A model is developed for prediction of axial concentration profiles of dissolved oxygen and carbon dioxide in tubular photobioreactors used for culturing microalgae. Experimental data are used to verify the model for continuous outdoor culture of Porphyridium cruentum grown in a 200-L reactor with 100-m long tubular solar receiver. The culture was carried out at a dilution rate of 0.05 h-1 appl...

Mixing patterns inside a simulated flat bottom digester were imaged using the non-invasive techniques of computer automated radioactive particle tracking (CARPT) and computed tomography (CT). Mixing/agitation was provided using gas (air) recirculation at three different flow rates (Q(g)) of 28.32, 56.64 and 84.96 l/h, corresponding to superficial gas velocities of 0.025, 0.05 and 0.075 cm/s, re...

This work presents a computational study of flow behaviour in a bubbling fluidized bed polymerization reactor. The model is developed by using the commercial CFD code Fluent 6.3. The model is based on an Eulerian description of the gas and the particle phase. The effect of distributor shape on fluidization is analyzed using the inbuilt Gidaspow and Syamlal-O’brien Drag Model. The computational ...

Bubble columns are multiphase equipments used to bring into contact gas and liquid phases. Gas, that constitutes the dispersed phase, is distributed at the bottom of the column and rises as bubbles through the liquid that constitutes the continuous phase. They are frequently used in the industry although the partial knowledge of the fluid dynamics of the gas-liquid flow have hindered a complete...

In granular flow operations, often particles are nonspherical. This has inspired a vast amount of research in understanding the behavior of these particles. Various models are being developed to study the hydrodynamics involving nonspherical particles. Experiments however are often limited to obtain data on the translational motion only. This paper focusses on the unique capability of Magnetic ...

Traditional gas-phase trace contaminant control adsorption process flow is constrained as required to maintain high contaminant single-pass adsorption efficiency. Specifically, the bed superficial velocity is controlled to limit the adsorption mass-transfer zone length relative to the physical adsorption bed; this is aided by traditional high-aspect ratio bed design. Through operation in this m...

Overall liquid side volumetric mass transfer coefficient kLa was determined experimentally for cocurrent Taylor flow moving upwards in a glass tube of an internal diameter of 3mm. Experiments were performed for physical absorption of oxygen in 20% aqueous solution of ethanol. Shadowgraph technique was deployed for precise measurements of bubble lengths and velocities. Experimental values of vol...

The design of bubble column for industrial applications is well known under near ambient pressure and temperature conditions, contrary to high conditions. Accurate data on the evolution behaviour bubbles proposed as a basis evaluation surface area developed in further such reactor. Two columns are used experiments: small (8 mL) with total visualisation flow, bigger one (1 L), necessary scale up...

A low SV causes relatively slow pyrolysis conditions at around 600°C, and produces high yields of charcoal 20-30%, large quantities of unburned tars, and a gas with high hydrocarbon content and high tar (volatile) content. A high SV causes very fast pyrolysis, producing less than 10% char-ash at 1050 C and hot gases at 1200-1400 C in the flaming pyrolysis zone. These gases then react with the r...

A new parabolic–shaped guided valve tray is proposed. The gas–liquid two–phase flow of parabolic and conventional rectangular trays simulated using the computational fluid dynamics (CFD) method. clear liquid height on was predicted for different combinations superficial gas velocity, intensity weir height. values were in good agreement with calculated ones. has a more uniform form by comparing ...