乙烯裂解气的拉曼光谱分析.pdf

石油化工
2016年第45卷第1期
PETROCHEMICAL TECHINOLOGY
DOl:10.3969/jiss1000-8144.2016.01.003
乙烯裂解气的拉曼光谱分析
刘逸,王国清,司字辰,张兆斌
(中国石化北京化工研究院,北京100013)
摘要]考察了4个不同平滑度(0,1,3,5)的光谱预处理对拉曼光谱测量结果的影响,并优选平滑度为1的预处理方法。考
察了最小二乘拟合基底及Ar基底两种不同基底扣除方法对拉曼光谱测量结果的影响,并优选Ar基底扣除方法,定期校正更新
Ar基底。在原有混合标准气体CH4,C2H4,C2H6,C3H6,C3Hs,H126组分交叉干扰定量分析的基础上,增加1,3-丁二烯、正
丁烯和异丁烯3种组分对以上6个日标组分计量峰干扰值的扣除,但分析精度没有明显提高。探讨了乙烯裂解气中C2H误差较
大、CH2未检出的原因。实验结果表明,要提高激光拉曼气体分析仪的测量精度,在改进计算方法的同时,更多地需要从硬
件人手,通过改进光路结构增强试样的拉曼信号,以最终达到提高仪器测量精度的目的。
关键词]激光拉曼光谱;气体分析;气态烃;裂解气;乙烯
文章编号]1000-8144(2016)01-0017-07
[中图分类号]TQ075
[文献标志码]A
Analysis of pyrolysis gas by Raman spectrometry
Liu Yi, Wang Guoqing, Si Yuchen, Zhang Zhaobin
(SINOPEC Beijing Research Institute of Chemical Industry, Beijing 100013, China
Abstract I Six major components(CH,, C, Ha, CHS, C H,, CHA, H )in pyrolysis gas were
analyzed by means of laser Raman spectrometry. The effects of spectral pretreatment with four different
smoothnesses(0, 1, 3, 5)on the Raman analysis results were investigated and the pretreatment with
smoothness 1 was the optimal. The influences of two baseline methods, namely the least squares
fitting baseline and the Ar baseline, on the Raman analysis results were researched, and the Ar
baseline method was better. Based on the quantitative analysis of the cross interference of the 6 target
components, the interferences of 3 additional components including 1, 3-butadiene, butane and
isobutene were deducted, which did not led to the significant improvement of the Raman analysis
accuracy. The reasons of the poor analysis for C2 H and C Hs were discussed. It was indicated that in
order to improve the measurement accuracy of the laser Raman gas analyzer, improving hardware
may be more important than modifying algorithm
I Keywords J laser Raman spectroscopy; gas analysis; gaseous hydrocarbons; pyrolysis gas
ethylene
随着乙烯裂解炉产能的増大以及优质裂解原化工艺操作参数。常用的乙烯裂解气分析方法为气
料的短缺,裂解炉的进料日趋复杂,且裂解炉出口相色谱法,采用微板流路控制技术及多阀多柱多检
产物的组成也很复杂。对裂解原料及产物的分析评测器的切割、分流系统,可分别在FID(检测气体
价,可以帮助把握裂解炉的运行状况。以乙烯裂中烃类的含量)、TCD(辅助检测器检测气体中H2
解炉裂解气的分析为例,测定其中的CH4,C2H4
的含量,后检测器检测气体中N2的含量)得到裂解
CH等含量,可以把握裂解炉的裂解深度,帮助优气从H2至甲苯的全组分分析结果,但两次进样的
收稿日期]2015-11-06;[修改稿日期]2015-1-14
作者简介]刘逸(1981-),女,重庆市人,博士,高级工程师,电话010-59202284,电邮lyi.bjhy@sinopet.como
[基金项目]国家重大科学仪器设备开发专项课题“激光拉曼光谱气体分析仪的研发与应用”(2012YQ160007)。