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The project investigates the effects of peanut FAME on diesel engine combustion and thermal efficiency. The cold flow properties and viscosity were tested and were found that the cloud point (CP) and pour point (PP) of peanut FAME were 17°C and 8°C respectively, and was able to achieve CP of 0°C when blended 20:80 (wt%) with diesel No. 2 (P20). The dynamic viscosity of peanut FAME was 4.2cP (P100) and 2.85cP at 54°C (P20), both fuels are within the ASTM standard for biodiesel. The lower heating value (LHV) of peanut FAME was 37.10MJ/kg (P100) and 41.3MJ/kg (P20) compared to 41.7MJ/kg for diesel No.2 (D100), which supports the usage of peanut FAME in compression ignition engines. At residence time of 5ms from start of injection, P50 has shown positive combustion characteristics with ignition delay of 1.072ms at 2600rpm, 4.78 bmep (100% load). The P50 heat release displayed similar development compared with diesel No. 2, where premixed phase combined with diffusion combustion and reaching a maximum of 20.0J/CAD, which was higher than 17.5J/CAD for D100. Convection flux for both D100 and P50 had values of 1.4MW/m2. The total heat flux, calculated by Annand model, produced maximum values of 2.1MW/m2 for D100 compared with 2.3MW/m2 for the P50. The mechanical efficiency was only a 4% loss when observing the transition from D100 to P50. These findings support peanut FAME as a viable option when blended and used with diesel engines in order to meet the standards set forth by the RSF-2 and EISA allowing the U.S. to decrease foreign energy dependency and benefiting society through a cleaner burning fuel than is currently in use.

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The US Army Single Fuel Forward policy mandates that deployed vehicles must be operable with aviation fuel JP-8. Therefore, an investigation into the influence of JP-8 on a diesel engine’s performance is currently in progress. The injection, combustion, and performance of JP-8, 20–50% by weight in diesel no.2 mixtures (J20-J50) produced at room temperature were investigated in a 77mm indirect injection, high compression ratio (23.5) diesel engine, in order to evaluate its effectiveness for application in Auxiliary Power Units (APUs) at 2000rpm continuous operation (100% load/BMEP 4.78 bar). Due to the viscosity requirements for proper injection the new fuel can contain as high as 100% JP-8 (J100). The blends had an ignition delay of 1.03ms regardless of the amount of JP-8 introduced. J50 and diesel no.2 exhibited similar characteristics of heat release, the premixed phase being combined with the diffusion combustion. The maximum combustion pressure remained relatively constant for all blends, 72.7bar for diesel and decreased slightly by 0.40bar for J50, with the peak pressure position being delayed by 0.5CAD for the J50. The instantaneous volume-averaged gas combustion temperature reached 2162K for diesel versus 2173K for J50; displaying a 1.2CAD delay in the position of the maximum temperature and retaining the higher temperature for a longer duration for J50. The heat flux in the engine cylinder exhibited comparable maximum values for all blends (diesel: 2.12MW/m2, J50: 2.14MW/m2). The cylinder heat losses were at a minimum during combustion before TDC with increased convection losses at TDC for all fuels and the beginning of the power stroke. The heat losses associated with the system increased slightly with the addition of JP-8. The BSFC for diesel no.2 was 242(g/kW/hr) and increasing by only 0.7% for J50. The engine’s mechanical efficiency displayed similar values for all blends, 83% and decreasing by only 1% for J50. Taking into account each fuels’ corresponding density, the engine’s overall efficiency remained relatively constant at 29% with the addition of the JP-8. The engine investigation demonstrated that up to 50% JP-8 by weight in diesel can be injected and burnt in a small diesel engine with a combustion duration of approximately 5ms, while maintaining the engine overall efficiency. The study validates JP-8 as an excellent source for power generation in a diesel APU based on its combustion characteristics. The next stage of research shall be the full emissions investigation.

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