Evaluation of operating conditions on sulfate reduction from acidic wastewater in a fixed-bed bioreactor

2022 ◽  
Vol 177 ◽  
pp. 107370
Author(s):  
Pedro Hernández ◽  
Gonzalo Recio ◽  
Christian Canales ◽  
Alex Schwarz ◽  
Denys Villa-Gomez ◽  
...  
2011 ◽  
Vol 6 (1) ◽  
Author(s):  
Valérie Gelbgras ◽  
Christophe E Wylock ◽  
Jean-Christophe Drugmand ◽  
Benoît Haut

In this work, a structured mathematical model of the VERvet Origin (VERO) cell metabolism in a fixed-bed bioreactor is developed. Mass balance equations for the extra- and intracellular species are written considering the main pathways of the animal cell metabolism. From the model equations, an undetermined set of equations relating the consumption or production velocities of the extracellular species and the velocities of the metabolic reactions can be developed. The monitoring of a reference cell culture enables to transform this undetermined set of equations in a determined one. The resolution of this determined set of equations enables to analyze and characterize the cell metabolism. From the model and the cell metabolism characterization, a monitoring tool is developed to simulate the time evolution of the species concentrations when the time evolution of the cell concentration is known. This simulation tool is used to simulate five experimental cell cultures. The comparison of the experimentally determined and computed time evolutions of the species concentrations enables to validate the developed monitoring tool. The validated monitoring tool can be used to optimize the operating conditions of the culture, as the medium feeding rate, the range of the species concentrations.


2011 ◽  
Vol 6 (1) ◽  
Author(s):  
Valérie Gelbgras ◽  
Christophe E Wylock ◽  
Jean-Christophe Drugmand ◽  
Benoît Haut

In this work, a mathematical model of a fixed-bed bioreactor for the animal cell culture is developed to study the optimization and the scale-up of this bioreactor. Several cell populations are considered: the cells in suspension in the medium at the beginning of the process and the adhering cells to the fixed-bed. The model includes a capture rate kinetic of the cells in suspension by the fixed-bed and a spatial distribution of the nutrient and by-product concentrations in the fixed-bed. Therefore, the model reports the potential gradients of the cell concentrations in the fixed-bed. Some model parameters are experimentally identified and the model is validated using experimental data obtained with two pilot bioreactors. The model is used as a simulation tool to study the influence of the bioreactor design or the velocity field of the culture medium on the cell concentration gradients in the fixed-bed bioreactor and to optimize the operating conditions, the design, and the scale-up of this bioreactor.


1990 ◽  
Vol 22 (1-2) ◽  
pp. 347-352 ◽  
Author(s):  
C. Paffoni ◽  
B. Védry ◽  
M. Gousailles

The Paris Metropolitan area, which contains over eight million inhabitants, has a daily output of about 3 M cu.meters of wastewater, the purification of which is achieved by SIAAP (Paris Metropolitan Area Sewage Service) in both Achères and Valenton plants. The carbon pollution is eliminated from over 2 M cu.m/day at Achères. In order to improve the quality of output water, its tertiary nitrification in fixed-bed reactors has been contemplated. The BIOFOR (Degremont) and BIOCARBONE (OTV) processes could be tested in semi-industrial pilot reactors at the CRITER research center of SIAAP. At a reference temperature of 13°C, the removed load is approximately 0.5 kg N NH4/m3.day. From a practical point of view, it may be asserted that in such operating conditions as should be at the Achères plant, one cubic meter of filter can handle the tertiary nitification of one cubic meter of purified water per hour at an effluent temperature of 13°C.


2016 ◽  
Vol 14 (1) ◽  
pp. 491-515 ◽  
Author(s):  
Zeeshan Nawaz

AbstractThe catalytic dehydrogenation of iso-butane to iso-butylene is an equilibrium limited endothermic reaction and requires high temperature. The catalyst deactivates quickly, due to deposition of carbonaceous species and countered by periodic regeneration. The reaction-engineering constraints are tied up with operation and/or technology design features. CATOFIN® is a sophisticated commercialized technology for propane/iso-butane dehydrogenation using multiple adiabatic fixed-bed reactors having Cr2O3/Al2O3 as catalyst, that undergo cyclic operations (~18–30m); dehydrogenation, regeneration, evacuation, purging and reduction. It is always a concern, how to maintain CATOFIN® reactor at an optimum production, while overcoming gradual decrease of heat in catalyst bed and deactivation. A homogeneous one-dimensional dynamic reactor model for a commercial CATOFIN® fixed-bed iso-butane dehydrogenation reactor is developed in an equation oriented (EO) platform Aspen Custom Modeler (ACM), for operational optimization and process intensification. Both reaction and regeneration steps were modeled and results were validated. The model predicts the dynamic behavior and demonstrates the extent of catalyst utilization with operating conditions and time, coke formation and removal, etc. The model computes optimum catalyst bed temperature profiles, feed rate, pre-heating, rates for reaction and regeneration, fuel gas requirement, optimum catalyst amount, overall cycle time optimization, and suggest best operational philosophy.


2015 ◽  
Vol 266 ◽  
pp. 233-240 ◽  
Author(s):  
C. Cortés-Lorenzo ◽  
M. Rodríguez-Díaz ◽  
D. Sipkema ◽  
B. Juárez-Jiménez ◽  
B. Rodelas ◽  
...  

2011 ◽  
Vol 6 (1) ◽  
Author(s):  
Amir Rahimi ◽  
Sogand Hamidi

In this study, the performance of a fixed–bed tubular reactor for the production of phthalic anhydride is mathematically analyzed. The conversion degree and reactor temperature values are compared with the measured one in a tubular reactor applied in Farabi petrochemical unit in Iran as well as reported data in the literature for a pilot plate. The comparisons are satisfactory. The effects of some operating parameters including reactor length, feed temperature, reactor pressure, and existence of an inert in the catalytic bed are investigated. The optimum value of each parameter is determined on the basis of the corresponding operating conditions.


Author(s):  
Vincent G Gomes

Product separation and regeneration of sorbent was accomplished in a novel pressure swing reactor through pressurisation, adsorption, blowdown and purge steps. The switching from sorption to reaction to regeneration was tested in a two bed sorption/reaction apparatus. Models developed for the mass and momentum transfer in the catalyst bed and sorber, were solved using orthogonal collocation within the method of lines. The effects of operating conditions and cycle configurations on performance were assessed. The results from dynamic experiments with propene metathesis to produce ethene and 2-butene in a fixed-bed catalytic reactor were in agreement with model predictions. Both pressure and vacuum swing demonstrated that conversion and product quality can be enhanced by periodic cycling with greater separation obtained with vacuum swing. The separation of products help reduce the downstream processing costs of exit mixtures, enable reactant utilisation by recycling and improve product handling at subsequent stages. The efficacy of the periodic separating reactor in terms of conversion, product purity and recovery were investigated.


2015 ◽  
Author(s):  
Luz M. Ahumada ◽  
Arnaldo Verdeza ◽  
Antonio J. Bula

This paper studied, through an experiment design, the significance of particle size, air speed and reactor arrangement for palm shell micro-gasification process in order to optimize the heating value of the syngas obtained. The range of variables was 8 to 13 mm for particle size, 0.8–1.4m/s for air velocity, and updraft or downdraft for the reactor type. It was found that the particle size and air velocity factors were the most significant in the optimization of the output variable, syngas heating value. A heating value of 2.69MJ / Nm3 was obtained using a fixed bed downdraft reactor, with a particle size of 13 mm and 1.4 m/s for air speed; verification of the optimum point of operation under these conditions verified that these operating conditions favor the production of a gas with a high energy value.


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