scholarly journals Scheduling of Energy-Integrated Batch Process Systems Using a Pattern-Based Framework

Processes ◽  
2019 ◽  
Vol 7 (2) ◽  
pp. 103 ◽  
Author(s):  
Sujit Suresh Jogwar ◽  
Shrikant Mete ◽  
Channamallikarjun Mathpati
Keyword(s):  
Optimal Schedule ◽  
Batch Process ◽  
Building Blocks ◽  
Batch Processes ◽  
Computational Time ◽  
Scheduling Problems ◽  
Process Systems ◽  
Batch Systems ◽  
On Line ◽  
Time Required

In this paper, a novel pattern-based method is developed for the generation of optimal schedules for energy-integrated batch process systems. The proposed methodology is based on the analysis of available schedules for the identification of repetitive patterns. It is shown that optimal schedules of energy-integrated batch processes are composed of several repeating sections (or building blocks), and their sizes and relative positions are dependent on the scheduling horizon and constraints. Based on such a decomposition, the proposed pattern-based algorithm generates an optimal schedule by computing the number and sequence of these blocks. The framework is then integrated with rigorous optimization-based approach wherein it is shown that the learning from the pattern-based solution significantly improves the performance of rigorous optimization. The main advantage of the pattern-based method is the significant reduction in computational time required to solve large scheduling problems, thus enabling the possibility of on-line rescheduling. Three literature examples were considered to demonstrate the presence of repeating patterns in optimal schedules of energy-integrated batch systems. The effectiveness of the proposed methodology was illustrated using an integrated reactor-separator system.

MONITORING OF BATCH PROCESSES WITH VARYING DURATIONS BASED ON THE HAUSDORFF DISTANCE

2006 ◽  
Vol 13 (03) ◽  
pp. 213-236 ◽  
Author(s):  
PHILIPPE CASTAGLIOLA ◽  
ARIANE FERREIRA PORTO ROSA
Keyword(s):  
Hausdorff Distance ◽  
Batch Process ◽  
Batch Processes ◽  
Multivariate Statistical Process Control ◽  
Multivariate Statistical ◽  
Statistical Process ◽  
Innovative Methods ◽  
Batch Process Monitoring ◽  
On Line ◽  
Case Data

In some industrial situations, the classical assumption used in the batch process monitoring that all batches have equal durations and are synchronized does not hold. A batch process is carried out in sequential phases and a significant variability generally occurs in the duration of the phases such that events signifying the beginning or the end of a phase are generally misaligned in time within the various batches. The consequence is that the variable trajectories, in the different runs of the same batch process, are unsynchronized. In this case, data analysis from process for performing the multivariate statistical process control can be difficult. In this paper, we propose several innovative methods for the off-line and on-line monitoring of batch processes with varying durations, all based on the Hausdorff distance. These methods have been successfully tested on a simulated example and on an industrial case example. The conclusion is that these methods are able to efficiently discriminate between nominal and non-nominal batches.

scholarly journals A new approach for scheduling of multipurpose batch processes with unlimited intermediate storage policy

2019 ◽  
Vol 13 (4) ◽  
pp. 784-802 ◽  
Author(s):  
Nikolaos Rakovitis ◽  
Nan Zhang ◽  
Jie Li ◽  
Liping Zhang
Keyword(s):  
Mathematical Models ◽  
Raw Materials ◽  
Batch Process ◽  
Batch Processes ◽  
Computational Time ◽  
Process Industries ◽  
Global Marketplace ◽  
Specific Event ◽  
Intermediate Storage ◽  
Event Based

Abstract The increasing demand of goods, the high competitiveness in the global marketplace as well as the need to minimize the ecological footprint lead multipurpose batch process industries to seek ways to maximize their productivity with a simultaneous reduction of raw materials and utility consumption and efficient use of processing units. Optimal scheduling of their processes can lead facilities towards this direction. Although a great number of mathematical models have been developed for such scheduling, they may still lead to large model sizes and computational time. In this work, we develop two novel mathematical models using the unit-specific event-based modelling approach in which consumption and production tasks related to the same states are allowed to take place at the same event points. The computational results demonstrate that both proposed mathematical models reduce the number of event points required. The proposed unit-specific event-based model is the most efficient since it both requires a smaller number of event points and significantly less computational time in most cases especially for those examples which are computationally expensive from existing models.

scholarly journals On-Line Optimization of Batch Processes by Tracking States and Costates

1999 ◽  
Vol 32 (2) ◽  
pp. 6633-6638 ◽  
Author(s):  
E. Visser ◽  
B. Srinivasan ◽  
D. Bonvin ◽  
S. Palanki
Keyword(s):  
Batch Processes ◽  
On Line

scholarly journals A Stochastic Model to Describe the Scattering in the Response of Polysilicon MEMS

2021 ◽  
Vol 2 (1) ◽  
pp. 95
Author(s):  
Luca Dassi ◽  
Marco Merola ◽  
Eleonora Riva ◽  
Angelo Santalucia ◽  
Andrea Venturelli ◽  
...  
Keyword(s):  
Silicon Film ◽  
Micro Fabrication ◽  
Micro Electro Mechanical Systems ◽  
Local Fluctuations ◽  
Stochastic Framework ◽  
On Line ◽  
Chip Testing ◽  
On Chip ◽  
Time Required ◽  
Polycrystalline Silicon Film

The current miniaturization trend in the market of inertial microsystems is leading to movable device parts with sizes comparable to the characteristic length-scale of the polycrystalline silicon film morphology. The relevant output of micro electro-mechanical systems (MEMS) is thus more and more affected by a scattering, induced by features resulting from the micro-fabrication process. We recently proposed an on-chip testing device, specifically designed to enhance the aforementioned scattering in compliance with fabrication constraints. We proved that the experimentally measured scattering cannot be described by allowing only for the morphology-affected mechanical properties of the silicon films, and etch defects must be properly accounted for too. In this work, we discuss a fully stochastic framework allowing for the local fluctuations of the stiffness and of the etch-affected geometry of the silicon film. The provided semi-analytical solution is shown to catch efficiently the measured scattering in the C-V plots collected through the test structure. This approach opens up the possibility to learn on-line specific features of the devices, and to reduce the time required for their calibration.

scholarly journals Backstepping Methodology to Troubleshoot Plant-Wide Batch Processes in Data-Rich Industrial Environments

Processes ◽  
2021 ◽  
Vol 9 (6) ◽  
pp. 1074
Author(s):  
Federico Zuecco ◽  
Matteo Cicciotti ◽  
Pierantonio Facco ◽  
Fabrizio Bezzo ◽  
Massimiliano Barolo
Keyword(s):  
Production Capacity ◽  
Batch Process ◽  
Batch Processes ◽  
Flow Diagram ◽  
Production Cycle ◽  
Multivariate Statistical ◽  
Process Flow Diagram ◽  
Root Cause ◽  
Industrial Batch ◽  
Specialty Chemical

Troubleshooting batch processes at a plant-wide level requires first finding the unit causing the fault, and then understanding why the fault occurs in that unit. Whereas in the literature case studies discussing the latter issue abound, little attention has been given so far to the former, which is complex for several reasons: the processing units are often operated in a non-sequential way, with unusual series-parallel arrangements; holding vessels may be required to compensate for lack of production capacity, and reacting phenomena can occur in these vessels; and the evidence of batch abnormality may be available only from the end unit and at the end of the production cycle. We propose a structured methodology to assist the troubleshooting of plant-wide batch processes in data-rich environments where multivariate statistical techniques can be exploited. Namely, we first analyze the last unit wherein the fault manifests itself, and we then step back across the units through the process flow diagram (according to the manufacturing recipe) until the fault cannot be detected by the available field sensors any more. That enables us to isolate the unit wherefrom the fault originates. Interrogation of multivariate statistical models for that unit coupled to engineering judgement allow identifying the most likely root cause of the fault. We apply the proposed methodology to troubleshoot a complex industrial batch process that manufactures a specialty chemical, where productivity was originally limited by unexplained variability of the final product quality. Correction of the fault allowed for a significant increase in productivity.

Rapid Polymer/Gas Solution Formation for Continuous Production of Microcellular Plastics

1996 ◽  
Vol 118 (4) ◽  
pp. 639-645 ◽  
Author(s):  
C. B. Park ◽  
N. P. Suh
Keyword(s):  
Rapid Heating ◽  
Continuous Production ◽  
Batch Process ◽  
Bubble Nucleation ◽  
Cycle Times ◽  
Solution Formation ◽  
Microcellular Plastics ◽  
Diffusion Phenomena ◽  
Order Of Magnitude ◽  
Time Required

An extrusion system that can create a polymer/gas solution rapidly for continuous processing of microcellular plastics is presented. Microcellular plastics are characterized by cell densities greater than 109 cells/cm3 and fully grown cells smaller than 10 μm. Previously these microcellular structures have been produced in a batch process by saturating a polymeric material with an inert gas under high pressure followed by inducing a rapid drop in the gas solubility. The diffusion phenomena encountered in this batch processing is typically slow, resulting in long cycle times. In order to produce microcellular plastics at industrial production rates, a means for the rapid solution formation is developed. The processing time required for completing the solution formation in the system was estimated from experimental data and the dispersive mixing theory based on an order-of-magnitude analysis. A means for promoting high bubble nucleation rates in the gas-saturated polymer via rapid heating is also discussed. The feasibility of the continuous production of microcellular plastics by the rapid polymer/gas solution formation and rapid heating was demonstrated through experiments. The paper includes not only a brief treatment of the basic science of the polymer/gas systems, but also the development of an industrially viable technology that fully utilizes the unique properties of microcellular plastics.

Use of the Orthogonal Projection Approach (OPA) to Monitor Batch Processes

2003 ◽  
Vol 57 (1) ◽  
pp. 80-87 ◽  
Author(s):  
S. Gourvénec ◽  
C. Lamotte ◽  
P. Pestiaux ◽  
D. L. Massart
Keyword(s):  
Orthogonal Projection ◽  
Spectroscopic Data ◽  
Batch Processes ◽  
Multivariate Curve Resolution ◽  
Concentration Profiles ◽  
Curve Resolution ◽  
On Line ◽  
Real Concentration ◽  
Projection Approach

The orthogonal projection approach (OPA) and multivariate curve resolution (MCR) are presented as a way to monitor batch processes using spectroscopic data. Curve resolution allows one to look within a batch and predict on-line real concentration profiles of the different species appearing during reactions. Taking into account the variations of the process by using an augmented matrix of complete batches, the procedure explained here calculates some prediction coefficients that can afterwards be applied for a new batch.

Rapid estimation of rate constants of batch processes using on-line SW-NIR

AIChE Journal ◽  
1998 ◽  
Vol 44 (12) ◽  
pp. 2713-2723 ◽  
Author(s):  
Sabina Bijlsma ◽  
D. J. Louwerse ◽  
Age K. Smilde
Keyword(s):  
Rate Constants ◽  
Batch Processes ◽  
Rapid Estimation ◽  
On Line

Developing and Comparing Alternative Design Optimization Formulations for a Vibration Absorber Example

2017 ◽  
Author(s):  
Siyao Luan ◽  
Deborah L. Thurston ◽  
Madhav Arora ◽  
James T. Allison
Keyword(s):  
Design Problem ◽  
Mathematical Optimization ◽  
Computational Time ◽  
Vibration Absorber ◽  
Solution Quality ◽  
Design Representation ◽  
Core Elements ◽  
Improved Design ◽  
Time Required ◽  
Level Of Effort

In some cases, the level of effort required to formulate and solve an engineering design problem as a mathematical optimization problem is significant, and the potential improved design performance may not be worth the excessive effort. In this article we address the tradeoffs associated with formulation and modeling effort. Here we define three core elements (dimensions) of design formulations: design representation, comparison metrics, and predictive model. Each formulation dimension offers opportunities for the design engineer to balance the expected quality of the solution with the level of effort and time required to reach that solution. This paper demonstrates how using guidelines can be used to help create alternative formulations for the same underlying design problem, and then how the resulting solutions can be evaluated and compared. Using a vibration absorber design example, the guidelines are enumerated, explained, and used to compose six alternative optimization formulations, featuring different objective functions, decision variables, and constraints. The six alternative optimization formulations are subsequently solved, and their scores reflecting their complexity, computational time, and solution quality are quantified and compared. The results illustrate the unavoidable tradeoffs among these three attributes. The best formulation depends on the set of tradeoffs that are best in that situation.

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