The work presented here describes the first results of an effective method of assessing the quality of electrostatic separation of mixtures of polymer materials. The motivation for the research was to find an effective method of mechanical separation of plastic materials and a quick assessment of the effectiveness of the method itself. The proposed method is based on the application of a dedicated vision system developed for needs of research on electrostatic separation. The effectiveness of the elaborated system has been demonstrated by evaluating the quality of the separation of mixtures of poly (methyl methacrylate) (PMMA) and polystyrene (PS). The obtained results show that the developed vision system can be successfully employed in the research on plastic separation, providing a fast and accurate method of assessing the purity and effectiveness of the separation process.

The aim of this study was to investigate and analyze the impact of selected parameters during the tribocharging process of shredded poly(ethylene terephthalate) (PET) and high-density polyethylene (PE-HD) plastics on accumulated electric charge and electrostatic separation effectiveness. The accumulation of electric charge on surfaces of polymer particles as a result of their circular motion forced by the airflow cyclone container was investigated. The impact of the container material, time of tribocharging and the airflow intensity were experimentally examined. A container in which the particles of the considered polymers are electrified with opposite charges was selected. A high ability to accumulate surface charge on small particles of both polymers was demonstrated. The electrified mixed PET/PE-HD was subjected to a separation process. An electrostatic separator designed and constructed by the authors was used for to the separation. In turn, to assess the effectiveness of this separation, a dedicated vision system was used. Based on the result of the carried out tests, it has been assumed that the proposed approach’s effectiveness has been demonstrated by means of empirical validation.

The issue of measuring and determining the calorific value of fuels is related to thermodynamic analysis of the effects of the combustion process aimed at determining the amount of heat transferred to the environment. Currently, there are several methods for determining the calorific value of fuels and their methodology is related to the type of fuel being analyzed. These methods are quite complicated and require the use of specialized measuring equipment. The energy demand of modern civilization along with the need to protect the natural environment prompts the search for new ways to generate energy directed at sources other than conventional fossil fuels. Technologies related to the use of biogas, synthesis gas obtained in biomass or waste gasification processes are being introduced. The use of these fuels in industrial processes of generating heat and electricity requires caloric stability of the fuel. The caloric stability of the fuel is necessary to ensure the stability of thermal energy conversion processes that translate directly into the set values of generated electricity using electric machines. One way to assess the energy quality of a fuel is to measure its calorific value. There are several methods for determining the calorific value of a fuel, but they all require special measurement conditions. The article presents the author’s concept of a calorimeter dedicated to the analysis of the calorific value of gaseous fuels.

Many researchers in the developed countries have been intensively seeking effective methods of plastic recycling over the past years. Those techniques are necessary to protect our natural environment and save non-renewable resources. This paper presents the concept of an electrostatic separator designed as a test bench dedicated to the separation of mixed plastic waste from the automotive industry. According to the current policy of the European Union on the recycling process of the automotive industry, all these waste materials must be recycled further for re-entering into the life cycle (according to the circular economy). In this paper, the proposed concept and design of the test bench were offered the feasibility to conduct research and technological tests of the electrostatic separation process of mixed plastics. The designed test bench facilitated assessing the impact of positions of high-voltage electrodes, the value and polarity of the high voltage, the variable speed of feeders and drums, and also triboelectrification parameters (like time and intensity) on the process, among others. A specialized computer vision system has been proposed and developed to enable quick and reliable evaluation of the impact of process parameters on the efficiency of electrostatic separation. The preliminary results of the conducted tests indicated that the proposed innovative design of the research stand ensures high research potential, thanks to the high accuracy of mixed plastics in a short time. The results showed the significant impact of the corona electrode position and the value of the applied voltage on the separation process effectiveness. It can be concluded that the results confirmed the ability to determine optimally the values of the studied parameters, in terms of plastic separation effectiveness. This study showed that this concept of an electrostatic separator designed as a test bench dedicated for separation of mixed plastic waste can be widely applied in the recycling plastic industry.