Year: 2011
Type: article
Abstract: Advanced sensors and controllers have been actively sought for enhancing energy efficiency, lowering operation cost, and reducing pollutant emission in fossil fuel power plants.Compared to conventional electrochemical and semiconductor sensors, fiber optic chemical sensors (FOCS) are attractive for applications in the harsh environments involved in fossil energy systems due to their advantages in miniature, immunity to electromagnetic interferences, robustness and capability of remote operation.FOCS has the potential to meet many analytical challenges in high temperature, high pressure, dusty, and corrosive environments associated with the fossil fuel energy processes where current gas sensors may fail to function effectively.This dissertation aims to develop and demonstrate two types of FOCS fabricated by physically and functionally integrating chemically sensitive nanomaterials with long-period fiber gratings (LPFG): one is the perovskite type doped ceramic thin film coated-LPFG sensor for in situ high temperature H 2 detection in fossil fuel derived syngas streams; the other is surface-acidified zeolite thin film integrated-LPFG sensor for potential uses for NH 3 detection in biomass-derived syngas and environmental monitoring.These two sensors have distinct operating mechanisms:The perovskite ceramic thin film coated LPFG is well fitted by a pseudo-two-layer model because the optical refractive index (RI) of the ceramic film is greater than the pure silica cladding of the fiber; the zeolite-coated LPFG sensors can be described by the three-layer model because the refractive index of the zeolite film is smaller than the fiber index.Three representative perovskite-type doped ceramics, i.e. the cerate-based SrCe 0.95 Tb 0.05 O 3-į (SCTb), the ceria-zirconia solution based SrCe 0.8 Zr 0.1 Y 0.1 O 3-į (SCZY), and the zirconate-based SrZr 0.95 Y 0.05 O 3-į (SZY) have been specifically evaluated to identify the appropriate sensing material for high temperature H 2 detection in the harsh environments.The H 2 sensing materials have been initially evaluated through the measurement and analysis of the material stability in different atmospheres, the high temperature H 2 uptake/sorption, and the thin film total electrical conductivity in Dr. William Connick, Dr. Vadim Guliants, and Dr. Hai Xiao, for devoting their time and efforts to serve on my committee and providing helpful comments and suggestions.
Author: Xiling Tang
Institution: University of Cincinnati
Language: English
Topic: Advanced Fiber Optic Sensors
Subfield: Electrical and Electronic Engineering
Field: Engineering
Domain: Physical Sciences
Open Access status: green
Award: G393636328
OpenAlex ID: W2282833103