Abstract

Online measurements of the raw gas composition, including tars and water, during biomass gasification provide valuable information in fundamental investigations and for process control. Mainly consisting of hydrocarbons, tars can, in principle, be measured using Fourier transform infrared (FT-IR) spectroscopy. However, an instrument subjected to raw gas runs the risk of condensation of tars on optical components and subsequent malfunction. Therefore, an external cell, heated to at least 400°C, has been designed to ensure that tars remain in the gas phase during FT-IR measurements. The cell was used for on-line FT-IR measurements of permanent gases (CO, CO₂, CH₄), water, and tars during the operation of a lab-scale downdraft gasifier using wood pellets, bark pellets, and char chips. Based on calibration, the measurement error of permanent gases was estimated to be 0.2%. Concentrations evaluated from spectral signatures of hydrocarbons in tar are in good agreement with results from solid-phase adsorption measurements and correlated well with operational changes in the gasifier.

© 2021 The Author(s)

In-situ measurement of pyrolysis and combustion gases from biomass burning using swept wavelength external cavity quantum cascade lasers

M. C. Phillips, T. L. Myers, T. J. Johnson, and D. R. Weise
Opt. Express 28(6) 8680-8700 (2020)

Custom-built light-pipe cell for high-resolution infrared absorption spectroscopy of tritiated water vapor and other hazardous gases

Johannes Müller, Magnus Schlösser, Frank Hase, Nicolas Ziegler, Robin Grössle, David Hillesheimer, and Johannes Orphal
Opt. Express 27(12) 17251-17261 (2019)

Infrared absorption spectrometer for the determination of temperature and species profiles in an entrained flow gasifier

Patrick Nau, Peter Kutne, Georg Eckel, Wolfgang Meier, Christian Hotz, and Sabine Fleck
Appl. Opt. 56(11) 2982-2990 (2017)

Quantitative measurements by Fourier-transform infrared spectroscopy of toxic gas production during inhibition of JP-8 fires by CF₃Br and C₃F₇H

Steven H. Modiano, Kevin L. McNesby, Paul E. Marsh, William Bolt, and Craig Herud
Appl. Opt. 35(21) 4004-4008 (1996)

Ultrafast-laser-absorption spectroscopy in the mid-infrared for single-shot, calibration-free temperature and species measurements in low- and high-pressure combustion gases

Ryan J. Tancin and Christopher S. Goldenstein
Opt. Express 29(19) 30140-30154 (2021)