[Zurück]

H. Moser, W. Pölz, J.P. Waclawek, J. Ofner, B. Lendl:
"Implementation of a quantum cascade laser-based gas sensor prototype for sub-ppmv H2S measurements in a petrochemical process gas stream";
Analytical and Bioanalytical Chemistry, 409 (2017), 3; S. 729 - 739.

The implementation of a sensitive and selective as
well as industrial fit gas sensor prototype based on wavelength
modulation spectroscopy with second harmonic detection (2f-
WMS) employing an 8-μm continuous-wave distributed feedback
quantum cascade laser (CW-DFB-QCL) for monitoring
hydrogen sulfide (H2S) at sub-ppm levels is reported.
Regarding the applicability for analytical and industrial process
purposes aimed at petrochemical environments, a synthetic
methane (CH4) matrix of up to 1000 ppmv together with
a varying H2S content was chosen as the model environment
for the laboratory-based performance evaluation performed at
TU Wien. A noise-equivalent absorption sensitivity (NEAS)
for H2S targeting the absorption line at 1247.2 cm−1 was
found to be 8.419 × 10−10 cm−1 Hz−1/2, and a limit of detection
(LOD) of 150 ppbv H2S could be achieved. The sensor prototype
was then deployed for on-site measurements at the
petrochemical research hydrogenation platform of the industrial
partner OMVAG. In order to meet the company´s on-site
safety regulations, the H2S sensor platform was installed in an
industry rack and equipped with the required safety infrastructure
for protected operation in hazardous and explosive environments.
The work reports the suitability of the sensor prototype
for simultaneous monitoring ofH2S andCH4 content in
the process streams of a research hydrodesulfurization (HDS)
unit. Concentration readings were obtained every 15 s and
revealed process dynamics not observed previously.

http://dx.doi.org/10.1007/s00216-016-9923-z