Question

In 2011, the USDA reported that 34.1 million beef cattle were slaughtered for human consumption in the U.S. with the animals having an average mass of 579 kg. For cattle, the average yield of tallow as a percentage of live weight is 1.5%. When tallow is converted to biodiesel, one kg of biodiesel is obtained for every one kg of tallow, and the resulting biodiesel has a density of 0.875 kg/Liter. How many gallons of biodiesel could be produced by the U.S. each year if all of the tallow derived from cattle is converted to renewable fuel?

Answer 1

Given:

Number of beef cattle slaughtered in one year (n) = 34.1 million
Average mass of animals (m) = 579 kg
Average yield of tallow as % of weight = 1.5%
Biodiesel obtained = 1kg of fuel per 1 kg of tallow
Density of fuel/biodiesel = 0.875kg/Liter

Total Biodiesel obtained in litres = n*m*(%yield of tallow)/(density of fuel) = 34.1*10⁶*579*(0.015)/0.875 = 338.47 million liters

1 litre = 0.264172 US Gallon

338.47 million liters = 0.264172*(338.47 million) US Gallon = 89.414 US Gallon