Application of Liquid Biofuels to Internal Combustion Engines.

Abstract

The main challenges for the development of internal combustion (IC) engines are the reduction of pollutant emissions and increase of thermal efficiency. To address both issues, particularly in compression ignition (CI) engines, there is strong interest to develop advanced CI engines with high efficiency and low particulate matter (PM) and NOx emissions. In order to accomplish the advanced CI engines, long ignition delay is essentially required. There are many trials to extend the ignition delay of diesel combustion such as variable compression ratio and variable valve actuation, introduction of high exhaust gas recirculation (EGR) level, early direct injection, late direct injection, and fuel modification. In this chapter, discussion will be concentrated on the fuel modification, particularly the introduction of clean and renewable biofuels, biobutanol. The physico-chemical property, basic combustion study, and combustion and emission characteristics of biobutanol in advanced CI engines will be discussed in order. The advanced CI engines fueled with biobutanol which deliver both high efficiency and very low NOx and soot emissions were divided into four groups, i.e., low-temperature combustion, homogeneous charge compression ignition, dual-fuel combustion, and reactivity controlled compression ignition modes. The application of acetone–butanol–ethanol blend to advanced CI engines is discussed separately.