3/2010
Polycondensation of polycyclic and heterocyclic hydrocarbons in presence of chlorides Al, Cu, Fe a
This work was aimed to study the effect of inorganic compounds in polycyclic and heterocyclic hydrocarbons especially the influence of lead, copper, iron and aluminum chlorides on the thermal polycondensation of anthracene, dibenzo/b,d/furane, dibenzo/b,d/thiophene and carbazole. For the experiment, prepared pure model compounds (> 99 % wt.) mixed with chlorides (10 % wt.) were used. The time of heat treatment was 4 hours and temperature was above 300°C. The kinetics of the process and the conversion of model compounds and their mixtures with chlorides were investigated by simultaneous thermogravimetry and differential thermal analysis. Also the content and the oxidation reactivity of carbonaceous polycondensates were examinated.
Laboratory study of influence of low temperature oxidation on coking properties of bituminous coal
Low temperature oxidation is a complex reaction which brings deterioration in quality of bituminous coking coal. Coking properties such as maximum fluidity (Gieseler), dilatation and free swelling index are significantly decreased by this natural reaction. This article deals with laboratory study of low temperature oxidation effects on these three indicators in order to characterize quality changes in coal matrix. Two totally different kinds of coking coal were submitted to low temperature oxidation under several basic conditions, i.e. three temperature levels (25, 50 and 100 oC) and three particle size levels (< 0,2 mm, < 3 mm and < 10 mm). It was found that all these indicators fell during oxidation time. The reaction rate depends on temperature, particle size and coal rank. The Gieseler maximum fluidity proved to be the most sensitive indicator characterizing impairment of coking properties. This finding is supported by the fact that this indicator is strongly reduced by the oxidation at laboratory temperature and 60 % air humidity within two months. On the other hand free swelling index wasn´t changed up to 50 oC but at the temperature of 100 oC it showed considerable decline.
Application of Fast GC-MS in gasoline analysis
The aim of this work is to demonstrate application of fast GC-MS in gasoline analysis. There are discussed optimization of chromatographic conditions, identification and quantification of gasoline components in this paper. Applied optimized procedure on given apparatus showed satisfying chromatographic separation and took acceptable 30 min. At the end there were identified 295 components present in gasoline. Automated software identification of gasoline components was tuned up for automotive gasoline.
Stabilization of NOx emission level using adsorption/desorption
The reduction problems of not very variable NOx emission concentration in the waste gases from continual processes are successfully solved, commercially applied and the research in this section is mostly oriented to improvement of current technologies. But the reduction of emissions in waste gases, where the concentration is not at the stable equilibrium and balances in a range of several orders, (as it is for example in periodic processes), that used to be problematic topic. Contribution summarizes measuring adsorption NOx by active coal. In first part was select nitrogen oxide and supporting gas as clear nitrogen, to eliminated oxidation NO. In the first planning stage we can see only adsorption NO. Experiment was carried out so that for to selective concentration NO (1 mol%) was searched input time NO, when the balancing did happened.
Behavior of Arsenic and Sulfur by Brown Coal Pyrolysis
Czech brown coals contain often elevated amounts some trace elements, such as arsenic or sulfur. By coal pyrolysis these elements are divided in all pyrolysis products. The paper deals with the arsenic and sulfur distribution in pyrolysis products using selected Czech brown coals containing different amounts of sulfur, ash and tar.
Corrosion resistance of ferritic-martensitic EUROFER 97 in melting Pb-17Li
Liquid Pb-Li alloys are considered as potential coolants and tritium breeding fluids for a fusion reactor blanket concept. Reduced activation ferritic-martensitic steels with 8-10 % Cr were developed and their compatibility with liquid metals was investigated. The main corrosion mechanism in Pb-17Li is dissolution of the steel components after some incubation period, which is affected by stability of original surface oxide layers, temperature and other parameters. In this paper corrosion resistance of the martensitic steel EUROFER 97 was examined in flowing Pb-17Li melt at the temperature of 500°C for 2500 hrs. Morphology and composition of surface layers were examined.