Investigation of Binary Mixtures of N-Butanol and Biodiesel in Reactive Control Compression Ignition

In this study the Reactive Controlled Combustion Ignition (RCCI) obtained by port fuel injection (PFI) of n-butanol and direct injection (DI) of biodiesel was compared with an in cylinder directly injected blend of n-butanol and biodiesel with the same mass ratio of n-butanol to biodiesel which change with respect to load. The combustion and emission characteristics were investigated at 2, 3, and 4 bar brake mean effective pressure (BMEP) for the initial Premixed Charge Compression Ignition study and 2, 4, and 6 bar BMEP at an engine speed of 1400 rpm. For the binary n-butanol-biodiesel mixture the cylinder pressure was decreased by 50% as opposed to the PFI of butanol. While the premixed charge combustion has been split into two regions of high temperature heat release, an early one, before top dead center (BTDC), and a second stage, after top dead center (ATDC), while the ignition for DI of n-butanol-biodiesel blends has been delayed approximately 10°CAD. The maximum in cylinder gas temperature decreased by 100K for the n-butanol-biodiesel mixture and also experienced a 10º CAD delay during the typical diffusion phase of the combustion cycle. Increasing the load to 6 bars BMEP heavy knock occurred for PFI case. The soot emissions showed a 90% decrease with n-butanol injection PFI and by 98% reduction for n-butanol binary mixture with the biodiesel, while th