Fossil Fuels Energy Content

Overview

Engineering reference data for Fossil Fuels Energy Content in food bio.

Key Formulas

pH

$pH = -\log_{10}[H^+]$

Measure of acidity in food.

Water Activity

$a_w = \frac{P}{P_0}$

Ratio of vapor pressure of food to pure water.

Thermal Death Time

$\log\frac{N_0}{N} = \frac{t}{D}$

Microbial reduction during heating.

Q10 Temperature Coefficient

$Q_{10} = \left(\frac{k_2}{k_1}\right)^{10/(T_2-T_1)}$

Rate change per 10°C temperature increase.

Variables

Symbol	Description	Unit
$pH$	Acidity level	—
$a_w$	Water activity	—
$N$	Microbial count	CFU
$D$	Decimal reduction time	min
$Q_{10}$	Temperature coefficient	—

Fuel Energy Content Comparison

Calorific Value Definitions

• Higher Heating Value (HHV) or Gross Calorific Value (GCV): The total heat released when a fuel is completely burned, assuming that the water of combustion is entirely condensed and the latent heat of vaporization is recovered. It represents the maximum theoretical energy yield.
• Lower Heating Value (LHV) or Net Calorific Value (NCV): The heat released when a fuel is burned, assuming the water in the combustion products remains as vapor. The latent heat of vaporization is not recovered. This value is more realistic for most combustion applications where exhaust gases leave as vapor.

Fuel Equivalents

For quick reference in energy calculations:

• 1 U.S. gallon of gasoline ≈ 115,000 Btu ≈ 121 MJ ≈ 32 MJ/liter
• 1 U.S. gallon of diesel ≈ 129,000 Btu ≈ 136 MJ ≈ 36 MJ/liter
• 1 barrel of oil equivalent (boe) = 42 U.S. gallons ≈ 5.1 GJ ≈ 4.8 million Btu ≈ 1,400 kWh
• 1 metric tonne of gasoline ≈ 8.44 barrels ≈ 1,342 liters ≈ 42.8 GJ

Interactive Charts

References

• Original Source