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Traditional liquid fuel, such as kerosene, is still the primary fuel in air transport for longer distances. Other types of propulsion, like electric batteries, fuel cells, or their combination with solar panels, are only practical for smaller aeroplanes designed for transportation purposes. In order to replace at least some fossil kerosene with waste raw materials, kerosene production from waste polyalkenes has become more important. This work investigates the possibility of using a laboratory continuous conical spouted bed reactor for the study of the production of jet fuel fraction from waste polypropylene. Optimal reaction conditions of cracking for producing high yields of hydrocarbon liquids were determined. Tested pyrolysis temperatures changed from 420 to 460°C, and CO2 flow from 0.05 to 0.2 L.min-1 at various polypropylene dosing speeds. Yields and composition of liquid and gaseous products were measured. Monomer propene dominated with almost 60 wt% in pyrolysis gases. The highest yield of jet fuel fraction, 34 wt%, was obtained at 420°C and 0.1 L.min-1 of inert gas flow. [ABSTRACT FROM AUTHOR]

Study of kinetics during hydrogenation of hydrocarbon fractions prepared by pyrolysis of waste plastic is presented. Fractions were separated by distillation from oily/wax depolymerizates obtained during pyrolysis of polyethylene and polypropylene from end-of-life vehicles at 450°C in the batch reactor. The hydrogenation of liquid fractions in the boiling range of diesel was studied as a way of upgrading before their addition into fossil diesel fuels. Optimized experimental conditions of hydrogenation and optimized conditions for chromatographic separation are reported. The success rate of hydrogenation based on the alkane/alkene ratio in the samples after hydrogenation was evaluated by chromatography and by IR spectroscopy. Finally, the selected properties prescribed in fuel standards before and after hydrogenation are compared. [ABSTRACT FROM AUTHOR]

This work includes the study of mixing conditions on properties of asphalt modified by crumb rubber. For measuring were used five-level, three-factor design of experiment. Determinate were three dependent variable - softening point, penetration at 25°C and dynamic viscosity at 135°C. The monitored variables for mixing were concentration of crumb rubber (wt.%), mixing temperature (°C) and mixing time (min.). The results allowed us to estimate the influence of mixing conditions on modified asphalt samples and also showed that the most suitable criteria is dynamic viscosity. [ABSTRACT FROM AUTHOR]

Steam cracking belongs to the most important processes in petrochemical industry. Steam cracking is accompanied always by formation of coke deposits on inner walls of steam cracking tubes and of TLE. Coke formation significantly and negatively influences economic and energetic balance of the process. Different ways to minimize the coke deposition in steam cracking units are searched together with detailed understanding of coke formation mechanisms. The amount and character of created coke depends on operating parameters, feedstock type, on the reactor and TLE material, their surface modifications and also on addition of inhibitors. Summary of information about coke formation during steam cracking and of coke inhibition methods is given. [ABSTRACT FROM AUTHOR]

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In a previous paper we have reported thermal cracking of individual and mixed plastics into oil/waxes. Now we are getting insight into thermal cracking of model seven components mixed plastics. Thermal cracking of mixture composed of high-density polyethylene (HDPE) /low-density polyethylene (LDPE) /linear-low-density polyethylene (LLDPE) /polypropylene (PP)/polyvinyl chloride (PVC)/ polyethyleneterephthalate (PET) /polystyrene PS/ (HDPE/LDPE/LLPE/PP/PS/PET/ PVC = 34.6/17.3/17.3/9.6./9.6./10.6/1.1 %wt.) was carried out in the batch reactor at temperatures from 350 to 500°C in atmospheric pressure. The main objective of this study was converting the seven components mixed plastics into oil/wax product for use as hydrocarbon fuel oil or chemical feedstock. The effect of temeperature and reaction time have been studied to ascertain the optimum conditions necessary for the production as well as to investigate the effects of these parameters on the composition of pyrolysis products, with special emphasis on the oil/waxes. [ABSTRACT FROM AUTHOR]