Optimization of physical filtering for selective high temperature H2 sensors

Weh, Thomas; Fleischer, M.; Meixner, H.

doi:10.1016/s0925-4005(00)00475-5

Cited by 25 publications

(10 citation statements)

References 3 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Examples range from the measurement of the ppm hydrogen levels for the early detection of partial discharge in power transformers [16], [17] to hydrogen-level monitoring in metal-melting furnaces [2]. Fabrication of selective hydrogen detectors based on different types of molecular sieves or membranes for hydrogen separation have been reported [18], [19]. In these devices, the selective sensitivity of the sensor basically depends on the specifications of the filters used.…”

Section: Introductionmentioning

confidence: 99%

A Novel Approach to Hydrogen Sensing

Hossein‐Babaei

Orvatinia

2004

IEEE Sensors J.

View full text Add to dashboard Cite

A novel sensor for the selective detection of hydrogen in the presence of other reducing gases is presented. The device comprises a commercially available non-or partially-selective semiconductor gas sensor and an air filled centimeter-long capillary tube. The attachment is so that upon exposure, the target gas diffuses in air through the length of the capillary before affecting the sensor. The hydrogen component of the gas mixture diffuses much faster than other components, and is sensed at an earlier stage of the sensor response. The response of a capillary-attached gas sensor (CGS) to a gas mixture containing hydrogen is mathematically analyzed. The results indicate that the hydrogen concentration can readily be extracted from certain mathematical features of the transient response. The fabrication of a prototype CGS and experimental verification of the analytical results are reported. The prototype can measure hydrogen concentration at the presence of other reducing and combustible gases exceeding its concentration by two orders of magnitude.

show abstract

Section: Introductionmentioning

confidence: 99%

A Novel Approach to Hydrogen Sensing

Hossein‐Babaei

Orvatinia

2004

IEEE Sensors J.

View full text Add to dashboard Cite

show abstract

“…Approach (2) necessitates machine learning algorithms to interpret the response pattern [23]. In approach (3), a filter that selectively (physi-or chemi-)adsorbs the interferent [24][25][26][27][28][29]-such as a zeolite membrane [27]-will eventually saturate with gas and thus require regeneration or replacement [20].…”

Section: Introductionmentioning

confidence: 99%

A toy model of a catalytic filter in series with a gas sensor

Fabusola

Noh

Simon

2022

Preprint

View full text Add to dashboard Cite

The cross-sensitivity of a gas sensor can be mitigated by installing a catalytic filter upstream. The objective of the filter is to convert interferents into species that interact weakly with the recognition element of the sensor. Mathematical models may be useful for optimizing the design parameters of the catalytic filter. Particularly, if the catalyst is not perfectly selective for the interferent over the analyte, we hypothesize the existence of an optimal residence time of the gas in the filter. Short residence times allow too much interferent to reach the sensor and corrupt its response, while long residence times degrade too much of the analyte, diminishing the signal-to-noise ratio. Herein, we develop a toy mathematical and probabilistic model of a catalytic filter and gas sensor in series. We model (a) the catalytic filter as an isothermal, packed-bed reactor that decomposes the interferent and analyte with first-order kinetics and reactant-selectivity for the interferent and (b) the cross-sensitive gas sensor as gravimetric, producing a response with contributions from the analyte and interferent, governed by the competitive Langmuir adsorption model. Under distributions of (a) concentrations of interferent and analyte in the sensing environment and (b) measurement noise corrupting the response of the sensor, we simulate deployment of the model catalytic filter-gas sensor, where the objective is to accurately predict the concentration of the analyte in the gas phase from the response of the sensor. The performance of the catalytic filter-gas sensor is measured by the expected error in the predicted concentration of the analyte. Indeed, our toy model shows an optimal residence time of gas in the catalytic filter, which depends on the reactant-selectivity of the catalyst. While just a caricature of a catalytic filter-gas sensor, our toy model illustrates the utility of mathematical and probabilistic models for optimizing their design parameters.

show abstract

“…On the other hand, inorganic membranes for special applications of microfiltration (MF) and ultrafiltration (UF) are now established. Among these are silica-based membranes of high importance [19][20][21][22][23] but also zeolites [24][25][26][27][28][29][30]. Other materials involve perovskites [31,32], Al 2 O 3 [19,33,34], or copper oxide [35].…”

Section: Introductionmentioning

confidence: 99%

Organic Membranes for Selectivity Enhancement of Metal Oxide Gas Sensors

2016

View full text Add to dashboard Cite

We present the characterization of organic polyolefin and thermoplastic membranes for the enhancement of the selectivity of metal oxide (MOX) gas sensors. The experimental study is done based on theoretical considerations of the membrane characteristics. Through a broad screening of dense symmetric homo- and copolymers with different functional groups, the intrinsic properties such as the mobility or the transport of gases through the matrix were examined in detail. A subset of application-relevant gases was chosen for the experimental part of the study: H2, CH4, CO, CO2, NO2, ethanol, acetone, acetaldehyde, and water vapor. The gases have similar kinetic diameters and are therefore difficult to separate but have different functional groups and polarity. The concentration of the gases was based on the international indicative limit values (TWA, STEL). From the results, a simple relationship was to be found to estimate the permeability of various polar and nonpolar gases through gas permeation (GP) membranes. We used a broadband metal oxide gas sensor with a sensitive layer made of tin oxide with palladium catalyst (SnO2:Pd). Our aim was to develop a low-cost symmetrical dense polymer membrane to selectively detect gases with a MOX sensor.

show abstract

Optimization of physical filtering for selective high temperature H2 sensors

Cited by 25 publications

References 3 publications

A Novel Approach to Hydrogen Sensing

A Novel Approach to Hydrogen Sensing

A toy model of a catalytic filter in series with a gas sensor

Organic Membranes for Selectivity Enhancement of Metal Oxide Gas Sensors

Contact Info

Product

Resources

About