The many colors of ULSD

What color is your new Ultra-Low Sulfur Diesel (S-15) fuel?

We are seeing some almost as clear as water, some a brilliant green, some a bright yellow, some amber, and some an unusual oily blue color.

Why is this happening, and what does it mean to you, the end user.

If you have been following my previous columns we have discussed how no two refineries in the US are of the same design. Each one is a one-off, custom unit, each with its own combination of processes and equipment.

Diesel fuel has always been sold as a homogenous product that is supposed to the same no matter where you get it from. The reality is that different crude oils refined at different refineries, using different process have always produced different fuels.

Refiners use a combination of additives and blending of different stocks to obtain fuel that meets the ASTM specifications.

This process is similar to blenders of whiskey blending different whiskeys together to produce a consistent product as opposed to a distiller producing a single malt Scotch, a product that tries to be unique. Both will accomplish the same result, it just a question of how you get there.

Today the addition of catalytic crackers used for hydrodesulphurization or severe hydrotreating affects fuel in many ways, some good, some not so good.

The colors we are seeing in the fuel are the result of different crude oils being run through different refining processes and the catalysts used in the catalytic cracking during that refining.

The colors themselves do not appear to be important at this time.

There are a few high end laboratories that can take a sample of crude oil and identify what oil field it came from. I believe in time we will be able to identify not only where the crude for a given diesel fuel came from, but at which refinery it produced. This may lead to a way to tell who is producing the best fuel for the money.

The use of Enertech Labs, Inc. Complete Diesel Fuel Treatment provides cost effective protection of equipment. Complete will improve the quality of any diesel fuel, which can increase mileage, enhance operability, reduce emissions, add lubricity, prevent gelling, and save money for the operator.