Phosphorus Poisoning and Characterization of Al2O3 Based Support Material
Hussain, Nazia (2014)
Metropolia Ammattikorkeakoulu
2014
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Julkaisun pysyvä osoite on
https://urn.fi/URN:NBN:fi:amk-201405208915
https://urn.fi/URN:NBN:fi:amk-201405208915
Tiivistelmä
Purpose of this thesis project was to study the effect of phosphorus poisoning on Al2O3 based support material. Al2O3 is widely used as a support material in natural gas oxidation catalysts as a part of support material. The work was done in the Mass and Heat Transfer process Laboratory, University of Oulu as a part of a larger project that focuses on catalyst poisoning in more detail.
The first part of the study was consisted of poisoning monolith samples by gaseous phase under three different phosphorus feed concentrations. The second part of the project focused on characterization of the poisoned samples. Techniques used for characterization were physisorption analyses, field emission scanning electron microscopy (FESEM) and X-ray diffraction (XRD).
It was found that phosphorus changes the specific surface area of the support material. Total BET surface area and pore volume were lower in the phosphorus-poisoned samples compared to the fresh sample. It was also found that these changes are related to the amount of phosphorus available in the feed during poisoning. In addition, phosphorus accumulation in the inlets of the samples was much larger than the phosphorus accumulation in the sample outlets. It was also found that phosphorus binds chemically with Al2O3 based support forming AlPO4.
The results of this project can be utilized in further understanding of phosphorus-induced catalyst deactivation. It will help developing catalysts that are more resistant to phosphorus.
The first part of the study was consisted of poisoning monolith samples by gaseous phase under three different phosphorus feed concentrations. The second part of the project focused on characterization of the poisoned samples. Techniques used for characterization were physisorption analyses, field emission scanning electron microscopy (FESEM) and X-ray diffraction (XRD).
It was found that phosphorus changes the specific surface area of the support material. Total BET surface area and pore volume were lower in the phosphorus-poisoned samples compared to the fresh sample. It was also found that these changes are related to the amount of phosphorus available in the feed during poisoning. In addition, phosphorus accumulation in the inlets of the samples was much larger than the phosphorus accumulation in the sample outlets. It was also found that phosphorus binds chemically with Al2O3 based support forming AlPO4.
The results of this project can be utilized in further understanding of phosphorus-induced catalyst deactivation. It will help developing catalysts that are more resistant to phosphorus.