Příprava aktivovaných uhlíkatých materiálů vícestupňovou mikrovlnou pyrolýzou odpadních živočišných kostí pro snižování koncentrace xylenu z odpadních plynů

Abstract

The diploma thesis deals with the preparation and use of biochars and activated biochars by microwave pyrolysis as effective sorbents for elimination of the pollutants from the waste gases. The theoretical part describes current knowledge in the field of microwave pyrolysis of animal by-products and adsorption of pollutants from both waste gases and water. The practical part is divided into several chapters. The first part of the work deals with the preparation of biochars and activated biochars from animal by-products (waste animal bones - pork and beef), namely by one-stage microwave pyrolysis without activation at different set magnetron powers (200, 400 and 600 W) and two-stage microwave pyrolysis with activation (KOH, K2CO3, H3PO4) and 200 W magnetron power. Based on the most suitable textural and structural properties of the prepared sorbents, the best ones were selected for testing the sorption capacity of xylene from air. On the basis of experiments, it was found that the sorption capacity of xylene is primarily dependent on the volume of micropores – as the volume of micropores increases, the sorption capacity of xylene increases linearly. The ratio of graphitic and amorphous structure (ID/IG) of carbon had no effect on the sorption capacity. The best sorbent was prepared by two-stage pyrolysis and K2CO3 activation with high specific surface area (SBET 258 - 815 m2.g-1), micropore volume (Vmicro 49 - 247 mm3liq.g-1) and xylene sorption capacity of 30.2 - 84.4 mg xylene.g-1. This sorption capacity is comparable or/higher than the sorption capacity of sorbents prepared from waste corn (24 mg xylene.g-1).