In hydrocracking and other foaming reactors, the foam rises to the top because it has a higher gas fraction than the bubbly mixture from which it comes. The high gas hold-up in foams is undesirable in chemical reactors because it strongly decreases the liquid residence time and in hydrocracking reactors also promotes the formation of coke. To study foams we built a cold slit bubble reactor whic...

Methane pyrolysis is a promising bridging technology to mitigate the effects of climate change. By decarbonizing natural gas, hydrogen can be produced from fossil fuels without creating CO2 emissions. The focus future process optimization should not only on yield and energy efficiency but also carbon products possible byproduct formation. During methane in liquid metal (LM) bubble column reacto...

Residence time distribution (RTD) study of solids in a three-phase pilot-scale bubble column photoreactor has been carried out in order to provide data for the development of an artificial neural network model usable for process optimisation. The experimental data indicated that the RTD of solids was a complex nonlinear function of gas and liquid velocities as well as the contacting pattern (co...

Wastewater treatment and re-use of industrial process water are critical issue for the development of human activities and environment conservation. Catalytic wet air oxidation (CWAO) is an attractive and useful technique for treatment of effluents where the concentrations of organic pollutants are too low, for the incineration and other pollution control techniques to be economically feasible ...

The aim of this work was to study the physiological changes of immobilized brewing yeast Saccharomyces cerevisiae in a continuous reactor. Continuous cultivation was carried out at three different temperatures (15, 20 and 25°C) with an industrial brewing yeast strain (UNICER, Bebidas de Portugal, S.A.). During the continuous experiment the viability of free and immobilized cells was followed us...

The present work focuses on the measurements of bubble properties in heterogeneous bubbly flows in a square bubble column. A four-point optical fibre probe was used for this purpose. The accuracy and intrusive effect of the optical probe was investigated first. The results show that the optical probe underestimates bubble properties, such as, bubble velocity, local void fraction. The presence o...

14 15 The catalytic activity and durability of 2 wt. % Pd/Al2O3 in powder and washcoated on cordierite 16 monoliths were examined for the liquid phase hydrodechlorination (LPHDC) of polychlorinated 17 dibenzo-p-dioxins/polychlorinated dibenzofurans (PCDD/Fs). NaOH was employed as a 18 neutralizing agent, and 2-propanol was used as a hydrogen donor and a solvent. Fresh and spent 19 powder and mo...

A large amount of effluent is generated in textile industries. Dyes used in the dyeing stage of a textile industry is a constant, ardent and keen source of concern to the environmental scientist. This dye effluent cannot be degraded through primary and secondary treatments. Primary treatment involves coagulation and flocculation while secondary treatment encompasses activated sludge process. So...