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Line 229: − '''9.6 Fuel colour'''+ Line 238:
Line 238: − '''9.7 Manufacturing processes'''+ − '''9.8 Visual haze'''+ − '''9.9 Mercaptan sulphur'''+ − '''9.10 Hydrogen sulphide'''+ − '''9.11 Fuel flammability'''+ − '''9.12 Synthetic hydrocarbons'''+ − '''9.13 Fuel lubricity'''+
CGSB ONGC/003 0002 2019 ENG (view source)
Revision as of 15:54, 25 October 2019
, 15:54, 25 October 2019→9. Precautions
NOTE Negative interactions can occur between some biodiesels and conductivity additives.
NOTE Negative interactions can occur between some biodiesels and conductivity additives.
<h5>9.6 Fuel colour</h5>
Fuels having unusual shades of colour should be investigated to determine fitness for use.
Fuels having unusual shades of colour should be investigated to determine fitness for use.
Fuel in long term storage can darken owing to oxidation of trace components. If the darkening is accompanied by the formation of sediment, the fuel could be rendered unacceptable for use.
Fuel in long term storage can darken owing to oxidation of trace components. If the darkening is accompanied by the formation of sediment, the fuel could be rendered unacceptable for use.
<h5>9.7 Manufacturing processes</h5>
Contamination from manufacturing processes or treatments can be carried over in trace quantities into the fuel and cause unexpected problems. Moreover, these contaminants might not be detected by the requirements listed in this standard. It is recommended that adequate quality assurance procedures be put in place to ensure that manufacturing processes capable of such contamination are identified and controlled. Sodium, calcium, chlorides, sulphates, clay, sand, acids, caustics, soaps, and amine process additives are examples of possible contaminations or potential precipitates.
Contamination from manufacturing processes or treatments can be carried over in trace quantities into the fuel and cause unexpected problems. Moreover, these contaminants might not be detected by the requirements listed in this standard. It is recommended that adequate quality assurance procedures be put in place to ensure that manufacturing processes capable of such contamination are identified and controlled. Sodium, calcium, chlorides, sulphates, clay, sand, acids, caustics, soaps, and amine process additives are examples of possible contaminations or potential precipitates.
<h5>9.8 Visual haze</h5>
The solubility of water in fuel is a function of temperature. When fuel is exposed to low ambient temperatures, water can separate causing a haze or cloudy appearance in heating fuel oil Types 0, 1 and 2. It has been a common industry practice to predict the solubility of water in fuel by performing the visual haze test at 4°C for fuel destined for winter use, and at 15°C for fuel intended for summer use. Experience has indicated that fuel passing these requirements has been acceptable in the appropriate season. For further information on the visual haze test, refer to CAN/CGSB-3.0 No. 28.8 or to ASTM D4176 Procedure 2.
The solubility of water in fuel is a function of temperature. When fuel is exposed to low ambient temperatures, water can separate causing a haze or cloudy appearance in heating fuel oil Types 0, 1 and 2. It has been a common industry practice to predict the solubility of water in fuel by performing the visual haze test at 4°C for fuel destined for winter use, and at 15°C for fuel intended for summer use. Experience has indicated that fuel passing these requirements has been acceptable in the appropriate season. For further information on the visual haze test, refer to CAN/CGSB-3.0 No. 28.8 or to ASTM D4176 Procedure 2.
<h5>9.9 Mercaptan sulphur</h5>
The plugging of domestic heating oil burner fuel screen filters or nozzles can be caused by the formation of copper mercaptide gels. Limiting the amount of mercaptan sulphur in heating fuel oil Types 0, 1 and 2 can reduce this problem. Eliminating the use of copper and copper alloys in heating fuel systems as well as the use of metal deactivator additives can also mitigate this problem.
The plugging of domestic heating oil burner fuel screen filters or nozzles can be caused by the formation of copper mercaptide gels. Limiting the amount of mercaptan sulphur in heating fuel oil Types 0, 1 and 2 can reduce this problem. Eliminating the use of copper and copper alloys in heating fuel systems as well as the use of metal deactivator additives can also mitigate this problem.
<h5>9.10 Hydrogen sulphide</h5>
Hydrogen sulphide (H<sub>2</sub>S) is often found in the vapour phase above Types 4, 5 and 6 fuel oils and occasionally in more limited concentration in the vapour phase above Types 0, 1 and 2 fuel oils. H<sub>2</sub>S is toxic at low concentrations in air. Additives are available that can react with H<sub>2</sub>S in the liquid phase and reduce the concentration of H<sub>2</sub>S both in the fuel and in the vapour phase. Some sulphur compounds present in Types 4, 5 and 6 can, over time, react to form additional H<sub>2</sub>S and this should be considered in determining the additive treat rate.
Hydrogen sulphide (H<sub>2</sub>S) is often found in the vapour phase above Types 4, 5 and 6 fuel oils and occasionally in more limited concentration in the vapour phase above Types 0, 1 and 2 fuel oils. H<sub>2</sub>S is toxic at low concentrations in air. Additives are available that can react with H<sub>2</sub>S in the liquid phase and reduce the concentration of H<sub>2</sub>S both in the fuel and in the vapour phase. Some sulphur compounds present in Types 4, 5 and 6 can, over time, react to form additional H<sub>2</sub>S and this should be considered in determining the additive treat rate.
<h5>9.11 Fuel flammability</h5>
A number of properties should be considered in assessing the overall flammability hazard of a fuel. Flash point is the minimum fuel temperature at which a mixture of air and fuel vapour can form and be ignited by a spark or flame under specified laboratory conditions. However, the flash point is only an indication of the potential flammability risk of a fuel. Oxygen concentration in the atmosphere is an additional factor affecting flammability. Investigation of fuel-related fires in marine vessel engine rooms and underground mining applications has shown that these fires are generally initiated through direct contact of a fuel spray or spill with hot surfaces having a temperature exceeding the auto-ignition temperature of the fuel. The flash point of the fuel has little bearing on the probability of such fires occurring. Similarly, fires in fuel tanks are typically initiated as a result of hot work (e.g., welding) on the exterior surface of the tank causing fuel adhering to the interior tank wall surface to evaporate and spontaneously ignite after having exceeded its auto-ignition temperature.
A number of properties should be considered in assessing the overall flammability hazard of a fuel. Flash point is the minimum fuel temperature at which a mixture of air and fuel vapour can form and be ignited by a spark or flame under specified laboratory conditions. However, the flash point is only an indication of the potential flammability risk of a fuel. Oxygen concentration in the atmosphere is an additional factor affecting flammability. Investigation of fuel-related fires in marine vessel engine rooms and underground mining applications has shown that these fires are generally initiated through direct contact of a fuel spray or spill with hot surfaces having a temperature exceeding the auto-ignition temperature of the fuel. The flash point of the fuel has little bearing on the probability of such fires occurring. Similarly, fires in fuel tanks are typically initiated as a result of hot work (e.g., welding) on the exterior surface of the tank causing fuel adhering to the interior tank wall surface to evaporate and spontaneously ignite after having exceeded its auto-ignition temperature.
<h5>9.12 Synthetic hydrocarbons</h5>
Synthetic hydrocarbons include hydrocarbons derived from non-petroleum sources such as biomass, natural gas, coal, fats and oils by processes such as gasification, reforming, Fischer-Tropsch synthesis, hydroprocessing or hydrocracking (including co-processing with petroleum). Other terms used to refer to synthetic middle-distillate hydrocarbons include: biomass-to-liquid (BTL) diesel, gas-to-liquid (GTL) diesel, coal-to-liquid (CTL) diesel, hydrogenation-derived renewable diesel (HDRD), hydrotreated vegetable oil (HVO), renewable hydrocarbon diesel (RHD) and synthesized paraffinic diesel (SPD). As with petroleum hydrocarbons, fuel suppliers should consider potential impacts of significant and abrupt changes in blend properties (e.g., density, aromatic content) associated with the use of synthetic hydrocarbons.
Synthetic hydrocarbons include hydrocarbons derived from non-petroleum sources such as biomass, natural gas, coal, fats and oils by processes such as gasification, reforming, Fischer-Tropsch synthesis, hydroprocessing or hydrocracking (including co-processing with petroleum). Other terms used to refer to synthetic middle-distillate hydrocarbons include: biomass-to-liquid (BTL) diesel, gas-to-liquid (GTL) diesel, coal-to-liquid (CTL) diesel, hydrogenation-derived renewable diesel (HDRD), hydrotreated vegetable oil (HVO), renewable hydrocarbon diesel (RHD) and synthesized paraffinic diesel (SPD). As with petroleum hydrocarbons, fuel suppliers should consider potential impacts of significant and abrupt changes in blend properties (e.g., density, aromatic content) associated with the use of synthetic hydrocarbons.
<h5>9.13 Fuel lubricity</h5>
Some processes that are used to desulphurize heating fuel oil, if severe enough, can also reduce its natural lubricating qualities. Since fuel pumps on furnaces require the fuel to act as a lubricant, heating fuel oils require sufficient lubricity to give adequate protection against excessive fuel pump wear. Additives can be used to improve fuel lubricity. Lubricity additives can have unwanted side effects particularly when used at excessive concentrations or in combination with other additives or contaminants. Adding over 1% by volume of biodiesel generally results in acceptable lubricity.
Some processes that are used to desulphurize heating fuel oil, if severe enough, can also reduce its natural lubricating qualities. Since fuel pumps on furnaces require the fuel to act as a lubricant, heating fuel oils require sufficient lubricity to give adequate protection against excessive fuel pump wear. Additives can be used to improve fuel lubricity. Lubricity additives can have unwanted side effects particularly when used at excessive concentrations or in combination with other additives or contaminants. Adding over 1% by volume of biodiesel generally results in acceptable lubricity.
