Diesel and Biodiesel Fuel Filter Clogging- Filter Blockage (Plugging and Clogging) Analysis; Cold Weather Properties; Cold Soak Filterability; Sterol Glucosides; R. W. Heiden Associates

DIESEL AND BIODIESEL FUEL PROBLEMS-FILTER BLOCKAGE (PLUGGING) ANALYSIS; COLD WEATHER PROPERTIES; COLD SOAK FILTERABILITY; STEROL GLUCOSIDES---FUEL FILTER BLOCKAGES: A FRUSTRATING AND POTENTIALLY COSTLY AND/OR DANGEROUS EXPERIENCE

*NOTE ABOUT FUEL FILTER BLOCKAGES (PLUGGING) EPISODES AND BIODIESEL

Since 2006 we have we have made several private and public presentations on this subject (see About Us). People at these meetings discovered that during that widely publicized Minnesota winter fiasco of 2006, another lesser discussed episode of fuel filter blockages happened on the East coast. We have presented definitive lab data describing the composition of field fuel filter deposits from field incidents and the blended fuels from which the deposits originated. We have isolated contaminants from blended commercial fuels that have accumulated on filters. We offer a comprehensive package of analyses to define these deposits and determine their origin.

If you have an incident you would like us to investigate, keep in mind that fuel filter blockages above the cloud point are caused by any of a number of different substances that might result in the buildup of debris and the occlusion or "plugging" of filter pores. One or several substances may act in concert to collect on a filter matrix. These substances may or may not come from the biodiesel. While sometimes considered just a nuisance, filter blockages can cause damage to engines and necessitate expensive repairs.

Improperly processed biofuel can contribute to, or cause fuel filter blockages. The agents causing blockages can originate from: feedstocks; an incomplete transesterification process; oxidation; transport; storage; interaction with engine or fuel system components.

Petroleum diesel or ULSD, impurities and additives are also possible causes of filter blockages, clogging or plugging. Sometimes the appearance of a filter may be misleading, and discolorations can hide underlying blocking components. While some discolorations are merely cosmetic, dark deposits themselves can be a source of blockages.

Key to finding the main culprit is a full analysis of the filter plugging incident which we can provide. When examining filter blockage episodes we evaluate the facts surrounding the event, and consider all possibilities. We can put our experience to work for you finding the cause of fuel filter blockages.

You get into the diesel pickup or tractor on a cold winter morning and the engine refuses to start. Or, you are pumping fuel and very little emerges from the fuel storage tank. Maybe you are fuming, in need of getting somewhere right away. Fuel is unable to reach the engine. Later, you find out that the fuel filter is clogged with deposits. Those deposits could be caused by a number of different substances that can compromise fuel quality. You need a top-notch lab to help figure it all our. We can provide comprehensive fuel filter analysis services to get to the root cause. Also, take a look at our value added biodiesel testing services.

Subscribe to our routine quality testing services or filter analysis packages and your $$$ will contribute to our research efforts to improve the processing and quality of biodiesel !

During the cold winter of 2006 a spate of blocked fuel filters involving biodiesel blends with petrodiesel struck several locations in the U.S. causing delays and frustrations at best. The most publicized of these events happened in Minnesota shortly after the implementation of a B2 mandate. Subsequently, similar reports have surfaced from many places in the world, typically cold spots in winter and but also in places that have experienced sudden unusual drops in temperature. We have studied fuel filter blockage incidents extensively, researched their causes, and have developed special procedures for comprehensive evaluations. We can perform these evaluations for you. Contact us for additional information on how to proceed.

There are generally two types of fuel chemistry issues associated with filter blockages in the field. The first has to do temperature induced chemical changes akin to freezing of the main constituents of the bulk fuel causing flow impeding agglomerations. The second is associated with fuel impurities with limited solubility which become less soluble as temperature declines forming gel like precipitates. Both biodiesel and petrodiesel fuels are susceptible, but differ reasons associated with the chemical composition of the fuels. The bulk cold weather properties are generally adequately predicted by cloud point and pour point measurements, tools developed long ago for the transportation industry. The second type has only recently had some attention, as commercialization has become more widespread. The causal impurities begin have a dominant effect at temperatures well above the cloud or pour point. See our note below which discusses the role of impurities. These types of cold weather problems persist despite efforts to improve the character of the fuel by: implementing new standards; blending the B100 with petrodiesel; introducing additives to impede agglomeration and various process purification schemes.

While sometimes considered a nuisance problem, filter flow blockages cause a restriction of fuel flow which can cause damage to an engine, and should be treated seriously.

We have completed numerous investigations of fuel quality and filter plugging episodes associated with fleets and large commercial vehicles. See a list of our presentations in About where fuel/filter analysis was used to diagnose a fuel obstruction problem, and then the client was assisted in finding a satisfactory strategy for a solution. We have investigated numerous situations involving blends with biodiesel, and just straight unblended petrodiesel. To find out more, give us a call at 717 299 6860, or send an email to: biodiesel@supersleuthchemists.com.

The standards ASTM D 6751 and EN 14214 specify limits that B100 and blended fuels must meet. Biodiesel is derived from a variety of vegetable oils or animal fats which because of their unique fatty acid composition impart different temperature dependent properties in the finished FAME product. Among several properties directly influenced by the fatty acid signature is viscosity, or resistance to flow. The viscosity of FAME tends to become substantially greater as temperature drops. Meeting the limits for practical cold weather use of biodiesel requires a judicious selection of feedstocks to get an optimum product for cold environments.

Biodiesel derived from soy and canola (or rape seed) tends to have better cold weather performance than fuel made from animal fats, such as lard and tallow. Currently, in addition to cloud point data which is essential for defining cold temperature limits of the bulk fuel, a cold soak filtration test is used to assess the magnitude of additional precipitates. The cold soak test appears to pick up room temperature insoluble impurities, such as sterol glucosides. However, the cold soak filterability test can fail to detect some cold weather limiting entities, such as saturated monoglycerides. These represent a portion of the residual monoglycerides remaining after processing.

At any particular total monoglyceride level, the saturated fatty acid levels in rape or soy feedstocks are normally lower than those found in animal fats or palm. So, other variables being equal, particularly monoglyceride levels, a reduced risk for formation of insoluble saturated monoglycerides at low temperatures is also likely in fuels made from rape or soy. Because of day to day variations in pretreatment of feedstock and fuel processes these risks, though mitigated, may not be eliminated altogether.

If you have a concern about these cold weather problems or have experienced them, we are prepared to work with you to: a) find the cause of the filter blockages; b) to devise a strategy that will minimize the possibility of a future experience.