How to "Spec" Premium Diesel Fuel Additives - Part 5

A “good” quality Premium Diesel Fuel Additive MUST effectively address the natural degradation process of today’s distillate gas oils (diesel fuels and fuel oils) – “Stability”. This article will discuss how this process can be interrupted and minimized with the right chemical additives formulated in a Premium Diesel Fuel Additive.

Because today’s distillate gas oils (diesel and fuel oils) are predominantly catalytically cracked using very high pressures and very high temperatures, the molecules of crude oil (a mixture of chemical compounds) are actually broken down and split apart during refinery production. This production process is much more economical for the refiner because it yields a much greater quantity of finished products and all of the crude oil in every barrel can be utilized. The catalytic cracking process also allows the refiner to select a much broader range of crude oils thereby reducing the crude costs per barrel of finished fuel. Unfortunately, this modern refinery process highly stresses the crude oil and negatively affects the stability of most of the finished products – including distillate gas oils (diesel fuels and fuel oils).

Prior to the catalytic cracking of crude oils, fuels were manufactured at much lower temperatures and only at atmospheric pressure. These "straight-run” distilled refinery fuels are thermally stable and can be easily stored for longer periods of time with little or no natural degradation. Accordingly, straight-run fuels pose no significant short-term stability problems for the fuel user.

Straight-run fuels generally are inherently stable for periods from four to eight months without additional chemical treatments. These straight-run fuels are naturally more stable because the molecules are not fractured in the refining process, they do not inter-react with each other and are much less influenced by outside factors (heat, moisture, contamination, etc).

Today’s catalytically cracked distillates (diesel fuels and fuel oils) pose different challenges because the chemical makeup of the fuel and related process chemicals adversely react with the individual components in the fuel. Accordingly, catalytically cracked fuels are dramatically affected by outside influences (such as, heat, moisture, dirt, debris and other fuel system contaminants).

While the chemical industry offers various chemical treatments (additives) for completely resolving stability problems, these additives are seldom used at their most effective treat rates during the refining process. Too often decisions based solely on economics are made instead of opting for more user-friendly solutions to protect the fuel for Long-Term storage. These actions result in fuel products that may be stable for as little as 30-60 days.