Application of wavelength-scanned wavelength-modulation spectroscopy H2O absorption measurements in an engineering-scale high-pressure coal gasifier
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A real-time, in situ water vapor (H2O) sensor using a tunable diode laser near 1,352 nm was developed to continuously monitor water vapor in the synthesis gas of an engineering-scale high-pressure coal gasifier. Wavelength-scanned wavelength-modulation spectroscopy with second harmonic detection (WMS-2f) was used to determine the absorption magnitude. The 1f-normalized, WMS-2f signal (WMS-2f/1f) was insensitive to non-absorption transmission losses including beam steering and light scattering by the particulate in the synthesis gas. A fitting strategy was used to simultaneously determine the water vapor mole fraction and the collisional-broadening width of the transition from the scanned 1f-normalized WMS-2f waveform at pressures up to 15 atm, which can be used for large absorbance values. This strategy is analogous to the fitting strategy for wavelength-scanned direct absorption measurements. In a test campaign at the US National Carbon Capture Center, the sensor demonstrated a water vapor detection limit of ~800 ppm (25 Hz bandwidth) at conditions with more than 99.99 % non-absorption transmission losses. Successful unattended monitoring was demonstrated over a 435 h period. Strong correlations between the sensor measurements and transient gasifier operation conditions were observed, demonstrating the capability of laser absorption to monitor the gasification process.
KeywordsMole Fraction Gasification Syngas Water Vapor Content Syngas Product
The Stanford research was supported by the Electric Power Research Institute with Mr. Jose Marasigan as technical monitor and by US Department of Energy NETL with Dr. Susan Maley as technical monitor. The operation of the NCCC by Southern Company Services was supported by DoE.
- 2.S.J. Clayton, G.J. Stiegel, J.G. Wimer, US DoE report DOE/FE-0447 (2002)Google Scholar
- 12.V. Ebert, K.-U. Pleban, J. Wolfrum, in In situ Oxygen-Monitoring Using Near-Infrared Diode Lasers And Wavelength Modulation Spectroscopy, OSA 1998 Technical Digest Series Vol 3: Laser Applications to Chemical and Environmental Analysis, paper LWB3 (1998)Google Scholar
- 14.S. Lundqvist, P. Kluczynski, in Process Analytical Applications in the Mid-Infrared, Proceedings of the SPIE 7945, Quantum Sensing and Nanophotonic Devices VIII, 79450N (January 24, 2011). doi: 10.1117/12.871571
- 33.L.S. Rothman, I.E. Gordon, Y. Babikov, A. Barbe, D. ChrisBenner, P.F. Bernath, M. Birk, L. Bizzocchi, V. Boudon, L.R. Brown, A. Campargue, K. Chance, E.A. Cohen, L.H. Coudert, V.M. Devi, B.J. Drouin, A. Fayt, J.-M. Flaud, R.R. Gamache, J.J. Harrison, J.-M. Hartmann, C. Hill, J.T. Hodges, D. Jacquemart, A. Jolly, J. Lamouroux, R.J. LeRoy, G. Li, D.A. Long, O.M. Lyulin, C.J. Mackie, S.T. Massie, S. Mikhailenko, H.S.P. Müller, O.V. Naumenko, A.V. Nikitin, J. Orphal, V. Perevalov, A. Perrin, E.R. Polovtseva, C. Richard, M.A.H. Smith, E. Starikova, K. Sung, S. Tashkun, J. Tennyson, G.C. Toon, Vl.G. Tyuterev, G. Wagner, The HITRAN2012 molecular spectroscopic database. J. Quant. Spectrosc. Radiat. Transf. 130, 4–50 (2013)CrossRefADSGoogle Scholar