2 research outputs found
Nitrogen-Based Catalysts for the Electrochemical Reduction of CO<sub>2</sub> to CO
The
synthesis and application of carbon-supported, nitrogen-based
organometallic silver catalysts for the reduction of CO<sub>2</sub> is studied using an electrochemical flow reactor. Their performance
toward the selective formation of CO is similar to the performance
achieved when using Ag as the catalyst, but comparatively at much
lower silver loading. Faradaic efficiencies of the organometallic
catalyst are higher than 90%, which are comparable to those of Ag.
Furthermore, with the addition of an amine ligand to Ag/C, the partial
current density for CO increases significantly, suggesting a possible
co-catalyst mechanism. Additional improvements in activity and selectivity
may be achieved as greater insight is obtained on the mechanism of
CO<sub>2</sub> reduction and on how these complexes assemble on the
carbon support
Techno-economic Analysis of Sustainable Biofuels for Marine Transportation
Renewable, low-carbon biofuels offer the potential opportunity
to decarbonize marine transportation. This paper presents a comparative
techno-economic analysis and process sustainability assessment of
four conversion pathways: (1) hydrothermal liquefaction (HTL) of wet
wastes such as sewage sludge and manure; (2) fast pyrolysis of woody
biomass; (3) landfill gas Fischer–Tropsch synthesis; and (4)
lignin–ethanol oil from the lignocellulosic ethanol biorefinery
utilizing reductive catalytic fractionation. These alternative marine
biofuels have a modeled minimum fuel selling price between 3.98 per heavy fuel oil gallon equivalent in 2016 U.S. dollars based
on a mature plant assessment. The selected pathways also exhibit good
process sustainability performance in terms of water intensity compared
to the petroleum refineries. Further, the O and S contents of the
biofuels vary widely. While the non-HTL biofuels exhibit negligible
S content, the raw biocrudes via HTL pathways from
sludge and manure show relatively high S contents (>0.5 wt %).
Partial
or full hydrotreatment can effectively lower the biocrude S content.
Additionally, co-feeding with other low-sulfur wet wastes such as
food waste can provide another option to produce raw biocrude with
lower S content to meet the target with further hydrotreatment. This
study indicates that biofuels could be a cost-effective fuel option
for the marine sector. Marine biofuels derived from various feedstocks
and conversion technologies could mitigate marine biofuel adoption
risk in terms of feedstock availability and biorefinery economics