Well to propeller analysis of alternative fuels abstract

1. CONSEIL INTERNATIONAL
DES MACHINES A COMBUSTION
INTERNATIONAL COUNCIL
ON COMBUSTION ENGINES
PAPER NO.: 265
Well-To-Propeller Analysis of Alternative Fuels for
Maritime Applications
Christos Chryssakis, DNV, Norway
Selim Stahl, DNV, Norway
Abstract: The global merchant fleet currently con-
sumes approximately 330 million tonnes of fuel, 80-
85% of which is residual fuel with high sulfur con-
tent, and the remaining are distillate fuels complying
with stricter regulations. Upcoming regulations regard-
ing the sulfur content of marine fuels, both in emis-
sion control areas and globally, are likely to create
increased demand for low-sulfur fuels for shipping in
the next few years. The advent of new regulations
in the next decade can lead to significantly increased
fuel prices for distillate fuels, due to competition with
other uses, such as road transportation, while refin-
ery capacity for producing distillates can turn out to
be insufficient for meeting the vastly increasing de-
mand. In this case the use of alternative fuels is a
promising solution. There are many potential alter-
native fuels to oil-based marine fuels and each one
is characterized by advantages in certain areas (such
as availability, safety, pollutant emissions, greenhouse
gas emissions, cost, etc.), compared with its counter-
parts. This work screens a number of alternative fu-
els available today (or expected to be available in the
near future) that could be used to propel a ship, and
gather state of the art data regarding different fuel pro-
duction and transport pathways from a life cycle per-
spective. The results show that LNG improves the sit-
uation regarding GHG emissions by 9-11%, and this
can be further improved with new engines eliminat-
ing methane slip. LPG can be a promising alterna-
tive, based both on its GHG emissions and on its price
and availability. Sustainable biofuels like ethanol from
sugar cane, as well as rapeseed-based diesel alter-
natives could present a viable solution for the ship-
ping industry in the future if their price becomes at-
tractive. They are available in relatively large volumes,
show clear GHG emission reduction, with low capital
cost for fuel system/engine retrofitting. It is important
to consider a Well-To-Propeller perspective when pre-
senting alternative fuels, since the way a fuel is pro-
duced and distributed can have a significant impact on
its overall GHG emissions. This could be a menace if
a fuel is branded as a climate friendly alternative with-
out putting emphasis on its entire life cycle. More work
is required when it comes to other aspects of alterna-
tive fuels, such as local air pollution, land use, and
powertrain technologies, to ensure an optimal overall
emissions reduction strategy in the future. This work
highlights the fact that, with respect to greenhouse
gas emissions, the way a fuel is produced and trans-
ported (Well-To-Tank part of the fuel cycle) contributes
approximately 10% to 20% to its overall greenhouse
gas emissions (Well-to-Propeller), while for biofuels
the Well-To-Tank part corresponds to 100% of its GHG
emissions. Currently, the most promising alternative
fuel for shipping is LNG, due to large volumes avail-
able, SOx and NOx emissions benefits, price compa-
rable to oil-based fuels (and in some parts of the world
lower), and the relative maturity of infrastructure and
the technology. However, all available candidate fu-
els for the future should be further investigated, since
they can play an increasingly significant role in the long
term.
©CIMAC Congress 2013, Shanghai