Author(s)

Isack Kandola, Alexander Pogrebnoi, Tatiana Pogrebnaya

Department of Materials, Energy Science and Engineering, The Nelson Mandela African Institution of Science and Technology, Arusha, Tanzania.

Oldoinyo Lengai mountain located in Northern Tanzania is the only active natrocarbonatite volcano with unusually alkali-rich natrocarbonatites which are not found elsewhere in the world. Volcanic ash formed earlier during eruptions was collected from different sites along the mountain, and its potency to adsorb hydrogen sulfide (H₂S) and ammonia (NH₃) from biogas was investigated. The samples were calcinated at different temperatures (550℃ - 850℃) and were characterized by X-ray florescent, scanning electron microscopy and X-ray diffraction techniques. The on-site adsorption experiments were conducted at the biogas digester at ambient conditions. The calcinated ash was packed into the reactor bed, biogas allowed to pass through the adsorbent, and the inlet and outlet concentrations of H₂S and NH₃ were measured. The height of the site where the adsorbent was taken from, calcination temperature, biogas flowrate and mass of the adsorbent were variable parameters and found to influence greatly on the efficiency of H₂S and NH₃ removal. The efficiency is increased with calcination temperature raise and mass of adsorbent and decreased with flowrate increase. The samples collected from the top site of the mountain and calcinated at 850℃ exhibited the best sorption performance.

Adsorption, Calcination, Flowrate, Oldoinyo Lengai, Volcanic Ash, H₂S and NH₃ Removal

Kandola, I. , Pogrebnoi, A. and Pogrebnaya, T. (2018) Oldoinyo Lengai Volcanic Ash for Removal of Hydrogen Sulfide and Ammonia from Biogas. Journal of Materials Science and Chemical Engineering, 6, 78-93. doi: 10.4236/msce.2018.64010.