Safer operating conditions and optimal scaling-up process for cyclohexanone peroxide reaction

2015 ◽  
Vol 618 ◽  
pp. 6-14 ◽  
Author(s):  
Na Zang ◽  
Xin-Ming Qian ◽  
Zhen-Yi Liu ◽  
Chi-Min Shu
Keyword(s):  
Scaling Up ◽  
Optimal Scaling ◽  
Operating Conditions

Mathematical Modeling, Verification and Optimization for Catalytic Membrane Esterification Micro-reactor

2015 ◽  
Vol 13 (1) ◽  
pp. 71-82
Author(s):  
E. El-Zanati ◽  
S.M.C. Ritchie ◽  
H. Abdallah ◽  
S. Elnashaie
Keyword(s):  
Scaling Up ◽  
Operating Conditions ◽  
Lumped Parameter Model ◽  
Process Time ◽  
Esterification Reaction ◽  
Optimum Process ◽  
Model Parameters ◽  
Efficient Production ◽  
Catalytic Membrane ◽  
Regeneration Time

Abstract Analysis of efficient production of ethyl acetate utilizing a Catalytic Membrane Micro-Reactor (CMMR) was theoretically investigated and verified using published results for the esterification reaction. Grafted sulfonic groups in the pores of a polyethersulfone membrane catalyzed the reaction. Theoretical analysis of the catalytic membrane reactor was achieved through development of a lumped parameter model to describe the CMMR behavior and performance. The developed model was solved numerically for different design and operating conditions using MATLAB Simulink software. The model parameters were verified and validated using the experimental results to achieve a reliable tool for design, replication, scaling-up, and optimization. The approach to maximum conversion was simulated. Cumulative yield per unit time was investigated to determine the optimum process time. Membrane regeneration was conducted and the regeneration time was determined as well in order to reuse the membrane for other cycles. Reactor scaling-up was studied using the model for process design.

Scaling Up of Osmotic Distillation from Laboratory to Pilot Plant for Concentration of Fruit Juices

2005 ◽  
Vol 1 (2) ◽  
Author(s):  
A. V. Bui ◽  
H. M. Nguyen
Keyword(s):  
Pilot Plant ◽  
Grape Juice ◽  
Scaling Up ◽  
Pilot Scale ◽  
High Viscosity ◽  
Hollow Fibre ◽  
Fruit Juices ◽  
Operating Conditions ◽  
High Concentration ◽  
Osmotic Distillation

A step-by-step procedure for scaling up of an osmotic distillation system from laboratory to pilot plant is discussed. The newly built pilot scale OD system featured a flexibility of using 1 or 2 hollow fibre modules at a time to suit the concentration demands. Three types of hollow fibres were tested on the new system. Pilot trials for OD concentration of apple, grape juices and freeze concentrated (FC) grape juice were successfully carried out to achieve a final concentration up to 65°Brix with fluxes ranging from 2.4 to 0.69kg.m-2.h-1 depending on the fibre types and the operating conditions. Cascade effect was also employed to deal with high viscosity to achieve high concentration. The obtained pilot OD fluxes were comparable to the ones obtained in the lab under similar conditions, and they fitted well with the developed models. Sensory evaluation indicated that OD well preserved the quality attributes of the fruit juices.

scholarly journals Prediction of Permeate Flux in Ultrafiltration Processes: A Review of Modeling Approaches

Membranes ◽  
2021 ◽  
Vol 11 (5) ◽  
pp. 368
Author(s):  
Carolina Quezada ◽  
Humberto Estay ◽  
Alfredo Cassano ◽  
Elizabeth Troncoso ◽  
René Ruby-Figueroa
Keyword(s):  
Phenomenological Models ◽  
Membrane Filtration ◽  
Membrane Surface ◽  
Scaling Up ◽  
Fruit Juices ◽  
Operating Conditions ◽  
Percentage Error ◽  
Permeate Flux ◽  
Predictive Capacity ◽  
Theoretical Derivation

In any membrane filtration, the prediction of permeate flux is critical to calculate the membrane surface required, which is an essential parameter for scaling-up, equipment sizing, and cost determination. For this reason, several models based on phenomenological or theoretical derivation (such as gel-polarization, osmotic pressure, resistance-in-series, and fouling models) and non-phenomenological models have been developed and widely used to describe the limiting phenomena as well as to predict the permeate flux. In general, the development of models or their modifications is done for a particular synthetic model solution and membrane system that shows a good capacity of prediction. However, in more complex matrices, such as fruit juices, those models might not have the same performance. In this context, the present work shows a review of different phenomenological and non-phenomenological models for permeate flux prediction in UF, and a comparison, between selected models, of the permeate flux predictive capacity. Selected models were tested with data from our previous work reported for three fruit juices (bergamot, kiwi, and pomegranate) processed in a cross-flow system for 10 h. The validation of each selected model's capacity of prediction was performed through a robust statistical examination, including a residual analysis. The results obtained, within the statistically validated models, showed that phenomenological models present a high variability of prediction (values of R-square in the range of 75.91–99.78%), Mean Absolute Percentage Error (MAPE) in the range of 3.14–51.69, and Root Mean Square Error (RMSE) in the range of 0.22–2.01 among the investigated juices. The non-phenomenological models showed a great capacity to predict permeate flux with R-squares higher than 97% and lower MAPE (0.25–2.03) and RMSE (3.74–28.91). Even though the estimated parameters have no physical meaning and do not shed light into the fundamental mechanistic principles that govern these processes, these results suggest that non-phenomenological models are a useful tool from a practical point of view to predict the permeate flux, under defined operating conditions, in membrane separation processes. However, the phenomenological models are still a proper tool for scaling-up and for an understanding the UF process.

scholarly journals Heat transfer effect in scaling-up a fluidized bed reactor for propylene polymerization

RSC Advances ◽  
2018 ◽  
Vol 8 (50) ◽  
pp. 28293-28312 ◽  
Author(s):  
Panut Bumphenkiattikul ◽  
Sunun Limtrakul ◽  
Terdthai Vatanatham ◽  
Parinya Khongprom ◽  
Palghat A. Ramachandran
Keyword(s):  
Fluidized Bed ◽  
Fluidized Bed Reactor ◽  
Scaling Up ◽  
Transfer Effect ◽  
Operating Conditions ◽  
Propylene Polymerization ◽  
Fluidized Bed Reactors ◽  
Cfd Models ◽  
Reactor Temperature ◽  
And Performance

The effects of operating conditions and scaling-up on reactor temperature control and performance in propylene polymerization fluidized bed reactors were studied by phenomenological and CFD models.

scholarly journals Engineering Considerations to Produce Bioactive Compounds from Plant Cell Suspension Culture in Bioreactors

Plants ◽  
2021 ◽  
Vol 10 (12) ◽  
pp. 2762
Author(s):  
Elizabeth Alejandra Motolinía-Alcántara ◽  
Carlos Omar Castillo-Araiza ◽  
Mario Rodríguez-Monroy ◽  
Angélica Román-Guerrero ◽  
Francisco Cruz-Sosa
Keyword(s):  
Suspension Culture ◽  
Cell Suspension ◽  
Cell Suspension Culture ◽  
Large Scale ◽  
Scaling Up ◽  
Operating Conditions ◽  
Scale Production ◽  
Plant Cell Suspension Culture ◽  
Plant Cell Suspension ◽  
Large Scale Production

The large-scale production of plant-derived secondary metabolites (PDSM) in bioreactors to meet the increasing demand for bioactive compounds for the treatment and prevention of degenerative diseases is nowadays considered an engineering challenge due to the large number of operational factors that need to be considered during their design and scale-up. The plant cell suspension culture (CSC) has presented numerous benefits over other technologies, such as the conventional whole-plant extraction, not only for avoiding the overexploitation of plant species, but also for achieving better yields and having excellent scaling-up attributes. The selection of the bioreactor configuration depends on intrinsic cell culture properties and engineering considerations related to the effect of operating conditions on thermodynamics, kinetics, and transport phenomena, which together are essential for accomplishing the large-scale production of PDSM. To this end, this review, firstly, provides a comprehensive appraisement of PDSM, essentially those with demonstrated importance and utilization in pharmaceutical industries. Then, special attention is given to PDSM obtained out of CSC. Finally, engineering aspects related to the bioreactor configuration for CSC stating the effect of the operating conditions on kinetics and transport phenomena and, hence, on the cell viability and production of PDSM are presented accordingly. The engineering analysis of the reviewed bioreactor configurations for CSC will pave the way for future research focused on their scaling up, to produce high value-added PDSM.

scholarly journals Qualification of operating conditions to extend oxygen carrier utilization in the scaling up of chemical looping processes

2022 ◽  
Vol 430 ◽  
pp. 132602
Author(s):  
Arturo Cabello ◽  
Alberto Abad ◽  
María T. Izquierdo ◽  
P. Gayán ◽  
Luis F. de Diego ◽  
...  
Keyword(s):  
Oxygen Carrier ◽  
Scaling Up ◽  
Operating Conditions ◽  
Chemical Looping

Cathodoluminescence of Catalyst Crystallites

1982 ◽  
Vol 40 ◽  
pp. 664-665
Author(s):  
E.D. Boyes ◽  
P.L. Gai ◽  
D.B. Darby ◽  
C. Warwick
Keyword(s):  
Defect Density ◽  
Chemical Properties ◽  
Operating Conditions ◽  
Semiconductor Materials ◽  
Environmental Cell ◽  
High Resolution Structure ◽  
Commercially Important ◽  
Crystallographic Defects ◽  
Resolution Structure

The extended crystallographic defects introduced into some oxide catalysts under operating conditions may be a consequence and accommodation of the changes produced by the catalytic activity, rather than always being the origin of the reactivity. Operation without such defects has been established for the commercially important tellurium molybdate system. in addition it is clear that the point defect density and the electronic structure can both have a significant influence on the chemical properties and hence on the effectiveness (activity and selectivity) of the material as a catalyst. SEM/probe techniques more commonly applied to semiconductor materials, have been investigated to supplement the information obtained from in-situ environmental cell HVEM, ultra-high resolution structure imaging and more conventional AEM and EPMA chemical microanalysis.

Comparison of Deterministic and Linear Cosine Spatial Filtering of Transmission Electron Micrographs

1972 ◽  
Vol 30 ◽  
pp. 596-597
Author(s):  
David A. Ansley
Keyword(s):  
Spherical Aberration ◽  
Focal Length ◽  
Chromatic Aberration ◽  
Spatial Filter ◽  
Operating Conditions ◽  
Objective Lens ◽  
List Type ◽  
Spatial Filters ◽  
Transmission Electron ◽  
Wide Range

The coherence of the electron flux of a transmission electron microscope (TEM) limits the direct application of deconvolution techniques which have been used successfully on unmanned spacecraft programs. The theory assumes noncoherent illumination. Deconvolution of a TEM micrograph will, therefore, in general produce spurious detail rather than improved resolution.A primary goal of our research is to study the performance of several types of linear spatial filters as a function of specimen contrast, phase, and coherence. We have, therefore, developed a one-dimensional analysis and plotting program to simulate a wide 'range of operating conditions of the TEM, including adjustment of the:(1) Specimen amplitude, phase, and separation(2) Illumination wavelength, half-angle, and tilt(3) Objective lens focal length and aperture width(4) Spherical aberration, defocus, and chromatic aberration focus shift(5) Detector gamma, additive, and multiplicative noise constants(6) Type of spatial filter: linear cosine, linear sine, or deterministic

Slow-scan CCD cameras and low-dose High-Resolution Electron Microscopy: Direct and quantitative

1994 ◽  
Vol 52 ◽  
pp. 412-413
Author(s):  
M. Pan
Keyword(s):  
Electron Microscopy ◽  
High Resolution ◽  
Structural Damage ◽  
Low Dose ◽  
Dynamic Range ◽  
High Resolution Electron Microscopy ◽  
Operating Conditions ◽  
Digital Data ◽  
Ccd Cameras ◽  
Resolution Electron

It has been known for many years that materials such as zeolites, polymers, and biological specimens have crystalline structures that are vulnerable to electron beam irradiation. This radiation damage severely restrains the use of high resolution electron microscopy (HREM). As a result, structural characterization of these materials using HREM techniques becomes difficult and challenging. The emergence of slow-scan CCD cameras in recent years has made it possible to record high resolution (∽2Å) structural images with low beam intensity before any apparent structural damage occurs. Among the many ideal properties of slow-scan CCD cameras, the low readout noise and digital recording allow for low-dose HREM to be carried out in an efficient and quantitative way. For example, the image quality (or resolution) can be readily evaluated on-line at the microscope and this information can then be used to optimize the operating conditions, thus ensuring that high quality images are recorded. Since slow-scan CCD cameras output (undistorted) digital data within the large dynamic range (103-104), they are ideal for quantitative electron diffraction and microscopy.

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