Development of an impedance-based sensor for detection of catalyst coking in fuel reforming systems

SENSORS AND ACTUATORS B-CHEMICAL

卷:183

Article

Wheeler, Jeffrey L.¹  Sullivan, Neal P.¹  Porter, Jason M.¹ 

[1] Colorado Sch Mines, Dept Mech Engn, Golden, CO 80401 USA

关键词: Fuel reforming;    Coke formation;    Solid oxide fuel cell;    Wheatstone bridge;    Carbon nanofibers;    Inkjet printing;   

DOI  :  10.1016/j.snb.2013.03.084

来源: Elsevier

【 摘 要 】

A novel sensor for detecting the early stages of catalyst coking in fuel reforming systems has been developed. The sensor was manufactured by inkjet printing a colloidal suspension of ceramic powders to create thin (20 mu m) catalytic and conductive elements of the sensor. The catalytic elements are composed of a Ni-YSZ cermet. The Ni-YSZ cermet was prepared with a concentration below the percolation limit (20 vol.%) of nickel, ensuring a low electrical conductivity. As coke forms on the catalyst material, the nickel nodules in the Ni-YSZ are connected by electrically conductive carbon and the conductivity of the catalyst material increases, indicating coke formation. Sensors were tested in a 1% ethylene environment to induce coking. The sensor showed a strong response to coking by producing a signal on the order of hundreds of millivolts. The mass of the coke load was determined to be below the detection limit of available thermogravimetric analyzers (TGA) (< 10 mu g). The coke load was further examined with a field effect scanning electron microscope (FESEM) and was found to be primarily carbon nanofibers. Carbon nanofibers 10-50 nm in diameter connected nickel nodules in the sensors catalyst material resulting in the observed change in resistance. (C) 2013 Elsevier B.V. All rights reserved.

【 授权许可】

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