Comment on Hydrogen and C2–C6 Alkane Sensing in Complex Fuel Gas Mixtures with Fiber-Enhanced Raman Spectroscopy

Response to Comment on Hydrogen and C2–C6 Alkane Sensing in Complex Fuel Gas Mixtures with Fiber-Enhanced Raman Spectroscopy

“…Differences in relative signal strengths as well as peak shape could otherwise lead to substantial errors. For example, combining the pure gas spectra from Petrov leads to a spectrum (Figure A) that looks very similar to the spectrum we acquired with the compact spectrometer (Figure B). However, there are considerable differences in relative signal strengths that would lead to errors in quantification if we would use the pure gas spectra from Petrov as reference spectra.…”

“…Petrov further pointed out the differences between his experimental spectra and the spectra calculated using DFT presented in our paper . He specifically mentions the differences in the number of bands and in the intensity distribution.…”

“…Looking at our data (Figure ), however, we would not instead use the peaks at 815 or 732 cm –1 but the one we already suggested for unambiguous identification in the original publication at 892 cm –1 . This peak is discernible in our spectra and has only minor overlap with other alkanes and no overlap with H 2 . The limit of detection for this weak peak is between 0.2 and 0.5%.…”

“…In a comment on our original article, Petrov provides separate Raman spectra for each of the different C2–C6 alkanes. These pure-gas spectra as well as the accompanying tables, which contain relevant information about the signal intensities of characteristic bands of the main natural gas components together with the intensities of other components at the same spectral position, add to the existing literature on the subject.…”

“…Comparison of C2–C6 alkane spectra. (A) Sum of all pure gas spectra acquired by Petrov . (B) Spectrum acquired with SP2, which is a compact spectrometer with a large spectral range but medium resolution.…”