The Science of B5 Ultra Blend

It’s easy for any fuel marketer to say the fuel they offer is the “best.” When you hear us say that the B5 Ultra Blend we deliver is better for both your equipment and the earth, we understand that some may consider that standard-issue “marketing-speak.” Fair enough. The best way to put some substance behind the words is with science. With that in mind, here’s a crash course in the science of modern heating fuel!


One of the most important characteristics of heating fuel is its ability to ignite, a characteristic that is reflected in something called the cetane number. Simply put, the higher the cetane number, the faster the fuel burns and the more complete and efficient the combustion cycle becomes. As the fuel burns faster and more completely, your burner performs more efficiently and produces fewer harmful emissions.


In addition to 5% biofuel, B5 Ultra Clean contains 95% ultra-low sulfur heating oil (ULSHO) as a way to lower maintenance, improve efficiency, and reduce pollution resulting from heating systems. When burned, sulfur causes sooting, scaling and reduced efficiency, hence, the move to ULSHO facilitates both economic and environmental benefits. Reducing fuel’s sulfur content also prolongs the life of heat exchangers, particularly condensing boilers and furnaces. Burning ULSHO can also reduce sulfur dioxide emissions by 75%, particulate matter by 80%, nitrous oxide by 10% and carbon dioxide by 2% compared to the fuel it replaces. And with biodiesel blends you can add 5-10 points to each of those numbers.


Unfortunately, there can be a downside to reducing sulfur content: sulfur is a natural lubricant. During the refinement of ULSHO, fuel is flooded with hydrogen to remove sulfur. But this process also removes much of the fuel’s lubrication properties, as well as cetane content. Lubricity – a measure of lubricating properties – is another important characteristic of heating oil, and some components in your heating system rely on this. Here’s where the functional benefits of B5 Ultra Blend come into play.


Biodiesel offers better lubricity than low-sulfur diesel, which contains 500 parts per million (ppm) sulfur by weight. Massachusetts recently required heating oil dealers to reduce the sulfur in heating oil by 83 percent. With our B5 Ultra Blend, Fsi Oil and Propane has gone much further, reducing sulfur by 99.5 percent – down to 15 ppm. At this greatly reduced sulfur level, B5 Ultra Blend plays a critical role in providing the lubrication properties your heating system requires while also maintaining the environmental and economic benefits that come from reduced sulfur levels. According to a National Biodiesel Board report on lubricity, even a 1- or 2-percent volumetric blend of biodiesel in low-sulfur heating oil improves lubricity substantially (remember: B5 Ultra Blend contains 5% biodiesel). The Board further reports that biodiesel from vegetable oil sources has been found to have a higher cetane number than standard heating oil, which means it also helps replenish the cetane lost in the desulfurization process.


We’ll say it again: B5 Ultra Blend is good for both your equipment and the earth. And now you know why!