Recently, I read an article on the Newswire that said that the World’s Largest BioJet Fuel Contract was Signed between a company called "JatrophaBioJet" and another company called "Abundant Biofuels".
In the article they announced a jatropha oil sales contract for exclusive use as aviation bio-jet fuel with Abundant Biofuels Corporation that would have them "quickly producing 5 million barrels per year" of "aviation bio-jet fuel" sourced from the oils of the jatropha fruit. The article went on to state that, "Both companies expect demand from aviation for biofuels to exceed 200 million barrels annually."
But, if we look at these numbers critically, what do we find?
Through a quick internet search I was able to find some information on the historical Yield of different jatropha plants in different years. Using this data I was that the average yield from a jatropha plant varied between low of 9 and a high of 1295 grams per year. This is a yield difference of about 144X year-to-year.
The data also showed that the total yields for the entire crop (20 plants) varied between 102g and 432g in different years, which is a factor of about 4 (from year to year). I also found some data showing that jatropha seeds contain about 20% to 40% non-edible oil.
Assuming that all of this oil can be pressed out of a seed and on average an individual plant produced between 100g and 400g of seed, then each plant could theoretically only produce between 20g and 160g of jatropha oil (a factor of 8).
Since jatropha oil has a Density of ~0.92 g/cm3, this means that 1 g of jatropha oil has a volume of 1.087 cubic centimeters (cc) and 20g has a volume of 21.74cc and 160g has a volume of 173.9cc.
5 million barrels per year is 586,739 m3 = 586,739,000,000 cubic centimeters (cm3)
This 5 million barrels thus requires a minimum of 586,739,000,000 / 173.9 = 3,373,749,250 (3.37 billion) jatropha bushes to be planted and possibly as many as 586,739,000,000 / 21.74 = 26,988,914,443 (27 billion) plants.
I also found the crop density of jatropha and saw that the plants are grown at a density of between 4,000 to 6,700 plants per km for a single hedgerow and double that when two rows are planted. Actual field trials have shown satisfactory planting widths of 2 x 2 m, which is equivalent a to crop density of 2500 plants/ha.
Since we need up to 26,988,914,443 (27 billion) plants and these can be planted at densities of 2500 plants/ha, we therefore need 10,795,566 hectares to grow this crop. 10,795,566 hectares is 107,956 square kilometers.
This is an area about the size of Guatemala.
If we were to ramp up production to 200 million barrels annually (fourty times more), the area that would need to be planted in jatropha would be 431,822,640 hectares (4,318,226 square kilometers).
This is an area that is more than twice the size of Mexico.
Remember, the United States now uses more than 20 million barrels of oil -- per day.
200 million barrels of jatropha oil would satisfy only about 2.65% of total yearly demand.
Put another way, 200 million barrels of jatropha oil produced annually would only supply the United States for about 10 days.
Using two Mexicos.