Wyniki wyszukiwania - BazTech

1

Akumulacja ciepła w monolitach węglowych dla magazynowania energii - rozważania modelowe

Bałys M. R., Buczek B.

Polityka Energetyczna

|

2009

|

T. 12, z. 1

119-127

PL

Opierając się na równaniu bilansu ciepła, masy, stanu fazy objetoociowej i zaadsorbowanej zaproponowano model matematyczny pozwalający określić zmiany temperatury monolitów pod wpływem adsorpcji par metanolu. Obliczenia modelowe wykonane dla monolitów otrzymanych: z pylistego węgla aktywnego - AC35 oraz węgli aktywnych otrzymanych w procesie aktywacji chemicznej karbonizatu z węgla kamiennego - ACS i mezofazy pakowej - APM wykazały znaczne różnice we właściwoociach termicznych wystepujące pomiedzy nimi. Stwierdzono najwyższą zdolność do akumulowania ciepła w kolejności dla monolitów ACS i APM, a znacznie niższą dla AC35. Przewidywana różnica temperatur pomiędzy monolitem ACS a AC35 wynosi oko3o 3K. Uzyskano bardzo dobrą zgodność w zdolności do akumulowania ciepła, przewidywanych różnic przyrostu temperatury pomiędzy monolitami i dynamiki tych zmian z wynikami uzyskanymi z pomiaru ciepła zwilżania monolitów metanolem. Zaprezentowane wyniki wskazują na szczególną przydatność monolitów ACS i APM dla układu magazynującego ciepło adsorpcji.

EN

A mathematical model of heat accumulation caused by methanol vapour adsorption on carbon monoliths is presented using equations of heat and mass balances for adsorbed and gas phases. Monoliths were prepared utilizing as raw materials: powdered active carbon (AC35), coal carbonizate (ACS) and pitch mesophase (APM). Model calculations result in substantial differences in their thermal properties. The highest accumulation of heat was for monolith ACS, similar value was found for APM, but a much lower for AC35. Predicted temperature difference between monoliths ACS and AC35 amounts to 3K. Correlations were found between heat accumulation, differences of temperature, heat of methanol immersion and the dynamics of temperature changes for all monoliths. The results confirm thatmonolithsACS and APMare particularly useful for energy storage systems.

2

Kinetic of Methanol Decomposition on Cu/ZnO/ZrO2 Catalysts

Grabowski R., Kozłowska A.

Polish Journal of Chemistry

|

2004

|

Vol. 78 / nr 2

287-298

EN

Interaction of methanol with Cu/ZnO/ZrO2 (with different copper content) has been investigated by gravimetric and TPD methods. The TPD measurements of methanol adsorption on these catalysts show that it forms the complexes of two types. The first complex (I) decomposes at low temperature (453 K) yielding H2 and CO2and second (II) decomposes at the temperature (573 K) giving CO andH2. In the process of the decomposition of the complex (I) takes part water which is adsorbed on the surface of the catalyst and the decomposition of the complexes (II) occurs without participation of adsorbed water. Gravimetric measurements of methanol adsorption show that Cu facilitates adsorption of methanol and that an increase of copper content leads to the changes in the kinetics of methanol adsorption and its decomposition. On the basis of gravimetric measurements a model of methanol adsorption and decomposition on Cu/ZnO/ZrO2 catalyst has been proposed and the rate constants of methanol adsorption (ka) and decomposition with and without participation of water (k1 and k2) have been determined.

3

Influence of Active Carbon Modification on Its Porous Structure and Heat Effects of Methanol Vapours Adsorption

Buczek B., Czepirski L.

Polish Journal of Chemistry

|

2003

|

Vol. 77 / nr 9

1191-1198

EN

Methanol adsorption of the active carbon seems to be very interesting for use in thermodynamic systems such as heat pumps and transformers as well as cooling systems. The porous structure of commercial active carbon modified by successive removal of external layers from a particle surface as produced by abrasion in a spouted bed and by demineralization was evaluated on the basis of the nitrogen adsorption data and those for methanol. The modifications improve densimetric characteristics and heat effects of methanol adsorption. Porous structure parameters obtained for nitrogen and methanol agreed reasonably well and Dubinin-Radushkevich approach can be a useful method for characterization of these systems. The methods for calculation of heat effects of methanol adsorption in a wide range of temperature and pressures are discussed.