search query: @supervisor Lehtonen, Juha / total: 32
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| Author: | Yan, Chao |
| Title: | Hydrocarbon decomposition on oxygen permeable perovskite membranes |
| Publication type: | Master's thesis |
| Publication year: | 2015 |
| Pages: | 8 + 94 s. + liitt. 31 Language: eng |
| Department/School: | Kemian tekniikan korkeakoulu |
| Main subject: | Process Systems Engineering (KE3004) |
| Supervisor: | Lehtonen, Juha |
| Instructor: | Kihlman, Johanna |
| Electronic version URL: | http://urn.fi/URN:NBN:fi:aalto-201511205253 |
| Location: | P1 Ark Aalto 3216 | Archive |
| Keywords: | synthesis gas hydrocarbon decomposition oxygen permeable perovskite membranes partial oxidation |
| Abstract (eng): | Synthesis gas (CO+H2) can be produced via various pathways such as steam reforming, partial oxidation as well as autothermal reforming. Steam reforming is strongly endothermic and partial oxidation is weakly exothermic. By combing of the steam reforming and partial oxidation process can be operated at autothermal conditions (autothermal reforming). However, using the pure oxygen as oxidant is quite expensive and using the air would have the nitrogen content in the downstream processes. Oxygen permeable membrane enables the oxygen ions to be selectively transported through the membrane by blocking the nitrogen and other gases outside. In the literature part of the study, the mechanism and applications of the perovskite membranes as well as the preparation methods were introduced. There were 12 membranes (A-H) tested in this thesis for toluene decomposition on the perovskite membrane under different temperatures, air flow rates, toluene amounts, bottom flow rate of toluene and nitrogen. Furthermore, the effect of the steam and gasification gas at atmospheric pressure were investigated. The results showed that the oxygen flux increased with the increased temperature and air flow rate. Higher bottom flow rate (2 l/min) of toluene and nitrogen results in lower oxygen flux value and the toluene amount has less effects on the oxygen permeability. Moreover, the oxygen flux reached to 3.03 ml/min*cm2 at 900 oC, air flow rate of 0.45 l/min and total bottom flow of 0.5 l/min by adding the gasification gas, of which oxygen flux value of 1.8 ml/min*cm2 for a normal run under the same condition. Regarding to the toluene conversion, it was clear that the toluene conversion increased with the increase of the temperature and it was higher with the gasification gases than with the steam. In summary, the oxygen fluxes were in the same range from 1.75 to 2.46 ml/min*cm2 and C7 membrane had the highest oxygen flux and the optimal condition for the membrane was high temperature (900 oC), high air flow rate (0.45 l/min),with gasification gases and the optimal toluene amount dependent on the oxygen flux value. |
| ED: | 2015-11-29 |
INSSI record number: 52593
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