## 1 Introduction  
Multimaterial waste is a significant group of waste that requires the application of special recycling techniques in order to reduce its negative impact on the environment [1]. In general, it is made of at least two different materials connected permanently [2]. According to the regulations (Polish Act of 13 June 2013 on Packaging and Packaging Waste and Polish Act of 14 December 2012 on Waste), it is treated like the material that is present in the highest amount, i.e., if the material consists of 70% paper and 30% plastic it should be treated like paper and collected in the designated container [3, 4]. The European Union's strategy in the plastics field is closely linked to the circular economy. This strategy pays special attention to plastic recycling and the possibilities of reducing it. Currently, 59% of plastic products are plastic packaging, including blisters for drugs, which are very difficult to manage. Packaging recycling is very difficult, but the pyrolysis of waste medicine blisters is one of the answers to the challenges of the circular economy. In the future, the process proposed in this article can be treated as a closed circuit in this group of packaging waste. Waste pharmaceutical blisters (WPBs) are a type of multimaterial waste. They are the most commonly used type of packaging to store pharmaceutical products [5; 6]. They contain approx. 80% thermoformable plastic films (usually polypropylene (PP) and pure polyvinyl chloride (PVC), or polyvinyl with diaphone addition (PVC/PVDC) or chlorotrifluoroethylene PVC/CTFE)) and 20% aluminum alloy (containing approx. 85% Al, 11,5% Mg, and 0.8% Ti) [7; 8]. The type of plastic used to produce the blister is usually chosen based on moisture permeability, which has a huge influence on the durability of the products and the price. In order to provide the highest protection from external conditions, the companies sometimes use the Al/Al type blisters, which contain polyamide, aluminum, and PVC. Two layers of aluminum protect the products from moisture, which may decompose the active ingredients and affect the expiration date of the medicine, oxygen, and sunlight [9]. Currently, used blisters are either treated as plastic waste or collected at pharmacies together with the expired medicine and directed to thermal utilization plants, where metal is not recovered [4; 10]. As for most multimaterial waste, the mechanical separation of the materials used to produce them is complicated or, sometimes, impossible [11]. Therefore, in order to comply with the circular economy requirements, WPBs require a special treatment to efficiently recycle both metal and plastic fractions [12; 13]. [PERSON] et al. [5] analyzed the hydrometallurgical method to recycle waste blisters. The method was based on the leaching of 1 cm x 2 cm pieces of WPBs in hydrochloric acid. Under optimum conditions, this method allowed to separate as much as 100% of plastic from the metal. The obtained aluminum was of excellent quality, but the metal recovery required additional steps, i.e., precipitation, solvent extraction, adsorption, or the application of the ion-exchange method. Also, large amounts of HCl were required to separate the materials. [PERSON] et al. [14] analyzed the thermal method of aluminum recovery, which also generates high-quality gaseous fuel. The material used in the research was a similar multimaterial packaging waste used to store face mask sheets--a postconsumer Neutrogena face mask packaging made of aluminum foil, PET (polyethylene terephthalate), and PP (polypropylene). The produced aluminum was characterized by a high purity and an extremely low surface oxidation level. The process also resulted in the production of 67 wt% of hydrocarbon gases, which can be used as a fuel. Pyrolysis is a thermal decomposition process that occurs in the absence of oxygen. The products can be divided into a solid, a liquid, and a gaseous fraction.