Hydrogenated Turpentine: A Biobased Component for Jet Fuel

Abstract

The need to find sustainable alternatives to fossil fuels in aviation without requiring drastic structural changes in turbines and tanks has prompted a search for new components to blend with the standard Jet A1. Turpentine obtained by vacuum distillation of resin extracted from the common pine Pinus pinaster or as a byproduct of the paper industry is compared with hydrogenated turpentine at different levels of conversion as a component of jet blends. Properties such as density, kinematic viscosity, heating values, lubricity, flash point, pour point, crystallization onset temperature, and smoke point are reported. Turpentine shows high soot formation tendency. Hydrogenation was carried out as a method to saturate the double bonds of pinenes and to overcome this problem. The performance of four hydrogenated turpentines at different levels of turpentine–hydroturpentine conversion proves improvements in some key properties and especially reductions in the sooting tendency, concluding that partially hydrogenated turpentine can be blended up to 50% v/v with Jet A1, fulfilling the limit required by the standard specification for aviation turbine fuels containing synthesized hydrocarbons.

Hydrogenated or oxyfunctionalized turpentine: options for automotive fuel components

“…Turpentine has been studied as a renewable fuel for transport sector (diesel, 4–6 biodiesel, 7 gasoline 8 and jet fuels 9 ). In particular, this renewable component can be suitable for heavy-duty diesel engines, which can hardly be replaced by electrification in the medium term.…”

“…Despite turpentine has similar energy density to diesel fuel, unsaturated hydrocarbons and cyclic structure of the molecules makes turpentine inadequate as a diesel fuel component because of their high sooting tendency. Hence, some transformations have been proposed to overcome this negative effect, such as hydrogenation 9,10 and oxyfunctionalization, 11 among others. 12 These transformations have shown convincing effects on the properties of the fuels obtained.…”

“…For instance, the oxyfunctionalized turpentine showed noticeable decrease in emissions of nitrogen oxides and particulate matter, 13 in addition to its high suitability for diesel fuel applications due to its fuel properties, 14 whereas hydrogenated turpentine possesses high fuel benefits such as high energy density, excellent cold flow properties and lower propensity to produce soot. 9 However, a comparison of the fuels obtained from oxyfunctionalization and hydrogenation can help determine their suitability as automotive fuel components.…”

Sooting tendencies of terpenes and hydrogenated terpenes as sustainable transportation biofuels

“…The scaling analysis in SI E indicates that YSI is proportional to SP/S, where S is the moles of oxidizer required to stoichiometrically combust one mole of fuel [44]. The figure in SI E shows that this relationship fits a wide range of pure hydrocarbons and mixtures where both YSI and SP have been measured [2,19,25,27,45]. Based on the linear least-squares fit to the data in this figure, a derived smoke point (DSP) can be calculated from the measured YSIs with the equation:…”

“…Products made from one isoprene (hemiterpenes; C5) are suitable as gasoline alternatives, while products from two isoprenes (monoterpenes; C10) and three isoprenes (sesquiterpenes; C15) can replace jet fuels and diesel fuels. Proposals for large-scale production of terpenes include harvesting them from agricultural crops or from microorganisms growing in bioreactors [1][2][3]. The compartmentalized nature of terpene biosynthesis provides opportunity to genetically engineer favored organisms such as Eucalyptus or E. coli to make any desired terpene, and to metabolically engineer yields that are beyond the natural baseline [4,5].…”