Investigation of Cyclic Variations, Ignition Delay and Physicochemical Properties of Diesel–n-Butanol–Waste Tire Pyrolytic Oil Blends in a CI Engine
Description
The disposal of waste tires and minimizing their environmental impact are of great importance worldwide. For this purpose, waste tires are converted into Crude Pyrolytic Oil (CPO) through a pyrolysis reaction and used as an alternative fuel in ICEs. In this study, CPO was blended with n-butanol, diesel fuel and cetane number improver (2-ethylhexyl nitrate, 2-EHN) to prepare 7 different blends. The study focuses on the cyclic variation analysis, ignition delay, combustion duration and physicochemical characterization of diesel-n-butanol-CPO ternary blends tested in a CI engine under various speed and load conditions. Experiments were conducted under 2 different engine speeds (1500 and 2000 rpm) and 5 different loads (0, 12.5, 25, 37.5 and 50 Nm). Firstly, analyzes of maximum pressures and indicated mean effective pressures were performed on in-cylinder pressure data for all fuel samples and COVPmax and COVimep values were calculated to determine cycle-to-cycle differences. Additionally, combustion analysis was conducted by calculating ignition delay and combustion durations. The analysis results revealed that the PO35Bu15CN1 blend, with COVimep values consistently below 3% at loads above 25 Nm, exhibited the most stable combustion stability. Physicochemical characterization analyzes have shown that all fuel blends have lower crystallization temperatures than pure diesel. This thermal behavior indicates that the prepared blends will exhibit higher engine operating performance under low-temperature ambient conditions.