Impact assessment of measures to prevent
explosions on tankers transporting low flash point
cargoes
Port of Rotterdam Authority
9 februari 2012
Final Report
9X0291
CONTENTS
Page
1
INTRODUCTION
1.1
Background
1.2
Objective
1.3
Contents
1
1
2
3
2
INERT GAS SYSTEMS
2.1
Introduction
2.2
Inert Gas: Nitrogen and Flue Gas
2.3
Inert Gas System Lay-out
2.3.1
Nitrogen Generation on Board
2.3.2
Nitrogen Supplied from Shore
3
3
3
4
4
5
3
SHIP IMPACT ASSESSMENT
3.1
Introduction
3.2
Service Time
3.3
Methods of applying inert gas
3.3.1
Purging+inerting
3.3.2
Blanketing
3.4
Options for Ships to Reduce Impact on service time
3.5
Quantification of Inerting Time
3.5.1
Time Required for Applying Inert Gas based on Interviews
3.5.2
Time Required for Applying Inert Gas based on Selection of Port
Logs
3.6
Summary Ship Impact
10
11
4
PORT IMPACT ASSESSMENT
4.1
Introduction
4.2
Data Input and Analysis
4.3
Current Ship Movements
4.4
Growth Scenarios
4.5
Impact on Service Time for the PoR
4.6
Analysis of Specific Berths with High Impact
4.6.1
Overview Impacted Calls 8 – 20 kDWT
4.6.2
Impacted calls versus other ship sizes at most Impacted Berths
4.7
Utilisation Rate for Most Impacted Berths
4.8
Utilisation Rate for Vopak Terminals in the Botlek area
4.9
Amount of 4,000 – 8,000 DWT ships
13
13
13
14
16
18
18
18
20
21
23
23
5
ENVIRONMENTAL EFFECT IGS
5.1
Nitrogen Consumption for Purging + Inerting
5.2
Nitrogen consumption for blanketing
5.3
Environmental Impact
25
25
26
26
6
FINANCIAL IMPACT ASSESSMENT
6.1
Introduction
6.2
Port of Rotterdam
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6.2.1
6.2.2
6.3
6.3.1
6.3.2
6.3.3
6.4
7
Costs of Increased Service Time in Terms of Lost Revenues (Port
Dues)
Indication of Costs for Additional Facilities (Jetties)
CAPEX and OPEX Ship
Lost Revenues due to Delay
CAPEX and OPEX of the IGS
Costs for Shore Supplied Nitrogen
Terminal
CONCLUSIONS
7.1
Impact on the PoR
7.2
Impact on Ships
7.2.1
Additional Service Time
7.2.2
Lost Revenues for Ship Operators or extra Costs for Charterers
7.2.3
OPEX of IGS
7.3
Terminals
7.4
Summary of Financial Impact
Annex 1
Annex 2
Annex 3
33
33
34
34
34
35
35
35
Ship and cargo types
Inert Gas systems
Data collection
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1
INTRODUCTION
1.1
Background
The Marine Safety Committee of IMO, and in particular, the sub-committee on Fire
Protection received several propositions1 to amend the SOLAS2 regulations regarding
the additional safety measures for newly built oil and chemical tankers under 20,000
DWT carrying low flashpoint cargoes (flashpoint of <60ºC).
The propositions concern the installation and application of inert gas systems, nitrogen
bottles or shore-supplied inert gas where appropriate. The lower size limit was
discussed; lower size limits between 4,000 and 8,000 tonnes deadweight were
proposed. The lower size limit for the application of inert gas is currently set at 8,000
DWT.
Currently these ships are exempted from having to operate with an Inert Gas System
(IGS). However, numerous fire and explosion events suspected of originating in the
ship’s hold were reason for concern. Reference is made to documents FP 51/10/1 and
FP 52/INF.2, in which the fire and explosion casualties are listed that occurred in cargo
tanks on tankers of 4,000 DWT and upwards.
The Sub-Committee on Fire Protection agreed that the fitting of appropriate IGS to new
oil tankers of less than 20,000 tons deadweight and new chemical tankers carrying lowflash point cargoes would minimize the risk of fires and explosions. It was also agreed
that the benefits of such fitting should outweigh any negative effects of the introduction
of IGS, such as:
 increased fuel consumption;
 increased CO2 emissions;
 increased building costs;
 increased complexity of procedures;
 increased risk associated with tank entries.
Reference is made to two other documents that were submitted to IMO:
1. Japan prepared a Formal safety Assessment and a cost benefit assessment on
application of requirement of IGSs to tankers;
2. China provided comments and recommendations for the installation of IGSs on
new oil and chemical tankers of less than 20,000 DWT, in which the lower
deadweight limit should be 8,000 DWT, as the FSA study from Japan (FP
51/10/1 and FP 52/INF.2) indicated that installation of IGSs on oil tankers of less
than 8,000 DWT would not be cost-effective.
3. Norway and Oil Companies International Marine Forum (OCIMF) proposed that
the additional requirements should apply to all tankers of 500 gross tons and
above. Furthermore Norway and OCIMF mentioned that no explosions are
known to have occurred during the loading phase of the carriage of lowflashpoint cargoes, and therefore proposed that Inert gas on chemical tankers
1
Norway and OCIMF (FP 54/6/2) proposed amendments to SOLAS regulation II-2/4.5.5 to require the inerting of
tanks on new tankers carrying low-flashpoint cargoes, which would apply to all tankers of 500 gross tonnage and
above, regardless of the size of the ship or the size of the tanks
2
SOLAS regulation II-2/4.5.5 (SOLAS = Safety Of Life At Sea)
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(regardless of size) can, under certain conditions, be applied after the low-flash
point cargoes have been loaded.
The documents that were submitted mainly evaluated the safety aspects and the impact
on ship operations.
An impact assessment was initiated by the Port of Rotterdam Authority (PoRA) of the
additional IGS requirements on ships operating in ports and the impact on port facilities
and port logistics in the Port of |Rotterdam (PoR), since these impacts have not been
assessed in the earlier mentioned assessments.
The underlying report elaborates on the above mentioned impact assessment. The
impact assessment was supported by interviewing representatives of the PoRA,
terminals, ship operators and a major oil company. The interviewed companies are
listed in Annex 3.
The International Chamber of Shipping and the International Parcel Tankers Association
have suggested implementing the new IGS requirements for new built ships from 2015
onwards. After evaluation of the practicality of the new IGS requirements it is expected
that these new regulations will also be applied to existing ships. It should be noted that
these amendments need to be agreed by the Maritime Safety Committee in May 2012.
1.2
Objective
The objective of this study is to analyze the impact on the Port of Rotterdam of the
suggested additional regulations regarding the application of Inert Gas Systems for
newly built tankers between 8,000 and 20,000 DWT carrying low flashpoint Marpol
Annex II cargoes (flashpoint <60 ºC ) on:
 Operation of ships in ports;
 Logistics in ports;
 The environment;
 Financial Impact.
Remarks:
 The new inert gas requirements will impact chemicals and clean petroleum
products3 with a flashpoint below 60ºC that are included in Marpol annex II;
 Other black oil products as listed in Marpol annex I (such as for instance crude
oil, fuel oil or reformate) are exempted from this impact analysis since inert gas
systems are mandatory for these products already;
 A target group of ships is defined as the group that is expected to show the most
impact. This target group is defined as chemical tankers ranging 8,000 – 20,000
DWT carrying low flashpoint (<60ºC) Marpol annex II cargo;
 In paragraph 4.9, an outline is given of the additional amount of ships that will be
impacted if the lower size limit would be set at 4,000 DWT;
 As the earliest date for the entry into force of the regulations would be January
2015, and the expected duration for implementation for all ships is 5 years, the
impact will be assessed for 2020 using growth scenarios as outlined in the vision
of PoRA towards 2030.
3
commonly referred to as chemicals and mineral oil products by Port of Rotterdam
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1.3
Contents
Chapter 2 describes the different types of inert gas and the configurations used to inert
tankers.
In Chapter 3 the impact on ships operating in port is assessment is described. Firstly,
the different methods to apply inert gas as safety measure in tankers are described and
secondly the quantification of the impact on ships operating in ports is presented in
Paragraph 3.5.
In Chapter 4, the data input and the impact on the sea-going ships operating in the PoR
is presented. In Paragraph 4.4, the situation of 2011 is converted to the expected
situation in 2020, based on the growth scenarios as defined by PoRA for the Port Vision
towards 20304. Paragraph 4.5 presents the impact on the most impacted berths,
expressed as an indication of the increase in utilization rate for sea-going ships.
In Chapter 5 the environmental effects for the additional inert gas requirements for seagoing ships are presented.
Chapter 6 indicates the financial impact of the additional inert gas requirements and in
Chapter 7 the conclusions are presented.
2
INERT GAS SYSTEMS
2.1
Introduction
In order to obtain insight into inert gas systems, this Chapter shortly addresses the
method of application and system lay-out of inert gas. For a thorough analysis,
reference is made to Annex 2.
2.2
Inert Gas: Nitrogen and Flue Gas
In the context of tanker operations an inert gas system is used for the purpose of fire
and explosion prevention5. Inert (non-reactive) gas is used to fill the vapour space of the
cargo tanks to reduce the oxygen content to a level6 where the atmosphere will no
longer support the combustion of flammable vapour7. In the context of tanker operations,
an inert atmosphere is created using either Nitrogen (N2) or oil fired inert gas generators
(Flue Gas).
Oil fired inert gas generators (either boilers or burners) are mainly applied on oil product
tankers, where the inert gas is flue gas (mainly CO2 and combustion products). As flue
gas imposes the risk of contaminating cargo it is exclusively used for inerting low
flashpoint petroleum products such as crude oil. Burners generate cleaner inert gas than
boilers and are sometimes applied for mineral oil products. For chemicals nitrogen is the
4
www.havenvisie2030.nl/files/downloads/pdf/C073_Ramingen_Goederenstromen_HV_2030_LR.pdf
5
Other purposes include prevention of chemical reactions or maintaining cargo quality
6
For nitrogen based systems rules refer to a lower limit of 5% remaining oxygen, while for flue gas based systems a
limit of 8% oxygen is mentioned.
7
www.scribd.com/doc/24570288/Tanker-Safety-Guide-Chemicals
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commonly applied inert gas since it is relatively simple to separate from ambient air by
separation techniques and does not contaminate the cargo. The working principle of
inerting is outlined in Annex 2 of this report.
In short the current situation regarding the inerting of tanks shows the following:
 Crude oil and petroleum products are mostly inerted with flue gas due to current
SOLAS regulation or due to oil companies corporate HSE policy;
 Since ships transporting crude oil are already inerted, crude oil is excluded from
this study.
 The study will hence focus on white oil products and chemicals (substances
subject to Marpol annex II). These cargoes will mostly be inerted with nitrogen
due to the risk of contamination when using flue gas as inert gas;
 Some chemical products are currently inerted with nitrogen for quality
requirements or (only rarely) due to corporate HSE policy;
 Due to an exemption in the IBC code8 for <3,000 m3 tanks in parcel tankers
chemicals are only very rarely inerted for safety reasons. It is expected by the
PoRA that this exemption in the IBC code will also be removed so that these
tankers are assumed to be subject to the new inert gas requirements from 2015
onwards.
2.3
Inert Gas System Lay-out
Two lay-outs for supplying nitrogen can be distinguished:
1. On board generation or storage of inert gas:
 Nitrogen separation9 from ambient air
 Compressed nitrogen stored on board
 Liquid or gaseous nitrogen stored on board in tanks or bottles
2. Shore supply of nitrogen
 Gaseous nitrogen supplied form shore
Since compressed or liquid nitrogen stored on board is not widely used these will not be
elaborated on in this assessment.
2.3.1
Nitrogen Generation on Board
Nitrogen is generated on-board of ships by separating oxygen from ambient air, which
consists of roughly 78% nitrogen (N2) and 21% oxygen (O2). Two ways of nitrogen
generation are available:
1. Adsorption: Pressure Swing Adsorption using activated carbon to adsorb oxygen;
2. Membrane separation using a membrane through which oxygen passes much faster
than nitrogen.
Membrane separation is the fastest, most compact solution and therefore most
commonly applied technique on-board of ships.
8
IBC code = The International Code for the Construction and Equipment of Ships Carrying Dangerous Chemicals in
Bulk and provides detailed standards for the construction and equipment of chemical tankers. The bulk carriage of
any liquid product other than those defined as oil (subject to MARPOL Annex I) is prohibited unless the product
has been evaluated and categorized for inclusion in Chapter 17 or 18 of the IBC Code.
9
Common applied separation techniques are membrane filtration or pressure swing adsorption
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Good engineering practice shows that nitrogen separation capacity should be designed
at 125% of the maximum pump capacity of the ships pumps.10
To operate nitrogen separation units a significant amount of diesel generated electrical
power is required and this may not affect the availability of power for the cargo pumps.
Especially on the smaller sized ships, i.e. 8,000 – 12,000 DWT, it is expected that the
available diesel generated power is not sufficient for reaching the 125% flow rate.
If sufficient diesel generated electrical power is not available for simultaneous operation
of the nitrogen generator and the cargo pumps either the maximum pump capacity will
decrease or the diesel generation capacity must be increased. However, available
space on board of ships can be limited. Space can sometimes be available in the
forepeak of ships but this is uncommon, and on occasion even rejected by regulation.
2.3.2
Nitrogen Supplied from Shore
Some large terminals in the PoR are connected to a nitrogen distribution pipeline that is
serviced by an industrial scale nitrogen producer. The nitrogen capacity of the
distribution pipeline is much higher (up to 4,000 m3/hour) than the nitrogen capacity at
the jetties (varying between 450 and 800 m3/hour). This is caused by the relatively small
pipe diameter at the jetty (typically 2 inch) in combination with the nitrogen pressure that
is reduced form 6 down to 2 bar. Nitrogen pressure needs to be reduced when inerting
ships to avoid damage to the ships.
Other terminals receive liquid nitrogen supplied in batch by tank trucks. This liquid
nitrogen is evapourated with a capacity of around 1,000 to 1,500 m3/hour but here also
the nitrogen capacities at the jetties are limited due to the small diameter pipes on the
jetties in combination with the reduced nitrogen pressure. In interviews with terminal
operators, the nitrogen capacity of a few terminals were discussed. Four terminals with
nitrogen facilities are listed below in Table 2-1.
Table 2-1: Inert gas system capacity at terminal jetties
Terminal
cap N2 (m3/h)
Vopak Terminal Chemiehaven
450
650 @7 bar
Vopak Terminal TTR
300 @3 bar
Vopak Vlaardingen
500
Odfjell
800
10
Based on input from Inert Gas Installation Supplier.
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3
SHIP IMPACT ASSESSMENT
3.1
Introduction
In this Chapter the impact of the application of inert gas on ships is assessed. The
impact on a ship is twofold:
1. Increase in service time;
2. Increase in capital and operational expenses (CAPEX and OPEX);
This Chapter will outline the impact on service time concluding with a quantification of
service time and delay caused by inerting activities. For the impact of the capital and
operational expenses of both board and shore supplied inert gas reference is made to
Chapter Error! Reference source not found..
3.2
Service Time
The turn-around time is defined as the time needed for loading, unloading, and servicing
a ship.
But since it is sometimes defined as the time from entering a port (end of sea passage)
until leaving a port (start of sea passage) and since the time required for a ship
navigating through the PoR is not impacted by the new IGS requirements,only the
impact on service time is evaluated in this study.
The service time is defined as the time from berthing until departing a terminal jetty.
Figure 3-1 shows all possible steps in which inert gas systems are used as extra activity
(dots) in relation to discharge and loading of cargo (squares).
Figure 3-1: Schematic overview of the possible steps of discharge and loading and the use of inert
gas
Purging is related to discharging, whilst inerting11 and blanketing is related to loading.
Depending on the situation, a ship will choose the appropriate method.
Cleaning and gas freeing of low flashpoint cargoes should be done under inert
conditions to prevent the risk of obtaining an explosive mixture. In practice purging can
be performed simultaneously with loading and cleaning.
11
Supplying inert gas to an empty tank after inspection is called inerting to indicate the difference with purging a
tank filled with cargo vapour after discharge. In day-to-day operation both activities are often called “purging”.
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3.3
Methods of applying inert gas
Two methods of application of inert gas can be identified:
1. Purging+inerting:
Purging is the dilution or displacement of cargo vapour in the tanks after
discharge to a level at which combustion cannot take place.
Inerting is performed before loading to decrease the level of oxygen to a level at
which combustion cannot take place by refreshing the tank vapour space with
inert gas.
2. Blanketing: As an alternative to the procedure of inerting before loading,
blanketing can be applied after loading. Tank blanketing is the process of
applying inert gas to the tank vapour space above the loaded product in the
cargo tanks.
For a clarification of the terms used in this paragraph, reference is made to Annex 2.
One of the safest ways to prevent explosions or fires is to follow the steps of discharge,
purging, gas freeing, inspection and inerting before loading a new product. If legislation
or customers require all operations involving flammable cargoes or cargo vapours to be
carried out under inert conditions then ships will have to apply purging + inerting.
Only applying blanketing after loading is a compromise to avoid the time consuming
steps of purging and inerting, since it is less safe but much faster.
In the following three paragraphs both methods of using inert gas are outlined.
3.3.1
Purging+inerting
Figure 3-2: Purging
Purging is carried out during or after discharge and cleaning of the tanks and before gas
freeing. Figure 3-2 includes discharge itself and simultaneously supplying inert gas to
the cargo tanks to prevent the ingress of ambient air.
After discharge the cleaning of the tank can begin and if purging is not performed
simultaneously the after cleaning purging can be started to reduce cargo vapour
concentration. Subsequent to cleaning and purging, gas freeing is carried out with
ambient air to make the tank accessible for a tank inspection.
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In relation to service time there are two variations for purging :
 If the ship requires shore supplied nitrogen, purging will have to take place at the
berth, i.e. within service time (red dot);
 If the ship has board supplied nitrogen at its disposal, it may consider to save
service time and clean and purge outside service time (e.g. while sailing, at the
anchorage position outside the port or at a lay by jetty, see the hashed red dot).
Figure 3-3: Inerting
Inerting is done after inspection of clean and ambient air filled tanks and before loading
cargo. Figure 3-3 includes the survey of the tanks, inerting of the tanks and loading.
In relation to service time there are two variations for inerting:
 If the ship requires shore supplied nitrogen, purging will take place at the berth,
within service time (green dot).
 If the ship has board supplied nitrogen and permission from their client (mostly
the product owner) for remote survey12, it may consider to save service time by
remote survey before berthing at the loading jetty and inert its tanks while sailing
towards the loading jetty (hashed green dot).
In many cases the product owner or the terminal demands for a survey at the terminal
jetty due to the liability for contamination of loaded products with remainders of previous
cargo when tanks are not properly cleaned.
3.3.2
Blanketing
Figure 3-4: Blanketing
12
surveying while sailing or while berthed at another jetty prior to berthing at the loading jetty
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Blanketing is done after loading. In case of blanketing, the inerting system is used to fill
the vapour space in the cargo tanks on top of the cargo in the tanks.
In relation to service time there are two variations to this scenario:
 If the ship requires shore supplied nitrogen, blanketing will take place at the
berth, within service time (coloured dot);
 If the ship has board supplied nitrogen it may consider to save service time and
add the blanket to the tanks while sailing (hashed dot).
Blanketing is expected to be allowed, as stated in draft amendments to SOLAS
regulations, ad 10:
In consideration of concerns expressed about the potential for increased congestion at
loadports, the Sub-Committee further agreed that chemical tankers should be allowed to
apply inert gas on completion of loading but before commencement of discharge;
3.4
Options for Ships to Reduce Impact on service time
Options for ships to reduce impact can be separated into two categories:
A) Planning of activities outside service time and
B) Optimization of activities inside service time.
A) Planning of inert gas activities outside service time (off berth)
There are occasions in which the inerting activities can be performed outside service
time, saving up to a 100% of time needed for the inert gas activity.
The conditions for these situations to occur are:
1. Cleaning, purging and gas freeing can be done outside service time when the
ship is equipped with an inert gas installation and blowers for gas freeing. If not,
the ship is depending on shore supplied inert gas and must stay berthed at the
jetty.
2. Remote Survey and inerting can be done outside service time if:
a. the ship is equipped with an inert gas installation and
b. the terminal or cargo owner has given permission13 for remote survey.
3. Blanketing can be done outside service time when the ship is equipped with an
inert gas installation. If not, the ship is depending on shore supplied inert gas.
This shows that blanketing outside service time only requires board supplied nitrogen,
while inerting requires remote survey and board supplied nitrogen. Therefore, blanketing
is expected to offer more opportunities to reduce the impact on service time.
B) Optimization of inert gas activities within service time (at berth)
The port logs show that even though inerting activities are performed within service time,
the actual delay can in some cases be mitigated or reduced to even zero. This is due to
the diversity of cargoes that are loaded at the same berth in different tanks. For
example: if one of two products to be loaded needs a blanket, and if loading of the two
products cannot be done simultaneously, blanketing time can be minimized by starting
loading of the product that requires blanketing first and subsequently blanketing together
13
In many cases the terminal or product owner will demand for surveying at the terminal jetty due to the liability for
contamination of loaded products with remainders of previous cargo when tanks are not properly cleaned.
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with loading the second product. While the first tank receives its blanket, the other tank
is still loading.
3.5
Quantification of Inerting Time
3.5.1
Time Required for Applying Inert Gas based on Interviews
Based on interviews with operators of ships in the range of 8,000 – 10,000 DWT an
estimation of the delay was made. This estimate is based on their current experience
with shore supplied inert gas, since on-board generation of nitrogen is not common
practice for their ships. In Table 3-1, typical durations are presented including the extra
time for inert gas requirements.
Table 3-1: Example for discharging and loading cycle for a 10.000 DWT tanker
Activity
duration (h)
extra time IG (h)
Discharge + stripping
16
--
Cleaning tanks
4
--
Purging
--
8
Gas freeing
12
--
Survey
2
--
Inerting
--
8
Loading
16
--
Turnaround
50
16
The prediction in the Table 3-1 can be regarded as a worst case scenario since this is a
non-optimized scenario where shore supplied nitrogen is applied. The worst case impact
is therefore a delay of 16 hours on a service time of 50 hours (this equals 32% additional
service time).
It is expected that this worst case scenario will not be economically feasible for ship
operators and/or terminals and that therefore optimizations will be initialized.
3.5.2
Time Required for Applying Inert Gas based on Selection of Port Logs
Six port logs received from an operator of approximately 40,000 DWT parcel tankers,
loading in the PoR, are analysed. It should be noted that these ships all operate onboard generation of nitrogen with a capacity of roughly 1,000 m3/hour. The average time
needed for inerting and blanketing was derived from these port logs and is presented in
Table 3-2 and Table 3-3.
Table 3-2: Inerting Time for 40,000 DWT ship
Inerting time per call
unit
average
[h:mm/call]
4:49
unit
average
[h:mm /call]
2:20
Table 3-3: Blanketing Time for 40,000 DWT ship
Blanketing time per call
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Table 3-4: Service Time for 40,000 DWT ship
unit
Average
optimized
scenario
Service Time
Extra ST because of Inert Gas Activity
[hh:mm /call]
46:19
[h:mm/call]
3:27
Remarks:
 Purging is not included in this data but since the interviews point out that purging
generally is the same exercise as inerting, we assume the purging time to be equal
to the inerting time.
 The average inerting and blanketing time shows the time per cargo transfer, i.e. not
per tank transfer.
The data show that blanketing time is much shorter than inerting time; blanketing is
about 60% of the inerting time. Because of logistics, the difference between the actual
impact of the two systems of inerting and blanketing may be even bigger, as will be
explained in the next Chapter.
3.6
Summary Ship Impact
The information derived from the interviews and gathered data leads to the additional
service time due to inert gas requirements as presented in Table 3-5.
Table 3-5: Service time
Service Time
Port logs
Interviews
Average Case (optimized ship)
Worst Case
scenario
scenario
Total Service Time [hh:mm]
46:19
50:00
Extra ST because of Inert Gas Activity [hh:mm]
3:27
16:00
Table 3-5 shows an average service time based on the port logs of 46:19 hours, of
which 3:27 hours accounts for extra service time due to inert gas activities for large
ships that feature optimized operations like remote survey and high capacity on-board
nitrogen separation units.
Since behaviour of large and small ships is mostly similar in terms of cargo transfer and
number of tanks involved per call (see also Paragraph 3.5; i.e. the main difference being
that large ships visit more terminals), the identified additional service time of 2:27 hour
for >20,000 DWT is expected to be a representative range of impact for ships in the
8,000 – 20,000 DWT range when they are fully equipped with on-board inert gas
generators.
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For ships in the lower part of the 8,000 – 20,000 DWT range, ship operators expect a
much higher duration for purging and inerting, which is reasonable since these smaller
sized ships are not as well equipped as the larger sized ships. Moreover, the smaller
sized ships have fewer optimization possibilities due to the lower amount of tanks per
ship. These operators expect a purging and inerting time of 16 hours per discharge and
load cycle. This does match with the maximum duration that was measured in the port
logs for the larger ships (total of 7,175 ton was loaded into 6 tanks). This scenario will
therefore be used as a worst case scenario (8 hours for purging plus 8 hours for
inerting).
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4
PORT IMPACT ASSESSMENT
4.1
Introduction
In this Chapter the impact on the PoR is presented, converting the impact on ships as
given in Chapter 3 to the impact on the entire port area.
4.2
Data Input and Analysis
The PoRA provided detailed information on port calls for Marpol annex II products, ship
sizes, cargo transfer volumes and berth location. A spread sheet was provided by PoRA
that was derived from the Informatie Verwerkend Systeem (IVS), containing 4,153
administrative calls in the period January 1, 2011 until January 04, 2012.
Total cargo transfer amounts to 13.8 Mton14 of Marpol Annex II liquid bulk transfers that
are classified as flammable15 in the Port of Rotterdam, Vlaardingen, Schiedam,
Dordrecht and Moerdijk16.
From these calls a selection was made for ship sizes between 8,000 and 20,000 DWT.
This selection reduces the number of calls to 882 Impacted Calls (that will be subject to
the new IGS requirements). The total amount of cargo that was transferred within these
882 Impacted Calls is 3.9 Mton of low flash cargo.
Table 4-1: Overview calls and cargo Annex II
Marpol Annex II
Low flash annex II cargo
in 8-20k DWT ships
Cargo Transfer (tons)
13.8 Mton
3.9 Mton
The total amount of sea-going ship calls in the PoR are also registered IVS. IVS
provided also information about the duration of sea-going ships at a berth, which is used
to indicatively determine the berth occupancy. The data contained the total amount of
sea-going ship calls in the Ports of Rotterdam, Vlaardingen, Schiedam, Dordrecht and
Moerdijk for all cargoes (so including dry bulk, containers and other piece-goods, which
are not relevant for this impact assessment).
The total amount of calls within the used data set was 22,523 at 327 different berths in
the period January 6th 2011 – November 28th 2011. A selection was made to delete unlogical calls that stated negative berth time and a berth time of less than 120 minutes,
resulting in 19,078 calls at 327 different berths. Within these calls both loading and
unloading transactions were registered and therefore a selection was made in loading or
unloading activities, resulting in:
1. 12,779 loading transactions;
16,245 discharging transactions.
14
Mton = million tonnes
15
IMDG code 3
16
Both Dordrecht (0.4% of relevant calls) and Moerdijk (5,4% of relevant calls) ports report to the IVS database but
the vast majority of port calls are located in the Rotterdam area (94%).
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4.3
Current Ship Movements
To determine the impact on logistics in the Port of Rotterdam the current traffic (2011) is
analysed. The figures below provide insight in the distribution of ship size and
transferred cargo of Annex II cargo.
Figure 4-1 shows the distribution of ship sizes transferring Marpol Annex II cargo over
2011. The upper chart shows the distribution for all analysed calls; the middle shows all
ship sizes carrying flammable cargo and the lower chart shows the distribution within the
target group by size of 8,000 - 20,000 DWT.
Figure 4-1: Distribution of ship size (Annex II cargo)
Within the target group both extremes (ships just above 8,000 DWT and ships just below
20,000 DWT) visit the Port very frequently.
Figure 4-2 shows the transferred cargo per call per ship size.
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Figure 4-2: Transferred cargo per call per ship size (red dots indicate the target group)
As shown in the upper graph of figure 4.3, the transferred cargo per call shows to be
relatively independent of ship size (dots in the lower part of the graph). Also, the figure
shows that most calls are done by relatively small ships (high concentration of dots in
the lower left corner) and that there is a large amount of ships just below 20,000 DWT.
Figure 4-3 shows the total amount of calls in relation to ship size and transferred cargo.
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Figure 4-3: Distribution of transferred cargo and ship size
Figure 4-3 shows that some ship types visit the PoR more frequent than others,
however, most transferred cargo is in the same tonnage range. The figures indicate the
traffic behaviour in the PoR. In terms of calls, ships are mostly relatively small.
Transferred cargo per call is in most cases independent of ship size. This indicates the
behaviour of larger parcel tankers to handle more relatively small cargo transfers
(related to their capacity) equally to smaller ships, rather than to handle fewer large
cargo transfers.
4.4
Growth Scenarios
The most influential factors in forecasting freight flows are economic growth, the volume
of world trade, oil prices and environmental policy. Based on these factors, four different
economic scenarios have been selected to assess future developments in freight
handling in the PoR. These scenarios have been drawn up by the Netherlands Bureau
for Economic Policy Analysis (CPB) and the European Commission. They are:
 Low Growth (LG):
Low economic growth and low oil prices, fossil fuels remain dominant and
environmental policy is cautious.
 European Trend (ET):
Existing policy and a moderate growth of the economy.
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
Global Economy (GE):
Further globalisation combined with low oil prices leading to high economic
growth and cautious environmental policies.
 High Oil Price (HOP): high oil prices, a strict environmental policy, moderate
economic growth and a relatively rapid increase in sustainability of industries
and logistics.
These growth scenarios are used to develop growth scenarios for transfer of chemicals
by the PoRA in their vision towards 2030 (Port of Rotterdam, 2010)17 and are presented
in Figure 4-4.
Figure 4-4: Growth scenarios for chemical cargo in the PoR (Port Vision 2030)
For this study two scenarios are used to identify the range of minimum and maximum
growth:
1. Low Growth (LG 2020) scenario represents the minimum increase in transfer of
chemical cargo;
2. Global Economy (GE 2020) represents the highest increase in chemical cargo
transfer.
Table 4-2: Growth scenario chemicals PoR
2008
18
LG 2020
GE 2020
Chemical cargo transfer [Mton]
26
28
35
Increase
--
8%
35%
The figures show an increase in chemical product transfer of 8% for the LG scenario
and an increase of 35% for the GE scenario.
The growth scenarios use 2008 as reference year while this study is based on data from
2011 as reference year. Since the growth percentages are indicative and the total
transfer of chemical cargo in 2011 was 28 Mton the growth percentages from 2008
towards 2020 are used to predict the situation in 2020 for this study. The fact that the
2011 transfer volume of chemical cargo has already reached the LG expectation for
2011 confirms that this is really a minimum approach.
17
www.havenvisie2030.nl/files/downloads/pdf/C073_Ramingen_Goederenstromen_HV_2030_LR.pdf
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Since the fleet mix is not expected to change significantly, growth will be realized by an
increasing number of ships.
Also the impact on service time per ship is assumed not to change significantly towards
2020, so the growth scenarios will only affect the amount of ships.
4.5
Impact on Service Time for the PoR
As discussed in Paragraph 3.4 the impact on service time due to the new IGS
requirements is expected to range from 3:19 hours per call for a ship that has optimized
both logistics (remote survey) and technology (on-board IG generation capacity) up to
16 hours per call for a ship that has not mitigated the effects of the new requirements
(i.e. survey during service time and depending on shore supplied nitrogen).
Since no data is available on the exact activities during each call it is assumed that all
459 impacted calls will be affected by the new IGS requirements.
In Table 4-3, this impact range is used to predict the additional service time of the total
amount of impacted calls in the PoR for the LG 2020 and GE 2020 growth scenarios
combined with the average case (AC) and worst case (WC) impact:
Table 4-3: Impact on the PoR for the average (AC) and worst case (WC) impact on service time
Unit
2011
LG 2020
GE 2020
impacted calls
[#]
882
953
1,191
AVG impact
[min/berth]
199
199
199
Total impact PoR_AC*
[hour]
2,925
3,159
3,949
WC impact
[min/berth]
Total impact PoR_WC*
[hour]
960
960
960
14,112
15,241
19,051
* Total delay PoR_AC = total delay in the PoR using the average impact of 3,5 hours
** Total delay PoR_WC = total delay in the PoR using the average impact of 16 hours
It has to be noted that the impact on service time can be assumed to be linear, while at
high berth occupancy the effect of increasing service time on waiting time is not linear
but progressive. The effect on waiting time was not studied in this report.
4.6
Analysis of Specific Berths with High Impact
4.6.1
Overview Impacted Calls 8 – 20 kDWT
The total amount of impacted Unique Berth Calls in the PoR was 822. In Table 4-4 the
most impacted berth locations are presented. Analysis of Table 4-4 results in the
following:
1. The total amount of impacted berths is 89 but the majority of highly impacted
calls is located in the Botlek area of the PoR (PET 3, TORTH, CHEMH,
WER19);
2. 321 calls out of 822 impacted calls are located in the 3rd petroleum harbour
(‘PET 3’)
19
rd
Abbreviations of berth locations are first port name (e.g. PET3 = “3 petroleumhaven” or TORTH=
“Torontohaven”), followed by company name and berth number.
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3. The high concentration of impacted calls in PET 3 may cause additional
waiting time;
4. Three other locations show a high impact (in the top 10): Caldic, located at
the Caland canal, Shell in the 2nd petroleumhaven and Shell Moerdijk;
Table 4-4: Top 26 impacted berth locations based on 2011 data
Low flash annex II cargo in
Impacted
8-20kDWT ships
Berth name
calls
[tons]
PET 3 ESSO 2
62
384977
TORTH VOPAK TTR 1
52
211669
PET 3 VOPAK 2
41
311213
PET 3 ODFJELL 9
39
160085
TORTH VOPAK TTR 4
36
210017
PET 3 VOPAK
35
133241
MOERD HDIEP SHELL 5
28
154392
CHEMH VOPAK 1
27
151487
CALNK CALDIC STG MID
26
172259
PET 2 SHELL 35
24
34925
PET 3 VOPAK 6
24
159052
PET 3 VOPAK 4
23
73711
PET 3 VOPAK 1
20
77718
CHEMH RUBIS ST ZUID
20
95617
PET 3 B 61
19
68214
PET 3 VOPAK 3
19
111353
PET 3 ESSO 1
18
96784
PET 1 SHELL 18
16
13669
PET 3 LBC STG
16
34463
PET 3 VOPAK 5
16
59936
WER 2 STR 75
15
56726
CHEMH RUBIS ST NOORD
14
42569
WER 2 STR 73
13
52236
PET 1 SHELL 17
12
17175
PET 3 ODFJELL 10
11
68592
PET 3 ODFJELL 7
11
73675
TORTH VOPAK
11
31928
EUROH LYONDELL PL 1
11
26365
PET 1 SHELL 3
10
98365
MOERD HDIEP SHELL
10
54342
PET 3 ODFJELL
10
51693
CALNK CALDIC STG WZ
10
47014
MOERD HDIEP SHELL 4
10
60686
DORDR JULHV STANDIC3
10
13922
EUROH LYONDELL
9
31541
WER 2 STR
8
30190
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4.6.2
Impacted calls versus other ship sizes at most Impacted Berths
In order to relate the impacted calls to other ship sizes the impacted calls are presented
versus the other Marpol annex II cargo transfers at specific berths.
In Table 4-5 the total berth calls are presented.
Table 4-5: Current and impacted berth occupancy
BERTHNAME
Impacted calls
8-20 kDWT
all calls flammable annex II cargo
PET 3 ESSO 2
62
136
TORTH VOPAK TTR 1
52
182
PET 3 VOPAK 2
41
131
PET 3 ODFJELL 9
39
164
TORTH VOPAK TTR 4
36
122
PET 3 VOPAK
35
124
MOERD HDIEP SHELL 5
28
74
CHEMH VOPAK 1
27
114
CALNK CALDIC STG MID
26
104
PET 2 SHELL 35
24
45
PET 3 VOPAK 6
24
72
PET 3 VOPAK 4
23
83
PET 3 VOPAK 1
20
81
CHEMH RUBIS ST ZUID
20
34
PET 3 B 61
19
30
PET 3 VOPAK 3
19
66
PET 3 ESSO 1
18
108
PET 1 SHELL 18
16
29
PET 3 LBC STG
16
62
PET 3 VOPAK 5
16
70
WER 2 STR 75
15
52
CHEMH RUBIS ST NOORD
14
45
WER 2 STR 73
13
34
PET 1 SHELL 17
12
52
PET 3 ODFJELL 10
11
65
PET 3 ODFJELL 7
11
74
TORTH VOPAK
11
29
EUROH LYONDELL PL 1
11
38
PET 1 SHELL 3
10
14
MOERD HDIEP SHELL
10
59
PET 3 ODFJELL
10
42
CALNK CALDIC STG WZ
10
42
MOERD HDIEP SHELL 4
10
53
DORDR JULHV STANDIC3
10
12
EUROH LYONDELL
9
42
WER 2 STR
8
20
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4.7
Utilisation Rate for Most Impacted Berths
This paragraph focuses on the impact on jetties in terms of utilisation rate for most
impacted berths.
In Table 4-6, the utilisation rate is presented using the average the average service time
at these berths from the IVS database and the calculated increased utilisation rates are
presented for the following scenarios.




2011:
2011 AC
2011 WC:
LG 2020:
based on

LG 2020 AC:
Growth”
GE 2020:
based on


GE 2020 WC:
Economy”
Current utilization rates as provided by PoRA;
Average case impact based on situation in 2011;
Worst case impact based on situation in 2011;
Utilization rate in 2020 without additional IGS requirements,
growth scenario “Low Growth”;
Average case impact in 2020 based on growth scenario “Low
Utilization rate in 2020 without additional IGS requirements,
growth scenario “Global Economy”;
Worst case impact in 2020 based on growth scenario ”Global
The utilisation rate will be defined for the most impacted berths. Absolute utilization (U)
of berths is defined as the number of calls (C) times the service time (S), U = C*S.
Average Case delay caused by inerting operations is 3.5 hour and worst case delay
caused by inerting operations is 16 hours (see also paragraph 3.5).
Since no data is available on the amount of 8-20kDWT ships that currently use inert gas
assumed is that currently no ships use inert gas and due to the new requirements all
relevant ships will be delayed by 3.5h in 2020 for the average case and 16 hours for the
Worst Case.
The absolute utilization in 2015 is given by Ui= (C-Ci)*S+Ci*Si, in which Ci is the number
of impacted calls, and Si is the additional time due to inert gas activities.
The fleet mix is assumed to remain the same so only the total number of ships will
increase due to the growth scenarios.
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2011
2011 AC
2011 WC
LG 2020
LG 2020 AC
GE 2020
GE 2020 WC
Average service time
all calls flammable Annex II cargo
Impacted calls
Table 4-6: Current and impacted berth utilisation rates
PET 3 ESSO 2
62
136
27
42%
45%
54%
46%
48%
57%
61%
TORTH VOPAK TTR 1
52
182
24
49%
51%
59%
53%
55%
66%
69%
PET 3 VOPAK 2
41
131
28
42%
44%
49%
45%
47%
57%
59%
PET 3 ODFJELL 9
39
164
22
41%
42%
48%
44%
45%
55%
57%
TORTH VOPAK TTR 4
36
122
24
34%
35%
41%
37%
38%
46%
48%
PET 3 VOPAK *
35
124
31
44%
45%
50%
47%
49%
59%
61%
MOERD HDIEP SHELL 5 *
28
74
31
26%
27%
31%
28%
29%
35%
37%
CHEMH VOPAK 1
27
114
19
24%
25%
29%
26%
27%
33%
34%
BERTH NAME
CALNK CALDIC STG MID
26
104
25
29%
30%
34%
31%
33%
39%
41%
PET 2 SHELL 35
24
45
31
16%
17%
20%
17%
18%
21%
23%
PET 3 VOPAK 6
24
72
31
26%
27%
30%
28%
29%
35%
36%
PET 3 VOPAK 4
23
83
30
28%
29%
32%
31%
32%
38%
39%
PET 3 VOPAK 1
20
81
40
37%
38%
41%
40%
41%
50%
51%
CHEMH RUBIS ST ZUID
20
34
38
15%
16%
19%
16%
17%
20%
21%
PET 3 B 61
19
30
32
11%
12%
14%
12%
13%
15%
16%
PET 3 VOPAK 3
19
66
40
30%
31%
33%
32%
33%
40%
41%
PET 3 ESSO 1
18
108
28
35%
35%
38%
37%
38%
47%
48%
PET 1 SHELL 18 *
16
29
31
10%
11%
13%
11%
12%
14%
15%
PET 3 LBC STG *
16
62
31
22%
23%
25%
24%
24%
30%
30%
PET 3 VOPAK 5
16
70
33
26%
27%
29%
29%
29%
36%
37%
WER 2 STR 75
15
52
43
25%
26%
28%
27%
28%
34%
35%
CHEMH RUBIS ST NOORD *
14
45
31
16%
16%
18%
17%
18%
21%
22%
WER 2 STR 73
13
34
44
17%
18%
20%
19%
19%
23%
24%
PET 1 SHELL 17
12
52
15
9%
10%
11%
10%
10%
12%
13%
* For these berths the average service time from IVS was used
It has to be noted that in the IVS database only sea-going vessels are registered.
Furthermore only flammable Marpol annex II cargo was analysed. Hence, the current
utilisation rate as presented in this chapter does not include barges and other types of
cargo. During the interviews with terminal and ship operators it was stated that the most
impacted berths already show very high utilisation rates (approximately 70% up to 80%)
due to the servicing of barges and other chemicals at these same berths.
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4.8
Utilisation Rate for Vopak Terminals in the Botlek area
Vopak provided the real utilisation rates including barges for their jetties. These figures
are presented and used as a starting point for adding the impact due to additional IGS
requirements in table 4-7 and 4-8,
Utilisation rates above 70 % will lead to a progressive increase in waiting time for the
ships.
Impacted calls
2011
2011 AC
2011 WC
LG 2020
LG 2020+AC
GE 2020
GE 2020+WC
LG 2020+WC
GE 2020+AC
Table 4-7 Utilisation rates including barges plus impact IGS Vopak Terminal Botlek
PET 3 VOPAK 2
19
68%
69%
72%
73%
74%
91%
97%
78%
90%
PET 3 VOPAK 3
10
71%
71%
73%
76%
77%
95%
98%
79%
94%
PET 3 VOPAK 4
10
62%
63%
65%
67%
68%
84%
87%
70%
83%
PET 3 VOPAK 6
9
62%
62%
64%
67%
67%
84%
87%
69%
82%
PET 3 VOPAK 5
8
65%
65%
66%
70%
70%
87%
90%
72%
86%
PET 3 VOPAK 1
7
75%
76%
77%
81%
82%
102%
104%
83%
100%
BERTH NAME
4.9
82%
83%
84%
103%
111%
GE 2020+AC
LG 2020+AC
78%
LG 2020+WC
LG 2020
77%
GE 2020+WC
2011 WC
25
GE 2020
2011 AC
TORTH VOPAK TTR 4
2011
BERTHNAME
Impacted calls
Table 4-8 Utilisation rates including barges plus impact IGS Vopak TTR & Chemiehaven
89%
102%
TORTH VOPAK TTR 1
23
77%
78%
82%
84%
85%
104%
111%
89%
103%
CHEMH VOPAK 1
14
72%
73%
75%
78%
79%
98%
102%
81%
96%
Amount of 4,000 – 8,000 DWT ships
Should the additional IGS requirements also cover 4,000 – 8,000 DWT ships then an
additional amount of 1094 calls would be impacted.
These 1094 port calls versus the impacted port calls of 8,000-20,000 DWT ships are
presented in table 4-9 . The grey shaded rows represent other berths that would
significantly be impacted if additional IGS requirements would cover 4,000 – 8,000
DWT ships.
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Table 4-9 Port calls 4 – 8 kDWT versus 8-20 kDWT at most impacted berths
BERTH NAME
4-8 kDWT
PET 3 ESSO 2
52
8-20 kDWT
62
TORTH VOPAK TTR 1
59
52
PET 3 VOPAK 2
32
41
PET 3 ODFJELL 9
52
39
TORTH VOPAK TTR 4
48
36
PET 3 VOPAK
37
35
MOERD HDIEP SHELL 5
39
28
CHEMH VOPAK 1
41
27
CALNK CALDIC STG MID
31
26
PET 2 SHELL 35
7
24
PET 3 VOPAK 6
23
24
PET 3 VOPAK 4
36
23
PET 3 VOPAK 1
27
20
CHEMH RUBIS ST ZUID
9
20
PET 3 B 61
6
19
PET 3 VOPAK 3
29
19
PET 3 ESSO 1
55
18
PET 1 SHELL 18
5
16
PET 3 LBC STG
14
16
PET 3 VOPAK 5
21
16
WER 2 STR 75
5
15
CHEMH RUBIS ST NOORD
7
14
WER 2 STR 73
5
13
PET 1 SHELL 17
24
12
PET 3 ODFJELL 10
17
11
PET 3 ODFJELL 7
48
11
TORTH VOPAK
10
11
EUROH LYONDELL PL 1
13
11
MOERD HDIEP SHELL
35
10
PET 3 ODFJELL
20
10
CALNK CALDIC STG WZ
17
10
MOERD HDIEP SHELL 4
29
10
EUROH LYONDELL
17
9
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5
ENVIRONMENTAL EFFECT IGS
Additional IG requirements cause environmental effects due to:
 additional energy consumption for separation of nitrogen from ambient air;
 additional cargo vapour emission by refreshing the cargo vapour space with inert
gas.
The nitrogen consumption for 8,000 – 20,000 DWT ships transporting low flash cargo is
mainly depending on the method that is applied: purging of complete cargo tanks prior to
loading will consume a much larger amount of nitrogen compared to applying a blanket
after loading. In the following paragraphs the difference between these methods is
quantified.
5.1
Nitrogen Consumption for Purging + Inerting
Based on interviews, as a rule of thumb, the oxygen content in a cargo tank will be
reduced by 50% by refreshing the tank volume once with nitrogen with 5% oxygen
content. This means that each tank that must be inerted needs to be refreshed two
times:
1. After the first refreshment the oxygen content will be reduced from 21% down to
10.5%
2. After the second refreshment the oxygen content will be reduced 10.5% down to
5.25%
From the interviews it was clear that it is common practice to refresh the tank volumes at
least 2.5 times and mostly even 3 times at higher inert gas flow rates because this is
faster than applying a lower flow rate. Inerting at higher flow rates consumes larger
amounts of nitrogen but this is faster than inerting at lower flow rates (see also
attachment 2 where the difference between high flow rate (dilution method) versus low
flow rate (displacement method) is explained)
Thus, the worst case scenario for nitrogen consumption will be set at 3 tank volumes of
nitrogen for purging and three tank volumes for inerting. Thus for the worst case
scenario 3,000 m3 of nitrogen will be consumed to purge a 1,000 m3 tank from 21%
oxygen down to about 5.25% oxygen (which is well below the maximum of 8% oxygen).
Typical nitrogen consumption for a complete cycle of discharge and loading are
presented in Table 5-1, for the scenario where all operations involving flammable cargo
vapours are subject to inert gas requirements and where the cargo tanks must be
inspected prior to loading.
Table 5-1: Typical nitrogen consumption for purging + inerting
Activity
explanation
Discharge & stripping
prevent air from entering tanks, nitrogen supplied during discharge
IG volume / cargo volume
1
Cleaning tanks
Relevant for non-compatible next cargo, tanks already inerted
--
Purging
Dilution of cargo concentration below LEL
Gas freeing
Replacing nitrogen with air
20
20
3
--
LEL = Lower Explosion Limit
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Activity
explanation
IG volume / cargo volume
Survey
Surveyor to enter the tanks
--
Inerting
Replace air with nitrogen
3
loading
Loading next cargo (tank already inerted)
--
IG volume for 1 cargo exchange (factor of tank volume)
7
The total amount of impacted low flash cargo transfers is approximately 2.4 million ton
per year in the PoR. With an assumed average density of 0.8 ton/m3 this equals
approximately 4,9 million m3 of impacted cargo volume and thus 34 million m3 of
nitrogen consumption in 2011 if all cargo operations must be inerted. The environmental
impact of this nitrogen consumption for 2011 and for the LG202 and GE2020 growth
scenarios is presented in Table 5-2. `
5.2
Nitrogen consumption for blanketing
If operational guidelines will allow to only apply a nitrogen blanket after loading of low
flash cargo and the cargo tanks will be kept inert during discharge then the nitrogen
consumption will be approximately 1.5 times the impacted cargo volume.
If a blanket is only applied after loading the nitrogen consumption will be lower since
only the vapour space will have to be refreshed three times. The nitrogen consumption
will depend on the vapour space in the tanks, which is depending on cargo volume
related to the cargo tank size. Since this information is not available the nitrogen
consumption for blanketing is estimated at 1.5 times the loaded cargo volume.
The total impacted cargo volume is 4,9 million m3 of low flash cargo and thus, nitrogen
consumption for blanketing will be 7.4 million m3. This can be seen as the lowest
environmental impact scenario.
5.3
Environmental Impact
Nitrogen consumption
The most widely used technique to separate nitrogen from air on board of ships is
membrane separation and therefore this technique will be evaluated. The environmental
impact from on-board nitrogen separation is based on a 1,000 m3/hour membrane
separation unit producing nitrogen with 5% oxygen content. For such a membrane unit a
450 kW diesel generator is required with an average power consumption of 0.2 kg of
diesel/ kWh (= 90 kg diesel/hour)21. The combustion of diesel fuel results mainly in
emissions of CO2, NOx, VOC and SO222.
Additional vapour treatment
If a blanket is applied additional cargo vapours will be emitted from the cargo tanks
together with the excess of nitrogen. These cargo vapours contain VOC and must
therefore be treated with a vapour combustion or vapour recovery unit.
21
22
Inertiseren en ontgassen van binnenvaartschepen (TNO R2002/150, December 2001)
CO2=carbon dioxide, NOx=nitrogen oxide,VOC = Volatile organic compounds; SO2= sulfur dioxide
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When a vapour combustion technique is applied roughly 15 normal23 cubic meter of
natural gas (or the energetic equivalent in propane) will be consumed for every 1,000
Nm3 of nitrogen/cargo vapour emission from the cargo tanks (assuming that the thermal
efficiency of the vapour combustion unit is optimized). Furthermore the vapour
combustion unit will emit 50 mg of VOC per m3.
The environmental impact is presented in
Table 5-2 based on the scenarios for either:
1. purging for 2011 and the GE 2020 scenario (worst case scenario);
2. blanketing for 2011 and the LG 2020 scenario (low impact scenario);
3. emission from additional vapour treatment.
23
3
cubic meter at standard conditions: 0 ºC and 1013 mbar (also referred to as Nm )
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Table 5-2 Estimated environmental impact IGS requirements 8-20 k DWT, low flash cargo
Issue
Diesel consumption
2011
GE 2020
blanket
purge
blanket
m /year
34,358,511
7,362,538
45,353,235
7,951,541.18
3
N2 consumption
Membrane separation
2011
Purge
unit
Unit
Emission factor
3
kg/m N2
kg/year
3,092,266
662,628.43
4,174,559
715,639
0.0002765
11
ton/year
9,500
2,036
12,825
2,198.60
3
0.0000015
11
ton/year
53
11
72
12
3
0.0000016
11
ton/year
53
11
72
12
3
0.0000006
11
ton/year
21
4
28
ton/m N2
NOx emission
ton/m N2
SO2 emission
ton/m N2
VOC emission
ton/m N2
0.09
16
3
CO2 emission
Additional vapour treatment
Natural gas
3
3
Nm /m N2
3
0.015
16
3
5
m /year
515,378
110,438.07
695,759.85
119,273
24
ton/year
915
196
1,235
212
25
ton/year
0.7
0.1
0.9
0.2
CO2 emission
kg / m NG
1.78
NOx emission
kg NOx/GJ
0.04
24
Standard CO2 emission factor for natural gas (www.emissieautoriteit.nl)
25
2010 Performance Standard Rate from the Dutch Emission authority (www.emissieautoriteit.nl)
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6
FINANCIAL IMPACT ASSESSMENT
6.1
Introduction
In this chapter an estimate of the financial impact of the introduction of the new IGS
requirements is presented.
The main impacted parties are:
- PoRA;
- Ship operators and charterers;
- Terminals.
In the following paragraphs a rough order of magnitude is estimated for the additional
costs or lost revenues due to the new IGS requirements for all of the above mentioned
parties.
6.2
Port of Rotterdam
6.2.1
Costs of Increased Service Time in Terms of Lost Revenues (Port Dues)
As presented in Paragraph 4.5, the additional service time due to inerting activities is
expected to vary from 3,159 hour per year in the LG 2020 scenario with average impact
up to 19,051 hour per year in the GE 2020 scenario plus the WC impact (see also
paragraph 4.4 on growth scenarios).
Since the utilisation rate of jetties in the PoR is high, availability of jetties can become a
bottleneck for chemicals logistics, resulting in increased waiting time or even ships to
call at another port. If ships decide to avoid the PoR this will cause a loss in revenues
(port dues) for the PoRA. In the “General Terms and Conditions, Including Port Tariffs
2012”, the build-up of the port dues at the PoR are presented. Five steps need to be
taken:26





Step 1: Determine the applicable type of ship and switch percentage.
Step 2: Calculate the port dues related to the GT-size of the ship with (GT-size x
GT-tariff).
Step 3: Calculate the maximum port dues related to the cargo by multiplying the
GT-size, the switch percentage and the cargo rate that corresponds with the
‘first type of cargo that needs to be paid’ (GT-size x switch percentage x cargo
rate).
Step 4: Calculate per type of transhipped cargo the port dues related to the
transhipped quantity in tons (transhipped quantity x cargo rate).
Step 5: Determine the amount on port dues owed to PoRA NV by adding the
result of step 2 with the lowest result of step 3 and 4.
Port dues are calculated using two extremes to obtain the range of the indicative
financial impact for the PoR:
1. Ship of 5,500 GT (= approx. 8,000 DWT) transferring 3,000 ton cargo.
2. Ship of 11,500 GT (= approx. 20,000 DWT) transferring 5,000 ton of cargo
26
www.portofrotterdam.com/nl/Scheepvaart/havengelden/Documents/general-terms-conditions-2012.pdf
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In Table 6-1, this additional service time due to IGS activities is converted to lost port
dues for the PoRA, indicating the worst case scenario in which all additional service time
will lead to a decrease in ship calls in the PoR.
Table 6-1: Port dues for two chemical tankers at high and low end of range
5,500 GT ship and
11,500 GT ship and
3,000 ton of cargo
5000 ton of cargo
LG 2020 + AC
GE 2020 + WC
GT tariff 0.298 € * GT ship
1,639
3,427
€
Cargo rate 0.485 * cargo transfer
1,455
2,425
€
Total port dues
3,094
5,852
€/call
31
31
hours
3,159
19,051
hours
calc. port dues
Average service time
27
Total impact GE 2020
Reduction ship calls
Lost port dues
Conversion rate January 2012
Lost port dues
6.2.2
102
615
315,321
3,601,170
1.31
1.31
414,521
4,734,098
unit
calls/year
€/year
€/$
$/year
Indication of Costs for Additional Facilities (Jetties)
If a berth suffers from a high impact, it is most likely that mitigation measures will be
taken specifically for that berth as soon as the cost of such measures outweighs the
benefits.
If the availability of jetties will become a bottleneck in the logistic chain the impact can
be mitigated by constructing new jetties. The most impacted berths in the PoR as
presented in paragraph 4.6.2 are located at different companies (e.g. ESSO, Odfjell,
VOPAK TTR, VOPAK Botlek zuid, VOPAK Chemiehaven, LBC, CALDIC, RUBIS, STR,
Shell Pernis and Buoy 61).
Hence, if the impact has to be mitigated by constructing new berths/jetties this will be
complex, since cargo transfers cannot be optimized between the different terminals.
A waiting berth is expected to cost approximately 2 - 4 M€ (4 mooring piles suitable for
berthing a 8,000 – 20,000 DWT ship). A complete jetty costs approximately 10 - 12 M€.
6.3
CAPEX and OPEX Ship
For ships the main costs to comply with the new IGS requirements will be:
1. Lost revenues due to delay;
2. OPEX of the IGS;
3. Additional ship building costs for IGS.
27
Average service time for tankers calling at most impacted berths, see table 4-5
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6.3.1
Lost Revenues due to Delay
Based on the interviews, the additional service time can be converted into a financial
impact for ship operators at the following rates:
 14,000 $ per day for a 8,000 DWT ship
 22,500 $ per day for a 20,000 DWT ship
In Table 6-2 all additional service time caused by IGS is converted into lost revenues for
ship operators for two scenarios:
 LG 2020 +AC = Low Growth scenario + average case impact calculated for an
8,000 DWT ship;
 GE 2020 + WC = Global Economy + worst case impact calculated for a 20,000
DWT ship.
The range of lost revenues for ships in the PoR is presented in Table 6-2.
Table 6-2: Estimated lost revenues ship operators / charterers in PoR
LG 2020 + AC
GE 2020 + WC
Unit
3,159
19,051
hours
1,842,939
17,860,500
Total impact
Lost revenues
$
Contracts mostly include demurrage28 clauses to charge the charterers for costs of extra
service time when the agreed maximum service time is exceeded. But, whether the ship
operator or the charterer have to pay the additional costs, in the end the cost of product
transfer will be affected and it will be added to freight tariffs.
6.3.2
CAPEX and OPEX of the IGS
Costs of operation of IGS include:
1. Investment for IGS
2. Diesel consumption for power generation to operate IGS;
3. Maintenance, depreciation and insurance costs for IGS;
4. Increased CO2 emissions (currently the shipping sector is not included in the
European Emission Trading Scheme, but possibly it will be included in the future).
5. Labour related to increased complexity of operational procedures;
6. Measures to control the risk associated with tank entries.
Ad 1: Investment for IGS
Depending on the required capacity, indicative equipment costs are presented in Table
6.3 Equipment costs of an IGS are presented for nitrogen generators with different
capacities29 (flow rates are given for nitrogen production with 5% remaining oxygen
content):
28
The term demurrage refers to the period when the charterer remains in possession of the vessel after the period
normally allowed to load and unload cargo. By extension demurrage refers to the charges that the charterer pays to
the ship owner for its extra use of the vessel. Officially, demurrage is a form of liquidated damages for breaching the
service time set out in the contract.
29
Based on information from a supplier of IGS for ships.
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Table 6-3: Indicative equipment costs new built IGS
Capacity of nitrogen
Equipment cost new built ship
3
[in m /hour]
[in $]
300
158,000
410
184,000
550
210,000
750
226,000
1000
263,000
Ships may choose to install two separate installations of 50% of the required capacity to
obtain redundancy and gain reliability if one of the systems is not working properly.
Ad.2 Fuel consumption
The expected fuel consumption for the additional IGS requirement is calculated in
chapter 5. In both the Low Growth (LG 2020) and the Global Economy scenario (GE
2020) the oil prices are expected to be low, therefore the actual price for Marine gasoil30
on February 7 2012 in Rotterdam (991.5 $/ton) is indexed with 1.5 % per year towards
2020 to obtain a marine gasoil rate of 1.12 $/ kg.
Table 6-4: Diesel consumption IGS systems in the PoR
GE 2020 purge
LG 2020 blanket
Diesel consumption
4,174,559
715,639
kg/year
Diesel cost
4,662,638
799,309
$/year
Ad 3. Maintenance, depreciation and insurance costs for IGS
The calculation of maintenance, depreciation and insurance costs for IGS will acount for
approximately 9% of the equipment cost. This is based on the following assumptions:
 maintenance 4%;
 depreciation 25 year;
 insurance 1%.
For a 263,000 $ IGS this would mean roughly 23,662 $/year.
Ad 4 - 6
These are considered secondary effects of IGS and are therefore not elaborated on.
6.3.3
Costs for Shore Supplied Nitrogen
Based on the interviews shore supplied nitrogen ranges from 0.04 €/m3 at refineries or
chemical plants up to 1.05 €/m3 at terminals.
6.4
Terminal
Terminals will be subject to the following financial impact:
1. Lost revenues by decreasing throughput if ships will avoid the PoR
2. Cost of additional vapour treatment
3. (possibly) de-bottlenecking of shore supplied nitrogen systems
Ad. 1: Lost revenues
30
Prices in US$ per metric tonne, delivered on board basis
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If it is assumed that extra service time will become a bottleneck for throughput then
terminals will lose revenues due the additional IGS requirements. However, since
commercial contracts between terminals and their clients are very different depending
on types of chemicals, throughput volumes and storage duration it is not possible to
estimate the lost revenues of extra service time.
Ad. 2: Cost of additional vapour treatment
The cost of additional vapour treatment can be calculated using the natural gas
consumption as stated in Paragraph 5.3, which adds up to approximately 47,000 $ in the
LG 2020 blanket scenario and in the worst case 274,400 $ for the GE 2020 purge
scenario at a tariff31 of 0.39 $/Nm3 This is just the natural gas consumption, but also
other OPEX factors will increase due to increasing utilisation of vapour treatment
facilities. These are however depending on each specific situation and therefore not
elaborated on in this study.
Ad. 3: (possibly) de-bottlenecking of shore supplied nitrogen systems
If the capacity of the nitrogen distribution systems will become a bottleneck at terminals
in most cases only the nitrogen distribution system at the jetties needs to be modified.
Since these costs are very location specific they will not be estimated in this study.
7
CONCLUSIONS
7.1
Impact on the PoR
The additional IGS activities will lead to additional service time, but to what extent will
mainly depend on the operational optimization that the sector can realize (like for
instance remote survey, also see paragraph 3.4). The range in expected impact is
summarized below for the two growth scenarios for 2020.
Table 7-1: Impact on the PoR for the average (AC) and worst case (WC) impact on service time
Unit
LG 2020
GE 2020
1,191
impacted calls
[#]
953
Total impact PoR_AC*
[hour]
3,159
3,949
Total impact PoR_WC*
[hour]
15,241
19,051
* Total delay PoR_AC.IMP = total delay in the PoR using the average impact of 3,5 hours
** Total delay PoR_WC.IMP = total delay in the PoR using the average impact of 16 hours
The maximum impact in 2020 will thus be 19,051 hours of additional service time,
divided over 82 berths in the PoR but highly concentrated in the Botlek area (3rd
petroleumhaven, chemiehaven, torontohaven and werkhaven).
However the average impact (3,159 hours) is an optimistic approach, since it is based
on ships with high capacity IGS and highly optimized logistic management. This will not
be technically and economically feasible for all types of ships and all types of ship
operators. The impact is therefore expected to vary between the average and maximum
approach.
31
http://statline.cbs.nl
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7.2
Impact on Ships
7.2.1
Additional Service Time
Average impact on ships will be around 3 hours and 27 minutes of extra service time if
inert gas systems are installed and logistics can be optimized. For some ships the
impact will be higher, up to 16 hours per call. In the tables below the ship impact is
summarized:
Table 7-2: Inerting Time for 40,000 DWT ship
Inerting time per call
unit
Average port logs
[h:mm/call]
4:49
Table 7-3: Blanketing Time for 40,000 DWT ship
Blanketing time per call
unit
Average port logs
[h:mm/call]
2:21
Port logs
Interviews
unit
Average optimized
Worst case scenario
Table 7-4: Service time
Service Time
7.2.2
scenario
Total Service Time [h]
[h:mm/call]
46:19
50
Extra ST because of Inert Gas Activity
[h:mm/call]
3:27
16
Lost Revenues for Ship Operators or extra Costs for Charterers
Lost revenues for ship operators or extra costs for charterers due to extra service time in
the PoR is presented in table 6-2, where all additional service time caused by IGS is
converted into lost revenues for ship operators for two scenarios:
 LG 2020 +AC = Low Growth scenario + average case impact calculated for an
8,000 DWT ship;
 GE 2020 + WC = Global Economy + worst case impact calculated for a 20,000
DWT ship.
Table 7-5: Estimated lost revenues ship operators / charterers in PoR
Unit
LG 2020 + AC
GE 2020 + WC
Total impact
hours
3,159
19,051
Lost revenues
$
1,842,939
17,860,500
Contracts mostly include demurrage32 clauses to charge the charterers for costs of extra
service time when the agreed maximum service time is exceeded. But, whether the ship
operator or the charterer has to pay the additional costs, in the end the cost of product
transfer will be affected.
32
The term demurrage refers to the period when the charterer remains in possession of the vessel after the period
normally allowed to load and unload cargo. By extension demurrage refers to the charges that the charterer pays to
the ship owner for its extra use of the vessel. Officially, demurrage is a form of liquidated damages for breaching the
service time set out in the contract.
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7.2.3
OPEX of IGS
The operation of IGS leads to additional fuel consumption for power generation and
other operation costs of operating IGS.
The expected additional diesel consumption is presented in Table 6-4.
Table 7-6: Diesel consumption IGS systems in the PoR
GE 2020 purge
LG 2020 blanket
Diesel consumption
4,174,559
715,639
kg/year
Diesel cost
4,662,638
799,309
$/year
Main other OPEX are maintenance, depreciation and insurance costs for IGS. The
calculation of maintenance, depreciation and insurance costs for IGS will acount for
approximately 9% of CAPEX. For a 1,000 m3/hour IGS (investement approximately
263,000 $), this would mean roughly 23,662 $ per ship per year.
The cost for shore supplied nitrogen varies from 0.04 €/m3 at refineries or chemical
plants up to 1.05 €/m3 at terminals.
7.3
Terminals
Main impact for terminals will be an increase in jetty utilisation. For the berths in the
PoR, a maximum increase of 20% was calculated. For the highest impacted berths an
average increase of 11% in utilisation rate was calculated.
For many of these berths, this is expected to cause logistic problems, since utilisation
rates will rise above 70% or 80% (which will cause extra waiting times and is expected
become a bottleneck for throughput of volumes of this type of cargo).
The majority of impacted berths are located in the 3rd petroleumhaven.
7.4
Summary of Financial Impact
Table 7-1: Summary of financial impact
Party
Financial impact
PoRA
Lost port dues PoR
Ship operators charterers
Lost revenues
Ship operators charterers
Diesel consumption
Ship operators charterers
Depreciation, maintenance & insurance.
Terminals
Natural gas vapour treatment
Total
LG 2020 + AC
GE 2020 + WC
414,521
4,734,098
1,842,939
17,860,500
$/year
799,309
4,662,638
$ /year
$/year
See note below
47,039
274,394
$ /year
3,103,808
27,531,630
$ /year
Depreciation, maintenance and insurance costs for IGS are estimated at approximately
9% of the equipment cost (maintenance 4%; depreciation 25 year and insurance 1%).
For an IGS with a capacity of 1,000 m3/hour, costing approximately 263,000 $ this would
mean 23,662 $/year. Depending on a.o. the ships pump capacity, each ship type will
select a suitable IGS capacity. Due to the fact that sea vessels berth at various ports
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worldwide, the costs of depreciation, maintenance and insurance cannot be assigned to
costs for the PoR in particular.
Other impacts that are not included in this summary are ship to ship transfers between
sea going ships and barges. In these cases the barges would be effected by the new
IGS requirements as well.
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Annex 1
Ship and cargo types
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SHIP TYPES
Chemical tanker
6. Tank heating / tankwash room
14. Tanktop
8. Vent pipes with pressure-vacuum valves
15. Longitudinal vertically corrugated bulkhead
11. Manifold
16. Transverse horizontally corrugated bulkhead
13. Double bottom tank
22. Cargo heater
Tank instrumentation chemical tanker
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Relevant cargo types
Relevant cargo types are flammable liquids with a flashpoint below 60°C as listed in
Marpol annex II (further referred to as low flashpoint cargo).
Below some relevant examples of low flashpoint chemical cargoes are given that are
frequently transferred in the Port of Rotterdam:
 Acetic anhydride;
 Acetone;
 Acrylonitrile;
 Benzene and mixtures having 10% benzene or more;
 Decene;
 Ethyl alcohol;
 Hexane (all isomers)l;
 Isobutyl alcohol;
 Methyl alcohol;
 Pyrolysis gasoline;
 Reformate benzene heartcut;
 Styrene monomer;
 Ethyl alcohol.
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Annex 2
Inert Gas systems
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INERTING OPERATIONS OF CARGO TANKS
The following scenarios illustrate the different uses of IGS33.
1. Discharge
When a tanker has reached destination and is discharged, the IGS is started as a
parallel activity. As the volume of cargo decreases in the tank, this volume is replaced
by inert gas, thus preventing the ingress of oxygen in the tank.
2. Cleaning
Tank cleaning is required ff the next cargo to be loaded is not compatible with the
discharged cargo. During tank cleaning the tanks must remain fully inerted due to the
risk of sparks caused by equipment/fittings falling down inside the tank of static
electricity produced by water jets from cleaning machines. For oil products flue gas can
be used as an inert gas and nitrogen is used as an inert gas for low flashpoint chemical
cargoes.
3. Purging
To dilute or displace the hydrocarbon vapour to a level at which combustion cannot take
place (generally a level below 10% of LEL34), the tanks, now filled with hydrocarbon
vapour and inert gas, are purged and filled with IG. In the case of a product tanker the
common IG is flue gas which is injected through a system at the deck (left figure).
Chemicals tankers commonly use nitrogen as IG, and often use the cargo lines for
purging (right figure).
33
34
http://thenauticalsite.com/Advanced%20Notes/Inert%20Gas%20Sys%20Ops.htm
LEL= Lower Explosion Limit
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The flow of nitrogen received from shore may be as low as 100m3/hr or as high as
several thousand m3/hr. In all cases the atmosphere in the cargo tank will be replaced
by nitrogen. As a rule of thumb the Oxygen content in a cargo tank will be reduced by
50% by exchanging the tank volume once. This means that 3000 m3 of Nitrogen will be
needed to purge a 1000 m3 tank from 21% down to about 6.25% oxygen (which is well
below the required 8% oxygen).
4. Gas Freeing & survey
Before loading a new product in a chemical tanker, the empty tanks are freed of
containing gases and filled with ambient air, allowing people to enter the tank for a
survey of the tanks. For oil products the chance of having a compatible next cargo is
bigger than for chemical products.
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5. Inerting
To decrease the level of oxygen back to a level at which combustion cannot take place,
the tanks, now filled with ambient air, are purged and filled with IG. In the case of a
product tanker the common IG is flue gas which is injected through a system at the
deck. Chemicals tankers commonly use nitrogen as IG, and often use the cargo lines for
purging. The process of inerting is equal to purging, except that after inerting the tank is
directly sealed instead of starting the process of gasfreeing. For an illustration please
see the figure for purging.
6. Loading
As cargo is loaded into the tank the mixture of vapour and IG is pushed out of the tank
via the stack or to the vapour recovery system35.
7. Topping up
To prevent oxygen from entering the tank when sailing, the IGS is used to keep a
positive pressure in the tank.
8. Blanketing
As an alternative to the procedure of inerting before loading, blanketing can be applied
after loading.
Tank blanketing (also referred to as tank padding) is the process of applying inert gas to
the empty space above the loaded product in the cargo tanks.
Dilution versus displacement method
The term purging is used to describe the introduction of inert gas into a cargo tank with
the object of reducing the hydrocarbon content and/or further reducing the oxygen
content. Purging is carried out by the dilution or displacement method.
35
In most cases the product vapours are led to a gas treatment plant where the gas is treated before admittance to
atmosphere.
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Dilution method
This means forced mixing with high
velocity injection of inert gas. On a ship
which is not fitted with a purge pipe in the
cargo tanks, this method is applied. In
this case, the tank atmosphere is diluted
by inert gas.
Displacement method
Here the tank atmosphere is filled with inert
gas by utilization of density difference
between inert gas and cargo vapour. If a
ship is fitted with a purge pipe in the cargo
tanks, this method is applied. Inert gas
being supplied is kept at a low velocity to
minimize mixing with cargo vapour.
Tank cleaning and inspection will be effected due to the use of nitrogen. Entering tanks /
holds with reduced oxygen is extremely dangerous and will lead to fatal injuries within
seconds. Due to this risk stringent safety procedures for cleaning and inspection will
have to be arranged to control this risk.
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Annex 3
Data collection
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DATA COLLECTION
Data is derived from:
Port of Rotterdam
 Public documents;
 Data sheets (IVS);
 Interviews.
Interview with independent terminals
 Odfjell Terminals Rotterdam.
 Vopak.
Interview with Chemical Marine Technical Advisor of Shell
Interviews with ship-operators
 Stolt Tankers;
 Marine Facilities Management;
 North Sea Tankers.
Inert Gas Installation producers and installers
 Verhaar Omega.
Impact inert Gas <20 kDWT tankers
Final Report
Annex 3
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8 February 2012