Cold filter plugging point

The characteristics of diesel fuel taken into account in this area are the cloud point, the pour point, and the cold filter plugging point (CFPP). 

The cold filter plugging point (CFPP) is the minimum temperature at which a given volume of diesel fuel passes through a well defined filter in a limited time interval (NF M 07-042 and EN 116 standards). For conventional diesel fuels in winter, the CFPP is usually between —15 and —25°C. 

Additives acting on the pour point also modify the crystal size and, in addition, decrease the cohesive forces between crystals, allowing flow at lower temperatures. These additives are also copolymers containing vinyl esters, alkyl acrylates, or alkyl fumarates. In addition, formulations containing surfactants, such as the amides or fatty acid salts and long-chain dialkyl-amines, have an effect both on the cold filter plugging point and the pour point. 

Cold filter plugging point EN 116 (NF M 07-042) Vacuum filtration through a calibrated filter... 

Some additives have the ability to lower the pour point without lowering the cloud point. A number of laboratory scale flow tests have been developed to provide a better prediction of cold temperature operability. They include the cold filter plugging point (CFPP), used primarily in Europe, and the low temperature flow test (LTFT), used primarily in the United States. Both tests measure flow through filter materials under controlled conditions of temperature, pressure, etc, and are better predictors of cold temperature performance than either cloud or pour point for addithed fuels. 

COLD FiLTER PLUGGING POINT (CFPP) REDUCTION... 

The cloud point and the cold filter plugging point temperatures for fuel which does not contain a wax crystal modifier can often be the same. Typically, untreated cloud point and CFPP values will be within 2°F to 4°F (about 1°C to 2°C) of each other. If the temperature difference between an untreated fuel s cloud point and CFPP differ by 10°F (5.6°C) or more, the fuel probably contains a wax crystal modifier. 

Test method IP 309 is used to determine the low-temperature filterability of distillate fuels including those treated with a cold flow improver. The cold filter plugging point (CFPP) is defined as the highest temperature at which the fuel, when cooled under the prescribed conditions, will not flow through the filter or requires more than 60 seconds for 20 mL to pass through or fails to return completely to the test jar. This method is part of a series of standardized tests developed by the Institute of Petroleum. Test method IP 309 is summarized as follows ... 

Cold Filter Plugging Point of Diesel and Heating Fuels... 

CFPP (Cold Filter Plugging Point) A measure of the ability of a distillate fuel to be filtered satisfactorily in cold environments. This test measures the temperature at which fuel wax crystals can reduce or halt the flow of fuel through a standardized test filter. 

Ethylene Vinyl Acetate Copolymers 203 Table 7.2 Cold Filter Plugging Points with Certain Additives (26)... 

For example, rapeseed oil methyl ester has a cold filter plugging point of -14°C. The cold filter plugging point is a standardized test method (27,28). 

For a long time is has been impossible to obtain a cold filter plugging point value of -20°C, which is required for use as a winter diesel in central Europe. This problem is still more increased when oils based on sunflowers and soya are used. 

An additional problem may arise in the lacking cold temperature change stability of the formulated oils, i.e., the cold filter plugging point value of the oils attained rises gradually when the oil is stored for a prolonged period at changing temperatures in the region of the cloud-point or below. 

The cold filter plugging points (CFPP)s with certain additives are shown in Table 7.2. More details are given in the literature (26). A deviation between the mean values of the CFPP values after storage and the CFPP value before storage and also between the individual phases of less than 3 K shows a good cold temperature change stability. 

Standard test method for cold filter plugging point of diesel and heating fuels, ASTM Standard ASTM D 6371, ASTM International, West Conshohocken, PA, 2005. 

However, one of the limitations of using biodiesel fuel for diesel engines is higher cold flow properties compared with petroleum diesel fuel (4). Cold properties consist of cloud point, pour point, and cold filter plugging point. The cloud point is a temperature at which the fuel starts to thicken and cloud, the pour point is a temperature at which the fuel thickens and no longer pours, and the cold filter plugging point is the lowest temperature at which fuel still flows through a specific filter. These... 

The cold filter plugging point (CFPP) indicates the possibility of using the fuel in low-temperature conditions. Similar information is given by the pour point , as well as by the cloud point . Biodiesel shows higher CFPP values, namely at larger content in saturated esters. The rapeseed methyl ester (pour point at —9°C) exhibits good behavior compared with the palm methyl ester (pour point at 10 °C). 

The cold filter plugging point (CFPP) test was developed to predict more accurately low-temperature limits. After the oil is cooled at a specified rate to the test temperature, a 20 mL volume is drawn through a 45 pm wire mesh filter screen under 0.0194 atm vacuum. The method is repeated in 1 °C increments and CFPP is recorded as the lowest temperature where oil safely passes through the filter within 60s (Chandler et al, 1992 Owen and Coley, 1990 Westbrook, 2003 Nadkarni, 2000). Although CFPP holds nearly world-wide acceptance as a standard test, in North America more stringent test conditions are necessary to correlate with performance in the field. Thus, the less user-... 

CP = cloud point PP = pour point CFPP = cold filter plugging point LIFT = low-temperature flow test. 

Cold flow properties are of major importance in winter diesel. Cold performance limits are set to guarantee lack of crystallization. These are expressed as Cloud Point (CP), Pour Point (PP), or as Cold Filter Plugging Point (CFPP). For B100 biodiesel these have to be fully met with the biodiesel, and, if needed, with extra crystal retardation additives. In B2-B30 blends, though, the tendency is rather towards two types of Biodiesel, one for summertime (for example with CFPP of 0°C), and one for wintertime (for example with CFPP -10 °C). 

Other significant parameters related to the low-temperatnre characteristics are pour point (PP) and cold filter plugging point (CFPP). These parameters are coded and measured by the ASTM and DIN methods and generally vary in a mntnally coherent manner. The ponr point can be reduced by using additives, bnt these have no appreciable effect on the clond point. 

Vegetable oils have also been considered in applications as fuels and attempts to maintain solutions of triacylglycerol oils at low temperatures have also been attempted. Blends of vegetable oil and lower alcohols have suitable viscosity for use in fuels, but they separate into two phases as temperature is lowered (62). Higher molecular weight alcohols can be used to lower the temperature of phase separation. In a soy oil number 2 diesel blend with ethanol, phase separation was deferred to 16°C whereas the cold filter plugging point was lowered to 24°C. 

An analogous property, the cold filter plugging point is suitable for estimating the lowest temperature at which diesel fuel will give trouble-free flow in certain fuel systems (ASTM D-6371, IP 309). In this test, either manual or automated apparatus may be used, which is cooled under specified conditions and, at intervals of 1°C, sample is drawn into a pipette under a controlled vacuum through a standardized wire mesh filter. As the sample continues to cool, the procedure is repeated for each 1°C below the first... 

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