km traveled and NEV
of 1.00 MJ per km traveled for a process using grid electricity. Monte Carlo uncertainty
analysis shows a range of results, with all values better than those of conventional
gasoline in 2005. Results for GHG emissions and NEV of gasoline and diesel from pyrolysis
are also reported on a per MJ fuel basis for comparison with ethanol produced via
gasification. Although pyrolysis-derived gasoline and diesel have lower GHG emissions
and higher NEV than conventional gasoline does in 2005, they underperform ethanol
produced via gasification from the same feedstock. GHG emissions for pyrolysis could
be lowered further if electricity and hydrogen are produced from biomass instead of
from fossil sources.