IGF project 202 ZN / 1

Development of metal oxide sensors for gas analysis for the control of gas atmospheres in industrial furnaces 

In many indus­tri­al sec­tors, gas ana­ly­sis is an indis­pensable tool for eco­no­mic and relia­ble pro­cess con­trol. Par­ti­cu­lar­ly in indus­tri­al fur­nace tech­no­lo­gy, know­ledge of the cur­rent sta­te of the fur­nace cham­ber atmo­sphe­re plays an important role and ser­ves pro­duct qua­li­ty, pro­cess con­trol and com­bus­ti­on opti­miza­ti­on as well as func­tion moni­to­ring, plant and per­son­nel safe­ty and envi­ron­men­tal protection.

The rese­arch objec­ti­ve is to make semi­con­duc­tor sen­sors known from the auto­mo­ti­ve indus­try appli­ca­ble for indus­tri­al fur­nace tech­no­lo­gy by adapt­a­ti­on and fur­ther deve­lo­p­ment. Cost-effec­ti­ve metal oxi­de sen­sors for H2O, CO and NO mea­su­re­ment open up the pos­si­bi­li­ty of imple­men­ting the moni­to­ring of pro­cess and pro­tec­ti­ve gas atmo­sphe­res at low cost through inno­va­ti­ve mea­su­re­ment, con­trol and auto­ma­ti­on stra­te­gies.
For this pur­po­se, labo­ra­to­ry samples of the humi­di­ty, car­bon mon­oxi­de and nitro­gen oxi­de sen­sors have been pro­du­ced at the Insti­tu­te for Inor­ga­nic Che­mis­try (IAC). The­se labo­ra­to­ry samples were eva­lua­ted at the IAC under labo­ra­to­ry con­di­ti­ons and elec­tri­cal­ly characterized.

A gas sen­sor test bench has been set up at the Depart­ment for Indus­tri­al Fur­naces and Heat Engi­nee­ring (IOB). The humi­di­ty sen­sor was tes­ted in a cham­ber fur­nace after being trans­fer­red to the gas sen­sor test bench at the IOB.

The tests on the humi­di­ty sen­sor based on the zeo­li­te H‑ZSM‑5 have shown that

  • the sen­sor mate­ri­al H‑ZSM‑5 is ther­mal­ly sta­ble up to 1000°C and is not redu­ced in an H2 atmosphere,
  • the sen­sor shows a signi­fi­cant increase in con­duc­ti­vi­ty in an H2 atmosphere,
  • no direct influence of the flow velo­ci­ty on the sen­sor impe­dance can be detected,
  • at a tem­pe­ra­tu­re of 500°C humi­di­ty con­cen­tra­ti­ons up to 1600 ppm(V) can be cle­ar­ly detected,
  • the sen­sor shows no signi­fi­cant impe­dance chan­ges to chan­ges in humi­di­ty con­cen­tra­ti­on at 750°C ope­ra­ting temperature.

Inves­ti­ga­ti­ons on the car­bon mon­oxi­de sen­sor have shown that

  • gal­li­um oxi­de as only one of the inves­ti­ga­ted mate­ri­als (Ga2O3, WO3, BaS­nO3) shows a sen­si­ti­vi­ty to CO at 600°C,
  • gal­li­um oxi­de is nano­par­ti­cu­lar and sin­gle-pha­se even after a tem­pe­ra­tu­re tre­at­ment of 1000°C.

The tests on the nitro­gen oxi­de sen­sor have shown that

  • which (NO+,Na+)-Al2O3mem­bra­ne is not sui­ta­ble for use in a tem­pe­ra­tu­re ran­ge of T ≥ 300°C.

Final report

Ech­ter­hof, T.; Neu­mei­er, S.; Böl­ling, R.; Pfei­fer, H.; Simon, U.: Ent­wick­lung von Metall­oxid-Sen­so­ren zur Gas­ana­ly­se für die Über­wa­chung von Gas­at­mo­sphä­ren in Indus­trie­öfen, FOGI-Nr. FV 685, For­schungs­ge­mein­schaft Indus­trie­ofen­bau e.V., Frank­furt, Mai 2008

BMWi_Web_de_WBZ

This rese­arch pro­ject was appli­ed for by the For­schungs­ge­mein­schaft Indus­trie­ofen­bau e.V. via the For­schungs­ku­ra­to­ri­um Maschi­nen­bau e.V. and finan­ci­al­ly sup­port­ed by the Bun­des­mi­nis­te­ri­um für Wirt­schaft via the Arbeits­ge­mein­schaft indus­tri­el­ler For­schungs­ver­ei­ni­gun­gen e.V., AiF-Nr. 202 ZN / 1.