Simultaneous improvement in both exhaust emissions and fuel consumption by means of Fischer–Tropsch diesel fuels

Abstract

In recent years, paraffinic fuels have attracted attention because of their potential for reducing diesel exhaust emissions, mainly smoke or particulate matter emissions. One of the paraffinic fuels, a Fischer-Tropsch diesel fuel, was selected to demonstrate the lower exhaust emissions while improving fuel economy in this study. To examine the detailed effects of fuel specifications on diesel combustion and emissions, preliminarily tests for three Fischer-Tropsch fuels and a baseline diesel fuel were carried out with three diesel engines having different engine displacements. In addition, differences in combustion phenomena between Fischer-Tropsch fuels and the baseline diesel fuel were observed by means of a singlecylinder engine with optical access. From these findings, one of the tested engines was modified to improve both exhaust emissions and fuel consumption, simultaneously, dedicated to the use of neat Fischer-Tropsch fuels. The conversion efficiency of an oxides of nitrogen reduction catalyst has also been improved. The desirable properties of Fischer-Tropsch fuels for diesel combustion, namely high cetane number and absence of poly-aromatic hydrocarbon contents, have been fully utilized to enhance the conventional diesel combustion limits to show the possibility to achieve very low exhaust emissions with substantial improvement in fuel economy. The results of this study indicate not only the superior emission characteristics of the Fischer-Tropsch fuels, but also evidence that higher exhaust gas recirculation and lower excess air ratios will be a key concept of both engine and aftertreatment optimization for further fuel consumption improvement.

Diesel flame imaging and quantitative analysis of in-cylinder soot oxidation

“…The single-cylinder HD optical engine was converted from a Hino production engine, and the combustion system features a pancake combustion chamber with a six-hole injector and a medium intensity swirl. 12 The engine was operated at a 20% light load with an excess air ratio of 1.92 and a boost pressure of 123 kPa (abs) using JIS#2 diesel fuel. Two injection strategies with only main injection and with pilot injection were tested.…”

Impact of Fischer-Tropsch diesel and methanol blended fuel on diesel engine performance

“…The researcher studies about the application of F-T Diesel engine shows that [1][2][3][4][5], F-T diesel has higher cetane ratio, shorter ignition delay period and softer combustion, which can effectively reduce the vibration and noise of Diesel engine. The cetane number is a sign of the ignition delay of diesel fuel, and higher cetane numbers indicate that the fuel is easier to ignite.…”