Red diesel, which receives its color through a marker dye, is used in a wide range of applications, especially in off-road industries. It is a useful fuel that has come to the forefront over the past several years. If you have been curiously asking yourself the question, “How is Red Diesel Made”?, here is a brief look at the process that should catch you up to speed.
The most important thing to understand about the fuel is that it is chemically equivalent to the regular clear variety. The dye is added as a marker and cannot usually be used in cars and trucks. While the dye marker can be removed, the chemical process is somewhat complex and is generally considered illegal to do so.
The original diesel is made from crude oil just like most other petroleum products. The decay of animal and vegetable matter is removed from geologic and brought to the surface, where it is refined through pressure and heat. Using large distillation towers, the extreme heat causes the crude oil to separate into liquid and gas components.
The separation process creates several layers of products that are staggered throughout the crude column. At the top of the column of the column is propane, while the diesel forms near the middle. Lubricants are found at the bottom. All of these products are useful in a variety of industries, but diesel is used in very specific types of engines.
A purification process is usually the last step in the refinery process. This removes sulfur and other impurities from the oil and prepares it to be used in the engines that bear its name. All purification mechanisms are tested by refineries to ensure that all the sulfur is removed. It ultimately contains more energy per mass unit than regular petroleum, which makes it highly sought after by certain companies.
Various dyes are then added to the fuel by different governing agencies. Solvent Red 26 and Solvent Red 164 are both commonly used, and they are of course the last step in the process of marking the fuel with dye. These solvents are soluble in water, which means they permeate the mixture and make it a uniform color. This makes it easy to identify during spot checks.
The tax on this particular fuel is much lower than on standard fuels, which means it is illegal to use it unless you belong to a particular in industry. The product generally has a higher than normal sulfur percentage, which means it is simply not suitable for on-road use. Some off-road applications are allowed, but these are strictly regulated. It is most commonly used in industries that are related to construction and agriculture.
Red diesel is ultimately not much harder to manufacture than the clear variety. The fuel itself is the same, but it contains an added dye that marks it as acceptable for certain industries. The process of refining the original fuel is quite chemically complicated, but the dye is only added near the end when the initial fuel has already been created.