Gas and Particle Emissions From a Diesel Engine Operating in a Dual-Fuel Mode Using High Water Content Hydrous Ethanol

Abstract

Diesel engines running in a dual-fuel fumigation mode using injection of a high volatility fuel into the intake air and direct injection of diesel fuel can reduce NOX and particulate matter emissions. Fuels such as methanol, hydrogen, gasoline, and anhydrous ethanol have been studied as fumigants; however there has been less published regarding the use of high water content hydrous ethanol. Current production of ethanol yields anhydrous (200 proof) ethanol with no water content. The distillation and dehydration processes used to remove excess water from fermented starches during production require large amounts of input energy, reducing the renewability of the resulting fuel. This paper describes an experimental investigation of an aftermarket fumigation system provided by CleanFlex Power Systems, LLC. Experiments to measure gaseous and particulate emissions were conducted using 120 proof hydrous ethanol and non-oxygenated ultra-low sulfur diesel fuel. A John Deere 4045HF475 Tier 2 engine was modified to incorporate the fumigation system in the intake plumbing downstream of the charge-air cooler, just prior to the intake manifold. Data was collected for dual fuel fumigation combustion and compared to diesel only combustion. This study shows that the fumigation system achieved lower levels of NOX and soot proportional to the fumigant energy fraction (FEF), but increased CO and hydrocarbon levels as compared to diesel-only combustion modes. The results suggest that increasing the FEF by using lower water content or better mixing through port-injection may increase the emissions reduction potential of hydrous ethanol fumigation.

Hydrous Ethanol Steam Reforming and Thermochemical Recuperation to Improve Dual-Fuel Diesel Engine Emissions and Efficiency

“…Overall, soot emissions decreased drastically, reaching near 90% reduction from CDC levels at high FEF. This result is somewhat contrary to our earlier hydrous ethanol PFI work [1][2][3] which showed that soot emissions remained high even at significant FEF. With reformed ethanol, as FEF increased, engine combustion was more premixed with significantly less directly injected diesel.…”

“…However, the high load condition experienced only a minor increase before decreasing, indicative of the high CE seen during this condition, providing further evidence that ISR operation is most beneficial at high loads. Unlike our previous work with hydrous ethanol [1][2][3], no unburned ethanol was present at engine outlet conditions. Instead, THC emissions consisted mainly of methane, depicted in Figure 6 and smaller amounts of acetaldehyde and formaldehyde.…”

“…Our previous work [1][2][3] explored the use of hydrous ethanol in diesel dual-fuel combustion modes using a stock engine fuel injection calibration to determine how effective such a system could be if implemented as an aftermarket solution. When introduced through port fuel injection (PFI), hydrous ethanol achieved stable combustion with negligible impact on engine performance and up to 60% fumigant energy fraction (FEF), defined as the ratio of energy provided by the ethanol over total fuel energy.…”

Particulate Matter and Gaseous Emission of Hydrous Ethanol Gasoline Blends Fuel in a Port Injection Gasoline Engine

“…From the literature, no information can be gained on the impact of hydrous ethanol gasoline blends on particulate matter emissions from a port injection gasoline engine. Several investigations have studied the effects of hydrous ethanol fuel on PM emissions from diesel engines [31][32][33], and they found that hydrous ethanol was effective in reducing PM emissions from diesel engines. Hence, research on PM emissions for the hydrous ethanol gasoline blends is needed.…”