Sulphur Compliance Methods: SOx Scrubbers and Marine ...
Transcript of Sulphur Compliance Methods: SOx Scrubbers and Marine ...
MARINE ENVIRONMENT DIVISION
Sulphur Compliance Methods:
SOx Scrubbers and Marine Alternative Fuels
Seminar on the regulations and reduction
of air emissions from ships
Bangkok, Thailand, 27 June 2019
Dr Zabi Bazari
IMO Lead Consultant
MARINE ENVIRONMENT DIVISION
Content
• Regulatory requirements and drivers
• Compliance options:
• Multi-fuel option
• Exhaust Gas Cleaning System (SOx Scrubbers)
• LNG as marine fuel
• Biofuels
• Other fuels and their overall comparisons
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Regulatory drivers for change
Reg. 14 Sulphur Oxides & Particular Matter (SOx & PM)
Significant reduction in
regulatory sulphur levels.
Compliance options:
1. Use of compliant fuel oil
(e.g. low sulphur fuel)
2. SOx scrubbers
3. LNG
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• Sets a target of 50% reduction in GHG
emissions from international shipping
by 2050 relative to 2008.
• Compliance options
• Such a big reduction almost certainly
will need new low-carbon or zero-
carbon fuels.
• Thus, regulatory scene for:
• Short term is driven by SOx
concerns.
• Long–term is driven by CO2
concerns.
Initial IMO GHG Strategy
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ECA compliance strategies - SOx
Option 1. Use compliant fuel oil (e.g. low sulphur fuel)
→ Multi–fuel bunkering
• Fuel system segregation (various tanks as a minimum).
• Segregated cylinder lube oil tanks may be required.
• Fuel change over and log book recording needed for ECA-SOx
operation.
• More complex system and therefore more vigorous “fuel management”.
• Planning of voyages for having correct fuel onboard prior to entering an
ECA-SOx.
• Cost concerns / availability concerns / fuel quality concerns
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Option 2 - SOx Scrubber (EGCS)
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EGCS (Exhaust Gas Cleaning System)
• EGCS is the term used by the IMO for
SOx scrubbers.
• Regulation 4 of MARPOL Annex VI
allows the use of “equivalents”; subject
to approval by the Flag Administration.
• EGCS has been accepted by IMO as
an “equivalent” method to sulphur
compliance.
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SOx scrubber – How does it work?
• Processes:
• PM also ends up in
washwater.
• NOx is also partially
converted to acids
(nitrous or nitric)
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SOx scrubber: How does it work?
• SOx is removed via using
wash water.
• System includes:
• Water supply
• Water treatment
• Exhaust gas monitoring
• Water quality monitoring
• Supply of water treatment
agent
• Types of scrubbers:
• Open loop
• Closed loop
• Hybrid (open/closed)Source: Force Technology, 2012
See: http://www.youtube.com/watch?v=J8_D7ASh0_g
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Scrubber – Monitoring of exhaust gases for compliance
• Compliance method via monitoring
according to MEPC.259(68) :
• Ratio of SO2 (ppm) to CO2(% v/v)
should be according to the table.
• The Table is valid when petroleum
based distillates or residuals are
used.
Source: ABS Advisory on “Exhaust Gas Scrubber Systems”
MARINE ENVIRONMENT DIVISION
Scrubber – Monitoring of wash-water quality
The following parameters need to be monitored:
• pH > 6.5 (with some exceptions)
• PAH (Polycyclic Aromatic Hydrocarbons) has specific limits < 50 micro gram/Litre
PAH when flowrate is 45 t/MWh (normalised value).
• Turbidity/suspended particles: Need to be limited and continuously monitored
and be below certain limits.
• Nitrates: These need to be monitored and specific limits observed. The limit is
below 60 mg/litre for a capacity of 45 tonnes/MWh (normalised value).
• Specific techniques or standards are given for wash water monitoring equipment.
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Scrubber certification – Applicable regulations
The IMO EGCS Guidelines (MEPC.259(68)) permit two schemes for survey and
certification purposes:
• Scheme A (Unit Certification with periodic Emissions and Parameter Checks)
• Scheme B (Continuous Emission Monitoring with Parameter Checks).
The Guidelines make provisions for each EGCS’s:
• Approval
• Survey and certification
• Emissions limits and emissions monitoring
• On-board demonstration of compliance
• Washwater criteria
• Washwater monitoring
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• SOx Emissions Compliance Certificate (SECC) for systems certified based on
Scheme A.
• EGCS Technical Manual (ETM): Includes all technical details of the system
including verification methods.
• Approved SOx Emissions Compliance Plan (SECP): This is for a ship that has
EGCS and indicates how the ship overall is going to comply with sulphur
regulation.
• EGCS Record Book: For recording of changes to the system in terms of
maintenance, EGCS residue, supply of agents, etc.
• On-board Monitoring Manual (OMM): Details all aspects of monitoring system for
exhaust gases and washwater.
• All the above need to be approved by Flag Administration and are also subject to
Port State Control.
Documentations required on-board
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Scrubber residues – Delivery to port reception facilities
• All residues from water treatment plant should be kept on board.
• They cannot be incinerated on-board and must be delivered to reception facilities.
• All information about EGCS residues (storage, delivery, times, dates, quantities,
location, etc.) should be recorded in an EGCS Record Book.
• EGCS Record Book could be an independent one or be part of existing log books,
or an electronic recording system as approved by Administration.
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• Concerns on washwater quality and its impacts
• Some countries set limits for the content of pollutants in ports, estuaries and
coastal areas.
• This may mean that the discharges of washwater in some areas will face
restrictions.
• In some areas, washwater discharges might be prohibited by port State
legislation.
• The resulting lack of harmonisation / clarity will hamper the uptake of
scrubbers.
• To alleviate the above concerns, MEPC 74 (May 2019) agreed to include
investigation of this matter at PPR 7 with a reporting back by 2021.
• MEPC 74 also encouraged GESAMP to establish a task team to assess the
available evidence relating to the environmental impact of discharges of EGCS
effluent.
EGCS (Open-loop SOx Scrubber) concerns - Uncertainties
MARINE ENVIRONMENT DIVISION
Option 3 - Liquefied Natural Gas
(LNG) as Marine Fuel
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LNG as marine fuel
• Natural gas is mainly methane (~ 95%) with some ethane and propane
(together about 2-3%)
• Cooled to around -162°C, at which point it contracts by a factor of
600:1 to form a liquid
• LNG is re-gasified before burning in engines or boilers
• Clean fuel (SOx and PM are negligible)
• LNG may be used to meet the NOx Tier III
MARINE ENVIRONMENT DIVISION
LNG as compared to liquid fuels
• Volumetric energy density of LNG is less than FO (fuel oil)
• LNG (22 TJ/m3) and FO (39 TJ/m3)
• Mass energy density of LNG is higher than FO
• LNG (55 MJ/kg) and MDO (42.8 MJ/kg)
• Almost no sulphur
• Very low flash point at ~ -149 0C (gas oil is ~74 0C).
• Vey high auto-ignition temperature of 540 (Gas Oil is ~315 0C) – Thus
combustion need to start externally.
• Dual fuel engines
• Spark ignited engines
MARINE ENVIRONMENT DIVISION
Dual fuel engines: Basic principles
• Work according to diesel principle (Compression Ignition).
• Liquid fuel is used as pilot injection to initiate combustion.
• NG is mixed with air prior to pilot injection.
• The design could facilitate a varied ratio between liquid fuel and LNG.
Source: Wartsilla
MARINE ENVIRONMENT DIVISION
Pure natural gas engines
MARINE ENVIRONMENT DIVISION
• Works with 100% gas.
• Single fuel natural gas engines
• Low pressure gas
• Spark plugs initiate combustion:
• Works according to Otto cycle
• Less efficient than the diesel
options
Source: Rolls Royse (Bergen K-GE)
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LNG emissions compared to HFO and MDO
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LNG as fuel: Other
considerations
• DF and pure natural
gas engines have
some Methane Slip
• LNG has a significantly
more Supply Chain
GHG Emissions
(upstream) as
compared to liquid
fuels
Source: ICCT White Paper on Assessment of the fuel cycle impact of liquefied natural gas as used in international shipping
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IMO - LNG studies
Main studies / initiatives performed:
• Feasibility study on the use of LNG as a
fuel for international shipping in the
North American ECA
• Pilot study on the use of LNG as a fuel
for a high speed passenger ship from
the Port of Spain ferry terminal in
Trinidad and Tobago
• Feasibility study on LNG fuelled Short
Sea and Coastal Shipping in the Wider
Caribbean Region
MARINE ENVIRONMENT DIVISION
LNG as fuel regulatory aspects: IGF Code
• IMO IGF Code “International Code of Safety for Ships using Gases or other Low-Flash Point Fuels”.
• Harmonised with IGC Code with more focus is on bunkering and fuel management aspects.
• There is no specific rule on LNG as marine fuel in MARPOL Annex VI
IGF Code contents:
1. Preamble
2. General
3. Goals and functional requirements
4. General requirements
5. Ship design and arrangement
6. Fuel containment system
7. Material and general pipe design
8. Bunkering
9. Fuel supply to consumers
10.Power generation and propulsion
11.Fire safety
12.Explosion protection
13.Ventilation
14.Electrical installations
15.Control, monitoring and safety
system.
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LNG: Pros and cons
Pros
• Clean fuel:
• No sulphur
• Up to 90% less NOx
• No Particulate Matters
• GHG reduction potential
• LNG is often cheaper than MGO when available
• Less engine maintenance?
Cons
• Lack of infrastructure for LNG bunkering
• LNG safety issues
• Cost of LNG ships
• Range of LNG ships
• Methane slip
• Port operation: Likely need for BOG gas combustion
• Reduced cargo space
• Large fuel tank volumes due to low energy density and need for insulation and containment
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Vessels expected to use LNG as marine fuel: Main features
• Operate mostly inside the ECA, e.g. short sea shipping
• Coastwise and regionally bound vessels, e.g. ferries, tugs, offshore vessels
• Fuel cost sensitivity
• Sufficient size and on-board space to accommodate the installation
• LNG bunker availability and cost
• Possibilities for conversion
• Fleet renewal demand
• Liner service, vessel on fixed routes
• Environmental profile is beneficial
MARINE ENVIRONMENT DIVISION
Comparison of compliance alternatives
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MARINE ENVIRONMENT DIVISION
Other Alternative Fuels
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Biofuels
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Bio-fuels production from bio-mass
MARINE ENVIRONMENT DIVISION
Biofuels generations
MARINE ENVIRONMENT DIVISION
• The production cycle include production of bio-material and process conversion (all would require land, energy, water, etc.).
• Depending on the above, biofuels are divided into generations:
• 1st generation: Produced directly from food crops (wheat, sugar, etc.)
• 2nd generation: Produced from non-food crops such as wood, organic waste, food crop wastes, food wastes, etc.
• 3rd generation: Based on specially engineered energy crops
such as algae with no impact on food/dforestation.
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Biofuel production
• Currently mainly produced from food crops.
• Production involves:
• Land use
• Energy use
• Fertilizer use
• Water use
• Production of biofuels are generally subsidised.
• Sustainable production of biofuels is currently an issue.
• Sustainable production potential is currently limited worldwide.
MARINE ENVIRONMENT DIVISION
Diagram source: http://www.geni.org/globalenergy/library/articles-renewable-energy-transmission/graphics/biofuels_compare.gif
The lifecycle “CO2 performance” of various bio-fuels vary significantly.
How green are biofuels?
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Methanol
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• Traditionally methanol is produced from wood but now mostly through “industrial
synthesis” from natural gas
• Methanol has the advantage of remaining liquid at ambient temperature
• Methanol and LNG are similar in terms of energy density
• Low emissions fuel
Stena Germanica ferry converted to methanol
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Methanol: IMO Study
MARINE ENVIRONMENT DIVISION
• A study was done for IMO. The main conclusions are:
• Methanol produced from natural gas (synthetic methanol) has higher GHG
emissions than conventional fuels.
• Methanol produced from biomass (bio methanol) have the potential to reduce
emissions provided that the electricity used for its production is clean.
• The lifecycle NOx emissions of methanol is 45% of conventional fuels per unit
energy
• The lifecycle SOx emissions of methanol is approximately 8% of those from
conventional fuels per unit energy
• Technology Readiness exists to a large extent and feasible. However, there are
additional safety barriers.
• From cost/economic perspective, methanol can only be justified if MGO prices
are high and the ship is largely operating in ECA zones.
MARINE ENVIRONMENT DIVISION
Biodiesel
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FAME (Fatty Acid Methyl Esters )
• Biodiesel refers to a mixture of
different FAME.
• FAME is produced from vegetable
oils, animal fats and waste cooking
oils.
• FAME has physical properties similar
to those of conventional diesel.
• It is also non-toxic and
biodegradable.
Source: European Biofuel Technology Platform, factsheet
MARINE ENVIRONMENT DIVISION
Biodiesel pros
• Clean burning – No SOx, HC or PM; reduced CO2
• Biodegradable in water / non-toxic / high flash point 1600C
• Usable in existing diesel engines with little or no modification
• Improves lubricity – additive for ultra low sulphur distillates
• Blends well with petroleum diesels.
MARINE ENVIRONMENT DIVISION
Biodiesel issues
• Limited availability
• Food-fuel links, impact on food production
• Relatively expensive and normally subsidised.
• Cold filter plugging properties: Low temperature issues
• Solvent may degrade rubber & attack lead, copper, brass, zinc
• Oxygen Content 10-12 %
• Lower Heating Value than fossil fuel
• Fuel stability issues: Storage max 6 months recommended.
MARINE ENVIRONMENT DIVISION
• Hydrogen (H2) is the
candidate fuel.
• Production mainly from
renewable electricity.
• Supplement to LNG and
other gaseous fuels.
• Long term prospect
positive.
• Compatible with fuel cell
technology as well as
future hybrid electric
propulsion zero-carbon
ships.
Renewable electricity marine energy pathway - Hydrogen
Batteries Synthetic fuel
MARINE ENVIRONMENT DIVISION
Ammonia (NH3) as Marine Fuel
(a form of synthetic fuel)
Image courtesy of C-Job-Naval-Architect, Netherlands, https://www.maritime-executive.com/article/new-research-shows-benefits-of-ammonia-as-marine-fuel
MARINE ENVIRONMENT DIVISION
“Green ammonia” as marine fuel
• “Green Ammonia” has recently
been advocated as a marine fuel.
• Green Ammonia refers to
ammonia produced using
renewable electricity.
• Existing ammonia (not-green) is
produced from fossil fuel and is
highly energy-intensive, water-
intensive and GHG-intensive
material.
• Green Ammonia is thus fully
linked to renewable electricity
sector.
MARINE ENVIRONMENT DIVISION
• Current not-green ammonia
• Used by the international fertiliser industry
• Global market and international transportation already exist.
• Production is based on use of fossil fuels (highly GHG-intensive).
• Existing ammonia as marine fuel is much worse than fossil fuels.
• Future green ammonia: When developed, it will provide advantages:
• Existing global logistics infrastructure (unlike e.g. hydrogen).
• Does not require cryogenic storage (unlike e.g. hydrogen).
• Energy density of liquid ammonia is reasonable (unlike e.g. batteries).
• Changes to ship engines or future fuel cells technologies are feasible.
• Although toxic, corrosive and unsafe, the risk profile can be managed.
Green versus not-green ammonia
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Ammonia properties
• Ammonia liquefies at -33 oC; or at a moderate pressure of 10 bar.
• Requires less energy for liquefaction than H2 / Less boil off gases
• Liquid ammonia requires 46% less on-board storage space than H2
• Lower fire risk compared to H2 (narrower flammability range and
higher ignition temperature).
• Heating value is 18.67 MJ/kg; less than half of current marine fuels.
• Production is water intensive (~1.5 tonne water/tonne ammonia) and
energy intensive (~28 MJ/kg when natural gas is used as feedstock).
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Ammonia as marine fuel: Pathways
• Production from renewable energy is key.
• Three main pathways:
• Pathway 1: As H2 carrier thus conversion back to H2 and then use. Fuel cell is ideal technology.
• Pathway 2: As a primary fuel via burning in dual fuel engines.
• Pathway 3: As a mix of pathways 1 and 2.
MARINE ENVIRONMENT DIVISION
Ammonia as marine fuel - Emissions
• Green ammonia will produce significantly less life-cylce GHG
emissions.
Source: Sailing on Solar, Environmental Defence Fund and Riccardo report, 2019
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Solar-to-liquid fuels (green kerosene for jet fuel)
• A new technology for converting solar energy into liquid synthetic fuel.
• SUN-to-LIQUID project (EU funded) has recently produced its “solar kerosene” under real field conditions, using sunlight, water and CO2.
• The project has developed a solar reactor, located at the top of a tower, to reach reaction temperatures of more than 1,500 °C.
• The solar reactor then synthesizes hydrogen and carbon-monoxide, produced from water and CO2.
• Compared to conventional fossil-derived jet fuel, the net CO2 emissions to the atmosphere can be reduced by more than 90%.
• The produced fuel is a drop in one for aviation.
MARINE ENVIRONMENT DIVISION
Summary of alternative marine fuels and conclusionIFO LSFO MGO FAME Methanol LPG LNG
Engine and fuel
system costDrop-‐in Drop-‐in Drop-‐in Drop-‐in Dual fuel Gas tank
Dual fuel
Cryo tanks
Projected fuel
costRefining Refining Land use
Infra-‐
structure
Infra-‐
structure
Emission
abatement cost
SOx, NOx,
PM, CO2
NOx,
PM, CO2
Safety related
costFlash point Venti lation Press/temp
Indirect cost Ethics Cargo space Cargo space Cargo space
Serious impediment
Signifficantcost
Feasible solution available
MARINE ENVIRONMENT DIVISION
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