Predicting the packed-bed reactor performance with immobilized microbial lactase

2006 ◽  
Vol 41 (7) ◽  
pp. 1627-1636 ◽  
Author(s):  
Enrique J. Mammarella ◽  
Amelia C. Rubiolo
Keyword(s):  
Packed Bed ◽  
Packed Bed Reactor ◽  
Reactor Performance

scholarly journals Heat and Mass Transfer during Lignocellulosic Biomass Torrefaction: Contributions from the Major Components—Cellulose, Hemicellulose, and Lignin

Processes ◽  
2020 ◽  
Vol 8 (8) ◽  
pp. 959
Author(s):  
Ken-ichiro Tanoue ◽  
Kentaro Hikasa ◽  
Yuuki Hamaoka ◽  
Akihiro Yoshinaga ◽  
Tatsuo Nishimura ◽  
...  
Keyword(s):  
Gas Flow ◽  
Model Simulation ◽  
Packed Bed ◽  
Douglas Fir ◽  
Packed Bed Reactor ◽  
Reactor Wall ◽  
Measured Temperature ◽  
Reactor Performance ◽  
Rate Vector ◽  
Determining Factor

The torrefaction of three representative types of biomass—bamboo, and Douglas fir and its bark—was carried out in a cylindrical-shaped packed bed reactor under nitrogen flow at 573 K of the reactor wall temperature. As the thermal energy for the torrefaction was supplied from the top and the side of the bed, the propagation of the temperature profile of the bed is a crucial factor for discussing and improving the torrefaction reactor performance. Therefore, the temperature and gas flow rate (vector) profiles throughout the bed were calculated by model simulation so as to scrutinize this point. The measured temperature at a certain representative location (z = 30 mm and r = 38 mm) of the bed was well reproduced by the simulation. The volume faction of the bed at temperatures higher than 500 K at 75 min was 0.89, 0.85, and 0.99 for bamboo, and Douglas fir and its bark, respectively. It was found that the effective thermal conductivity is the determining factor for this difference. The heat of the reactions was found to be insignificant.

scholarly journals Treatment of milk wastewater using up-flow anaerobic packed bed reactor

2015 ◽  
Vol 17 (2) ◽  
pp. 84-88 ◽  
Author(s):  
Kiran D. Bhuyar ◽  
Sanvidhan G. Suke ◽  
S.D. Dawande
Keyword(s):  
Rural Areas ◽  
Biogas Production ◽  
Packed Bed ◽  
Dairy Wastewater ◽  
Packed Bed Reactor ◽  
Reactor Performance ◽  
Reactor Model ◽  
Loading Rates ◽  
Empirical Relations ◽  
Low Costs

Abstract An up-flow anaerobic packed bed (UAPB) bioreactor has been designed on a laboratory-scale and used for treatment of domestic milk wastewater (MWW). The UAPB bioreactor was operated under mesophilic temperature (37-45°C) and reactor performance evaluated at various organic loading rates of MWW effluent at hydraulic retention times (HRT) of 1, 2, and 3 d based on the removal of organic matter COD, BOD, SS, pH changes and biogas production. The kinetic parameters were estimated using the experimental data to develop a reactor model. Empirical relations were generated for the characteristics like COD, BOD, and SS using modeling equations. This study proved that the UAPB reactor performance is excellent for treating domestic MWW and easily biodegradable dairy wastewater influent. Hence, this system can operate at low costs, making it suited for use in the developing countries and rural areas.

Packed-bed reactor performance with immobilized lactase under thermal inactivation

1998 ◽  
Vol 23 (1-2) ◽  
pp. 3-9 ◽  
Author(s):  
A. Illanes ◽  
C. Altamirano ◽  
A. Aillapán ◽  
G. Tomasello ◽  
M.E. Zuñiga
Keyword(s):  
Thermal Inactivation ◽  
Packed Bed ◽  
Packed Bed Reactor ◽  
Reactor Performance

Parametric Study of Split Flow Cylindrical Packed Bed Reactor for High-Temperature Thermochemical Energy Storage Using Cobalt Oxide Redox Reaction

2019 ◽  
Author(s):  
Nasser Vahedi ◽  
Alparslan Oztekin
Keyword(s):  
High Temperature ◽  
Energy Storage ◽  
Pressure Drop ◽  
Parametric Study ◽  
Redox Reaction ◽  
Packed Bed ◽  
Reactor Design ◽  
Packed Bed Reactor ◽  
Reactor Performance ◽  
Split Flow

Abstract Thermal energy storage has become an integral part of Concentrated Solar Power (CSP) plants to guarantee continuous supply of power demand. For cost-effective solar power generation, the size and operating temperatures of CSP plants should be increased. Thermochemical energy storage (TCES) is the only available solution to meet energy density and high-temperature requirements. Air is mostly used as Heat Transfer Fluid (HTF) for high-temperature CSP plants. For the air-based system, metal redox reactions are good candidates as storage reactant. Application of metal oxide gas-solid redox reaction in storage systems requires an efficient reactor design. Cost-effectiveness and simplicity have made packed bed reactors a viable candidate for high-temperature applications. The high-pressure drop along the bed is the main drawback of such reactors preventing them from widespread applications. Split flow design modification could aid in reducing pressure drop while providing more flexibility in reactor performance control. A cylindrical split-flow packed bed reactor with an annulus for HTF flow is considered as a modified reactor design. The transient two-dimensional axisymmetric numerical model is developed for solving mass, momentum, and energy equations for both gas and solid phases using suitable reaction kinetics for the cobalt oxide redox reaction. A parametric study is performed on cylindrical-shaped split-flow reactor design as a basis for future optimization for complete storage cycle. The effect of split flow ratio and side-channel width on reactor performance are considered. It is shown that both parameters could be used effectively to design and optimize the reactor.

scholarly journals Hydrodynamic effects on three phase micro-packed bed reactor performance – Gold–palladium catalysed benzyl alcohol oxidation

2016 ◽  
Vol 149 ◽  
pp. 129-142 ◽  
Author(s):  
Noor Al-Rifai ◽  
Federico Galvanin ◽  
Moataz Morad ◽  
Enhong Cao ◽  
Stefano Cattaneo ◽  
...  
Keyword(s):  
Benzyl Alcohol ◽  
Alcohol Oxidation ◽  
Packed Bed ◽  
Packed Bed Reactor ◽  
Reactor Performance ◽  
Benzyl Alcohol Oxidation ◽  
Three Phase ◽  
Hydrodynamic Effects

Integrated biological treatment of recalcitrant effluents from pulp mills

2004 ◽  
Vol 50 (3) ◽  
pp. 145-156 ◽  
Author(s):  
A. Ortega-Clemente ◽  
C. Estrada-Vázquez ◽  
F. Esparza-Garcia ◽  
S. Caffarel-Mendez ◽  
N. Rinderknecht-Seijas ◽  
...  
Keyword(s):  
Organic Matter ◽  
Black Liquor ◽  
Packed Bed ◽  
Pollutant Removal ◽  
Packed Bed Reactor ◽  
Soluble Carbohydrate ◽  
Fluidised Bed ◽  
Reactor Performance ◽  
Significant Difference ◽  
Fluidised Bed Reactor

This work aimed at determining the degree of depuration of a recalcitrant effluent (weak black liquor, WBL) achieved in a series treatment consisting of a first stage methanogenic fluidised bed reactor followed by a second stage aerobic, upflow reactor packed with “biocubes” of Trametes versicolor immobilised onto small cubes of holm oak wood. The mesophilic, lab scale methanogenic fluidised bed reactor contained a microbial consortium immobilised onto granular activated carbon 500 mm average size. The process removed decreasing amounts of organic matter at decreasing hydraulic retention times (HRT), eventually reaching an average of 50% at 0.5 day HRT. Colour and ligninoid removals also decreased with decreasing HRT. Although the methanogenic fluidised bed reactor provided an effective treatment for the degradable organic matter, important concentrations of recalcitrant organic matter and colour still remained in the anaerobic effluent. This anaerobic effluent was fed to the aerobic packed bed reactor. Two HRT were tested in this unit, namely 5 and 2.5 days. The reactor averaged an organic matter removal in the range of 32% COD basis, during an experimental run of 95 days. Colour and ligninoid contents were removed in high percentages (69% and 54%, respectively). There was no significant difference in reactor performance at 5- and 2.5-day HRT. There was a positive correlation between pollutant removal efficiencies and Laccase activity in crude extracts of the reactor liquor. No supplemental soluble carbohydrate was required to sustain the fungus activity and the consistent reactor performance. Overall, the two-stage treatment achieved approximately a 78% removal of the original organic matter of the WBL (COD basis) and ca. 75% of colour and ligninoid contents.

Treatment of Distillery Wastewater Using an Anaerobic Downflow Stationary Fixed-Film Reactor: Performance of a Large Plant in Operation for Four Years

1990 ◽  
Vol 22 (1-2) ◽  
pp. 361-372 ◽  
Author(s):  
Y. Racault
Keyword(s):  
Packed Bed ◽  
Packed Bed Reactor ◽  
Soluble Form ◽  
Liquid Volume ◽  
Reactor Performance ◽  
Treated Effluent ◽  
Start Up ◽  
Distillery Wastewater ◽  
Distillery Waste ◽  
The Stability

The results of the first four years' operation of a downflow submerged packed bed reactor treating distillery waste with a COD of 30 g/l (95 % in soluble form) are presented. The digester contains 4300 m3 of packing, and is operational six months a year. It is one of Europe's largest units using this technique. After a few problems with fixing the biomass on start-up, organic loading has been regularly increased, reaching an average of 6 kg COD/m3.d during the 2nd year and 10 to 12 kg COD/m3.d during the 4th year, with soluble COD reductions of 90 to 95 %. The biomass released into the treated effluent was in the region of 0.15 kg SS/kg COD eliminated in the latter campaign. Overall performance in the 2nd, 3rd and 4th seasons are presented and discussed. The stability of digestion was studied over the whole of the 2nd and 4th seasons using measures of VFA at various levels within the reactor. Tracer study was conducted at the end of 2nd year to characterize the hydraulic behavior of the reactor. Results indicated a flow pattern close to a complete mixing and dead space was in the region of 20 % of liquid volume.

Packed-Bed Reactor Performance Enhancement by Membrane Distributed Feed: The Case of Methanol Oxidative Dehydrogenation

2002 ◽  
Vol 752 ◽  
Author(s):  
Victor Diakov ◽  
Arvind Varma
Keyword(s):  
Oxidative Dehydrogenation ◽  
Membrane Reactor ◽  
Performance Enhancement ◽  
Fixed Bed ◽  
Packed Bed ◽  
Operating Conditions ◽  
Packed Bed Reactor ◽  
Fixed Bed Reactor ◽  
Reactor Performance ◽  
Wide Range

ABSTRACTFor methanol oxidative dehydrogenation to formaldehyde, the performance of the packed-bed membrane reactor (PBMR) is compared with that of the conventional fixed-bed reactor (FBR) over a wide range of operating conditions. The reaction was studied in three reactor configurations: the conventional FBR and the packed-bed membrane reactor, with either methanol (PBMR-M) or oxygen (PBMR-O) as the permeating component. The kinetics of methanol and formaldehyde partial oxidation reactions were determined and incorporated in a PBMR model. Both experimental data and model considerations demonstrate that the PBMR enhances reactant conversion and selectivity.Small oscillations in CO production were observed experimentally. Their amplitude was taken as a basis for comparison of packed-bed operation instability. The likely source of oscillatory behavior is the non-uniformity in reaction conditions along the reactor. It was found that membrane distributed feed, by providing a more uniform reactor operation, is an effective remedy from these instabilities.It is found, both by simulations and experimental observations, that relative reactor performance depends strongly on the operating conditions. Using formaldehyde yield as the basis for optimization, optimal reactor performances are determined to be in the order: PBMR-O > FBR > PBMR-M. Further PBMR productivity enhancement is possible by optimizing the membrane feed distribution pattern.

Continuous production of a chiral amine in a packed bed reactor with co-immobilized amine dehydrogenase and formate dehydrogenase

2021 ◽  
Vol 407 ◽  
pp. 127065
Author(s):  
Robert D. Franklin ◽  
Joshua A. Whitley ◽  
Adam A. Caparco ◽  
Bettina R. Bommarius ◽  
Julie A. Champion ◽  
...  
Keyword(s):  
Formate Dehydrogenase ◽  
Continuous Production ◽  
Packed Bed ◽  
Packed Bed Reactor ◽  
Chiral Amine ◽  
Amine Dehydrogenase
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