A. Angyal

Two stages catalytic pyrolysis of refuse derived fuel: production of biofuel via syncrude.

Thermo-catalytic pyrolysis of refuse derived fuels with different catalysts had been conducted in a two stages process due to its important potential value as fuel. The first stage was a pure thermal pyrolysis in a horizontal tubular reactor with feed rate of 0.5kg hourly. The second stage was a semi-batch process in the presence of catalysts. Results showed that the tested catalysts significantly have affected the quantity of products. E.g. gas yield could be increased with 350% related to the catalyst free case using ZSM-5, while that of pyrolytic oil was 115% over Y-zeolite. Gases consisted of mainly CO and CO(2) obtained from the tubular reactor, while dominantly hydrocarbons from the second stage. Ni-Mo-catalyst and Co-Mo-catalyst had shown activity in pyrolytic oil upgrading via in-situ hydrogenation-dehydrogenation reactions. Sulphur, nitrogen and chlorine level in pyrolytic oils could be significantly declined by using of catalysts.

Synthesis and Evaluation of Modified Polyethylene Wax Applied as Dispersant in Rubber Bitumen Composites

Grain rubber obtained from waste tyre has become one of the most important bitumen modifiers nowadays, but rubber precipitation from bitumen can cause problems during utilization. In our experimental work additives were synthesised as dispersant for rubber bitumen composites. Raw material was polyethylene wax (PEW) obtained from mild thermal cracking of polyethylene waste. The synthesis was a copolymerisation of olefins and maleic-anhydride. During the products evaluation the main analytical method was Fourier transform infra-red (FT-IR) spectroscopy. There were significant differences between the characteristic of raw material and synthesised products. The dispersant effect of the additives was studied in rubber-bitumen composites. All additives increased the stability of rubber-bitumen composites. From the results of the experiments it was stated that the modified polyethylene wax obtained from polyethylene waste can solve the instability problem of rubber-bitumen composites.

Environmental saving disposal of contaminated plastic wastes by their pyrolysis

The pyrolysis of different contaminated plastic wastes has been investigated in a 2.0 dm autoclave at 450 and 500°C under nitrogen. Results show considerable differences in yields and quality of products applying different pre-treatings and parameters. The properties of the products were determined by standardized methods, gas chromatography and FTIR. The gaseous products of the pyrolysis were distributed in the range of C1-C5 and consisted of different inorganic compounds. Liquids can be characterized as hydrocarbons in the carbon atom range of 5-34, with mainly aliphatic compounds. In the liquid products were different heteroatom containing organic compounds, too. The contaminant level of products considerably can be decreased by washing of the raw materials while the parameters of pyrolysis have only negligible effect on this.