Fuel and Vehicle Effects on Low–temperature Operation of Diesel Vehicles – The 1981 CRC Field Test

1999

J Americ Oil Chem Soc

The relatively poor cold-flow properties of monoalkyl esters of vegetable oils and animal fats (biodiesel) present a major obstacle to their development as alternative fuels and extenders for combustion in direct injection compressionignition (diesel) engines. In this work, differential scanning calorimetry (DSC) heating and cooling curves of methyl soyate (SME), methyl tallowate (TME), SME/TME admixtures, and winterized SME were analyzed. Completion of melt, crystallization onset (Onset), and other temperatures corresponding to melting and freezing peaks were correlated to predict cloud point (CP), pour point (PP), cold filter plugging point (CFPP), and lowtemperature flow test (LTFT) data. Effects of treating methyl esters with cold-flow improvers were examined. Low-temperature flow properties of biodiesel may be accurately inferred from subambient DSC analyses of high-melting or freezing (β-form) peaks. The temperature of maximal heat flow for freezing peaks gave the best accuracy for predicting CP, PP, and CFPP, while freezing point gave the best accuracy for predicting LTFT. Onset also gave good correlations with respect to predicting PP, CFPP, and LTFT. Cooling scan parameters were more reliable than heating scan parameters.

mentioning

confidence: 99%

Thermal analysis of alternative diesel fuels from vegetable oils

1999

J Americ Oil Chem Soc

“…During start-up, solid crystals in the fuel tank may cause operability problems, such as plugged filters and fuel lines. With respect to conditions in North America, diesel fuels develop problems when temperatures drop into the range of-10 to -15~ (9,12).…”

mentioning

confidence: 99%

Improving the low‐temperature properties of alternative diesel fuels: Vegetable oil‐derived methyl esters

Shockley

Bagby

1996

J Americ Oil Chem Soc

178

This work explores near-term approaches for improving the low-temperature properties of triglyceride oil-derived fuels for direct-injection compression-ignition (diesel) engines. Methyl esters from transesterified soybean oil were evaluated as a neat fuel and in blends with petroleum middle distil~ates. Winterization showed that the cloud point (CP) of methyl soyate may be reduced to -I 6~ Twelve cold-flow additives marketed for distillates were tested by standard petroleum methodologies, including CP, pour point (PP), kinematic viscosity, cold filter plugging point (CFPP), and low-temperature flow test (LTFT). Results showed that additive treatment significantly improves the PP of distillate/methyl ester blends; however, additives do not greatly affect CP or viscosity. Both CFPP and LTFT were nearly linear functions of CP, a result that compares well with earlier studies with untreated distillate/methyl ester blends. In particular, additives proved capable of reducing LTFT of neat methyl esters by 5-6~ This work supports earlier research on the low-temperature properties; that is, approaches for improving the cold flow of methyl ester-based diesel fuels should continue to focus on reducing CP. JAOCS 73, 1719-1728 (]996).

“…[23,29] The less user-friendly low-temperature flow test (LTFT) was developed to address the potential for operability issues in North America. [21,30] This test is analogous to CFPP and Manual and automated test methods Standardized test methods for measuring the cold flow properties of biodiesel and its blends with petrodiesel are summarized in Table 1. Manual test methods are those that require visual inspection of samples for the determination of CP and PP, or physical operation of a filtration apparatus for measuring CFPP and LTFT.…”

Section: Cold Flow Properties Of Diesel Fuelsmentioning

confidence: 99%

Cold flow properties of biodiesel: a guide to getting an accurate analysis

2015

Biofuels

Biodiesel has several advantages compared to conventional diesel fuel (petrodiesel). Nevertheless, biodiesel has poor cold flow properties that may restrict its use in moderate climates. It is essential that the cold flow properties of biodiesel and its blends with petrodiesel be measured as accurately as possible. This work provides an overview of the important cold flow properties and how they are analyzed. The utility of cloud point (CP), pour point (PP), and cold filter plugging point (CFPP) in evaluating biodiesel at low temperatures is discussed. Advantages and limitations of the experimental methods are evaluated. Finally, the use of sub-ambient differential scanning calorimetry (DSC) in the study of low temperature phase behavior of biodiesel is examined.