Influence of 1-Hexanol/Waste Plastic Oil Blends on Combustion, Performance, and Emission Characteristics of a Common Rail Direct Injection Diesel Engine

Waste plastic oils (WPOs) can help address the global energy crisis caused by the rapid depletion of fossil fuels, global warming, and strict emission regulations. The present research delves into the intricate interplay of higher alcohol blends in the context of combustion, performance, and emission characteristics within a common rail direct injection engine. In this regard, 1-hexanol has been selected as the blending constituent for the WPO to tackle emission challenges while concurrently reducing dependence on conventional fuel, as it stands out for its enhanced fuel properties compared to lower alcohols. Simultaneously, the investigation took into account the influence of varying exhaust gas recirculation (EGR) rates. Experimental scrutiny centers on 10 to 30% by volume of 1-hexanol content with the WPO blends for the engine running at 2000 rpm at 20 to 80% of engine load. The inclusion of 1-hexanol led to a maximum cylinder pressure of 86.42 bar, a heat release rate of 117.43 J/degree, and a brake thermal efficiency of 42.1%. Brake-specific energy consumption values decreased with increasing hexanol concentration, demonstrating improved fuel economy. However, emission analysis revealed that HC emissions increased with the hexanol concentration, reaching a maximum of 45 PPM for the H30WPO70 blend at low loads. Similarly, CO emissions were highest for the H30WPO70 blend, with a peak value of 0.40%vol at 20% load. NOx emissions, on the other hand, decreased with increasing hexanol content and EGR rates with a reduction of 11.3 and 12.55% at 10 and 20% EGR respectively. Thus, the comprehensive investigation of 1-hexanol augmentation in waste plastic oil provides the intricate details of combustion processes and performance metrics with emission profiles, which entail the 1-hexanol integration as an effective means for characteristic improvement of automotive engines.