手持式直读红外光谱仪快速测定在用润滑油总酸值和总碱值的方法

总酸值(TAN)和总碱值(TBN)能提供关于润滑油氧化程度和碱储备性能方面的信息,其值大小可以判断某些酸性添加剂的加量是否足够,常用于设备润滑油的老化度测量,以避免设备出现异常磨损、腐蚀、沉淀、堵塞过滤器等问题。润滑油的总酸性和总碱性的检测标准都以酸碱滴定为基础,多采用电位滴定法。然而,这种方法需要复杂的操作、昂贵的耗材、大量的油样、熟练的操作人员以及危险试剂的处理问题。由于润滑油的氧化产物和碱性添加剂在红外光谱中都有较强的信息,因此,可以通过红外光谱图研究对润滑油总酸值和总碱值的监测。建立了一种基于酸碱中和反应的定量中红外光谱总酸值和总碱值的手持式直读红外光谱方法,通过油品归类、建立油样库和多元回归三个步骤,可获得准确可靠的量化总酸值和总碱值。此方法获得最新的ASTM D7889标准支持,相比于其他方法,这种方法具有分析速度快、无需任何溶剂、直接得到检测结果并且结果准确,操作相对简单,并一定程度提高了检测速度。可广泛应用于离线实验室和现场在线油液检测。

A Fast Method to Measure TAN and TBN of Used Lubricant Oil Based on Portable Infrared Spectrometer

TAN and TBN which provide information about the degree of lubricating oil oxidation and the properties of alkali reserve is usually used in measurement of aging degree of lubricant,and its value can dete rmine whether the amount of certain acid additives added is enough.It can avoid the problems such as,the abnormal wearing,corruption,deposit,filter blockin g.The TAN and TBN of Lubricating oil is measured by the standard based on acid-base titration,in which potentiometric titration is used more.However it has to face the problems of complicated operation,expensive consuming material,an d large quantity of sample oil,well trained operator and difficulty in handling reagent.Due to the oxidation of lubricating oil products and alkaline additive s in the infrared spectrum has strong structural information,therefore,the TAN and TBN of lubricating oil can be monitored by infrared spectra.The quantification of TAN and TBN based on neutralization reaction was built up through the measurement of portable infrared spectroscopy.The reliable quantif ication of TAN and TBN can be archived by three procedures of lubricant type cla ssification,building up lubricant library and multi-parameters regression.Thi s method is supported by recent ASTM D7889 standard.Compared with the other sta ndard,this method has a high speed of analysis,and it can read out measurement result directly without any solvent.The accuracy of measurement is relatively high,operation is relatively simple,and improve the detection speed at a certa in degree.The method can be used widely in industry field,including in laborat ory offline measurement and in situ online measurement.