Cold flow improvers - also known as anti-gels - are the treatment of choice to keep diesel fuel from gelling. Some parties like to dilute with kerosene instead (an old-school solution), but that isn't always economically feasible in today's marketplace. And they may find themselves having to add heavier proportions of kerosene to achieve needed protection drops of 15 or 20 degrees (which would require 50-70% kerosene).
So here we are, circling back to cold flow improver treatment packages. We say packages because anti-gels aren't just one chemical, they're a package of chemicals that address all the important aspects of the gelling "situation". They keep the paraffin crystals apart, keep them suspended or dispersed in the fuel, causing them to form smaller crystals when they do become insoluble.
The interesting thing is that the market for cold flow improvers is projected to grow robustly and consistently over the next ten years, rising to $1.4 billion by 2032.
So what's driving this demand? Is it something to do with cars or is it something in the fuel?
The simple answer is that more cold flow improvers are going to be needed because of the global demand for cars. Despite the impending resurgence in electric vehicles, demands for internal combustion engine cars and trucks will be growing over the next 10 years. But that alone doesn't explain it. They're finding that both heavy and light vehicle engines are having problems with wax deposition. This means they need cold flow improvers made with ethylene-vinyl acetates, one of the primary chemistries used in cold flow improvers to mitigate this problem.
Another issue is the ever-improving fuel filter performance for diesel engines. We've written about the trend towards effective filter plugging temperatures rising due to common rail fuel filters being plugged at higher temperatures. This trend is only going to keep going up.
When To Treat For Cold Flow
The decision on when to add cold weather anti-gel rises and falls on the expected ambient temperature. Conventional wisdom suggests treating for cold flow when the temperature is 5 degrees above the fuel's cloud point. The fuel's cloud point is often controlled by the refiner, who will produce diesel fuel with a cloud point that tries to track at least 5 degrees above a region's 10th percentile temperature (the temperature in a given month where, statistically, it would not be expected to go below more than 3 times in a month).
How do the new filters change this? First, remember that the cold filter plug point is usually 3-5 degrees below the cloud point. So, before, if you lived in Alabama and your 10th percentile temperature in December was -6 deg C, your expected cloud point would be about freezing and your expected gelling temperature would be around -3 to -5 deg C. This means you'd be looking to add anti-gel to your diesel fuel when temperatures were approaching 5 degrees C. But with the new filters, the effective plug point temperature isn't -3 deg C, it's now practically freezing. And so you want to make sure you get that additive into the fuel when the temperature in December is approaching 40-45 degrees F.
This post was published on October 13, 2022 and was updated on October 13, 2022.