Abstract A detailed experimental study was conducted to investigate the production and fuel properties of bio-oil-in-diesel microemulsion (BDM) and its emission characteristics. Bio-oil was produced from liquefaction of methanol, castor oil and sewage sludge. Hydrophilic surfactant (Span 80) and hydrophobic surfactant (Tween 80) of different mixing ratio and different co-surfactant (alcohols) were tested to form BDM with higher bio-oil solubility and better stability. The best mixed ratio was proved to be 7/3 (Span 80/Tween 80) with 2% n-hexanol. The principle of “likes dissolve likes” was set as a guiding mechanism on bio-oil solubilization process. The emulsified fuel stabilized by mixed surfactant and co-surfactant, in comparison with other hybrid fuels and diesel, was tested in a single cylinder, four-stroke, water cooling, direct injection, diesel engine to study the emission characteristics. The results show that, compared with diesel, BDM performed well in brake specific fuel consumption (BSFC) and brake thermal efficiency (BTE) while reduced CO, CO2 and NOX emissions by 21.4%–66.7%, 7.1%–27.3% and 1.5%–14.7%, respectively. This was the first time of using surfactant compound to form bio-oil microemulsion, which provides a possibility for practical application of microemulsion fuels and further benefiting SS utilization.

中文翻译：

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Span80/Tween80 稳定的柴油包生物油微乳液：形成和燃烧

摘要 为了研究柴油包生物油微乳液（BDM）的生产和燃料特性及其排放特性，进行了详细的实验研究。生物油是由甲醇、蓖麻油和污水污泥液化生产的。测试了不同混合比和不同助表面活性剂（醇类）的亲水性表面活性剂（Span 80）和疏水性表面活性剂（Tween 80），形成具有更高生物油溶解度和更好稳定性的BDM。最佳混合比例被证明是 7/3（Span 80/吐温 80）与 2% 的正己醇。“喜欢溶解喜欢”的原则被设置为生物油溶解过程的指导机制。混合表面活性剂和助表面活性剂稳定的乳化燃料与其他混合燃料和柴油相比，在单缸、四冲程、水冷、直喷、柴油机排放特性研究。结果表明，与柴油相比，BDM 在制动比油耗（BSFC）和制动热效率（BTE）方面表现良好，同时减少了 21.4%–66.7%、7.1%–27.3% 和 1.5% 的 CO、CO2 和 NOX 排放–14.7%，分别。这是首次使用表面活性剂化合物形成生物油微乳液，为微乳液燃料的实际应用提供了可能，进一步有利于SS的利用。