Experimental Investigation of Performance, Emission and Combustion Characteristics of a Common-Rail Diesel Engine Fuelled with Bioethanol as a Fuel Additive in Coconut Oil Biodiesel Blends

Y.H Teoh,H.G How,H.-T Nguyen,K.H Yu

doi:10.3390/en12101954

Abstract

In the present study, the effects of adding of bioethanol as a fuel additive to a coconut biodiesel-diesel fuel blend on engine performance, exhaust emissions, and combustion characteristics were studied in a medium-duty, high-pressure common-rail turbocharged four-cylinder diesel engine under different torque conditions. The test fuels used were fossil diesel fuels, B20 (20% biodiesel blend), B20E5 (20% biodiesel + 5% bioethanol blend), and B20E10 (20% biodiesel + 10% bioethanol blend). The experimental results demonstrated that there was an improvement in the brake specific energy consumption (BSEC) and brake thermal efficiency (BTE) of the blends at the expense of brake specific fuel consumption (BSFC) for each bioethanol blend. An increment in nitrogen oxide (NOx) across the entire load range, except at low load conditions, was found with a higher percentage of the bioethanol blend. Also, it was found that simultaneous smoke and carbon monoxide (CO) emission reduction from the baseline levels of petroleum diesel fuel is attainable by utilizing all types of fuel blends. In terms of combustion characteristics, the utilization of bioethanol blended fuels presented a rise in the peak in-cylinder pressure and peak heat release rate (HRR) at a low engine load, especially for the B20E10 blend. Furthermore, the B20E10 showed shorter combustion duration, which reduced by an average of 1.375 °CA compared to the corresponding baseline diesel. This study therefore showed that the B20E10 blend exhibited great improvements in the diesel engine, thus demonstrating that bioethanol is a feasible fuel additive for coconut biodiesel-diesel blends.

Highlights

Increased modernisation, industrialisation and development have led to a huge demand for energy, and the major energy resources are from non-renewable fossil fuels such as petroleum, natural gas and coal
The effect of bioethanol as a fuel additive in coconut biodiesel blends was studied in a four-cylinder, direct-injection and common-rail diesel engine
20% coconut biodiesel blends was found feasible and it minimized the issues originating from the biodiesel

Summary

Introduction

Industrialisation and development have led to a huge demand for energy, and the major energy resources are from non-renewable fossil fuels such as petroleum, natural gas and coal. According to the British Petroleum (BP) Energy Output Report, the world’s primary energy demand is predicted to increase by 41% between 2012 and 2030, with growth averaging 1.5%. Growing concern about the plunge of the petroleum price as well as severe environmental issues, such as global warming, climate change, ozone depletion, desertification, etc., have encouraged more research into clean alternative fuels [3]. Researchers have studied the potential of biodiesel to be used in the conventional diesel engine for years [4,5,6]. Biodiesel works well in the engine with minor or even no modifications, it is harmless and can be decomposed naturally [8]

Methods

Results

Conclusion