LPG vs Diesel

Properties of Diesel

Combustion value:

8364 Kcal/Lit to 8856 Kcal/Lit (Depends on cleanliness of Diesel).

Specific weight:

About 0.82 Kg/Lit. Thus the Combustion value is between 10200 Kcal/Kg and 10800 Kcal/Kg.

Properties of LPG:

Combustion value:

11000 Kcal/Kg and 11800 Kcal/Kg (Depends on ratio of Propane and Butane in the mixture).

Efficiency:

LPG is a much cleaner fuel than Diesel, resulting in higher efficiency of LPG burners. For similar output, the LPG burner’s efficiency exceeds the diesel burner’s efficiency by 10%. For practical purposes’ the diesel burner’s efficiency is around 85% (in high quality burners’ such as the German made Weishaupt burners). The efficiency of a similar LPG burner is around 95%.

Equivalency:

Using mid values’ the combustion value of Diesel is 10600 Kcal/kg, and of LPG is 11400 Kcal/Kg.

Taking the efficiency into account, 1 Kg of diesel (1.22 Lit) will supply 9010 Kcal by a premium burner. 1 Kg of LPG will supply 10260 Kcal.

In other words, 1 Kg of LPG is equivalent to about 1.14 Kg of diesel, or about 1.39 Lit of diesel.

1Kg of diesel is equivalent to about 0.88 Kg of LPG.

1Lit of diesel is equivalent to about 0.72 Kg of LPG. 

Advantages of LPG vs Diesel:

1. LPG is cleaner and leaves no solid residues as diesel does. For that reason, LPG burns without smoke, while the smoke that comes out of diesel furnaces is heavy, chocking and may be hazardous to asthmatic people.

2. Diesel furnaces require high chimneys, which rise above the rooftop of the facility. LPG furnaces, on the other hand, allow for short chimneys, required mainly to provide for self intake of air for the combustion process.

3. Diesel leakage around threaded couplings is flammable, causes dirty patches, and penetrates the soil, damaging vegetation and water supply. LPG leakage will, eventually, evaporate into the air, causing environmental damage. Diesel equipment requires much service and cleaning while LPG equipment seldom does.

4. Diesel leakage will remain in liquid form, while LPG’s will be in gaseous form. Though Diesel has environmental disadvantages, and though both fuels are highly flammable, LPG may accumulate to its explosive concentration (2 – 10% in air). This situation hardly occurs in open areas, or in properly vented and drained enclosures. However, the hazard has to be accounted for in the design process, and proper safety measures have to be applied.