Session: 02-02: Alternative CI Fuels, Ignition, and Combustion Strategy

Paper Number: 191389

191389 - Mixing-Controlled Combustion of Light Naphtha Using Exhaust Rebreathe, Elevated Compression Ratio, and Fuel Blending – Low and High Load Single Cylinder Experiments 

Abstract: 

In an effort to reduce the carbon footprint in the heavy-duty sector while utilizing lower value fuel from refinery processing, replacing conventional fossil diesel fuel with a low-value byproduct fuel, like light naphtha (LN), is a pragmatic approach. LN serves as an attractive alternative liquid fuel due to its availability from existing petroleum/renewable refining, reduced fuel refinery processing, and higher hydrogen-to-carbon ratio compared to fossil diesel fuel attributing to its GHG emissions reduction potential. However, challenges achieving conventional mixing-controlled combustion (MCC) with LN are evident at hard-to-ignite operating conditions like low-load, altitude, and cold ambient conditions due to its lower fuel reactivity compared to conventional fossil diesel fuel. To mitigate the combustion challenges with LN, various methods are investigated in this work to achieve stable mixing-controlled combustion of LN at challenging operating conditions. The methods investigated include exhaust rebreathing, elevated compression ratio (CR), and blending LN with renewable diesel (RD). For the exhaust rebreathing method, the only engine architecture modification is the engine camshaft and for the elevated CR method the only engine architecture modification in the piston. The challenging operating conditions are simulated by conducting single-cylinder engine experiments fueled with LN and a LN-RD blend at low-load operating conditions with low intake pressures and cold thermal boundary conditions. The performance of the LN-RD fuel blend at mitigating the low-load combustion challenges with conventional LN is evaluated and compared to fossil diesel fuel subject to the same operating conditions. Additionally, the high-load performance of the ignition assistance methods with LN compared to the baseline engine configuration with diesel fuel is highlighted.

Presenting Author: Tyler Johnston Marquette University

Presenting Author Biography: Tyler Johnston is a graduate student at Marquette University pursuing his PhD degree in Mechanical Engineering. He completed his undergraduate studies at Milwaukee School of Engineering graduating with a BS in Mechanical Engineering. At Marquette University, Tyler is conducting research on internal combustion engines primarily focusing on investigating alternative low carbon fuels to use in place of conventional diesel fossil fuel in compression ignition engines. The extent of his research has focused on using variable valve actuation technologies as an ignition assistant to ignite low reactive fuels in a heavy-duty mixing-controlled compression ignition engine.

Authors:

Tyler Johnston Marquette University
Adam Dempsey University of Wisconsin-Madison
Alexander Voice Aramco Americas