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1

Coal combustion in the mixture of O2/CO2

Magdziarz A.

Environment Protection Engineering

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2010

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Vol. 36, nr 2

39-43

EN

This paper provides the review of research that has been carried out in the field of the coal combustion in the mixture of O2/CO2. It presents the most important advantages and disadvantages of such a combustion compared with air combustion. This study deals with the emission of nitrogen oxides, sulphur oxides and ash in the fuel gas from coal combustion in the mixture of O2/CO2. This combustion is a very important technology because of an easy CO2 recovery, low NOx emission and high desulphurisation efficiency.

2

Modelling and computer simulation of reagents diffusion in high temperature diffusion controlled heterogeneous reactions

Radune M., Radune A., Assous F., Zinigrad M.

Archives of Computational Materials Science and Surface Engineering

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2009

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Vol. 1, nr 4

225-231

EN

Purpose: In this paper a computational method which takes into account convection in the melting metal and slag phases is discussed. Design/methodology/approach: A deterministic computational model of high-temperature heterogeneous reaction between metal and oxide melts has been developed. Findings: Transport of reagents and products of reaction occur simultaneously both by diffusion and by laminar natural convection of the melting metal and oxide fluxes. The convection-diffusion equations have been numerically solved by a finite-differences time-implicit discretization scheme. The model was implemented by program which had been written in C# language. The computations have been performed for desulfurization reaction between liquid metal and slag phases. Research limitations/implications: To verify the reliability of the model, the computed results have been compared with experimental data. The good agreement has been obtained. The numerical results agree well with the results which were found by two independent experiments. Originality/value: This computational model enables to obtain results, for example sulfur concentration changes along the x axis, which is very difficult, almost impossible, to get by experiment. Using this mathematical model allows to predict the distribution of elements in the metal during the refining process and to reduce expenses in selection of optimum process' conditions, which provide the metal with required composition. This model can be used for quantitative analysis of the diffusion stage of the heterogeneous reactions.

3

Removal of heavy metals from excessive activated sludge

Gąsiorek J. A.

Polish Journal of Chemical Technology

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2002

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Vol. 4, nr 3

8-12

EN

This paper presents the laboratory scale anaerobic treatment results from an acidic autolysis of a waste activated sludge and from a desulfiirication process of this sludge, too. The sludge with high contents of the heavy metals used in the study was derived from the treatment plant at Cze_stochowa. The anaerobic first-stage treatment system includes an acid reactor or a fermentation reactor with the population of the sulfate reducing bacteria e.g. Desulfovibrio desulfuricans respectively. The second stage was carried out on the aerated reactor, which was used to heavy metals extraction during bioleaching of the sludge from the first stage with Thiobacillus ferrooxidans bacteria. The removal yield of the heavy metals are given after each stages of the sludge treatment. The organic sludge after second stage operation can be application within agriculture as its heavy metals content is very low. The liquid product on separation phosphates and the metal hydroxides as the carbon source can be used to enhance the nitrogen and phosphorus removal at the waste water treatment plants. These investigations are part of the recycling project called 1TP (integrated treatment plant) process depending on the integration of the desulfurication to waste water treatment with an activated sludge technology at a treatment plant.