近红外光谱法快速测定生物柴油调和比及理化指标

通过比较偏最小二乘法(PLS)处理调和生物柴油近红外光谱图与标准方法测定调和生物柴油所获得的基础数据,确立了调和生物柴油的调和比、密度、运动黏度、热值、闭口闪点及冷凝点之间的相互关系。结果表明:经优化后,在OPUS光谱分析软件推荐维数(Rank)下,各指标模型的预测值与标准测定值之间线性相关关系均显著。在用于测定未知调和生物柴油样品的上述指标方面具有测定快速简便、误差小、成本低等优点,并用马氏距离限制异常项,每份生物柴油各指标的马氏距离都处于允许范围内。对于新类型生物柴油,可向模型添加10个以上调配样本,扩充模型后即可用于测定这类型调和生物柴油相关理化指标,可成为测定调和生物柴油相关理化指标新方法。在此基础上,可进一步开发出生物柴油近红外光学理化指标测定仪,实现低成本与快速测定。

Rapid Determination of Mixing Ratio and Physical & Chemical Properties for Biodiesel by Near Infrared Spectroscopy

A rapid near-infrared spectroscopic method for the determination of mixing ratio,density,kinematic viscosity,heat value,closed cup flash point and cold filter plugging point for biodiesel blending with diesel was developed,in which the near-infrared spectroscopy and the basic data obtained from standard methods were treated with partial least squares(PLS).The result showed that linear correlation between fitted values and true values measured by standard methods all were significant on the recommended rank(Rec) by OPUS spectroscopy software after models optimized.It has convenient,low error,low cost advantages when these two models were used to determine these indexes for unknown biodiesel blending with diesel and Mahalanobis distance(MahDist) can be used to limit exception item.All were in the permissible range.For a new type of biodiesel,the model can be extended by adding 10 more new blend samples,the model obtained will provide more accurate results for these indexes of this type of biodiesel.The method could be a new one about determining these properties for biodiesel.Near Infrared physical and chemical properties analyzer for biodiesel could be developed based on the method,which can achieve determination of low cost and rapidity.