By Ranga Prakash, Fleet Group Manager, Fleet Group 2
Safe fuel handling onboard the vessel will be a highly critical and complex task in coming times , bearing in mind the various fuels that will be available in the market and supplied onboard plus the compliance issues required to reduce the Sulphur Oxides (SOx) emitted by ships from 1st January 2020. In order to comply with this regulation, the following fuels and arrangements are being considered:
a. Global Sulphur (S) Limit on marine fuels will be reduced from the present 3.50% to 0.50% Sulphur- effective from 1st January 2020.
b. Continue to use higher Sulphur Fuel (>0.5% S) beyond 1st January 2020 and reduce the Sulphur Oxide (SOx) emission by using scrubbers to remove excess SOx from ship exhausts to comply with the regulation.
c. Continue to use the current 0.10% or less sulphur fuels as required presently in the Sulphur Emission Control Areas (SECA).
d. Option of using alternative fuels such as LNG, Ethane, Methanol or LPG using dual fuel engines.
The decision to use which of the above options to comply with the new sulphur regulations will be driven mainly by the difference in the cost of these bunkers and the availability of the bunkers across various ports of the shipping trade. The present/ planned installation of scrubbers by various ship owners is mainly based on the assumption in the cost difference between compliant and non-compliant fuels and how quickly the cost of the scrubber installation can be recovered. With regards to the type of compliant fuel used (<0.50% S, Very Low Sulphur Fuel Oil – VLSFO), it will be a range of distillate (DM) or residual (RM) type of fuels.
Leaving the option of using dual fuel engines (using LNG, LPG ++) – most of the vessels are expected to handle a minimum of two and maximum three grades of fuels with 0.10%S distillate fuels for SECA, <0.50%S – Compliant fuel for outside SECA and >0.50%S non-compliant fuel for outside SECA on ships fitted with scrubbers. Also, the Compliant fuel (VLSFO – <0.50%S) will present the following challenges:
- Fuel quality will vary between batch to batch more frequently than before.
- Different fuel types may be incompatible, increasing the importance of proper segregation and mixing (comingling) onboard.
- Important fuel parameters and quality is expected to vary:
a. Viscosity could vary from low (distillate type) to high (residual type) and the temperature adjustment required in the fuel system
c. Cold Flow properties e.g. the optimal temperature required to maintain fuel flow and handling
d. Stability of the fuel – long storage and inadequate maintaining of the right temperature could result in asphaltene to precipitate and form sludge
e. Compatibility issues due to mixing
f. Catfines – Elevation due to processing and blending
On top of the above expected compliant fuel challenges, another extremely critical issue will be the process of changing over the present fuel tanks to the respective grade of fuel before 1st January 2020 which involves emptying the tanks, cleaning (either through chemicals/ additives or manual cleaning) and segregation from other grade tanks. In order to ensure this process of changing over to compliant fuel or to handle various grades of fuel for 2020 – the Ship Implementation Plan (SIP) is being developed as per the IMO guidelines.
This Ship Implementation Plan (SIP) will take care of the following:
a. Risk assessment and mitigation plan (impact of new fuels)
b. Fuel oil system modification and tank cleaning (tank segregation, fuel transfer and filtration modifications and removing sediments from the tanks)
c. Fuel capacity and segregation capabilities (sufficient tankage for different grades/ supplies)
d. Procurement of compliant fuel (ensuring timely supply of compliant fuel)
e. Fuel Oil Change over plan (conventional residual fuels to compliant fuel (<0.50%S) before the due date) and,
f. Documentation and reporting (in case of modification – update of trim & stability booklets, steps to limit the impact of using non-compliant fuel and a procedure for reporting Fuel Oil Non-Availability (FONAR).
For the safe handling of fuels as above – the following operational precautionary measures should be considered:
1. Avoid mixing of bunkers from different sources/ grades wherever possible.2. If mixing is unavoidable – consider:
a. Reducing the amount of fuel to a minimum before
bunkering new fuel
b. Fuels with similar viscosity, density and pour point,
show acceptable compatibility
c. Don’t mix distillate (MGO/ LSMGO) and residual
d. If it is impossible to avoid mixing, then don’t load on
top in excess of a 20% mixing ratio
3. Store the fuel separately until the Fuel Oil lab results are confirmed for the compatibility, stability and presence of cat-fines / harmful substances.
4. Check the heating and cooling capabilities of the fuel system to handle both high and low viscosity and pour point fuels and also maintain proper viscosity
5. Assessment of the fuel quality and effective use of the ship purification and filtering system to clean the fuel onboard (correct gravity discs and maintaining correct temperature),
6. Preparing an effective fuel change over procedure and take into consideration all possible risks and failures.
7. Crew training and raising the awareness of the challenges ahead and training them for effective operation.
8. Effective communication both onboard the ship and also with the office staff, principals and charterers to address the challenges.
9. Regular onboard test should focus more on the compatibility & stability factors of the fuels.
10. Shore lab analysis should be tested according to the latest standard.
Let’s all work together to handle this fuel management challenge both safely and effectively.