Fuel Phase Separation Causes, Detection, and Treatment

Most of the gasoline sold in the United States consists of an ethanol blend. The increased use of blended fuels creates a potential for a condition known as phase separation. Phase separation occurs when water is present. It can happen in almost any situation where gas is stored. In your car’s fuel tank, large above or underground fuel storage tanks, or boat tanks, even the gas can that you stored in your garage. Many times you may not be aware that phase separation has happened. However, using fuel that has experienced phase separation can cause considerable damage to engines and other systems.

Simple Chemistry

Ethanol bonds with water easier than it does fuel. Fuel blends containing ethanol are highly susceptible to phase separation. When fuel containing even the smallest amount of ethanol comes in to contact with water, regardless of liquid form or humidity, the ethanol absorbs some or all the water. When the liquid reaches the saturation point, the water and ethanol will phase separate. Therefore, creating two, and sometimes three, distinct new layers. It appears as an upper layer of gasoline with a cloudy layer of ethanol and water below it, and in many cases, the third layer of water at the bottom of it.

Temperature Dependent

Phase separation occurs at different rates depending upon the temperature. For example in E10 blends, one of the more common blends of gasoline in the U.S., the warmer the temperature to more phase separation occurs. So, you may surmise then, that the less ethanol, the better, correct? While this seems true, however many countries are turning to ethanol blended fuel to reduce emissions of CO2 (/clean-air-act-updates-to-renewable-fuel-standards/). Thus, decreasing greenhouse gases in an effort to curb global warming.

Phase Separation Effects

You may be wondering what happens if you try to start your engine if the fuel has separated. One likely occurrence is that your engine will simply fail to start or stall out immediately. If your engine starts and runs okay, but suddenly draws water, damage can result from thermal shock or hydro-lock. Or when the pick-up tube draws on an ethanol-water mixture or just the ethanol, it can cause significant engine damage.

Prevention and Treatment

The good news is that there is help for fuel phase separation. Clean Fuels Associates offers a variety of maintenance services.  From fuel storage tank cleaning to fuel polishing, our knowledgeable team is dedicated to preserving your tanks and fuel to prevent this condition. We also provide fuel testing, so if separation is detected, we can treat your tanks and fuel. Contact us today for a consultation, and keep your fuel in the best condition possible!