2/2013
Contribution to the carbon dioxide storage into coal
Deposition of carbon dioxide as the most abundant greenhouse gas within suitable geological reposi-tories including unexploitable coal seams has been of a great scientific interest for a long time. The basic pa-rameters in selection of a suitable repository based on simulating the deposition process include determination of the repository sorption capacity by laboratory measurement of the amount of CO2 adsorbed in a coal sample at a pressure and temperature corresponding to in situ conditions carried out in a high pressure sorption apparatus. A manometric sorption apparatus with the maximum pressure 25 MPa was constructed at the Institute of Rock Structure and Mechanics and its functionality was verified on the sample of activated charcoal Norit R 0.8 Extra and the sample of medium coalified bituminous coal from the Darkov mine. The experiments confirmed functionality of the experimental setup and its ability to provide accurate and reproducible results.
The influence of thermal strain on crude-oil behavior during its long-term storage
Experiments with model storage of crude oil were carried out in laboratory scale. Crude oil samples were thermally treated by heating and successive cooling to the temperature of model storage. Maximum temperature of the temperature program used was 40 °C, 60 °C, 80 °C and 100 °C. The crude oil sample, which did not undergo the thermal treatment used, was taken as a reference. The content and distribution of n-alkanes in the emerging deposits after the process of simulated crude oil storage were evaluated. The effect of heating temperature upon quantity and quality of deposits is discussed. It was found that the thermal history of crude oil had a strong influence on its behavior during model storage.
Oxidation tests for industrial and engine oils
The article discusses the oxidation tests used to evaluate industrial lubricants and motor oils. Attention was given to oxidation tests most commonly used for control of quality of industrial oils or for diagnostic purposes. Tests were divided into several groups according to the test type and test conditions. A separate chapter was devoted to a pressure DSC technique. Tests for motor oils were described only those included in some of the standardization systems.
Corrosion testing of etanol-gasoline blends on steel, aluminium, copper and brass
Bioethanol is one of the possible alternatives of surrogate of classic motor gasoline that is normally used for feeding the cars. There are high demands on compatibility of fuel with construction materials connected with the use of mixed bio fuels. The material compatibility may be limiting factor for biofuels use. The mixtures of alcohol-petrol E10, E40, E60, E85 and E100 with artificial contamination were tested in a laboratory apparatus. The model contaminants were water and trace amounts of chloride, sulphate, sulphuric acid and acetic acid. The corrosion behaviours of fuels were tested on steel of grade 11 (according to Czech standard), copper, aluminium and brass in static and dynamic system metal - fuel. The corrosion rates were calculated from weight loss of metal samples.
High temperature fuel cell
The high temperature fuel cell have a potential to be the most efficient and cost-effective system for direct conversion of a wide variety of fuels to electricity. This paper describes two basic types: SOFC (solid oxide fuel cell) and MCFC (molten carbonate fuel cell).
Measurement of Gas Discharge Coefficient
In case of gas pipeline leakage the gas leakage volume must be determined to calculate costs and losses of the accident. In order to calculate the exact volume of leaked gas it is necessary to specify the crosssection and discharge coefficient of the leak. The laboratory apparatus for the discharge coefficient determination has been built. The vessel pressurized by the gas is freely emptied through the studied orifice into the space at atmospheric pressure. Time course of the pressure and temperature of gas in the vessel is measured and evaluated in the form of the discharge coefficient. Data on several types of orifice (circular, triangular, square shaped, long narrow slot, flapped semi-open cut in the metal sheet) were measured in critical and sub-critical flow regime.