KEROSENE BLENDED DIESEL FUEL BASICS

INTRODUCTION

Kerosene is frequently blended with diesel fuel to improve winter cold flow operability. A kerosene blended diesel fuel is a combination of  #1 diesel fuel (kerosene) and #2 diesel fuel. The ratio of diesel fuel to kerosene is typically found in the range of 80:20, 70:30, 60:40, or 50:50. 

BENEFITS OF KEROSENE BLENDING

The primary, if not sole, reason for blending diesel fuel with kerosene is to improve cold flow operability. Kerosene has a better cold filter plugging point (CFPP) than diesel fuel, which means it can be successfully passed through a filter at a lower temperature than an untreated diesel fuel.  

COST DISADVANTAGES OF KEROSENE BLENDING

Kerosene blending is not a cost effective method of achieving desired cold flow operability. In most cases, treating fuel with a cold flow improver additive is the most cost effective solution. To calculate the cost of kerosene blending versus using a cold flow improver additive, perform the following analysis:

  1. Determine cost difference between kerosene and diesel fuel ($/Gallon)
  2. Determine blending ratio (70:30, 50:50)
  3. Calculate amount of kerosene needed (Gallons)    
  4. Calculate cost difference ($)
  5. Determine per gallon cost of additive ($/Gallon)
  6. Calculate net savings (kerosene cost - additive cost)

EXAMPLE

  1. Assume kerosene costs $0.10 more per gallon than diesel fuel
  2. Assume 50:50 blend at 50,000 gallons
  3. Kerosene needed equals 25,000 gallons
  4. Cost difference equals $2,500 ($0.10 x 25,000)
  5. Assume per gallon cost of additive is $0.02. Cost of additive to treat 50,000 gallons equals $1,000 ($0.02 x 50,000).
  6. Net Savings equals $1,500 ($2,500 - $1,000)!

NET SAVINGS

The net savings equals $1,500 or $0.03 per gallon using a cold flow improver additive instead of a 50:50 kerosene blend.

OTHER DISADVANTAGES OF KEROSENE BLENDING

Kerosene contains less energy (measured in British Thermal Units or BTUs) than diesel fuel which results in decreased engine power and fuel economy. Kerosene has an average BTU content of approximately 133,500 per gallon and diesel fuel has an average BTU content of approximately 139,500 per gallon. 

When using a 50:50 kerosene blend, BTU content is approximately 136,500 or two percent less than diesel fuel. The resulting fuel economy and power loss is also about two percent.  

Kerosene provides only a small amount of increased cold flow operability. Kerosene will decrease the CFPP by 2ºF for every 10% kerosene used. Diesel fuel additives, on the other hand, will reduce the CFPP by as much as 35°F- 45°F. 

Kerosene contains less lubricity than diesel fuel. Diesel fuel lubricity is a major concern because of Ultra Low Sulfur Diesel (ULSD). ULSD contains significantly less lubricity than Low Sulfur Diesel (LSD). As a result, metal components in the fuel system, including fuel pumps and injectors, are susceptible to premature failure. Many diesel fuel additives will actually increase overall fuel system lubricity.

Kerosene contains less cetane than diesel fuel. Cetane is the most universally accepted measure of diesel fuel ignition quality. Proper ignition during the combustion cycle is essential for optimum operation, economics, and durability. Insufficient cetane levels lead to hard starting, longer warm-ups and heavy white smoke. 

SUMMARY OF DISADVANTAGES OF KEROSENE BLENDING 

  1. Increased Cost
  2. Decreased Engine Power
  3. Decreased Fuel Economy
  4. Inadequate Cold Flow Operability
  5. Decreased Lubricity
  6. Decreased Cetane

CONCLUSION

Diesel fuel additives are the most economical and effective means of improving winter cold flow operability. It costs less to treat a gallon of diesel fuel with diesel fuel additives than it does with kerosene. Blending a diesel fuel additive with diesel fuel will improve cold flow operability without decreasing engine power and fuel economy.

The advantages of using diesel fuel additives include:

  1. Increased engine power and fuel economy
  2. Increased winter fuel operability
  3. Increased fuel system lubricity
  4. Increased cetane

E-ZOIL manufacturers several diesel fuel additives formulated to achieve these advantages including DIESEL AID, DIESEL AID + CETANE, ARTIC POWER, ARTIC FLO, and CLEAN & LUBE.   

Note: Users of kerosene blended diesel fuel should note that E-ZOIL diesel fuel additives are compatible with kerosene blended diesel fuel.