For decades, Testing Labs have helped customers around the world with their testing needs. However, many of the testing companies merely provided testing without spending time on innovations that benefited the entire supply chain of fuels. As the world around us made massive strides in terms of data, artificial intelligence, and machine learning, very little of that progress actually went toward helping the efficiency of supplier customer operations.
In 2020, when the marine world was dealing with the advent of newly formulated fuels, the biggest challenge was to understand the stability of fuels. In particular, there were 2 constraints:
- The existing model of stability at that time, was Total Sediment Potential or TSP. The issue was that TSP measured only instantaneous stability and moreover, the TSP test took 24 hours to get results from. Our R&D team, took select lab data, and the beauty of mathematics, to create an algorithmic based solution (or Labrithm), that gave our clients correlated TSPs in just 4 hours. Our customers were now able to dramatically reduce their testing times and make faster decisions. What used to take days, now only took hours, and we became to be known as the 4 Hour TSP team!
- The bigger challenge that suppliers faced was that these new fuels were blended with relatively newer and unknown feedstocks. As a result, the big concern for our customers was not knowing how long the fuels, that they had blended, stayed stable until the fuels failed. Expensive claims and unhappy customers were not something they wanted to deal with. With most commercial contracts written for a 30 day window, it was critical that these fuels stayed stable for at least 30 days, if not more. Our V-TIC team, worked with our customers, and as we created hundreds of blends, we realized that there was a way to use Labrithms again and come up with a solution to determine long term stability of fuels, which in essence is the shelf life of these fuels. Labs did not know how to handle this. They asked the fuel suppliers to keep sending them samples at different time points. It often took labs 30 days of testing to realize if a fuel was stable or not. With our latest Long Term Stability Labrithm, we were able to give the results in just three to four days. Our team changed the game again and V-TIC’s customers continue to use this Long Term Stability Labrithm and are confident of facing far fewer claims with dramatically improved operational efficiencies.
We see algorithms around us in all aspects of our lives. From dating apps like Tinder, to sports betting, the use of math and algorithms is helping us make better and faster decisions. At V-TIC services, we believe in the power of data and analysis of that data using tools like algorithms and artificial intelligence. Today, this blending of tech with the latest in instruments, is also helping the V-TIC team attract some of the best talent. Our aim is to become the company that our customers can rely on to develop solutions for them.
In the last few years, our team has developed several algorithms for fuels and lubes while working with our customers as they deal with their toughest challenges. As our clients race towards embracing the fuels of the future, V-TIC is positioned as the leading lab today that is using the technology of the future to help our clients with their challenges of today. Our R&D team and lab teams spend countless hours learning and sharing these learnings with our clients, so that we work together, to help create a sustainable future.
THE LABRITHM DIFFERENCE
LONG TERM STABILITY ASSESSMENT
Different chemical and physical properties of the VLSFO (Very Low Sulfur Fuel Oil) fuels have resulted in stability issues during long-time storage. VLSFOs are more paraffinic and differ from HSFO (High Sulfur Fuel Oil) with respect to their structure and chemical composition (70 % of tested VLSFOs were paraffinic and 30% were aromatic).
VLSFOs show degradation, which increases with an increase in storage temperature and storage time. Determining the long-term storage stability of more than 100 VLSFOs showed that more than 50% of the VLSFOs which are stable on day 1 of testing, became unstable after 1-4 weeks of storage. The below figure shows the sediment content of 5 VLSFOs which are stable on day 1 and will become unstable during storage at 50C.
The consequences of long-time storage result in fuel stability issues, filter choking, and purifier blocking causing problems during ship operations. This is important because, at the time of supply of the fresh VLSFO, the testing parameters including sediment potential will fall within the specifications. However, what has been repeatedly observed is that while in storage, the sediment potential increases cross the limit and cause filter and purifier choking. Therefore, determining and predicting the stability properties of VLSFOs during long-term storage is essential to problem-free fuels.
VTIC Services has developed a lab-developed algorithm to predict the stability of VLSFO during long-term storage over up to 60 days for the fuels stored at a typical storage temperature of 50C. This proprietary protocol involves subjecting the fuel to various stresses and extensive testing over a period of 5 days. The algorithm was developed based on testing more than 100 VLSFOs and was derived to help the fuel users with predictive modeling of future stability to minimize the instability issues, if possible. Based on VTIC Services’ new model any fuels can be categorized into 3 groups:
Group 1: The sediment content remained unchanged and will be less than 0.1% over period of 60 days.
Group 2: The sediment content will be less than 0.1% up to 30 days while the sediment content will increase and be greater than 0.1% over 60 days.
Group 3: The sediment content will be greater than 0.1% in less than 30 days.
STABILITY INDEX LABRITHM
In the past, for heavy fuel oil, RSN has been well correlated with total sediment potential (TSP) and used to predict the stability of samples. Very low sulfur fuel oils (VLSFO) have sulfur content less than 0.50% and have become mainstream to meet the IMO 2020 regulations. VLSFOs are different in characteristics. Most of the paraffinic VLSFOs have very low asphaltene content (less than 1 wt%) compared with the HSFO (High Sulfur Fuel Oil) with average asphaltene content of 4.5 wt%. In our experience based on testing more than 1000 VLSFOs, the current RSN method may not be as sensitive in predicting the stability properties of these samples.
In addition to RSN, there are 5 additional methods for determining the stability properties of VLSFOs which are shown in below table.
|Stability Index algorithm (VTIC)
|Total sediment potential TSP
|Zematra- P-Ratio and Max Flocculation Ratio
|PORLA method P- Value
|ROFA method or S-Value
|Paraffinicity Factor, Asphaltene Aromaticity
|Duration of analysis
|Quick and easy to run
|Referee method for stability prediction
|Automated, no manual interpretation
|Applicable for sample with low asphaltene content
|Automated, no manual interpretation
|Quick and easy to run
|False positive response in the case of paraffinic fuels
|Time consuming & large standard deviation
|Not applicable for sample with asphaltene lower than 1 wt. %
|Specialized operator to evaluate the results
|Not applicable for sample with asphaltene lower than 0.5 wt%
|Indirect way of predicting stability
Out of these six methods, the easiest and fastest methods are the VTIC Stability index algorithm and spot test.
A proprietary algorithm, Stability Index, was developed by VTIC to predict the stability of fuels by analyzing different types of samples which had purifier choking and sludging issues. This method is an alternative method for the stability prediction of VLSFO fuels. This algorithm is based on defining three parameters of paraffinicity factor, asphaltene aromaticity, and stability index.
Stability Index (SI): An algorithm developed to understand the true stability (homogeneity) of the fuel. This was developed as an alternative to the spot test due to the false positives that it may give for a certain types of fuels.
In order to have a stable fuel, asphaltene should be soluble in fuel media. Therefore, there should be a balance between paraffinicity factor and asphaltene solubility. By using this basic concept, we developed an algorithm based on the Stability index, asphaltene aromaticity, and paraffinicity factor to evaluate the stability properties.