Go for Rakhi Bazaar and Pick the Latest Bhaiya Bhabhi Rakhi.pptx
LNG fuelled ships bunkering
1. Stud.
Techn.
Nora
Marie
Lundevall
Arnet
Evaluation
of
technical
challenges
and
need
for
standardization
for
LNG
bunkering
Trondheim,
June
10,
2013
NTNU
Norwegian
University
of
Science
and
Technology
Faculty
of
Engineering
Science
and
Technology
Department
of
Energy
and
Process
Engineering
Project
thesis
Source:
Swedish
Marine
Technology
Forum
2. Preface
This
project
report
is
written
as
a
part
of
the
five
year
Master
Degree
Program
I
attend
at
the
Department
of
Energy
and
Process
Engineering
at
Norwegian
University
of
Science
and
Technology
(NTNU).
First
of
all
I
wish
to
express
my
gratitude
to
my
supervisor
Reidar
Kristoffersen.
During
the
semester
he
has
given
me
academic
guidance
on
report
matters
and
great
freedom
in
choosing
a
topic
of
interest.
The
project
report
consists
of
a
literature
review
regarding
LNG
bunkering.
The
topic
is
current
and
much
of
the
information
is
gathered
from
publications
made
within
the
last
five
years
and
from
direct
communication
with
people
in
the
industry.
The
list
of
people
who
have
contributed
and
whom
I
wish
to
thank
is
therefore
extensive.
The
report
is
written
in
cooperation
with
Det
Norske
Veritas
(DNV).
Lars
Petter
Blikom,
Segment
Director
for
Natural
Gas,
DNV,
has
been
my
industrial
supervisor.
I
would
like
to
thank
Mr.
Blikom
for
providing
me
with
assistance
on
the
topic
and
valuable
insight
form
the
industry.
His
support
and
encouragement
throughout
the
process
has
been
highly
appreciated.
I
also
wish
to
thank
the
natural
gas
team
at
DNV,
Erik
Skramstad
and
Katrine
Lie
Strøm
for
their
help
on
technical
matters.
Individuals
who
contributed
with
insight,
relevant
material,
outlining
and
establishing
the
basis
of
the
project
report
include;
Per
Magne
Einang
and
Dag
Stenersen
(MARINTEK/SINTEF),
Øystein
Bruno
Larsen
(BW
Offshore),
Ernst
Meyer
and
Henning
Mohn
(DNV),
Rolv
Stokkmo
(Liquiline),
Øystein
Klaussen
(Gassteknikk)
and
Jens
Kålstad
(Kongsberg).
Nora
Marie
Lundevall
Arnet
I
3. Abstract
The
shipping
industry
is
searching
for
cleaner
solutions
to
comply
with
upcoming
regulations
on
emissions.
A
favorable
solution
is
to
use
Liquefied
Natural
Gas
(LNG)
as
bunker
fuel,
on
ferries
and
other
smaller
vessel
travelling
set
routes.
Implementation
of
innovative
solutions
in
the
large-‐scale
LNG
distribution
has
been
successful,
but
the
industry
is
now
requiring
solutions
for
the
small-‐scale
LNG
distribution
networks.
An
expansion
of
small-‐scale
LNG
infrastructure
holds
a
great
potential
for
cost
effective
fuel
for
the
industry.
Several
LNG
bunkering
solutions
exist
today
and
new
projects
are
announced
frequently,
but
detailed
descriptions
are
rarely
published
due
to
the
intense
competition
in
the
emerging
market.
The
industry
is
also
faced
with
lack
of
standardization
within
certain
areas
of
the
bunkering
process.
Leaving
procedures
open
to
discretion
and
a
potentially
higher
risk
of
failure.
This
project
report
aims
to
evaluate
essential
aspects
relevant
to
the
emerging
LNG
bunkering
market
focusing
on
technical
challenges
and
need
for
standardization.
It
will
include
an
overview
of
LNG
safety
aspects,
a
technical
step-‐by-‐step
approach
to
LNG
bunkering
and
essential
equipment
used,
assessment
of
current
standards,
and
finally
a
discussion
of
critical
areas
for
LNG
bunkering
to
compete
with
current
solutions.
II
5. 5
Regulations
..........................................................................................................................................
20
5.1
Standardization
Bodies
.................................................................................................................
20
5.1.1
International
Maritime
Organization
(IMO)
..........................................................................
20
5.1.2
International
Organization
for
Standardization
(ISO)
............................................................
20
5.1.3
Society
of
International
Gas
Tanker
&
Terminal
Operators
(SIGTTO)
...................................
20
5.1.4
Oil
Companies
International
Marine
Forum
(OCIMF)
...........................................................
20
5.1.5
European
Committee
for
Standardization
(CEN)
..................................................................
21
5.2
International
Rules
and
Guidelines
..............................................................................................
21
5.2.1
IMO
International
Gas
Code
(IGC)
.........................................................................................
21
5.2.2
IMO
International
Gas
Fuel
Interim
Guidelines
(MSC.285(86))
.............................................
21
5.2.3
SIGGTO:
Guidelines
for
LNG
transfer
and
Port
Operation
....................................................
21
5.2.4
OCIMF:
Guidelines
for
Oil
transfers,
Ship-‐to-‐Ship
oil
bunkering
procedures
........................
21
5.2.5
CEN
–
European
Standard
.....................................................................................................
21
5.2.6
Local
regulations
and
authorities
..........................................................................................
22
5.3
The
ISO
Standard
–
ISO/TC
67/WG
10/PT1
..................................................................................
22
5.4
Foreseen
Governance
of
LNG
Bunkering
Operations
...................................................................
23
6
On
Site
.................................................................................................................................................
24
6.1
Best
Practice
.................................................................................................................................
24
6.2
Bunkering
Area
.............................................................................................................................
24
6.3
Purging
.........................................................................................................................................
24
6.3.1
Zero
Emission
Solutions
........................................................................................................
24
6.3.2
Pressure
Testing
....................................................................................................................
25
6.4
Filling
Sequence
-‐
Tank
Pressure
and
Temperature
.....................................................................
25
6.4
1
Standard
Quality
–
Explanation
of
the
Term
.........................................................................
25
7
Discussion
............................................................................................................................................
26
7.1
Standards
-‐
Current
Situation
.......................................................................................................
26
7.1.1
Bunkering
vs.
Large-‐Scale
Transfers
......................................................................................
26
7.1.2
LNG
vs.
Conventional
Fuels
...................................................................................................
26
7.1.3
Port
rules
...............................................................................................................................
26
7.1.4
Bunkering
scenarios
..............................................................................................................
27
7.2
ISO/TC
67/WG
10
.........................................................................................................................
27
7.2.1
Lacking
elements
...................................................................................................................
27
7.2.2
Implementation
.....................................................................................................................
27
7.2.3
Equipment
.............................................................................................................................
28
7.3
Passengers
....................................................................................................................................
28
7.4
Safety
Zones
.................................................................................................................................
28
8
Conclusion
...........................................................................................................................................
30
Appendix
A
.............................................................................................................................................
31
Appendix
B
.............................................................................................................................................
32
Appendix
C
.............................................................................................................................................
33
Standardization
bodies
.......................................................................................................................
33
International
Maritime
Organisation
(IMO)
...................................................................................
33
International
Organisation
for
Standardisation
(ISO)
.....................................................................
33
International
Electrotechnical
Commission
(IEC)
...........................................................................
33
Society
of
International
Gas
Tanker
&
Terminal
Operators
(SIGTTO)
............................................
34
Oil
Companies
International
Marine
Forum
(OCIMF)
....................................................................
34
European
Committee
for
Standardisation
(CEN)
...........................................................................
34
Reference
list
.........................................................................................................................................
36
IV
7. List
of
Abbreviations
NG
–
Natural
Gas
LNG
–Liquefied
Natural
Gas
LEL
–
Lower
Explosion
Level
UEL
–
Upper
Explosion
Level
HFO
–
Heavy
Fuel
Oil
MDO
–
Marine
Diesel
Oil
MGO
–
Marine
Gas
Oil
mmbtu
-‐
million
British
thermal
units
ECA
–
Emission
Control
Area
IEA
–
International
Energy
Agency
TTS
–
Truck-‐to-‐Ship
STS
–
Ship-‐to-‐Ship
PTS
–
Terminal
(Pipeline)-‐to-‐Ship
ERC
–
Emergency
Quick
Release
Connector/Couplers
ESD
–
Emergency
Shutdown
Systems
ERS
–
Emergency
Release
Systems
IMO
–
International
Maritime
Organization
ISO
–
International
Organization
for
Standardization
SIGTTO
–
Society
of
International
Gas
Tanker
&
Terminal
Operators
OCIMF
–
Oil
Companies
International
Marine
Forum
CEN
–
European
Committee
for
Standardization
NMD
–
Norwegian
Maritime
Directorate
EU
–
European
Union
IGC
–
IMO
International
Gas
Code
IGF
–
IMO
International
Gas
Fuel
Interim
Guidelines
Sorted
after
order
of
appearance
in
the
document.
VI
8. 1
Introduction
1.1
Motivation
“The
LNG
industry
is
the
fastest
growing
segment
of
the
energy
industry
around
the
world.”
Global
oil
is
growing
about
0.9%
per
annum,
global
gas
at
2%,
while
Liquefied
Natural
Gas
(LNG)
has
been
1
growing
at
a
comparatively
soaring
4.5%.
The
International
Energy
Agency
projects
the
natural
gas
used
to
account
for
more
than
25%
of
the
world
energy
demand
(amounting
to
a
50%
increase)
by
2035,
making
it
the
fastest
growing
primary
energy
source
of
the
world.
For
LNG,
a
9%
share
in
the
global
gas
supply
was
estimated
for
2010;
by
2
2030
it
is
projected
to
account
for
15%.
“Lloyd’s
Register
believes
LNG
could
account
for
up
to
9%
of
3
total
bunker
fuel
demand
by
2025.”
1.1.1
Bunkering
4
Small-‐scale
distribution
and
bunkering
of
LNG
has
been
booming
as
well.
LNG
was
created
as
a
way
to
transport
natural
gas
in
a
more
economical
way
over
long
distances,
as
it
is
reduced
to
th
approximately
1/600
in
volume
through
liquefaction.
Transportation
and
handling
of
LNG
as
cargo
on
both
land
and
sea
have
been
proven
for
many
decades.
With
new
emission
regulations
the
potential
applications
for
LNG
is
expanding.
Among
these
applications
is
use
of
LNG
as
marine
fuel.
Particularly
attractive
for
marine
vessels
travelling
set
routes
such
as
tug
boats,
ferries,
and
support
vessels.
LNG
as
main
propulsion
fuel
is
no
longer
a
new
invention
and
the
technology
is
already
5
6
classified
as
proven.
The
first
LNG
fueled
ship
in
the
world
(Glutra)
was
launched
in
Norway,
in
2001.
The
transportation
sector
being
the
single-‐biggest
contributor
to
oil
demand
in
many
countries
7
around
the
world,
is
always
looking
for
ways
to
cut
costs.
Vessels
running
on
LNG
instead
of
oil
are
8
already
saving
25%
on
fuels
costs
in
certain
markets.
Norway
is
currently
operating
38
gas-‐fuelled
ships.
Based
on
intrinsic
advantages
LNG
has
as
a
fuel,
it
can
and
will
probably
be
adopted
on
an
international
basis.
In
response
to
increasing
demand,
construction
of
LNG
bunkering
infrastructure
is
9
under
development.
Development
of
a
worldwide
LNG
supply
chain
based
on
ship-‐to-‐ship
or
shore-‐to-‐ship
bunkering
is
of
10
paramount
importance
for
LNG
to
become
a
real
alternative
to
heavy
fuel
oil.
The
bunkering
solutions
most
widely
used
today
are
truck
and
terminal
supply.
Both
solutions
are
considered
less
feasible
as
trucks
provide
small
volumes
and
terminals
have
high
operational
cost.
Bunkering
from
vessel/barge,
on
the
other
hand,
is
much
more
flexible
with
respect
to
covering
several
sizes
and
locations
that
in
turn
lowers
both
cost
and
time
spent
on
bunkering.
1.1.2
New
Projects
11
“New
LNG
projects
and
applications
are
being
announced
daily
around
the
world.“
• In
Europe,
the
commission
has
set
aside
€2.1bn
to
equip
139
seaports
and
inland
ports
–
about
10
per
cent
of
all
ports
–
with
LNG
bunker
stations
by
2025.
The
plan
forms
part
of
the
12
new
EU
strategy
for
clean
fuels.
13
• Singapore:
developed
and
opened
an
open-‐access,
multi-‐user
import
terminal.
• In
Norway,
Skangass
in
cooperation
with
Gassnor
in
Risavika
Stavanger
is
establishing
a
bunker
terminal.
• “Washington
State
Ferries
(WSF)
is
exploring
an
option
to
use
liquefied
natural
gas
(LNG)
as
a
14
source
of
fuel
for
propulsion.”
1
9. There
are
LNG
passenger
vessels
currently
under
construction
or
in
design
for
service
in
Argentina,
Uruguay,
Finland,
and
Sweden.
• The
M/S
Viking
Grace
was
launched
some
months
ago
and
is
the
world’s
first
large
passenger
15
vessel
to
be
powered
by
liquefied
natural
gas
(LNG)
• Break-‐bulk
terminal
in
Rotterdam.
16
• Port
of
Antwerp,
creating
a
LNG
bunker
vessel.
• “LNG
bunkering
Ship
to
Ship”
report
carried
out
by
Swedish
Marine
Technology
Forum
in
cooperation
with
Det
Norske
Veritas
(DNV)
and
others.
The
document
is
a
procedural
description
of
how
LNG
bunkering
between
two
ships
should
be
done
based
on
a
real
life
17
example.
Currently
there
are
74
confirmed
LNG
fuelled
ships
contracted.
The
following
figure
includes
developments
in
the
fleet
and
future
expansions
plans
for
the
next
three
years.
•
18
Figure
1:
The
LNG
fuelled
fleet
1.1.3
The
Drive
The
reason
for
this
strong
increase
and
interest
in
LNG
as
a
marine
fuel
is
based
on
two
main
factors:
1. The
Marine
Environmental
Protection
Committee
part
of
International
Maritime
Organization
(IMO)
is
introducing
emission
controls,
constraining
the
extent
of
exhaust
gas
19
emission.
This
is
forcing
the
industry
to
rethink
its
fueling
options.
2. The
availability
of
natural
gas
has
increased
due
to
large
offshore
discoveries
and
unconventional
gas
finds
in
the
US
(shale
gas),
creating
lower
prices
on
natural
gas
compared
to
conventional
fuels.
This
creates
a
drive
in
the
industry,
as
consumers
are
able
to
obtain
commercial
saving
against
alternative
fuels.
2
10. 1.2
Underlying
Hypothesis
The
industry
will
continue
to
introduce
technological
innovations
and
infrastructure
needed
to
supply
the
expanding
LNG
bunkering
market
as
long
as
there
is
a
cost
benefit
to
use
LNG
compared
to
alternative
fuels.
Over
the
last
decades
the
focus
in
the
market
has
been
on
technical
and
commercial
issues,
but
now
that
the
technical
solutions
are
in
place
and
markets
are
growing
the
industry
is
20
taking
a
closer
look
at
strategic
and
regulatory
matters.
As
LNG
marine
fuel
becomes
more
common,
regulations
and
standards
need
to
be
implemented
alongside
technical
and
procedural
developments.
Standards
are
necessary
as
it
ensures
a
level
of
safety
and
create
common
grounds
for
the
operators,
again
making
it
easier
for
the
LNG
industry
to
expand.
There
are
several
bodies
that
cover
various
aspects
of
currently
incomplete
legislation
for
the
industry.
One
of
the
regulatory
frameworks
is
the
upcoming
ISO/TC
67/WG
10
Technical
Report
(which
DNV
is
leading).
The
technical
report
will
be
a
high
level
document
scheduled
for
completion
in
2014.
“The
objective
of
the
ISO
TC
67
WG
10
is
the
development
of
international
guidelines
for
bunkering
of
gas-‐fuelled
vessels
focusing
on
requirements
for
the
LNG
transfer
system,
the
personnel
21
involved
and
the
related
risk
of
the
whole
LNG
bunkering
process.”
Within
this
definition
there
are
several
questions
raised
as
to
what
it
should
cover
and
what
it
needs
to
cover
to
be
an
effective
“tool”
in
future
bunkering
expansion
and
to
answer
the
industry’s
current
demand
for
standardization.
Currently
it
is
the
opinion
of
the
industry
that
comprehensive
international
standards
cannot
be
created,
as
the
experience
of
bunkering
LNG
is
too
limited.
Nonetheless,
with
increased
use
there
will
be
a
need
for
international
standardization
and
guidelines.
1.3
Main
Goal
of
the
Report
The
topic
of
the
report
will
be
an
evaluation
of
LNG
bunkering
solutions,
with
main
focus
on
identifying
technical
challenges,
and
to
identify
potential
areas
for
industry’s
standardization.
1.4
Scope
of
the
Report
The
report
will
cover
LNG
characteristics,
safety
aspects
and
the
current
state
of
technology
for
bunkering
of
LNG.
Present
a
technical
step-‐by-‐step
overview
over
the
bunkering
procedure
and
essential
equipment
used.
It
will
further
discuss
problem
areas,
safety
issues
and
areas
where
standards
could
be
useful
to
promote
more
widespread
use.
The
report
is
limited
by
the
available
technologies
comprising
a
discharging
unit
to
receiving
ship
for
transferring
LNG.
There
are
many
actors
in
the
industry
but
the
experience
is
limited
and
the
solutions
are
proprietary.
3
11. 2
LNG
2.1
LNG
characteristics
Liquefied
Natural
Gas
(LNG)
is
Natural
Gas
(NG)
cooled
to
about
-‐162°C
(-‐260°F)
at
atmospheric
pressure.
It
is
a
condensed
mixture
of
methane
(CH4)
approximately
85-‐96mol%
and
a
small
percentage
of
heavier
hydrocarbons.
LNG
is
clear,
colorless,
odorless,
non-‐corrosive
and
non-‐toxic.
In
liquid
form
it
is
approximately
45%
the
density
of
water
and
as
vapor
it
is
approximately
50%
density
of
air
and
will
rise
under
normal
atmospheric
conditions.
LNG
is
called
a
cryogenic
liquid
–
defined
as
substances
that
liquefies
at
a
temperature
below
-‐73°C
(-‐100°F)
at
atmospheric
pressure.
The
process
th
of
liquefaction
reduces
the
volume
to
1/600
of
its
original
volume,
providing
efficient
storage
and
22
transport.
2.2
LNG
Chain
23
Figure
2:
The
Large
Scale
LNG
Chain
2.2.1
Gas
Field
(Reservoir)
The
Chain
starts
with
gas
production. Raw
NG
comes
from
three
types
of
wells:
oil
wells
(associated
gas),
gas
wells,
and
condensate
wells
(both
non-‐associated
gas).
NG
is
a
mixture
of
hydrocarbons.
It
consists
mostly
of
methane,
but
also
heavier
hydrocarbons:
ethane,
propane,
butane,
and
pentanes.
In
addition,
raw
NG
contains
water
vapor,
hydrogen
sulfide,
carbon
dioxide,
helium,
nitrogen,
and
24
other
compounds.
NG
quality
will
vary
depending
on
its
composition.
A
full
composition
example
of
NG
can
be
found
in
Appendix
A.
2.2.2
Liquefaction
Terminal:
Onshore
Processes
The
rich
gas
from
the
reservoirs
is
purified
to
increase
its
methane
content.
The
pre-‐treatment
includes
removal
of
condensate,
carbon
dioxide
(CO2),
mercury,
sulfur
(H2S),
and
water
(through
dehydration).
After
pre-‐treatment
the
natural
gas
is
now
classified
as
dry/lean
gas.
This
gas
if
further
25
refrigerated
and
eventually
liquefied
and
stored.
2.2.3
Marine
Transport
Large-‐scale
LNG
is
shipped
from
the
liquefaction
terminal
to
the
receiving
terminal
by
LNG
carriers,
3
today
the
normal
capacity
range
for
carriers
is
145,000-‐180,000m .
2.2.4
Receiving
Terminal
At
the
receiving
terminal
LNG
is
stored
in
large
cryogenic
tanks.
The
liquid
is
re-‐gasified/vaporized
and
transported
to
local
market
via
the
gas
grid.
In
some
markets
a
portion
of
the
LNG
is
broken
into
smaller
cargoes
and
distributed
in
smaller
scale
by
rail,
road
or
smaller
LNG
vessels.
Small-‐scale
4
12. distributions
can
also
originate
from
small-‐scale
liquefaction
plants;
this
is
current
practice
in
Norway
and
the
US.
The
small-‐scale
distribution
scenarios
are
the
focus
of
this
project
report.
2.3
LNG
Safety
Issues
In
its
liquid
form
LNG
cannot
explode
and
it
is
not
flammable.
Hazards
arise
when
LNG
returns
to
its
gaseous
state
through
an
uncontrolled
release.
The
release
can
as
an
example
be
caused
by
a
tank
rupture
due
to
external
impact,
leaks
from
flanges
in
the
pipework
or
a
pipe
break,
etc.
The
hazards
can
be
divided
into
two
categories:
1. Cryogenic
effects
from
LNG
Exposure
to
a
liquid
at
-‐163°C
will
cause
humans
to
freeze
and
steel
equipment
to
become
brittle.
Brittle
steel
can
break
and
cause
additional
secondary
failures.
2. Fire
and
explosion
Once
the
LNG
has
leaked,
it
will
form
a
pool
of
liquid
LNG.
This
pool
will
start
to
evaporate
and
form
a
cloud
of
gas,
primarily
consisting
of
methane.
This
gas
will
start
mixing
with
air
(with
a
20.9%
oxygen
ratio)
and
once
it
reaches
a
mixture
between
5-‐15%
gas,
it
is
ignitable.
Outside
the
critical
level
an
explosion
or
fire
will
not
occur.
Below
the
lower
explosion
level
(LEL)
there
is
insufficient
amount
of
methane.
Similarly,
above
the
upper
explosion
level
(UEL)
there
is
insufficient
amount
of
oxygen
present.
The
critical
level
is
at
9%
ratio
of
NG
to
air.
Without
an
ignition
source,
the
gas
will
continue
to
evaporate,
disperse
at
ground
level
while
cold,
start
to
warm
and
rise
to
the
sky
(as
methane
is
lighter
than
air)
and
thereafter
drift
away
until
the
entire
liquid
pool
is
gone.
LNG
evaporates
quickly,
and
disperses,
leaving
no
residue.
There
is
no
environmental
cleanup
needed
for
LNG
spills
on
water
or
land.
If
an
ignition
source
is
present,
the
gas
cloud
could
ignite,
but
only
at
the
edges
where
the
methane
concentration
is
within
the
aforementioned
range.
There
will
be
an
initial
flash,
not
very
violent,
as
the
gas
cloud
ignites,
and
it
will
continue
to
burn
back
to
the
pool
as
a
flash
fire.
The
gas
will
continue
to
burn
as
it
evaporates
until
the
pool
of
LNG
is
gone.
For
an
explosion
to
take
place
the
gas
typically
needs
to
be
in
a
confined
space
(such
as
inside
a
building
or
vessel),
reach
the
right
mixture
with
oxygen
and
have
the
presence
of
an
ignition
source.
In
this
event,
there
could
be
an
explosion
causing
overpressure
and
drag
26
loads
and
potential
damage
to
life
and
property.
27
Figure
3:
Explosion/Flammability
Curve
5
13. 3
LNG
Advantages
For
the
shipping
industry,
as
in
all
other,
profit
is
crucial.
The
provider
of
the
lowest
voyage
cost
for
a
particular
cargo
wins
the
customers.
In
all
cases
fuel
prices
top
the
expense
list
representing
50%-‐70%
28
of
the
total
costs
of
owning
and
operating
a
ship.
For
LNG
to
be
a
viable
alternative
fuel
it
needs
to
be
price
competitive.
To
understand
why
the
industry
is
rethinking
it
fueling
options
and
how
LNG
is
a
sustainable
alternative,
this
chapter
will
present
some
of
the
advantages
of
LNG
as
marine
fuel.
The
main
source
used
is
“Greener
Shipping
in
the
Baltic
Sea”
DNV
Report,
June
2010.
3.1
Environmental
advantages
3.1.1
Alternative
Energy
Sources
Through
technological
developments
and
innovations
the
world
today
has
a
wide
range
of
alternative
energy
sources,
besides
its
hydrocarbon-‐based
sources.
Examples
are
wind,
solar,
biomass,
nuclear,
and
hydro
electric.
For
the
shipping
industry
though,
most
of
these
alternative
do
not
apply:
• Electric:
entire
cargo
area
would
have
to
be
filled
with
batteries
• Biomass:
would
have
to
empty
the
world
of
organic
material
• Solar:
not
enough
surface
area
for
the
number
of
panels
needed
• Wind:
there
is
not
enough
stability
in
the
vessels
to
carry
the
turbines
on
deck.
Another
type
of
wind
source
used
in
the
past
is
sailing,
but
with
respect
to
increased
travel
time
this
is
not
an
option.
The
shipping
industry
needs
to
remain
or
further
increase
its
efficiency
and
consequently
has
no
29
carbon
neutral
alternatives
at
their
disposal.
3.1.2
Emission
Control
Heavy
Fuel
Oil
(HFO),
Marine
Diesel
Oil
(MDO)
and
Marine
Gas
Oil
(MGO)
are
all
current
conventional
bunkering
fuels.
Ship
based
fuel
is
a
large
part
oil
consumption
and
all
these
fuels
are
high
on
emission
rates.
If
carbon
neutral
options
are
out
of
the
question
how
will
the
shipping
industry
meet
future
emission
regulations
dictated
by
international
authorities?
In
2015,
the
allowed
SOx
emissions
from
ships
sailing
within
the
Emission
Control
Area
(ECA)
will
be
reduced.
These
standards
of
emissions
are
already
adopted
on
a
case-‐by-‐case
basis
in
European
inland
waterways
and
ports,
by
certification
from
the
relevant
Classification
Societies.
Further,
in
2016,
the
International
Maritime
30
Organization
(IMO)
will
put
the
new
Tier
III
levels
of
NOx
emissions
into
force.
These
regulations
will
impose
taxes
on
emission,
which
will
increase
the
cost
of
using
conventional
fuels.
31
Figure
4:
ECA
zones
6
14. 3.1.3
Emissions
Requirements
ECA
requirements:
• Maximum
level
of
sulphur
in
fuel,
all
ships:
o 1,0%
by
July
1,
2010
o 0,1%
by
January
1,
2015
• Nitrogen
emission
for
new
buildings:
o 20%
reduction
in
NOx
emission
by
2011
(Tier
II)
o 80%
reduction
in
NOx
emission
from
2016
(Tier
III)
EU
fuel
requirements
now:
• 0,1%
sulphur
in
ports
and
inland
waterways
Global
requirements:
32
• 2020/2025:
sulphur
levels
less
than
0.5%
(date
TBD
pending
2018
review)
3.1.4
Natural
Gas
-‐
The
Solution
Based
on
a
review
of
existing
marine
engine
technology
and
expected
technology
development,
ship
33
owners
currently
have
three
choices
if
they
wish
to
continue
sailing
in
ECAs
from
2015.
• Switch
to
low
sulphur
fuel
–
minor
modifications
to
present
MGO
and
MDO
systems,
but
availability
is
already
limited
• Install
an
exhaust
gas
scrubber
–
expensive
option
• Switch
to
LNG
fuel
–
will
comply
with
upcoming
regulations
and
to
contribute
to
global
emission
reductions,
natural
gas
is
a
viable
option.
Reductions
in
emissions
form
using
LNG
as
a
fuel
• CO2
and
GHG
20-‐25%
• SOx
and
particulates
approximately
100%
• NOx
85-‐90%
34
Figure
5:
Fuel
Emissions,
for
a
typical
existing
ship
7
15. 3.2
Economical
Advantages
“The
marine
fuel
oil
market
is
a
large
global
market
supplying
about
300
million
tons
of
fuel
oil
35
annually,
and
the
price
developments
are
generally
following
that
of
crude
oil.”
Marine
fuels
on
long-‐term
contracts
have
trading
prices
of
14-‐15USD/mmbtu
(million
British
thermal
units)
for
LNG
36
and
107-‐116USD/barrel
for
crude
oil.
(Ref:
International
Energy
Agency
(IEA))
The
prices
are
measured
in
different
units
as
the
substance
is
different,
but
if
a
conversion
is
made
directly
1
barrel
is
approximately
equal
to
5.55mmbtu.
This
means
that
crude
oil
prices
lie
in
the
range
from
19-‐
21USD/mmbtu.
The
LNG
price
is
based
on
large-‐scale
sales,
not
distribution
in
the
small-‐scale.
The
global
natural
gas
market
is
today
not
set
up
to
supply
LNG
in
small
quantities
to
consumers
such
as
ferries.
There
are
currently
no
functioning
markets
for
this,
and
no
reference
prices
consequently
exist.
There
are
many
small-‐scale
LNG
developments
across
the
world,
but
contract
structures
and
prices
for
LNG
as
a
37
marine
fuel
is
uncertain
as
of
today.
3.2.1
Investment
Costs
A
switch
to
LNG
marine
fuel
necessitates
expenses
on
several
levels:
equipment
adaptation,
establishing
bonds
with
new
suppliers,
possibly
planning
new
shipment
routes
as
LNG
will
only
be
provided
in
certain
areas
and
training
of
personnel.
The
investment
cost
will
vary
significantly
between
ship
types
and
must
be
assessed
from
case
to
case.
Nevertheless,
the
added
investment
cost
of
choosing
LNG
fuel
for
new
ships
is
expected
to
decrease
in
the
future.
The
rate
and
extent
of
this
increment
will
largely
depend
on
the
number
of
LNG
fuelled
ships
being
contracted
(economies
of
38
scale).
Higher
volume
of
ships
running
on
LNG
will
create
the
motive
for
building
the
infrastructure
needed
to
support
small-‐scale
supply,
which
in
turn
will
reduce
the
present
day
costs.
Ships
operating
in
the
Baltic
Sea
have
a
fairly
even
age
distribution
from
new
to
40
years
old.
The
replacement
of
old
vessels
is
continuous,
and
it
takes
about
10
years
to
replace
25%
of
the
sailing
39
fleet.
3.2.2
Infrastructure
If
distribution
and
process
costs
could
be
brought
down
to
similar
levels
as
for
oil
by
economics
of
scale,
the
current
fuel
prices
indicates
a
great
economic
potential
for
LNG.
The
infrastructure
for
LNG
bunkering
today,
however,
does
not
allow
for
the
LNG
prices
to
remain
at
this
level.
As
soon
as
LNG
is
broken
into
smaller
volumes
and
distributed
further
through
the
small-‐scale
chain
prices
increase
drastically.
Small-‐scale
liquefaction
and
distribution
expenses
are
the
main
contributors
to
this
price
increase.
The
potential
savings
for
the
ship-‐owner
would
then
be
eliminated.
In
order
to
bring
down
the
price
of
LNG
for
bunkering,
it
must
be
bought
from
full-‐scale
liquefaction
plants
and
efficient
40
distribution
chain
must
be
established.
The
industry
is
already
well
aware
of
these
issues
and
is
searching
for
effective
solutions.
Trough
the
EU
initiative
to
establish
139
ports
(as
mentioned
in
chapter
1),
LNG
will
be
accessible
and
a
ship
will
not
have
to
limit
its
routes
to
specific
bunkering
areas.
Similar
initiatives
are
taken
all
over
the
world.
To
remove
the
cost
of
establishing
small-‐scale
liquefaction
terminals,
bunkering
from
vessel
barge
is
a
maintainable
alternative.
Ship-‐to-‐ship
transfer
is
the
scenario
with
the
best
projections,
both
with
respect
to
flexibility
in
bunkering
location
and
range
in
volume
supply.
The
various
bunkering
scenarios
will
be
discussed
in
the
next
chapter
‘4
Bunkering’.
8
16. 3.2.3
Marine
Fuel
Costs
Every
ship
requires
individual
calculations
with
respect
to
travelling
time
and
distance,
fuel
consumption
and
production
costs.
Overall
it
is
estimated
that
ships
with
an
economical
life
of
15
years
or
more
will
economically
benefit
from
using
LNG
as
a
fuel.
The
advantage
is
greater
with
increasing
fuel
consumption.
The
example
calculation
represents
a
typical
Baltic
Sea
cargo
ship
of
41
approximately
2,700
gross
tons,
3,300
kW
main
engine
and
5,250
yearly
sailing
hours.
Figure
6:
Lifecycle
economics
for
a
typical
ship
The
engine
size
and
consumption
levels
in
this
example
are
modest.
Still,
it
is
clear
that
MDO
is
the
most
expensive
option
and
LNG
is
found
to
be
a
superior
alternative.
The
results
are
favorable
to
such
an
extent
that
it
is
even
reasoned
to
be
profitable
without
ECA
requirements.
9
17. 4
Bunkering
This
chapter
will
define
LNG
bunkering,
present
the
various
bunkering
scenarios,
provide
a
detailed
technical
description
of
the
bunkering
procedure,
and
present
approved
equipment.
4.1
LNG
Bunkering
Definition
“The
definition
of
LNG
bunkering
is
the
small-‐scale
transfer
of
LNG
to
vessels
requiring
LNG
as
a
fuel
for
use
within
gas
or
dual
fuelled
engines.
LNG
bunkering
takes
place
within
ports
or
other
sheltered
42
locations
at
the
base
case.”
Bunkering
should
not
be
considered
in
the
same
context
as
large
scale,
commercial
transfer
of
cargo
between
ocean-‐going
LNG
carriers.
This
larger
operation,
where
3
volumes
are
typically
above
100,000m
is
covered
separately
under
preceding
technical
releases
and
43
standards.
4.1.1
Engines
The
ship
owners
have
two
options
with
regards
to
engine
design:
dual
fuel
engines
or
LNG
lean
burn
mono
fuel
engines.
Dual
fuel
engines
run
on
both
LNG
and
conventional
fuels
from
separate
tanks.
It
is
a
flexible
solution
for
varying
availability
in
LNG.
In
LNG
mode
these
engines
only
consume
a
minor
44
fraction
of
conventional
fuel.
Bunkering
procedure
for
dual
fuel
engines
is
a
process
that
can
take
place
simultaneously
for
both
fuels.
The
procedure
described
below
is
however
limited
to
the
LNG
transfer
system.
4.2
LNG
Bunkering
Scenarios
Truck-‐to-‐Ship
(TTS):
micro
bunkering,
discharging
unit
is
a
LNG
road
tanker
size
3
approximately
50-‐100m .
• Ship-‐to-‐Ship
transfer
(STS):
discharging
unit
is
a
bunker
vessel
or
barge
with
size
200-‐
3
10,000m .
• Terminal
(Pipeline)-‐to-‐Ship
(PTS):
satellite
terminal
bunkering
serves
as
the
discharging
unit
3
and
supply
sizes
are
approximately
100-‐10,000m .
PTS
and
TTS
are
the
most
established
bunkering
scenarios
per
today
and
they
are
both
classified
as
onshore
supply.
STS
will
also
take
place
while
the
receiving
unit
is
at
dock
or
in
a
port
environment,
but
both
units
involved
in
the
transfer
are
seaborne
and
the
transfer
is
therefore
classified
as
offshore.
Use
of
STS
makes
the
bunkering
location
more
flexible
than
PTS
and
it
can
supply
higher
volumes
than
TTS.
Developments
within
this
scenario
are
the
most
feasible
and
are
therefore
45
essential
in
making
LNG
competitive
against
other
marine
fuels,
especially
for
larger
ships.
•
10
18. 4.3
LNG
Bunkering
Procedure
Time
efficiency
and
safety
are
elements
of
paramount
importance
when
it
comes
to
the
bunkering
procedure.
Developing
a
suitable
procedure
is
fundamental
in
obtaining
these
facets.
The
industry
is
currently
developing
solutions
to
achieve
similar
duration
of
bunkering
operations
for
LNG
as
for
conventional
fuels.
As
LNG
bunkering
is
evolving,
technology
improvements
and
innovations
are
added
continually.
The
process,
being
relatively
new,
is
not
yet
regulated
or
standardized
(will
be
discussed
further
under
section
‘5
Regulations’)
and
therefore
there
are
several
elements
that
could
vary
for
each
individual
bunkering
case.
Nevertheless,
this
section
aims
to
provide
a
description
suited
for
various
needs
and
different
bunkering
scenarios.
Variations
in
bunkering
procedure
depending
on
scenario
will
be
mentioned.
In
this
section
of
the
report
there
will
be
no
elaborations
on
general
principles,
conditions,
requirements,
safety
aspects
and
communication
related
to
the
process.
The
same
applies
to
details
exclusively
relating
to
bunkering
of
fuels
other
than
LNG,
in
the
case
of
dual
fuel
engines.
The
focus
will
be
on
the
technical
aspects
of
the
procedure
and
the
equipment
used.
The
main
source
for
this
part
of
the
report
is
the
short
film
“Step
by
step
Bunkering
by
DNV”.
Additional
details
have
been
acquired
from
discussions
with
individuals
from
the
industry
(se
preface
for
names)
and
the
report
‘LNG
ship
to
ship
bunkering
procedure’
by
the
Swedish
Marine
Technology
Forum
et
al.
46
Figure
7:
Overall
Bunkering
Layout
The
diagram
is
schematic
not
to
scale,
especially
when
it
comes
to
pipe
length.
Initially
all
valves
are
closed
as
shown
in
the
diagram.
The
transfer
hose
is
not
connected
until
step
three
but
included
in
this
diagram.
The
first
step
takes
place
during
ship
mooring,
or
in
the
case
of
ship-‐to-‐ship
transfer
during
the
bunker
vessels
mooring
up
against
the
receiving
ship.
Discharging
unit
can
be
either:
terminal,
truck
or
bunker
vessel/barge.
Variations
in
design
and
layout
can
take
place,
but
overall
this
is
a
representative
example
of
a
layout
and
it
gives
a
good
basis
for
explaining
the
bunkering
procedure.
11
19. 4.3.1
Step
1
–
Initial
Precooling
1
Filling
lines
are
precooled
during
mooring.
Valves
V2,
V5,
V8
and
V9
are
opened.
The
system
needs
to
be
cooled
down
slowly,
otherwise
one
part
will
contract
and
another
not.
Improper
cooling
could
also
lead
to
pipe
cracking.
The
precooling
sequence
depends
on
cargo
pump,
design
of
the
discharging
47
unit
and
size
of
installation.
The
cold
LNG
(blue)
exits
tank
1
form
the
bottom,
and
slowly
“pushes”
the
warmer
NG
(red)
in
the
pipes
into
the
top
of
tank
1.
Figure
8:
Bunkering
Procedure
Step
1
During
this
stage
both
units
must
check
temperature
and
pressure
of
their
respective
LNG
tanks.
Within
the
tank,
temperature
is
directly
correlated
with
pressure.
If
the
temperature
of
the
receiving
tank
is
significantly
higher
than
the
discharging
(classified
as
a
“warm”
tank),
there
will
be
an
initial
vaporization
when
starting
to
transfer
LNG.
As
the
pressure
of
the
tank
might
be
too
high
for
the
LNG
transfer
to
be
initiated.
This
will
increase
the
tank
pressure
and
can
trigger
the
pressure
relief
valve
to
open
if
the
pressure
exceeds
the
set
limit.
The
pressure
of
both
tanks
must
be
reduced
prior
to
the
48
bunkering
in
case
of
a
high
receiving
tank
temperature.
When
the
levels
in
the
receiving
tank
are
low,
the
rate
of
evaporation
and
heat
ingress
to
the
tank
increases,
causing
a
higher-‐pressure
build-‐
up.
The
transfer
of
LNG
requires
a
certain
pressure
difference,
which
generally
is
determined
by
the
cargo
pump
capacity
and
the
pressure
in
the
receiving
tank.
The
larger
the
pressure
difference,
the
more
3
efficient
the
transfer.
For
TTS
bunkering
with
capacities
of
50
m /h,
a
typical
cargo
pump
can
deliver
at
around
4
barg.
In
a
warm
tank,
the
pressure
may
be
as
high
as
5
barg.
To
be
able
to
conduct
the
transfer
you
need
a
lower
pressure
in
the
receiving
tank
than
what
is
delivered
by
the
pump.
12
20. 4.3.2
Step
2-‐
Initial
Precooling
2
The
fixed
speed
cargo
pump
at
the
discharging
unit
also
requires
precooling.
Valves
in
step
1
remain
opened
and
additionally
valves
V3,
V4
and
V6
are
opened.
For
transfers
where
the
pressure
difference
between
the
discharging
and
receiving
unit
is
greater
than
2barg,
tank
1
pressure
will
be
49
utilized
as
a
driving
force.
This
makes
the
cargo
pump
redundant.
Figure
9:
Bunkering
Procedure
Step
2
4.3.3
Step
3
–
Connection
of
Bunker
Hose
All
previously
opened
valves
are
now
closed.
Dedicated
discharging
units
may
be
fitted
with
specialized
hose
handling
equipment
(i.e.
hose
crane)
or
loading
arms,
to
deliver
the
bunker
hose
to
the
receiving
ship.
The
hose
is
connected
to
the
manifold.
Each
manifold
are
to
be
earthed
and
the
receiving
ship
shall
be
equipped
with
an
insulating
flange
near
the
coupling
to
prevent
a
possible
50
ignition
source
due
to
electrostatic
build-‐up.
One
or
two
flexible
hoses
will
be
connected
between
the
units
–
one
liquid
filling
hose
and
one
vapor
return
hose
if
needed.
For
smaller
transfers
with
3
capacities
range
of
around
50-‐200m /h,
and
where
the
receiving
tank
is
an
IMO
type
C
tank
with
the
possibility
of
sequential
filling,
a
vapor-‐return
hose
will
generally
not
be
needed.
For
larger
transfer
rates
a
vapor
return
line
may
be
used
in
order
to
decrease
the
time
of
the
bunkering.
Still,
it
is
the
pressure
regulating
capability
of
the
receiving
tank
that
determines
whether
a
vapor
return
line
is
required
or
not.
This
step
will
visually
look
like
the
initial
drawing
of
the
entire
system
(Figure
7).
13
21. 4.3.4
Step
4
-‐
Inerting
the
Connected
System
Inert
gas,
nitrogen
(green),
is
used
to
remove
moisture
and
oxygen
(below
4%)
from
tank
2
and
associated
piping.
Inerting
is
accomplished
by
sequential
pressurization
and
depressurization
of
the
system
with
nitrogen.
Presence
of
moisture
in
the
tanks
or
pipes
will
create
hydrates,
which
is
a
form
51
of
ice
lumps
that
will
be
difficult
to
remove
from
the
system.
Oxygen
in
the
system
is
a
risk
as
explained
in
section
‘2
LNG’.
Valves
opened:
V10,
V11,
V12
and
V16.
Figure
10:
Bunkering
Procedure
Step
4
4.3.5
Step
5
–
Purging
the
Connected
System
The
remaining
system
is
purged
with
NG
(until
it
reaches
97-‐98%
ratio),
to
remove
remaining
nitrogen
according
to
engine
specifications.
Valve
V16
is
closed
prior
to
purging.
Valve
V15
is
opened,
natural
gas
is
now
moving
out
from
the
receiving
tank.
Venting
trace
amount
of
methane
through
the
mast
(vent
2)
is
current
practice.
Valve
V10
should
be
closed
quickly
after
the
pipes
have
been
cleaned
so
as
not
to
let
too
much
methane
escape
to
the
surroundings
through
the
vent.
The
industry
is
now
52
looking
for
zero
emission
solutions.
Figure
11:
Bunkering
Procedure
Step
5
14
22. 4.3.6
Step
6
–
Filling
Sequence
For
the
filling
sequence
both
bottom
filling
and
top
filling
(the
shower/spray)
can
be
used.
For
top
filling
valve
V15
remains
open,
for
bottom
filling
it
is
closed
and
valve
V13
is
opened.
To
start
the
transfer
from
tank
1
to
tank
2
valves
V3,
V4,
V7,
V8,
V11
and
V12
also
have
to
be
opened.
Common
practice
is
to
start
with
top
filling
as
this
will
reduce
the
pressure
in
the
fuel
tank
(tank
2),
and
then
move
over
to
bottom
filling
when
a
satisfying
pressure
is
achieved.
A
high
pressure
in
the
receiving
tank
will
make
it
harder
for
the
LNG
transfer
to
take
place
and
the
pump
would
have
to
work
harder.
An
example
of
a
tank
filling
sequence
and
associated
acceptable
levels
is
given
in
section
6.4.
Figure
12:
Bunkering
Procedure
Step
6
-‐
Bottom
Filling
Figure
13:
Bunkering
Procedure
Step
6
-‐
Top
Filling
(Spray)
3
Transfer
speed
range
from
100-‐1000m /h
depending
on
scenario,
tanks
and
equipment,
and
whether
bottom
or
top
filling
is
used.
Bottom
filling
can
take
much
higher
volumes
than
top
filling.
Bottom
filling
is
therefore
preferred
with
respect
to
time,
but
it
is
important
that
the
tank
pressure
allows
for
this
to
take
place.
Sequential
filling
i.e.
alterations
between
top
and
bottom
filling
during
the
transfer
is
also
standard
practice,
to
control
the
pressure
in
the
receiving
tank.
This
rate
can
be
withheld
during
the
transfer
until
agreed
amount
is
reached.
The
transfer
is
to
be
monitored
on
both
ships
with
regards
to
system
pressure,
tank
volume
and
equipment
behavior.
This
53
procedure
is
to
be
performed
for
each
tank
regardless
of
fuel
type.
Maximum
level
for
filling
the
LNG
tanks
is
98%
of
total
volume
according
to
class
rules,
but
is
normally
lower
for
system
design
reasons.
15
23. 4.3.7
Step
7
–
Liquid
Line
Stripping
The
liquid
that
remains
in
the
bunker
hoses,
after
the
pump
has
stopped,
must
be
drained
before
disconnection.
Valves
V3,
V4
and
V11
on
discharging
unit
is
closed,
while
valve
V6
is
opened.
This
valve
links
to
the
top
of
the
fuel
tank
(tank
2).
This
process
creates
a
pressure
build-‐up
due
to
a
rise
in
temperature
in
the
remaining
liquid
left
in
the
pipes
and
hose.
LNG
residuals
in
these
areas
are
forced
into
both
tanks.
Subsequent
opening
and
closing
of
the
shipside
valve
V12,
pushes
the
remaining
LNG
54
into
the
receiving
ships
tanks.
Figure
14:
Bunkering
Procedure
Step
7
4.3.8
Step
8
–
Liquid
Line
Inerting
Remaining
natural
gas
in
liquid
line
is
removed
by
inerting
gas
(nitrogen)
for
safety
reasons.
Valves
V6,
V7,
V8
and
V15
are
closed,
while
V10,
V11,
V12
and
V16
are
opened.
Venting
trace
amount
of
methane
through
the
mast
is
current
practice.
The
industry
is
now
looking
for
zero
emission
55
solutions.
4.3.9
Step
9
–
Disconnection
Upon
confirmation
of
transferred
amount
and
quality,
the
vessel
may
commence
disconnection
of
56
the
transfer
hose,
unmooring
and
departure.
Bunkering
time
will
vary
depending
on
bunkering
scenario,
transfer
rates,
system
and
equipment
57
design,
capacities,
and
the
use
of
vapor
return.
For
an
example
of
time
spent
see
Appendix
B.
16
24. 4.4
Equipment
This
section
will
cover
some
of
the
essential
equipment
used
in
the
transferring
process.
Information
from
this
part
is
obtained
from
the
following
sources:
M.
Esdaile
and
D.
Melton,
Shell
Shipping,
LNG
Bunkering
Installation
Guidelines
SST02167,
2012
and
LNG
ship
to
ship
bunkering
procedure,
Swedish
Marine
Technology
Forum
and
DNV
Class
rules.
4.4.1
Tanks
58
Figure
15:
IMO
Type-‐C
Tank,
CRYO
AB
4.4.1.1
Storage
Tank
–
Discharging
Unit
All
tank
types
-‐
A,
B,
C
and
membrane
tanks
are
approved
for
LNG
cargo.
There
are
major
differences
in
usage
and
regulations
between
tanks
A
and
B
vs.
C.
If
tanks
A
and
B
are
to
be
used
it
is
seen
as
an
exception
and
several
risk
analysis
would
have
to
be
completed
for
each
individual
case,
to
document
its
safety.
The
tanks
are
categorized
correspondingly:
• Atmospheric
tanks:
Typically
atmospheric
tanks
would
be
IMO
type
A
and
B
tanks
or
membrane
tanks
and
have
a
design
pressure
below
0.7
barg.
The
atmospheric
tanks
cannot
be
pressurized
and
it
is
therefore
necessary
with
additional
equipment
for
pressure
control
and
deep-‐well
pumps
to
ensure
sufficient
LNG
flow
to
the
engines.
In
order
to
operate
and
empty
the
tank
in
case
of
pump
breakdown,
redundancy
of
the
deep-‐well
pumps
is
necessary.
The
main
advantage
with
an
atmospheric
tanks
is
its’
high
volume
utilization,
due
59
to
the
prismatic
shape.
• Pressure
tanks:
Tanks
with
pressure
above
0.7
barg
are
normally
type
C
tanks.
These
tanks
are
made
after
recognized
pressure
vessel
standards
given
in
the
IGC
Code.
There
are
several
designs
available;
cylindrical
tanks
with
or
without
vacuum
insulation,
or
bi-‐lobe
tanks.
All
60
LNG
fuelled
ships
today
have
vacuum
insulated
IMO
type
C
tanks.
4.4.1.2
Fuel
Tank
–
Receiving
Ship
For
the
LNG
fuel
tank,
several
containment
systems
are
feasible,
with
many
new
tank
designs
under
development.
These
tanks
are
made
after
recognized
pressure
vessel
standards
given
in
the
IGC
Code.
The
tanks
are
cylindrical,
pressurized,
double
skinned
tank
systems
including
a
venting
system
for
discharging
excess
vapor.
These
features
are
crucial
in
vapor
management
and
maintaining
low
61
temperatures.
Type
C
tanks
have
a
maximum
operating
pressure
of
about
10
barg
and
are
approved
by
several
class
3 62
societies
as
fuel
tanks.
The
size
of
the
tank
will
vary
but
the
size
range
today
is
40-‐250m .
The
tanks
are
equipped
with
both
bottom
filling
and
top
spray
features.
Through
spraying
sub
cooled
LNG
into
the
vapor
space
(gas
pillow)
of
the
tank
the
cold
liquid
will
condense
the
vapor
and
reduce
the
tank’s
pressure.
This
process
eliminates
the
need
for
a
vent
return
in
the
tank.
This
function
of
the
tank
63
could
create
a
100%
fill
situation.
To
comply
with
the
issue
of
overfilling,
the
tank
has
a
high-‐level
switch,
which
will
activate
an
alarm.
This
will
automatically
shut
down
the
transfer
system
as
it
is
directly
linked
to
the
vessel’s
ESD
system.
As
previously
stated,
tanks
for
liquid
gas
should
not
be
filled
to
more
than
98%
full
at
the
reference
temperature,
where
the
reference
temperature
is
as
defined
in
the
IGC
Code,
paragraph
15.1.4.
Means
of
measuring
the
liquid
level,
both
volume
and
height,
17
25. within
the
tank
are
to
be
provided
and
installed
in
such
a
way
as
to
be
compliant.
The
preferred
means
of
level
measurement
is
a
radar
type
tank
measurement
system,
or
similar
technology,
which
64
is
also
able
to
measure
corresponding
pressures
and
temperatures
within
the
tank.
The
benefits
of
using
Type-‐C
tanks
are
standard
tanks
with
long
experience,
high
bunkering
rates,
easy
installation,
and
the
ability
the
handle
pressure
build-‐up
in
cases
of
zero
consumption.
The
65
disadvantages
are
space
requirements
due
to
its
cylindrical
shape.
4.4.2
Valves
The
valves
used
are
manifold
trip
valves
that
can
handle
both
liquid
and
vapor
transfers,
and
need
to
comply
with
regulations
set
in
EN1474.
A
manually
operated
stop
valve
and
a
remote
operated
shut
down
valve
in-‐series,
or
a
combined
valve,
should
be
fitted
in
every
bunkering
line
on
both
units
66
(discharging
and
receiving).
The
valves
should
be
controlled
from
the
control
room
of
both
units.
4.4.3
Hose
The
flexible
cryogenic
hose(s)
with
a
single
wall
construction
are
used.
Insulation
should
be
applied
to
the
hose
for
safety
reasons
but
should
not
limit
the
flexibility
of
the
hose.
The
hoses
are
connected
67
via
electrical
insulated
flanges
made
of
steel,
an
emergency
quick
release
connector
(ERC).
68
Maximum
velocities:
vapor
30m/s
and
liquid
7-‐10m/s.
Minimum
requirements
for
hoses
are
defined
by
the
international
standards:
EN
1472-‐2
and
IGC
chapter
5.7/IMO
document
MSC.285(86).
Approved
bunker
hoses:
EN
12434,
BS
4089,
EN
1474
part
1
LNG
Transfer
arms
(being
revised
as
an
ISO),
EN
1474
part
2
LNG
Hoses.
4.4.4
Loading
arms
Loading
arms
will
be
subjected
to
the
requirements
of
the
new
ISO
LNG
bunkering
standard.
They
shall
be
designed
in
accordance
with
ISO
/
DIS
28460
and
EN
1474-‐1,
Section
4,
Design
of
the
arms.
Weight,
size
and
handling
of
the
equipment
classified
as
cryogenic
will
affect
the
safety
assessment
of
the
given
operation.
The
equipment
used
during
TTS
today
does
not
include
loading
arms.
Hose
dimension
will
for
such
operations
be
around
4
inches.
For
STS
operations
the
dimensions
would
be
considerably
higher,
10
inches
or
more.
In
addition
to
that
you
have
torque
by
relative
movement
of
the
ship
in
relation
to
each
other,
making
the
need
for
loading
arms
necessary
to
ensure
that
the
hose
does
not
come
into
69
contact
with
water
or
the
steel
deck.
PTS
will
also
use
hoses
larger
than
TTS.
Additionally
the
installation
is
fixed
which
makes
the
option
to
use
loading
arms
even
more
favorable
as
it
secures
equipment
and
strengthens
safety
elements.
4.4.5
Pipes
Main
piping
systems
in
both
units
are:
liquid
bunker
line,
gas
return
line
and
nitrogen
supply
system.
The
pipelines
are
equipped
with
several
flow
meters
to
measure:
volume
delivered,
pressure
and
temperature
for
monitoring
of
the
operation.
Pipes
containing
LNG
or
associated
vapor
shall
be
double
walled
pipe
configurations
in
stainless
steel
with
perlite
filling
under
a
permanent
vacuum.
Pipe
work
should
be
fully
compliant
with
IGC
Code,
Section
6.2.
4.4.6
Pump
The
pump
is
designed
for
handling
cryogenic
material.
It
is
theoretically
possible
to
transfer
between
tanks
in
the
presence
of
a
delta
pressure
of
2
barg
or
more.
Seeing
as
the
pressure
difference
could
be
hard
to
control
and
maintain,
it
may
be
difficult
to
transmit
without
a
pump.
A
frequency
controlled
drive
for
the
pump,
which
will
allow
pump
speed
to
be
regulated
and
the
transmission
rate
70
accordingly
with
respect
to
pressure
and
temperature
is
recommended.
The
time
it
takes
to
refuel
is
18
26. critical
for
the
receiving
ship.
In
other
words,
if
you
want
to
optimize
the
transmission
rate
to
optimize
the
time
of
bunkering
a
variable
speed
pump
will
make
it
easier
to
achieve.
4.4.7
Emergency
Shutdown
Systems
(ESD)
“The
primary
function
of
the
ESD
system
is
to
stop
liquid
and
vapor
transfer
in
the
event
of
an
unsafe
71
condition
and
bring
the
LNG
transfer
system
to
a
safe,
static
condition.”
LNG
vessels
commonly
refer
to
the
emergency
shutdown
system
(ESD)
as
ESD1
and
the
emergency
release
system
(ERS)
as
ESD2.
4.4.8
Emergency
Release
Systems
(ERS)
To
comply
with
the
necessary
release
requirements,
an
ERS
is
usually
substituted
by
a
break
away
coupling
known
as
an
emergency
release
coupler
(ERC).
4.4.9
Emergency
Release
Couplers
(ERC)
The
ERC
unit
is
to
be
fitted
at
the
receiving
units
manifold
between
the
flexible
hose
and
the
flange
connection
of
the
receiver.
The
ERC
is
to
incorporate
integral
automatic
valves
that
will
close
when
separated,
either
by
nature
of
its
design
or
by
remote
motorized
operation.
Its
function
is
to
prevent
release
of
liquid
or
vapor
to
the
surroundings
through
rapid
closure.
Under
excessive
tension
it
serves
as
a
weak
link
providing
automated
release
to
avoid
the
hose
from
breaking.
It
allows
for
quick
connection
and
disconnection.
The
system
design
must
take
into
account
possible
ice
build-‐up
and
its
72
effects
on
operation.
This
would
generally
be
a
requirement
for
all
types
of
equipment
in
contact
with
cryogenic
material.
Figure
16:
Dry
Break
Coupling
(Mann
Teknik
AB)
4.4.10
Control
and
Monitoring
Systems
Control
and
Monitoring
Systems
need
to
comply
with
the
IMO
document
MSC
285(86).
All
installations
need
to
be
equipped
with
control
monitoring
and
safety
systems.
The
most
essential
monitoring
system
is
gas
detection.
The
areas
that
are
critical
for
supervision
are
areas
where
unintended
release
of
gas
can
occur
such
as
manifold
areas,
double
walled
pipes
and
enclosed
areas
73
containing
pipe
work
associated
with
the
bunkering
operation.
The
control
and
monitoring
system
should
be
directly
linked
to
the
ESD.
The
individual
shutdown
initiators
will
vary
for
each
installation.
Minimum
control
and
monitoring
requirements,
on
both
distributing
and
receiving
units,
are:
1. Position
(open/closed)
and
high-‐pressure
detector
in
all
bunker
manifold
valves.
2. Operation
of
any
manual
emergency
stop
push
button,
3. ‘Out
of
range’
sensing
on
the
fixed
loading
arm,
4. Gas
detection
(above
40%
LEL),
5. Fire
detection,
6. High-‐pressure
and
high-‐level
detectors
in
receiving
LNG
tank,
7. High/low-‐pressure
and
high-‐level
detectors
in
distributing
LNG
storage
tank.
19
