Fluorescence Noise Eliminating Fiber-Enhanced Raman Spectroscopy for Simultaneous and Multiprocess Analysis of Intermediate Compositions for C₂H₂ and H₂ Production

C2H2 and H-2, as importantchemicaland energy raw materials, can be produced effectively and environmentallyfriendly by the partial oxidation (POX) of CH4. Simultaneousanalysis of intermediate gas compositions in the multiprocess (cracking,recovery, degassing, etc) of POX can regulate product generation andimprove production efficiency. To overcome the disadvantage of commongas chromatography, we propose a fluorescence noise eliminating fiber-enhancedRaman spectroscopy (FNEFERS) technique for simultaneous and multiprocessanalysis of the POX process, in which the fluorescence noise eliminating(FNE) method can effectively eliminate the horizontal and verticalspatial noise to ensure ppm level limits of detection (LOD). The vibrationmodes of gas compositions related to each POX process such as crackedgas, synthesis gas, and product acetylene are analyzed. Meanwhile,the composition of three-process intermediate sample gases from SinopecChongqing SVW Chemical Co., Ltd is quantitatively and qualitativelyanalyzed simultaneously, along with the ppm level LODs (H-2: 11.2 ppm, C2H2: 3.1 ppm, CO2:9.4 ppm, C2H4: 4.8 ppm, CH4: 1.5ppm, CO: 17.9 ppm, allene: 1.5 ppm, methyl acetylene: 2.6 ppm, 1,3-butadiene:2.8 ppm) with a laser power of 180 mW, exposure time of 30 s, andaccuracy of higher than 95.2%. This study fully demonstrates the abilityof FNEFERS to replace gas chromatography to achieve simultaneous andmultiprocess analysis of intermediate compositions for C2H2 and H-2 production and to monitor other chemicaland energy production processes.