Authors: Peter Križan, Jozef Bábics, Juraj Beniak, Miloš Matúš
Abstract: The main aim of this paper is to present the research findings which come out from the experimental determination of the influence of input raw material properties and composition on the operating parameters of an injection press during the injection of biomass-plastic composites (BPC). During the injection process, important operating parameters such as injection speed, injection pressure and the temperature profile along the chamber can be recognized. In this research study, the aim was to produce BPCs of an acceptable and competitive level of quality which is determined from the final mechanical properties of BPCs. Using a variety combination of influencing variables the final quality of composites and also the operating parameters of the injection moulding press can be improved. Raw waste material variables influence, especially (a type of plastic matrix, type of biomass, particle size, moisture content) and biomass/plastic concentration ratio can be recognized during the production of composites. Their effect can be seen from the quality indicators and from the operating parameters of the injection press which has a direct impact on the production costs. The paper deals with the determination of the impact and the relationship between the input raw material variables and the operating parameters of the injection process (pressure, speed, and temperature profile). The experimental research findings were obtained using a semi-operational injection moulding press where the injection is provided by a working screw. As the input raw material, wheat straw and spruce sawdust, HDPE plastic matrix and recycled HDPE, represented by lids from PET bottles, was used. The effect of the input raw material composition was determined according to a combination and default levels of biomass/HDPE concentration ratio, using recycled HDPE instead of virgin HDPE and particle size of biomass.
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Authors: Peter Križan, Miloš Matúš, Juraj Beniak, Michal Svátek
Abstract: In this paper, we will present the research findings concerning relationships between technological and material variables (parameters) during densification of selected types of herbaceous biomass. In general during the biomass densification can be recognized various technological and also material variables which significantly influence the final solid biofuels quality. In case of herbaceous biomass densification there are some important differences with comparing the wooden biomass. These differences come from the material (herbaceous) composition and also from material structure and influencing also lonely treatment, densification and also the combustion of final briquettes from herbaceous biomass. The main goal of presented experimental research is to determine the relationship between compression pressure, compression temperature and raw material particle size. Experimental research described in this paper was realized by single-axis densification, which was represented by experimental pressing stand. The impact of investigated variables on the final briquettes density and briquettes dilatation was determined. Mutual interactions of these variables on final briquettes quality are showing the importance of mentioned variables during the densification process. The experimental findings presented here are significant from briquettes production point of view and also from densification machines engineering point of view.
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Authors: Awitdrus Awitdrus, Mohamad Deraman, Ibrahim Abu Talib, Rakhmawati Farma, Ramli Omar, M.M. Ishak, N.H. Basri, B.N.M. Dolah
Abstract: Green Monoliths (GMs) of self-adhesive carbon grain from fibers of oil palm empty fruit bunches were prepared by compression pressure at 1.43 × 107, 1.91 × 107 and 2.39 × 107 kg/m2, respectively. Activated carbon monoliths ACM-A, ACM-B and ACM-C prepared by CO2 activation from these GMs, respectively, were used as electrodes in supercapacitor cells which employed stainless steel 316L current collector and H2SO4 electrolyte. Evaluation of the electrochemical properties showed that ACM-A, ACM-B and ACM-C cells had specific capacitance of 30, 9 and 5 F/g, total ESR of 3.21, 4.95 and 7.33 Ω, specific power (maximum) of 173.41, 107.58 and 33.82 W/kg, and specific energy (maximum) of 0.67, 0.15 and 0.09 Wh/kg. These properties are directly associated with the surface area of the ACMs, i.e. 419, 336 and 302 m2/g for the ACM-A, ACM-B and ACM-C, respectively, indicating a direct effect of compression pressure on the physical and electrochemical properties of ACMs electrodes.
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