Answer EKG Question 32
Q32.
With reference to the fuel standards ISO-8217-2017 discuss the
amendments made as compared to its previous edition. Explain the
significance of the following:
(a) Pour point, cloud point and cold filter plugging point.
(b) Cat fines
(c) Fatty Acid methyl Easter
(a) Pour point, cloud point and cold filter plugging point.
(b) Cat fines
(c) Fatty Acid methyl Easter
(d) Dissolved H2S in fuel.
Answer:
Amendments to the Scope and General Requirements and the addition of DF grades containing biodiesel (FAME),plus the reporting of cold properties of Cloud Point (CP)and Cold Filter Plugging Point (CFPP)are of principal interest
Changes to the distillate fuels include the following:
— additional grades, DFA, DFZ and DFB have been added with a maximum fatty acid methyl ester(s) (FAME) content of 7.0 volume %;
— the sulfur content of DMA and DMZ has been reduced to a maximum of 1.00 mass %;
— the sulfur content of DMB has been reduced to a maximum of 1.50 mass %;
— requirements for the following characteristics have been added to winter grades of DMA and DMZ: cloud point and cold filter plugging point.
(a) No limit been put on Cloud Point (CP) and Cold Filter Plugging Point (CFPP)
The pour point of a liquid is the temperature below which the liquid loses its flow characteristics. It is defined as the minimum temperature in which the oil has the ability to pour down from a beaker.
Cloud point refers to the temperature below which wax in diesel or biowax in biodiesels forms a cloudy appearance. The presence of solidified waxes thickens the oil and clogs fuel filters and injectors in engines
Cold filter plugging point (CFPP) is the lowest temperature, expressed in degrees Celsius (°C), at which a given volume of diesel type of fuel still passes through a standardized filtration device in a specified time when cooled under certain conditions.
Increasingly we have seen that new ULSFO fuels can be more paraffinic in certain geographical areas, which may lead to cold flow operability issues when the ship is operating in a colder environment and does not have suitable fuel heating arrangements to compensate; more specifically this has been an issue for distillate fuel oils. While CFPP is part of the European auto diesel fuel specifications standard EN 590, climate related requirements within EN 590 are set at a national level taking into account the specific climate of the country.
Defining a suitable fuel characteristic and a limit to guarantee the cold operability of marine distillate fuels for all ships in all climate regions without significantly impacting other segments of the fuels market, requires more in depth study to ensure that there are no unintended adverse consequences. Therefore, the requirement to report CP and CFPP will provide additional information on the cold flow properties of the fuel that will help ship’s to mitigate cold operability issues ahead of any potential problems being experienced and supply important data to the next revision of the Standard.
(b) No changes to the maximum limits on cat fines (Al+Si)
Every edition of ISO 8217 is based on extensive statistical evaluation of the market at the time and this edition was not different. The Standard specifies the requirements prior to on-board settling, centrifuging and filtering of the fuel. With the centrifuge(s) at the correct operating settings, the cat fines content, as measured by the Al+Si level,can be reduced to an acceptable limit at the engine inlet. In order to provide an increased safety margin, the cat fines limit was reduced to 60 mg/kg in ISO8217:2010. A further reduction of the Al+Si limit would likely have a negative impact on fuel oil availability and cost of the product, therefore, lacking significant overriding evidence of a need, no change in the specification was deemed necessary
(c) FAME (fatty acid methyl ester)
With the increasing demand for maximum 0.10% sulphur fuel oils, some ports may offer automotive diesel fuel containing biodiesel (FAME) as the only fuel available. The maximum 7.0% (v/v) has been chosen as this aligns, at the time of writing this guideline,with the concentrations allowed in those countries applying environmental regulations.
In some areas, it may be difficult to buy FAME free distillate fuels and this Standard now provides a marine biodiesel specification that suppliers can offer instead of DMA or DMB when those grades are unavailable.
(d) Hydrogen sulfide (H2S),
Maximum limit of dissolved hydrogen sulfide is 2.00 mg/kg as per both 2010 and 2017 standard.
Hydrogen sulphide is commonly created by bacterial decomposition of organic matter such as septic tank debris and faecal material. This process is conducted by sulphate-reducing bacteria (SRBs) in the absence of oxygen. In the presence of water, it is acidic and is known as hydrosulphuric acid. This is the cause of the corrosion in sour gas or sour oil processing equipment. However, it can be neutralized using an (H2S) scavenger.
Hydrogen sulphide is lethal by inhalation at concentrations of 500ppm; it can quickly kill animals and humans at this concentration.
Benefits of using ISO 8217:2017 Standard over the previous editions (ISO 8217:2005 and/or 2010/12):-
While there are only minor changes to existing characteristics already included in the 2010/2012 edition, additional requirements have been included for distillate fuels to protect against cold operability issues. Hence, adopting the latest revision of the ISO 8217 offers improved quality control and better protection against operational issues while the introduction of DF (Distillate FAME) grades will improve fuel oil availability in some ports. Compared to ISO 8217:2005, this revision carries over the more stringent limits on minimum viscosity for distillate grades, lubricity, cat fines, acid number, H2S content and CCAI found in the 2010/2012 edition.
With the impending implementation in 2020 of MARPOL Annex VI’s global max 0.50% sulphur requirement for marine fuels, we anticipate a surge in VLSFO RM and DM type fuels coming to the market. We can therefore expect a broader choice from different geographic areas of fuel formulations which ships will have to manage. Although we expect similar fuels to those we have seen with the 0.10% ULSFO, the ISO Committee will continue to collect and monitor the statistics to strengthen the content of the next ISO 8217 Standard and will keep the industry advised.
Amendments to the Scope and General Requirements and the addition of DF grades containing biodiesel (FAME),plus the reporting of cold properties of Cloud Point (CP)and Cold Filter Plugging Point (CFPP)are of principal interest
Changes to the distillate fuels include the following:
— additional grades, DFA, DFZ and DFB have been added with a maximum fatty acid methyl ester(s) (FAME) content of 7.0 volume %;
— the sulfur content of DMA and DMZ has been reduced to a maximum of 1.00 mass %;
— the sulfur content of DMB has been reduced to a maximum of 1.50 mass %;
— requirements for the following characteristics have been added to winter grades of DMA and DMZ: cloud point and cold filter plugging point.
(a) No limit been put on Cloud Point (CP) and Cold Filter Plugging Point (CFPP)
The pour point of a liquid is the temperature below which the liquid loses its flow characteristics. It is defined as the minimum temperature in which the oil has the ability to pour down from a beaker.
Cloud point refers to the temperature below which wax in diesel or biowax in biodiesels forms a cloudy appearance. The presence of solidified waxes thickens the oil and clogs fuel filters and injectors in engines
Cold filter plugging point (CFPP) is the lowest temperature, expressed in degrees Celsius (°C), at which a given volume of diesel type of fuel still passes through a standardized filtration device in a specified time when cooled under certain conditions.
Increasingly we have seen that new ULSFO fuels can be more paraffinic in certain geographical areas, which may lead to cold flow operability issues when the ship is operating in a colder environment and does not have suitable fuel heating arrangements to compensate; more specifically this has been an issue for distillate fuel oils. While CFPP is part of the European auto diesel fuel specifications standard EN 590, climate related requirements within EN 590 are set at a national level taking into account the specific climate of the country.
Defining a suitable fuel characteristic and a limit to guarantee the cold operability of marine distillate fuels for all ships in all climate regions without significantly impacting other segments of the fuels market, requires more in depth study to ensure that there are no unintended adverse consequences. Therefore, the requirement to report CP and CFPP will provide additional information on the cold flow properties of the fuel that will help ship’s to mitigate cold operability issues ahead of any potential problems being experienced and supply important data to the next revision of the Standard.
(b) No changes to the maximum limits on cat fines (Al+Si)
Every edition of ISO 8217 is based on extensive statistical evaluation of the market at the time and this edition was not different. The Standard specifies the requirements prior to on-board settling, centrifuging and filtering of the fuel. With the centrifuge(s) at the correct operating settings, the cat fines content, as measured by the Al+Si level,can be reduced to an acceptable limit at the engine inlet. In order to provide an increased safety margin, the cat fines limit was reduced to 60 mg/kg in ISO8217:2010. A further reduction of the Al+Si limit would likely have a negative impact on fuel oil availability and cost of the product, therefore, lacking significant overriding evidence of a need, no change in the specification was deemed necessary
(c) FAME (fatty acid methyl ester)
With the increasing demand for maximum 0.10% sulphur fuel oils, some ports may offer automotive diesel fuel containing biodiesel (FAME) as the only fuel available. The maximum 7.0% (v/v) has been chosen as this aligns, at the time of writing this guideline,with the concentrations allowed in those countries applying environmental regulations.
In some areas, it may be difficult to buy FAME free distillate fuels and this Standard now provides a marine biodiesel specification that suppliers can offer instead of DMA or DMB when those grades are unavailable.
(d) Hydrogen sulfide (H2S),
Maximum limit of dissolved hydrogen sulfide is 2.00 mg/kg as per both 2010 and 2017 standard.
Hydrogen sulphide is commonly created by bacterial decomposition of organic matter such as septic tank debris and faecal material. This process is conducted by sulphate-reducing bacteria (SRBs) in the absence of oxygen. In the presence of water, it is acidic and is known as hydrosulphuric acid. This is the cause of the corrosion in sour gas or sour oil processing equipment. However, it can be neutralized using an (H2S) scavenger.
Hydrogen sulphide is lethal by inhalation at concentrations of 500ppm; it can quickly kill animals and humans at this concentration.
Benefits of using ISO 8217:2017 Standard over the previous editions (ISO 8217:2005 and/or 2010/12):-
While there are only minor changes to existing characteristics already included in the 2010/2012 edition, additional requirements have been included for distillate fuels to protect against cold operability issues. Hence, adopting the latest revision of the ISO 8217 offers improved quality control and better protection against operational issues while the introduction of DF (Distillate FAME) grades will improve fuel oil availability in some ports. Compared to ISO 8217:2005, this revision carries over the more stringent limits on minimum viscosity for distillate grades, lubricity, cat fines, acid number, H2S content and CCAI found in the 2010/2012 edition.
With the impending implementation in 2020 of MARPOL Annex VI’s global max 0.50% sulphur requirement for marine fuels, we anticipate a surge in VLSFO RM and DM type fuels coming to the market. We can therefore expect a broader choice from different geographic areas of fuel formulations which ships will have to manage. Although we expect similar fuels to those we have seen with the 0.10% ULSFO, the ISO Committee will continue to collect and monitor the statistics to strengthen the content of the next ISO 8217 Standard and will keep the industry advised.
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