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WHITEPAPER

CTI-Maritec Insights on VLSFO Issues & its Optimal Management

As Issued on 04 September 2024

Table of Contents

• 1. INTRODUCTION 
• 2. CTI-MARITEC DATA EVIDENCE ON MAIN CHALLENGES OBSERVED WITH VLSFO 
  • 2.1 Comparison of off-spec parameters (Chart-1) and machinery & operational issues for HSFO vs VLSFO (Chart-2) from 2022 till date 
  • 2.2 Cold Flow Properties Issues, Testing Recommendations & Pour Point vs WAT & WDT 
• 3. KEY INSIGHTS ON HANDLING ISSUES ASSOCIATED WITH ONBOARD SYSTEM TEMPERATURE AND STABILITY WITH RECOMMENDATIONS FOR OPTIMAL MANAGEMENT 
  • 3.1 Onboard System Temperature 
  • 3.2 Stability 
  • 3.3 Stability Reserve & P-value testing by SMS 1600 to measure Long Term Stability 
• 4. CHEMICAL CONTAMINATION ISSUES & CTI-MARITEC INVESTIGATIVE FINDINGS 
• 5. CTI-MARITEC ‘FUEL OPERATIONS MANAGEMENT PACKAGE’ (FOMP)
• 6. SUMMARY & CONCLUSION 

Introduction

Since 01 January 2020, the International Maritime Organization (IMO) enforced a 0.50% global sulphur cap in marine fuels for the shipping industry to reduce sulphur oxide (SOx) emissions, which is a significant reduction from the previous limit of sulphur at 3.5%. Therefore, greater use of Very Low Sulphur Fuel Oil (VLSFO) came into play post 2020. However, a comparison between fuel properties of High Sulphur Fuel Oil (HSFO) and VLSFO reveals that VLSFO exhibits greater instability, waxiness, lower density, and viscosity, lower calculated Carbon Aromaticity Index (CCAI), lower vanadium content, higher net specific energy, higher pour point, and higher acid number.

The decreased stability reserve (detected by higher paraffinic and lower aromatic content) of VLSFO also raises concerns about compatibility issues when different fuels are mixed. Even after four years of using VLSFO, the long-term storage of VLSFO still remains a challenge and pain-point for the marine industry.

All present-day complexities of VLSFO arise due to its formulation and the processes used to achieve 0.50% sulphur content. The composition of VLSFO varies widely because it is a blend of several types of refined petroleum products, including distillate oil, residual fuels and additives, among others. VLSFOs are more paraffinic than HSFOs owing to its composition, which consists predominantly of small and medium chain hydrocarbons, including alkanes (paraffins) and cycloalkanes (naphthene), among others.

Furthermore, due to the widely varied compositions of VLSFOs sold in the bunker fuel oil market, the physical and chemical properties and qualities vary greatly, thus exhibiting significantly different chemical behaviours, which can only be accurately determined through focused monitoring/testing. This variability can affect engine performance. The characteristics of VLSFO also demands more attention towards storage and handling practices to prevent issues like stratification or sludge formation, especially during the fuel change over process. VLSFO reduces SOx emissions, however, the emission of other pollutants, such as black carbon remain a concern. Therefore, a careful fuel management process is required to optimally manage VLSFO.

Additionally, the issue of chemical contamination has plagued the bunkering industry for years, and the risk of receiving contaminated bunker fuels is likely to persist due to the complexity of the fuel supply chain.

Download the full Whitepaper here