Cold flow properties

Triisopropan olamine is used in natural mbber cross-linking and as a color stabilizer for polyethylene formulations. Chain termination of polybutadiene with triisopropan olamine gives improved cold-flow properties. 

Hydrodewaxing Selective hydrocracking of paraffins from oil fractions or products to prevent wax precipitation (negative influence on cold flow properties) ... 

M. Feustel, M. Krull, and H. J. Oschmann. Additives for improving the cold flow properties and the storage stability of crude oil (Additive zur Verbesserung von KaltflieBeigenschaften und Lagerstabilitat von Roholen). Patent WO 0196503, 2001. 

The thermoset component in polyurethanes gives them better compression set than most thermoplastic polymers. They also have better cold flow properties. Polyurethanes are tough and more resilient than a large number of other plastics. 

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... 

Cold properties of biodiesel are highly correlated to the fatty acid composition. Biodiesel with a high content of saturated fatty acids, such as that from palm oil and coconut oil, possesses poor cold flow properties. On the other hand, biodiesel with a high content of unsaturated fatty acids possesses better flow properties at lower temperatures. However, biodiesel from highly unsaturated fatty acids with more than two double bonds has combustion problems. Therefore, in some countries, the content of highly unsaturated fatty acid methyl esters in biodiesel is kept low (5). 

Improving cold flow properties, operability and performance of... 

Biodiesel made from feedstocks containing large concentrations of long-chain saturated fatty acids will have very poor cold flow properties. Less expensive feedstocks such as palm oil or tallow (see Table 1.3) may not be feasible in moderate temperature climates. In contrast, feedstocks with lower concentrations of long-chain saturated fatty acids yield biodiesel with more attractive cold flow properties. For example, biodiesel from canola, linseed, olive, rape-seed, and safflower oils have CP and PP close to or below 0°C (Table 1.3). 

Nearly linear correlations for CFPP versus CP and LTFT versus CP were reported for neat biodiesel and its blends with petrodiesel (Dunn and Bagby, 1995,1996 Dunn et al., 1996). For LTFT, the correlation was essentially LIFT CP, suggesting the labor- and time-intensive LTFT test could be spared by simply measuring CP. A major conclusion from these studies was that development of approaches to improve cold flow properties of biodiesel should focus on technologies that decrease CP. 

TABLE 1.3. Cold flow properties of biodiesel (B100) derived from various feedstock lipids and alcohols.2... 

Improving Cold Flow Properties, Operability and Performance of Biodiesel... 

Many approaches for improving the cold flow properties of biodiesel have been explored. These include blending with petrodiesel, transesterification with medium or branched-chain alcohols instead of methanol or ethanol, crystallization fractionation, and treatment with cold flow improver (CFI) additives. 

Blends with Petrodiesel Cold flow properties of FAME and fatty acid ethyl esters of various feedstocks in blends with petrodiesel are summa-... 

Cold flow properties of liquid fractions obtained from dry fractionation of SME and FAME derived from tallow (TME) and used cooking oil (UCOME) are summarized in Table 1.5. These results showed that dry fractionation... 

TABLE 1.5. Cold flow properties of fractionated biodiesel."... 

TABLE 1.6. Cold flow properties of SME and its blends in No. 1 and low-sulfur (500ppm) No. 2 petrodiesel treated with commercial petrodiesel CFI additives.2... 

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