Renewable alternatives to fossil fuels, such as biodiesel, are necessary to lessen emission of greenhouse gases that are causing climate change. Using a high-pressure, medium-duty, common-rail, turbocharged four-cylinder diesel engine, this work studies the effect of adding Cocos nucifera biodiesel to conventional diesel on exhaust emissions, engine performance, and combustion characteristics. An analysis and characterization of the key physicochemical properties of diesel, biodiesel, and biodiesel–diesel blends were carried out. The engine was fuelled with pure petroleum diesel and blended diesel containing a 10%, 20%, 30%, and 50% volume of coconut oil at full throttle and six different speed settings, respectively. The results showed relatively close physicochemical properties between the biodiesel blend and conventional petroleum fuel. Observations made over the entire speed range indicated that a higher coconut oil biodiesel (COB) content lowers the torque and brake power compared to diesel. In the case of engine exhaust gas, a reduction in carbon monoxide (CO) and smoke emissions were observed. Notably, COB50 gives out the highest nitrogen oxides (NOx) but it is raised even for other blends. The experimental results also demonstrated that a higher COB content achieves a lower peak pressure while the peak heat release rate (PHRR) was lower than that of conventional diesel as the speed of the engine increases.

中文翻译：

---

用椰油生物柴油与柴油混合燃料驱动的普通导轨喷射发动机的性能，排放和燃烧的研究

化石燃料（例如生物柴油）的可再生替代品对于减少引起气候变化的温室气体的排放是必不可少的。这项工作使用高压，中载，共轨，涡轮增压四缸柴油发动机，研究了添加椰油椰子的效果生物柴油比传统柴油在废气排放，发动机性能和燃烧特性方面的优势。对柴油，生物柴油和生物柴油-柴油共混物的关键物理化学性质进行了分析和表征。发动机由纯石油柴油和混合柴油提供燃料，混合柴油在全节气门和六种不同的速度设置下分别包含10％，20％，30％和50％的椰子油。结果表明，生物柴油混合物与常规石油燃料之间的理化性质相对较近。在整个速度范围内的观察表明，与柴油相比，较高的椰子油生物柴油（COB）含量会降低扭矩和制动功率。在发动机废气的情况下，观察到一氧化碳（CO）和烟气排放减少。值得注意的是 COB50释放出最高的氮氧化物（NOx），但即使用于其他混合物也可以提高。实验结果还表明，随着发动机转速的提高，较高的COB含量可实现较低的峰值压力，而峰值放热率（PHRR）则低于常规柴油。