Guidelines revoked by resolution MEPC.170(57)
Resolution
MEPC.130(53)
GUIDELINES FOR ON-BOARD EXHAUST GAS-SOX CLEANING SYSTEMS
(Adopted
on 22 July 2005)
THE
MARINE ENVIRONMENT PROTECTION COMMITTEE,
RECALLING
Article 38(a) of the Convention on the International Maritime Organization
concerning the functions of the Marine Environment Protection Committee (the
Committee) conferred upon it by international conventions for the prevention
and control of marine pollution,
RECALLING
ALSO that the Conference of Parties to the International Convention for the
Prevention of Pollution from Ships, 1973, as modified by the Protocol of 1978
relating thereto (MARPOL 73/78), held in September 1997, adopted the Protocol
of 1997 to amend MARPOL 73/78 with a new Annex VI on the Prevention of Air
Pollution from Ships,
NOTING
that the 1997 Conference by regulation 14(4)(b) of Annex VI, agreed that ships
within a SOx emission control area are permitted to operate with an exhaust gas
cleaning system approved by the Administration and taking into account
guidelines to be developed by the Organization,
BEING
AWARE that the Protocol of 1997 entered into force on 19 May 2005 and that
exemptions from the requirements for SOx emission control areas will cease on
18 May 2006,
HAVING
CONSIDERED the recommendation made by the Sub-Committee on Ship Design and
Equipment at its forty-eighth session,
1.
ADOPTS the Guidelines for exhaust gas-SOx cleaning systems, as set out in the
Annex to this resolution;
2.
INVITES Governments to apply the Guidelines from the date of their adoption.
Annex.
GUIDELINES FOR EXHAUST GAS-SOx CLEANING SYSTEMS -MARPOL ANNEX VI, REGULATION
14(4)(b)
Regulation
14(4) of Annex VI to MARPOL 73/78 requires ships within SOx emission control
areas to either use fuel oil with a sulphur content not exceeding 1.5% or apply
an exhaust gas (SOx) cleaning system (EGCS-SOx) to reduce the total emission of
SOx to 6.0g/kWh. (6.0 g SOx/kWh or less should be calculated as the total weight
of sulphur dioxide emission). The EGCS-SOx unit is to be approved by the
Administration taking into account guidelines developed by the Organization.
Similar
to a NOx emission reduction system, a EGCS-SOx unit may be type approved
subject to periodic parameter and emission checks or the system may be equipped
with a continuous emission monitoring system. These guidelines have been
developed with the intention of being objective and performance oriented.
Introduction of the SO2 (ppm) / CO2 (%) ratio method
would simplify the monitoring of SOx emission and facilitate type approval of
the EGCS-SOx unit. See Appendix I for the rationale explaining the use of SO2
(ppm) / CO2 (%) as the basis for system monitoring.
These
Guidelines are recommendatory in nature, however, Administrations are invited
to base their implementation on these guidelines.
Due
attention is to be given to the safety implications related to the handling and
proximity of exhaust gases, the measurement equipment and the storage and use
of cylindered pure and calibration gases. Sampling positions and access staging
should be such that this monitoring may be performed safely. In locating
discharge outlet of waste water used in the EGCS-SOx unit, due consideration
should be given to the location of the ship's sea water inlet and other
implications of the acidic nature of such water.
SCHEME A.
EGCS-SOx UNIT TYPE APPROVAL AND CERTIFICATION
Unit
certification of Exhaust Gas-SOx Cleaning Systems (EGCS-SOx) by the
Administration with subsequent in service verification at survey intervals by
indirect means together with unit use monitoring.
The
purpose of these Guidelines is to specify the requirements for the design,
testing, survey and certification of exhaust gas cleaning-SOx systems
(EGCS-SOx) to ensure that they comply with the requirements of regulation
14(4)(b) of Annex VI of MARPOL 73/78.
1.2.1
These Guidelines apply to any EGCS-SOx unit as fitted to fuel oil combustion
machinery, excluding shipboard incinerators, installed onboard a ship which is
to operate within a SOx Emission Control Area (SECA).
1.2.2
These Guidelines cover only the certification, survey, and testing of the
EGCS-SOx unit for compliance with regulation 14(4)(b) of Annex VI.
"ppm"
means "parts per million". It is assumed that ppm is measured by gas
analysers on a molar basis, assuming ideal micro-moles of substance per mole of
total amount (µmol/mol), but ppm is used in order to be consistent with units
in the NOx Technical Code.
"Fuel oil
combustion unit" means any engine, boiler, gas turbine, or other fuel oil
fired equipment.
2.1.1
Prior to use within a SECA, each EGCS-SOx unit should be issued with a SECA
Compliance Certificate (SCC) by the Administration.
2.1.2
The EGCS-SOx unit should be subject to survey on installation and at Initial,
Annual/Intermediate and Renewals Surveys by the Administration, irrespective of
whether or not the ship is in a SECA at the time of Survey.
2.1.3
The ship's SCC should be duly endorsed at each survey as required by 2.1.2.
2.1.4
In accordance with regulation 10, EGCS-SOx units may also be subject to
inspection by PSC when operating within a SECA.
2.2 Procedures for the certification of an
EGCS-SOx unit
2.2.1
In order to meet the requirements of 2.1.1 either prior to, or after
installation onboard, each EGCS-SOx unit should be certified as meeting the
emission limit of 6.0 g SOx/kWh under the operating conditions and restrictions
as given by the EGCS-SOx Technical Manual (ETM) as approved by the
Administration.
2.2.2
Determination of the emission value should be in accordance with the provisions
of these Guidelines.
2.2.3
Each EGCS-SOx unit meeting the requirements of 2.2.1 should be issued by the
Administration with a SCC.
2.2.4
Application for a SCC should be made by the EGCS-SOx manufacturer, shipowner or
other party.
2.2.5
Subsequent EGCS-SOx units of the same design and rating as that certified under
2.2.1 may be issued with SCC by the Administration without the need for testing
in accordance with 2.2.1 subject to section 4.2 of these Guidelines.
2.2.6
EGCS-SOx units of the same design, but with ratings different from that
certified under 2.2.1 may be accepted by the Administration subject to section
4.3 of these Guidelines.
2.2.7
EGCS-SOx units which treat only part of the exhaust gas flow of the uptake in
which they are fitted should be subject to special consideration by the
Administration to ensure that under all defined operating conditions that the
overall emission value of the exhaust gas down stream of the system is no more
than 6.0 g SOx /kWh.
2.3.1
Each EGCS-SOx unit is to be supplied with a EGCS-SOx Technical Manual (ETM)
provided by the Manufacturer. This ETM should, as a minimum, contain the
following information:
(a) the
identification of the unit (manufacturer, model/type, serial number and other
details as necessary) including a description of the unit and any required
ancillary systems;
(b) the
operating limits, or range of operating values, for which the unit is
certified. These should, as a minimum, include:
(i) maximum and,
if applicable, minimum mass flow rate of exhaust gas;
(ii) the power,
type and other relevant parameters of the fuel oil combustion unit for which
the EGCS-SOx unit is to be fitted. In the cases of boilers, the maximum
air/fuel ratio at 100% load should also be given. In the cases of diesel
engines whether the engine is of 2 or 4 stroke cycle;
(iii) maximum
and minimum wash water flow rate, inlet pressures and minimum inlet water
alkalinity (pH);
(iv) exhaust gas
inlet temperature ranges and maximum exhaust gas outlet temperature with the
EGCS-SOx unit in operation;
(v) exhaust gas
differential pressure range and the maximum exhaust gas inlet pressure with the
fuel oil combustion unit operating at MCR or 80% of power rating whichever is
appropriate;
(vi) salinity
levels or fresh water elements necessary to provide adequate neutralizing agents;
and
(vii) other
factors concerning the design and operation of the EGCS-SOx unit relevant to
achieving a maximum emission value no higher than 6.0 g SOx/kWh;
(c) any
requirements or restrictions applicable to the EGCS-SOx unit or associated
equipment necessary to enable the unit to achieve a maximum emission value no
higher than 6.0 g SOx/kWh;
(d) maintenance,
service or adjustment requirements in order that the EGCS-SOx unit can continue
to achieve a maximum emission value no higher than 6.0 g SOx/kWh;
(e) the means by
which the EGCS-SOx unit is to be surveyed to ensure that its performance is
maintained and that the unit is used as required (see section 6);
(f) through
range performance variation in wash water characteristics;
(g) design requirements
of the wash water system; and
(h) the SCC.
2.3.2
The ETM should be approved by the Administration.
2.3.3
The ETM should be retained onboard the ship onto which the EGCS-SOx unit is
fitted. The ETM should be available for surveys as required.
2.3.4
Additions, deletions or amendments to the ETM should be approved by the
Administration. Where additions, deletions or amendments to the ETM are
separate to the ETM as initially approved, they should be retained with the ETM
and should be considered as part of the ETM.
2.3.5
As an alternative to the maximum emission rate stipulated in 2.3.1(b)(vii) of
6.0 g SOx/kWh, SO2 (ppm) / CO2 (% ) ratio of 65 or below,
measured downstream of EGCS-SOx unit may be used.
3.1
Each EGCS-SOx unit should be capable of reducing emissions to no more than 6.0
g SOx/kWh at any load point when operated in accordance with the criteria as
given within 2.3.1(b), as specified in paragraphs 3.2 through 3.5 of these
Guidelines, and as excepted in paragraphs 3.7 and 3.8.
3.2
EGCS-SOx units fitted to main propulsion diesel engines should meet the
requirements of 3.1 at all loads between 25-100% of the load range of the
engines to which they are fitted.
3.3
EGCS-SOx units fitted to auxiliary diesel engines should meet the requirements
of 3.1 at all loads between 10-100% of the load range of the engines to which
they are fitted.
3.4
EGCS-SOx units fitted to diesel engines which supply power for both main
propulsion and auxiliary purposes should meet the requirements of 3.3.
3.5
EGCS-SOx units fitted to boilers should meet the requirements of 3.1 at all
loads between 10-100% of the load range (steaming rates) of the boilers to
which they are fitted.
3.6
In order to demonstrate performance, emission measurements should be
undertaken, with the agreement of the Administration, at a minimum of four load
points. One load point is to be at 95-100% of the maximum exhaust gas mass flow
rate for which the unit is to be certified. One load point is to be within + 5%
of the minimum exhaust gas mass flow rate for which the unit is to be
certified. The other two load points are to be equally spaced between the
maximum and minimum exhaust gas mass flow rates. Where there are
discontinuities in the operation of the system the number of load points should
be increased, with the agreement of the Administration, so that it is
demonstrated that the required performance over the stated exhaust gas mass
flow rate range is retained. Additional intermediate load points should be
tested if there is evidence of an emission peak below the maximum exhaust gas
mass flow rate and above, if applicable, the minimum exhaust gas flow rate.
These additional tests should be sufficient number as to establish the emission
peak value.
3.7
For loads below those specified in 3.2 to 3.5, the EGCS-SOx unit should
continue in operation. In those cases where the fuel oil combustion equipment
may be required to operate under idling conditions, the SO2 emission
concentration (ppm) at standardized O2 concentration (15.0% diesel
engines, 3.0% boilers) should not exceed 50 ppm.
3.8
Alternatively to the provisions of 3.2-3.5 and 3.7, each EGCS-SOx unit should
be capable of reducing emissions to 65 or below, in SO2 (ppm) / CO2
(%) ratio at any load point when operated in accordance with the criteria as
given within 2.3.1(b) and 2.3.4.
4. APPROVAL OF AN EGCS-SOx
UNIT
4.1.1
An EGCS-SOx unit should be capable of meeting the limit value of 6.0 g SOx/kWh
(other than as given in section 3) with fuel oils of up to 4.5% m/m sulphur and
for the range of operating parameters, as listed in 2.3.1(b), for which they
are to be approved.
4.1.2
Where testing is not to be undertaken with fuel oils of 4.5% m/m sulphur
content or above, testing should be undertaken to demonstrate the effect of
fuel oil sulphur content on system performance. In such cases a minimum of two
tests, in accordance with section 3 as appropriate, should be performed. These
need not be sequential and could be undertaken on two different, but identical,
EGCS-SOx units. The minimum sulphur content of the fuel oil used in one test
should not be less than 2.0% m/m sulphur. The other fuel oil should have a
sulphur content of at least 1.0% m/m sulphur above that of the lower sulphur
content fuel oil. The EGCS-SOx unit manufacturer should justify, on the basis
of the above considerations, and other testing as may be required, that the
EGCS-SOx unit would meet the required limit of 6.0 g SOx/kWh when used with a
fuel oil of 4.5% m/m sulphur.
4.1.3
The maximum and, if applicable, minimum exhaust gas mass flow rate of the unit
should be stated. The effect of variation of the other parameters defined in
2.3.1(b) should be justified by the equipment manufacturer. The effect of
variations in these factors is to be assessed by testing or otherwise as
appropriate. No variation in these factors, or combination of variations in
these factors, should be such that the emission value of the EGCS-SOx unit
would be in excess of 6.0 g SOx/kWh.
4.1.4
Data obtained in accordance with this section should be submitted to the
Administration for approval together with the ETM.
4.2 Serially manufactured units
In
the case of nominally similar EGCS-SOx units of the same mass flow ratings as
that certified under 4.1, and to avoid the testing in accordance with 2.2.1
each EGCS-SOx unit, the equipment manufacturer may submit, for acceptance by
the Administration, a conformity of production arrangement. The certification
of each EGCS-SOx unit under this arrangement should be subject to such surveys
that the Administration may consider necessary as to assure that each EGCS-SOx
unit has an emission value of not more than 6.0 g SOx/kWh when operated in
accordance with the parameters defined in 2.3.1(b).
4.3.1
In the case of an EGCS-SOx unit of the same design, but of different maximum
exhaust gas mass flow capacities, the Administration may accept, in lieu of
tests on an EGCS-SOx unit of all capacities in accordance with section 4.1,
tests of EGCS-SOx systems of three different capacities provided that the three
tests are performed at intervals including the highest, lowest and one
intermediate capacity rating within the range.
4.3.2
Where there are significant differences in the design of EGCS-SOx units of different
capacities, this procedure should not be applied unless it can be shown, to the
satisfaction of the Administration, that in practice those differences do not
materially alter the performance between the various EGCS-SOx unit types.
4.3.3
For EGCS-SOx units of different capacities, the sensitivity to variations in
the type of combustion machinery to which they are fitted should be detailed
together with sensitivity to the variations in the parameters listed in
2.3.1(b). This should be on the basis of testing, or other data as appropriate.
4.3.4
The effect of changes of EGCS-SOx capacity on wash water characteristics should
be detailed.
4.3.5
All supporting data obtained in accordance with this section, together with the
ETM for each capacity unit, should be submitted to the Administration in
accordance with 4.1.6.
4.3.6
An SO2 (ppm) / CO2 (%) ratio of 65 may be used for
emission limit value specified in 4.1.2, 4.1.3 and 4.2.
5.1
Emission testing should follow the requirements of the NOx Technical Code,
chapter 5, and associated Appendices, except as provided for in these
Guidelines.
5.2
CO2, O2 and SO2 should be measured. CO2
and O2 as % to a precision of +/-1% of the true reading for a signal
averaging time of 10 seconds, but not less than a lower detectable limit of 5
ppm.
5.3
SO2 should be measured on a dry or wet basis using analysers
operating on NDIR or NDUV principles and with additional equipment such as
dryers as necessary. Other systems or analysers may be accepted, subject to the
approval of the Administration, provided they yield equivalent results to those
of the equipment referenced above.
5.4
An exhaust gas sample for SO2 should be obtained from a
representative sampling point downstream of the EGCS-SOx unit.
5.5
SO2 should be monitored on-line using either cross-duct or
extractive sample systems.
5.6
Extractive exhaust gas samples for SO2 determination should be
maintained at a sufficient temperature to avoid condensed water in the sampling
system and hence loss of SO2.
5.7
If an extractive exhaust gas sample for determination needs to be dried prior
to analysis it should be done in a manner which does not result in loss of SO2
in the sample as analysed.
5.8
Where SO2 is measured by a cross-duct system, the water content in
the exhaust gas stream at that point is also to be determined in order to
correct the reading to a dry basis value.
5.9
Where the exhaust gas mass flow is to be calculated in accordance with the NOx
Technical Code, Appendix 6, the complete combustion case calculations may be
used. The exhaust gas mass flow (GEXHW) should be determined in respect of the
mass flow into the EGCS-SOx unit.
5.10
In applying the NOx Technical Code, equation 15, the dry basis SO2
concentration should be converted to a wet basis value using the dry/wet
correction factor applicable to the exhaust gas at entry into the EGCS-SOx unit
(NOx Technical Code, equation 11, CO = 0):
w = 0.002855, u = w/exhaust gas density in g/m3
at 0°C and 101.3 kPa
5.11
The fuel oil as used in the test should be a residual blend product. A
representative sample of that fuel should be analysed in order to establish its
chemical composition (carbon, hydrogen and sulphur) together with the other
parameters as necessary to establish its grade in accordance with the ISO 8217
specification.
5.12
For diesel engines the power should be the uncorrected brake power.
5.13
For boilers the "power" should be determined based on the fuel rate
and assumed brake specific fuel consumption of 200 g/kWh.
5.14
The determined emission value at each test point should be equal to, or less
than, 6.0 g SOx/kWh.
5.15
In lieu of the testing procedure laid down in 5.9 to 5.10 and 5.12 to 5.14,
compliance may be demonstrated by continuous monitoring of and CO2
concentration in the exhaust gas down stream of the EGCS-SOx unit and
demonstrating that the SO2 (ppm) / CO2 (%) ratio, at each
test point is 65 or below.
5.16
Should the SO2 (ppm) / CO2 (%) ratio method be used:
(a) The
conditions stipulated in 5.4 and 5.5 should also apply to the measurement of CO2
(%) and it is recommended that SO2 and CO2 samples should
be obtained at the same location.
(b) Measurement
of SO2 and CO2 should either be carried out above the
respective dew points or on a fully dry basis recognizing that the conditions
stipulated in 5.6-5.8 should also apply to the measurement of CO2
(%).
(c) The carbon
and hydrogen content of the test fuel as stipulated in 5.11 need not be
determined.
(d) Calculation
of the SO2/CO2 ratio should comply with the requirements
of Scheme B, section 10.
6. PROCEDURES FOR
DEMONSTRATING COMPLIANCE WITH EMISSION LIMIT ON BOARD