The combined effect of superficial gas velocity, pH, initial phosphate concentration, and light intensity on cell growth was investigated for the mass production of cyanobacterial cells. The light intensity was manipulated to maintain a specific irradiation rate (q(i)) at a constant level for high cell density culture. The optimum condition for the batch culture was achieved at a superficial ga...

Danckwert's method was used to determine the specific interfacial area, a, and the individual mass transfer coefficient, k(L), during absorption of CO(2) in a bubble column with an anionic surfactant in the carbonate-bicarbonate buffer solution and NaAsO(2) as catalyst, the presence of which decreases the specific interfacial area and the individual mass transfer coefficient. The specific inter...

The purpose of the present study is to analyze effect different discrete representations continuous bubble size distribution function on flow structure in a column reactor. Poly- and monodisperse media were considered, such that mathematical expectation polydisperse case was equal at same volumetric contents. For these computations normalized variances velocity profiles carrier disperse phases,...

Aqueous wastes containing organic pollutants can be eciently treated by wet air oxidation (WAO), i.e. oxidation (or combustion) by molecular oxygen in the liquid phase, at high temperature (200±325 C) and pressure (up to 175 bar). This method is suited to the elimination of special aqueous wastes from the chemical industry as well as to the treatment of domestic sludge. It is an enclosed proce...

 Background: Sulfur compounds must be removed from petroleum because they contribute to environmental pollution. A strong alkaline solution such as caustic soda is used to remove these compounds. This spent caustic has high values for chemical oxygen demand (COD) concentration, pH and total sulfur. In this study, the regeneration and treatment methodology of sulfidic spent caustic was inve...

A batch reactor may be combined directly with a distillation column by distilling off the light component product in order to increase the reactor temperature or to improve the product yield of an equilibrium reaction. The same amount of the light product should be removed as the amount being formed by the reaction at any time. A linearized model has been developed which describes the process b...

In present paper, dynamic behavior and control of a fluidized bed reactor for polyethylene production has been considered. A double active sites model for Ziegler-Natta catalysts is used for simulation of polymerization reaction. Hydrodynamic behavior of the bed is modeled using a two phase model including bubble and emulsion phases in which bubble phase has plug flow pattern with different...

Experiments were performed in a three-phase bubble column to study variations of bubble rise velocities. The dynamic gas disengagement (DGD) technique and the fast response pressure transducers were utilized to investigate the bubble rise in the column. The superficial gas velocity of large bubbles and small bubbles, the rise velocities of larger and small bubble fractions were studied consider...

An experimental study has been carried out to characterize bubble formation, growth, and detachment mechanisms in a stagnant liquid column. Both bubble frequency and bubble detachment size were measured in different gas flow rates, injector diameters and orientations, submergence height, and liquid properties. Experiments were performed for air injection flow rate ranges between 200 mlph and 12...