High-Density Renewable Fuels Based on the Selective Dimerization of Pinenes
NAVAL AIR WARFARE CENTER WEAPONS DIV CHINA LAKE CA
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High-density fuel candidates have been synthesized in up to 90 yield from beta-pinene, a renewable strained bicyclic compound derived from wood and plant sources. The process is based on the heterogeneous acidic catalysts Montmorillonite-K10 and Nafion, which promote selective isomerization and dimerization of pinenes under moderate conditions 100-deg C and atmospheric pressure. Montmorillonite-K10 was shown to be a highly active catalyst for dimerization but was also active in the ring opening of beta-pinene followed by dehydrogenation to produce p-cymene, which limited the yield of the dimer to ca. 75. Nafion was capable of producing dimers in up to 90 yield primarily through isomerization followed by dimerization. Amberlyst-15, a common industrial catalyst had very poor activity and conversion even at 150-deg C. The dimer mixtures were upgraded through hydrogenation over PtO2 and fractional distillation. The synthesized fuels have a density of 0.94 gcm3 and a net volumetric heating value of 39.5 MJL 141 745 BTUgallon. These values are nearly identical to those for the widely used tactical fuel JP-10 primarily composed of exotetrahydrodicyclopentadiene, suggesting that these renewable fuels may have applications for rocket propulsion.
- Rocket Engines