Experimental determination of the particle dynamics into a rotating tube

This paper reports the procedure for analysing the biomass powder bed characteristics realized in an experimental pyrolysis reactor. The reaction apparatus is made of a quartz tube which can rotate, horizontally or slightly inclined, with different speeds. Depending on the tube inclination and rotation, different motion conditions (regime, hold-up, residence time and advancing rate) are possible; also the particle characteristics (nature, shape and size, humidity) and the flow rate affect the bed behaviour. After taking some pictures of the bed from the discharge side, they can be analysed by means of the geometry rules; this procedure is here described. In this way the bed profile can be obtained, and this information can be used to calculate the parameters of a proper model, already developed. The methodology here presented will be used in the future to find data to be used in the development of a whole pyrolysis process model including also heat exchange, gas fluid dynamics and pyrolysis reaction kinetics

Kinetic modelling of the gas-phase water oxidation of light hydrocarbons

The conversion of solid and liquid fuels to gas, whenever possible, is an important way for improving the efficiency and cleanness of processes. This paper presents the kinetic modelling of the water oxidation of light hydrocarbons in the gas phase at 500 °C with mixtures of heptane and water in different amounts. The aim of the work was to find information about kinetics of the homogeneous chemical reactions which take place in the gas phase during the biomass processing, particularly pyrolysis, performed with water steam as the oxidizing reactant. The experimental data here used were obtained by a continuous stainless steel reactor placed inside a heated muffle oven and maintained at a constant temperature. The gaseous product, after separation of the condensable components, was analysed by an in-line gas chromatograph. The apparatus showed to be effective for future operations with different experimental conditions (temperature and feed). The obtained data will be integrated with those coming from parallel studies about the biomass wet pyrolysis for gas production

La Provincia di Sassari: ambiente, storia, civiltà

Essere cittadino di una provincia non significa soltanto abitarvi. Significa anche lavorarvi, esercitarvi una attività che vada a vantaggio del benessere individuale e insieme del benessere della collettività. Per fare questo, per raggiungere meglio questo obiettivo, la realtà in cui si vive e si lavora bisogna conoscerla meno superficialmente di quanto normalmente non succeda. E' una constatazione che si può fare per tutti coloro che abitano in un luogo, ma che si deve fare in modo particolare quando lo strumento di conoscenza che si propone è un libro come questo

Possible non-thermal microwave effects on the growth rate of Pseudomonas aeruginosa and Staphylococcus aureus

The present work reports the effects of low power microwaves in the frequency range of 2.20-2.50 GHz with an incident power range of 0-400 mW on the growth rate of the bacterial species Pseudomonas aeruginosa and Staphylococcus aureus. Since culture temperatures were maintained constant (37°C) during irradiation, these effects can be considered as non-thermal. A continuous recirculating experimental structure was used for the purpose. It is very difficult to find a mathematical correlation between the observed effects and radiation power or frequency