Madrid, Feb 13 (EFE).- A group of researchers from the Polytechnic University of Madrid (UPM) and Castilla-La Mancha (UCLM) has developed a biofuel from orange peels that emits 55% less soot, which represents “a promising advance in the reduction of emissions both in aviation and in the automotive industry”.
The fruit industry and, specifically, the orange juice industry generates up to 30 million tons of by-products and waste per year, which must be managed to avoid serious economic and environmental problems, indicates the UPM in a press release.
After extracting orange oil from this waste and analyzing its potential as a fuel, the researchers conclude that “orange oil derived from the juice industry could replace 0.1% or 0.02% of the kerosene and diesel consumed in Spain in 2019, respectively».
In addition to having a high terpene content, these skins contain orange oil, made up mainly of D-limonene, which can be extracted by pressing or using solvents.
The results obtained show that this oil is “a viable alternative to be mixed up to 15% with jet fuel, without any significant inconvenience for their performance, and meeting all the requirements of aviation standards.”
Due to its “excellent density and calorific value (together, they indicate the amount of energy stored in the vehicle’s tank) and cold flow properties (that is, the behavior of biofuel at low temperatures)”, this oil could be used as ” biofuel in aviation and automotive.
However, the high tendency of orange oil to form soot during combustion makes it necessary to transform it through the chemical process of hydrogenation.
“The main advantage of this process is that the complete hydrogenation of the fuel makes it possible to reduce its soot emission by 55%, as we have verified in our study”, points out the UCLM researcher, David Donoso.
In addition to orange, there are other citrus fruits -lemon, grapefruit, lime, citron, yuzu, bergamot or combava- from which terpenes can be extracted, such as D-limonene present in oranges or tangerines, in different proportions.
For this reason, “the introduction of orange oil (and other citrus-derived terpenes) in a new market, such as fuels for transportation, is of special interest,” says David Bolonio, a researcher at the School of Mines and Energy. from UPM.
In addition to the waste derived from industry and food consumption, the waste of oranges in bad condition in the cultivation fields could be used, adds the study published in the journal Renewable Energy.
According to the researchers, the incorporation of orange oil into the biofuels market would contribute to mitigating the effects of the climate crisis. “In the future energy scenario, multiple sources of biofuels will have to be used to replace fossil fuels,” they conclude.