When cold weather sets in, there is no need to choose between biofuels and dependable winter operations. All diesel fuels face cold weather challenges. With proper pre-season preparation and wintertime management, you can expect biodiesel blends up to B20 to perform just as well as ultra-low sulfur diesel (ULSD) during sub-freezing temperatures.
Whether you are using a biodiesel blend or conventional ULSD fuel, the basic principles of winter fuel management apply. Know your fuel, understand its cold-flow characteristics, treat with additives before the weather turns, keep storage systems clean, and test to confirm the fuel is suitable for expected winter conditions.
“Think of winter fuel management as risk management to protect your diesel equipment investment,” says Paul Nazzaro, founder and owner of Advanced Fuel Solutions. “Preventative steps can help prevent fuel gelling, plugged filters, fuel-flow problems and other issues that can lead to downtime during cold winter months.”
Understand How Your Fuel Responds to Cold Weather
Different fuels respond differently when temperatures turn cold. Performance may vary based on the crude oil source, refining process and finished fuel blend. Biodiesel cold-flow characteristics depend on the feedstocks and process used to manufacture the fuel. For example, biodiesel made from animal fat may be more susceptible to cold weather challenges.
Regardless of the fuel you use, it’s important to ask your supplier to sample your bulk storage tank and test the cold-flow properties of the fuel before winter sets in.
Two common measurements are Cloud Point (CP) and Cold Filter Plug Point (CFPP). All fuel contains naturally occurring wax. In cold weather, this wax begins forming crystals. CP is the temperature at which wax crystals first become visible in the fuel, giving it a cloudy or hazy appearance. CFPP is the temperature at which wax crystals become large enough to restrict flow through a standard fuel filter.
“CFPP generally indicates the lowest temperature a vehicle can operate before experiencing gelling issues with the fuel,” says Pete Probst, technical director for the Michigan Advanced Biofuels Coalition. “To prevent these issues, operators need to ensure that the CFPP remains above expected wintertime low temperatures in their area.”
When evaluating biodiesel CP and CFPP, Clean Fuels Alliance America and the National Renewable Energy Laboratory (NREL) recommend testing finished fuel rather than assuming that every B5, B10 or B20 blend will behave the same in winter.
Plan for Winter Additives Before Temperatures Fall
Regardless of the fuel, it’s important to apply proper additives to help withstand cold temperatures and ensure reliable operations through the winter.
“Keep in mind that all liquid fuels are susceptible to degradation due to time and temperature,” Nazzaro points out. “Look at your total fuel package as you prepare for winter and consider cold-flow improvers and fuel stabilizers, which are especially helpful for unused fuel being stored over winter.”
Cold-flow improvers are designed to modify wax-crystal formation and help extend the fuel’s operability range, for ULSD as well as biodiesel blends.
Historically, operators added No. 1 diesel (kerosene) to diesel fuel to improve winter performance. However, kerosene is costly and has a lower BTU value than diesel; therefore it can reduce fuel economy.
“Commercial additives are less costly and perform just as well or better than kerosene for winter operations,” says Probst. “Modern additive technologies can save fleets added costs and reduce dependence on kerosene.”
Realize that fuel additives are not one-size-fits-all. “Your supplier can help select the appropriate winter additive and dosage based on the fuel you are using and the expected operating temperatures,” Nazzaro says.
Protect Your Fuel From Water
Water contamination in fuel is always problematic, but especially in winter, according to Probst.
“Free water can freeze and clog filters, fuel lines and dispensing equipment, he says. “The best strategy is to keep water out of your tank in the first place with routine fuel system housekeeping.”
Probst recommends the following steps before winter, whether you are running biodiesel blends or ULSD:
Top off fuel tanks to reduce headspace where condensation can form during temperature swings
Make sure fuel caps and fill connections are properly sealed
Inspect hoses, fittings, vents and gaskets for leaks or damage and replace if needed
Keep Accurate Records
Maintain records of fuel deliveries, sampling results, filter changes and additive treatments to help you troubleshoot potential issues. If you experience a fuel problem, pull samples from both the bulk storage tank and affected vehicle tanks, and save affected fuel filters. These materials can help your fuel supplier pinpoint whether the problem was caused by cold-flow properties, water, contamination or another issue.
“Cold weather performance issues are sometimes falsely blamed on biodiesel blends. In truth, all diesel fuels require maintenance steps in winter,” says Probst. “Biodiesel is an all-weather fuel with high performance year-round. With proper maintenance practices, you can expect a problem-free experience from either ULSD or biodiesel blends up to B20.”
Remember, proper winter fuel maintenance does not begin with the first frost warning. Preparation starts in advance. Understand your fuel’s cold-flow properties, work with your fuel supplier on a winter additive strategy, and keep your storage tank clean and dry.
Find more fuel storage and maintenance tips here.