PRELIMINARY RESEARCH OF WASTE BIOMASS AND PLASTIC PYROLYSIS PROCESS

Most plastic materials are non-biodegradable. Thus, disposing of such materials in landfills is undesirable, not only because of environmental concerns but also because of relevant EU policies requiring a certain degree of recycling and reuse of plastic materials. Furthermore, significant quantities of biomass waste, particularly waste sawdust as a consequence of intensive wood processing, represents another problem. Co-pyrolysis techniques have received much attention in recent years because they provide an alternative way to dispose of and convert waste plastic and biomass into high value feedstock and fuels. Recent investigations have shown that biomass and plastic co-pyrolysis achieve a synergistic effect, in the form of increased yield of liquid products, and the improvement of the overall process efficiency. This paper presents the results of technical analysis of waste plastics, waste biomass and mixtures biomass/plastic in the ratio 1:1; 3:1 and 1:3. The most common types of plastic waste in municipal waste: high density polyethylene, polypropylene and polystyrene, as well as two distinctive types of biomass, sawdust beech and spruce sawdust were selected for this investigation. The following parameters were determined: moisture, ash, coke residue, bonded carbon, volatile matter and combustible materials. During the test, the conditions of pyrolysis were simulated, in order to observe the changes of volatile substances in a mixture of biomass/plastic in comparison to theoretically expected values. The results of conducted measurements show that there is an increase in volatile matter, in all the mixtures and their ratios. The largest deviation of volatile matter in relation to the expected theoretical values was observed in the mixtures of sawdust beech/ polystyrene in the ratio 1:1.