Compression Ignition and Exhaust Gas Emissions of Fuel Molecules Which Can Be Produced from Lignocellulosic Biomass: Levulinates, Valeric Esters, and Ketones

Abstract

This paper presents the results of combustion experiments conducted in a single cylinder compression ignition engine with several fuel molecules which can be produced from lignocellulosic biomass through a variety of processing routes. The lignocellulosic fuel molecules tested were ethyl levulinate, butyl levulinate, ethyl valerate, butyl valerate, pentyl valerate, 5-nonanone, 3-heptanone, dipentyl ether and three alkanes. To ensure reliable compression ignition of all of the molecules, all of the molecules were tested after adding 30 wt % of heptane to them. Levulinates were observed to have longer ignition delays than valeric esters, which in turn had longer ignition delays compared to ketones. All of the tested oxygenated molecules ignited later than the corresponding alkanes, excluding dipentyl ether. The differences in ignition delays were mainly attributed to the higher electronegativity of oxygen atoms compared to that of carbon and hydrogen atoms. The tested molecules, excluding 3-heptanone, had s...