应用近红外光谱特征谱段快速分析甲醇汽油甲醇含量  

Rapid analysis of methanol content in methanol gasoline based on near-infrared spectroscopy characteristic spectrum

作　　者：丁超民 张正东[2] 张锦[1] 杜彪 王桂萱 李琪[2] 刘帆[2] 张鑫 李轲[2] DING Chaomin;ZHANG Zhengdong;ZHANG Jin;DU Biao;WANG Guixuan;LI Qi;LIU Fan;ZHANG Xin;LI Ke(Dalian Maritime University,Dalian 116026,China;National Institute of Metrology,Beijing 100029,China;Beijing Yixingyuan Petrochemical Technology Co.,Ltd.,Beijing 101301,China;Dalian University,Dalian 116622,China)

机构地区：[1]大连海事大学,辽宁大连116026 [2]中国计量科学研究院,北京100029 [3]北京易兴元石化科技有限公司,北京101301 [4]大连大学,辽宁大连116622

出　　处：《中国测试》2025年第2期88-96,共9页China Measurement & Test

基　　金：国家市场监督管理总局市场监管技术保障专项项目(2023YJ03);国家市场监督管理总局科技计划项目(2021MK153);中国计量院基本科研业务费项目(AKYZZ2332,AKYZZ2131)。

摘　　要：甲醇汽油因其辛烷值高和污染较低等优点已经成为一种广受关注的新型替代能源,而甲醇含量是衡量其油品品质的重要指标。近红外光谱技术因准确、快速和高效等特点有望成为测定甲醇汽油中甲醇含量的可靠分析方法。利用甲醇汽油的近红外光谱中O-H键特征谱段的峰强度和峰面积建立拟合曲线,还根据甲醇分子的特征谱段建立偏最小二乘法(PLS)预测模型。通过对比特征光谱、全波长光谱、变量重要性投影(VIP)光谱、蒙特卡罗无信息变量消除(MC-UVE)光谱的PLS模型以及O-H键特征谱段峰强度和峰面积拟合曲线的预测性能,最终确定C-H键对称伸缩特征光谱的PLS模型测定效果最佳,模型决定系数可以达到0.9999,测定结果的允许误差在国标要求范围内。研究结果表明,依据甲醇分子的化学结构筛选近红外特征谱段,基于此谱段建立的PLS模型可以实现甲醇汽油中甲醇含量的准确、快速分析。Methanol gasoline has become a popular new alternative energy source due to its high octane rating and low pollution.The methanol content in methanol gasoline serves as an essential indicator of its oil quality.Near-infrared(NIR)spectroscopy,owing to its fast,efficient,and non-destructive characteristics,holds potential as a dependable analytical method for determining the methanol content.In this study,we utilized the NIR spectra of methanol gasoline to establish a fitting curve based on the peak intensity and peak area of the distinctive O-H bond spectral bands.Additionally,we developed a partial least squares(PLS)prediction model using the characteristic spectral bands of methanol molecules.To determine the most effective model for measurement,various aspects were compared,including the prediction performances of PLS models for the characteristic spectrum,full-wavelength spectrum,variable importance projection(VIP)spectrum,Monte Carlo uninformative variable elimination(MC-UVE)spectrum,and the fitted curves of peak intensities and peak areas of the characteristic spectral segments of the O-H bond.The PLS model based on the symmetric telescopic characteristic spectrum of the C-H bond exhibited superior performance.The model determination coefficient can reach 0.9999,and the permissible error of the measurement results is within the range required by national standards.These findings confirm that the PLS model,utilizing the characteristic spectral bands of near-infrared spectra determined by the chemical structure of methanol molecules,can be employed for rapid methanol content analysis in methanol gasoline.

关 键 词：近红外光谱 特征谱段 甲醇汽油 快速分析 

分 类 号：TB9[一般工业技术—计量学]