Mikrovlnná pyrolýza odpadních pneumatik

Abstract

The bachelor thesis is focused on the processing of waste tires by microwave pyrolysis in a nitrogen atmosphere. This technology is a suitable recycling method. Its main advantage lies in speed, selectivity and energy savings. For the preferred mentioned reasons, microwave pyrolysis is a very attractive alternative to recycling, which allows the processing and recovery of inhomogeneous wastes and the recovery of gaseous, liquid and solid pyrolysis phases, which can be chemically and energetically useful materials. The aim of the bachelor thesis was to study microwave pyrolysis of waste tires, the effect of microwave reactor power (440 or 950 W) and retention time (5, 10, 20, 30 and 45 min) on the composition of individual pyrolysis phases. The result of the bachelor thesis is summarized in discussions. The first part deals with the comparison of the results of microwave pyrolysis of waste tires under different process conditions and the subsequent evaluation of the most effective conditions of the composition of products causing the most efficient microwave pyrolysis. The rest is devoted to whether this alternative to recycling waste is suitable for practical use. Microwave pyrolysis of waste tires creates 3 phases: liquid, gas and solid phase. BTX compounds (benzene (12 wt. %), toluene (20 wt. %), xylene (9 wt. %)), limonene (12 wt. %) and styrene (9 wt. %) were predominantly present in the liquid phase. In the gaseous phase, for both 440 W and 950 W power, the highest concentration was for H2 (~ 55 wt. %). The amount of fixed carbon (~ 77 wt. %) and ash (~ 21 wt. %) was determined for the solid phase. The calorific value of the solid phase by microwave pyrolysis was 40 MJ.kg-1. The input waste tires were characterized by non-porosity and low specific surface area (0.11 m2.g-1). Their pyrolysis destroyed the structure of the tires and created a meso-macroporous material with a specific surface area of ~ 72 m2.g-1 for 440 W and ~ 79 m2.g-1 for 950 W.