Calculation of Chemical Equilibrium Compositions

The catalytic reaction between steam and hydrocarbon into mixtures of hydrogen, carbon monoxide, carbon dioxide and methane forms the basic feedstock (synthesis gas) to produce ammonia, methanol and other chemicals. For reactor design and to find the most economic reaction conditions it is necessary to study theoretically the reaction behaviour with respect to the operating parameters. In the present thermodynamic study we examine the temperature dependence of chemical compositions at equilibrium. The mathematical computation system Maple is used for the symbolic and numerical calculations, for generating the graphics and formatting the document

Vergasung von heteroelementhaltigen organischen Schadstoffen nach dem Steam-Reforming-Prozess

In this thesis the possibility of the complete conversion of organic pollutants containing nitrogen, chlorine and sulphur into synthesis gas by the steam reforming process was investigated for utilising these frequently toxic wastes. For this purpose the Basis of anapplicable process technique was realised and the adaptability of a caleium aluminate catalyst tested. After thermodynamic studies for calenlafing the mass and energy balance along the apparatus, an experimental plant was constmeted allowing the gasification of non-evaporable hydrocarbons by means of a two-component feed nozzIe for direct injection into the reactor. Utility tests of the catalyst were made by the conversion of model hydrocarbons containing nitrogen, chlorine and sulphur to determine the influence of the heteroelements an the catalytic activity by comparison with a reference standard. For this purpose the maximum conversion capacity of the catalyst for the actual feed was determined at 2 bar and 900 °C and compared with the corresponding value and the product gas composition of the conversion of naphtha that was used as the solvent of the heteroorganie compounds. Finally, dinitrotoluene being a waste material from TNT produetim and tar oil in rape oil methyl ester from a soll remediation process were gasified

Contributions of Washcoat Components in Different Configurations to the NOX and Oxygen Storage Performance of LNT Catalysts

In addition to SCR systems, lean NOX traps (LNTs) are also used for exhaust aftertreatment of lean burn internal combustion engines to sustainably reduce NOX emissions. Modern LNTs consist of different functional compounds to maximize the performance during NOX storage and regeneration. Based on the material analysis of a serial production LNT, PGM loaded BaO, Al2O3, MgAl2O4, and CeO2 were identified as the main base materials. In this paper, the NOX storage capacity (NSC) of these compounds is investigated both as single catalysts and as physical mixtures to identify possible synergistic effects. Therefore, commercially available support materials were loaded with Platinum and tested in granular form under realistic conditions. To optimize the performance by reducing the diffusion pathways for NOX molecules during storage, PGM, BaO, and Ceria were combined in a composite by the incipient wetness impregnation of alumina. As a result, the temperature dependent NSC of the commercial LNT could be reached with the Pt/Rh/Ba10Ce25/Al2O3 infiltration composite, while reducing the oxygen storage capacity by about 45%. Without the additional Rhodium coating, the low-temperature NSC was insufficient, highlighting the important contribution of this precious metal to the overall performance of LNTs