Advancements in Optimization and Control Techniques for Intensifying Processes

Processes ◽  
2021 ◽  
Vol 9 (12) ◽  
pp. 2150
Author(s):  
Jesús Rafael Alcántara Avila ◽  
Zong Yang Kong ◽  
Hao-Yeh Lee ◽  
Jaka Sunarso
Keyword(s):  
Environmental Impact ◽  
Energy Cost ◽  
Chemical Engineering ◽  
Process Intensification ◽  
The Other ◽  
Control Techniques ◽  
Impact Reduction ◽  
Open Questions ◽  
Optimization And Control ◽  
And Control

Process Intensification (PI) is a vast and growing area in Chemical Engineering, which deals with the enhancement of current technology to enable improved efficiency; energy, cost, and environmental impact reduction; small size; and better integration with the other equipment. Since process intensification results in novel, but complex, systems, it is necessary to rely on optimization and control techniques that can cope with such new processes. Therefore, this review presents some advancements in the field of process intensification that are worthy of exploring in detail in the coming years. At the end, several important open questions that can be taken into consideration in the coming years are listed.

Long term developments in switching

1978 ◽  
Vol 289 (1356) ◽  
pp. 65-77
Keyword(s):  
Integrated Circuits ◽  
Distributed Control ◽  
Optical Transmission ◽  
Digital Transmission ◽  
Control Techniques ◽  
Control Functions ◽  
Open Questions ◽  
The Common ◽  
And Control

Developments are considered under the headings (i) connection techniques, (ii) control techniques, (hi) interaction of switching and transmission techniques, (iv) facilities offered, and (v) connecting network topology. In each topic, there are open questions. The major forecasts are: (i) the extensive use of electronic digital multiplex connecting networks, compatible with digital transmission systems; (ii) the introduction of optical connecting techniques, which offer both compatibility with optical transmission and some interesting new possibilities for the size and configuration of switches; (iii) the extensive use of stored program control; (iv) the supplementation of central processors by distributed control techniques for the common operational procedures, probably using microprocessors; and (v) the widespread use of semiconductor integrated circuits both for connection and control functions.

scholarly journals A Case Study on Optimization and Control Techniques for Entry Stability in Non-Pillar Longwall Mining

Energies ◽  
2019 ◽  
Vol 12 (3) ◽  
pp. 391 ◽  
Author(s):  
Xiaojie Yang ◽  
Eryu Wang ◽  
Xingen Ma ◽  
Guofeng Zhang ◽  
Ruifeng Huang ◽  
...  
Keyword(s):  
Large Deformation ◽  
Longwall Mining ◽  
Surrounding Rock ◽  
Control Techniques ◽  
Immediate Roof ◽  
Optimization And Control ◽  
Pillar Mining ◽  
And Control ◽  
Entry Roof

In order to reduce large deformation failure occurrences in non-pillar longwall mining entries due to roof weighting behaviors, a case study in Halagou coal mine was conducted on optimization and control techniques for entry stability in non-pillar longwall mining. The Universal Discrete Element Code (UDEC) modeling was adopted to study entry stability in non-pillar mining, and the characteristics of deformation and stress and crack propagation were revealed. The large deformation transmission between the entry-immediate roof and the gob-immediate roof could be eliminated by optimizing the entry roof structure through a directional roof-cutting method. The localized tensile stresses generated in the entry-surrounding rock caused the generation of coalescent macroscopic fractures, which resulted in the instability of the entry. The tensile stress state could be inhibited by an active flexible support system through enhancing the confining pressure on the surrounding rock. Serious rotation subsidence occurs in the entry roof due to periodic weighting of the main roof, which could be greatly reduced by a passive rigid support pattern. The numerical and field test results both showed that the roof weighting pressure was offloaded by the technique and that the deformation of the entry surrounding the rock in non-pillar mining was quite small. Thus, the technique can effectively ensure the stability of the gob-side entry, which can provide references for entry stability control in non-pillar longwall mining.

scholarly journals Pellet Production from Miscanthus: Energy and Environmental Assessment

Energies ◽  
2020 ◽  
Vol 14 (1) ◽  
pp. 73
Author(s):  
Alessandra Fusi ◽  
Jacopo Bacenetti ◽  
Andrea R. Proto ◽  
Doriana E. A. Tedesco ◽  
Domenico Pessina ◽  
...  
Keyword(s):  
Environmental Impact ◽  
The Other ◽  
Primary Data ◽  
Medium Size ◽  
Impact Categories ◽  
Wood Pellets ◽  
Main Contributor ◽  
Pellet Production ◽  
Impact Reduction ◽  
The Impact

The production of wood pellets has grown considerably in the last decades. Besides woody biomass, other feedstocks can be used for pellet production. Among these, miscanthus presents some advantages because, even if specifically cultivated, it requires low inputs such as fertilisers and pesticides and shows high biomass yield (up to 28 tons of dry matter ha−1 in Europe). Even if in the last years some studies evaluated the environmental impact of woody pellet production, there is no information about the environmental performances of miscanthus pellet production. In this study, the environmental impact of miscanthus pellet was evaluated using the Life Cycle Assessment approach with a cradle-to plant gate perspective. Primary data were collected in a small-medium size pelletizing plant located in Northern Italy where miscanthus is cultivated to be directly processed. The results highlight how the miscanthus pellet shows lower environmental impact compared to woody pellet, mainly due to the lower energy consumption during pelletizing. The possibility to pelletize the miscanthus biomass without any drying offsets the environmental impact related to the miscanthus cultivation for all the evaluated impact categories (except for Marine eutrophication). In detail, for global warming potential, 1 ton of miscanthus pellet shows an impact of 121.6 kg CO2 eq. (about 8% lower respect to woody pellet) while for the other evaluated impact categories the impact reduction ranges from 4 to 59%. Harvesting, which unlike the other field operations is carried out every year, is by far the main contributor to the impacts of the cultivation phase while electricity is the main contributor to the pelletizing phase.

Editorial: Special Issue of 8th World Congress of Chemical Engineering (WCCE 8) Symposium on Process Design

2009 ◽  
Vol 4 (5) ◽  
Author(s):  
Navid Mostoufi ◽  
Rahmat Sotudeh-Gharebagh ◽  
Norman W Loney
Keyword(s):  
Process Modeling ◽  
Process Design ◽  
Chemical Engineering ◽  
Learning Experience ◽  
Full Range ◽  
Special Issue ◽  
World Congress ◽  
Optimization And Control ◽  
Product And Process ◽  
And Control

The 8th World Congress of Chemical Engineering (WCCE 8) Symposium on Process Design, held on August 23-27, 2009 in Montreal, Canada, offered a unique opportunity to focus on a comprehensive participation and learning experience over the full range and diversity of methods in the broad fields of process modeling and their use for design, simulation, optimization and control of chemical processes. The major themes of the symposium are categorized into the following themes of the congress:• Energy • Green Processing • New Materials • BiotechnologyAuthors of selected papers accepted for presentation in the Process Design symposium were invited to submit the full papers to be considered for publication in the journal of Chemical Product and Process Modeling (http://www.bepress.com/cppm). The papers that successfully passed the reviewing process of the journal are now published in the WCCE8 special issue of the journal.

Prothrombin Time Standardization: Report of the Expert Panel on Oral Anticoagulant Control

1979 ◽  
Vol 42 (04) ◽  
pp. 1073-1114 ◽  
Keyword(s):  
Prothrombin Time ◽  
Expert Panel ◽  
The Other ◽  
Rabbit Brain ◽  
Calibration Constant ◽  
Freeze Dried ◽  
The Mean ◽  
Point Of Intersection ◽  
And Control ◽  
Standardization Report

SummaryIn collaborative experiments in 199 laboratories, nine commercial thromboplastins, four thromboplastins held by the National Institute for Biological Standards and Control (NIBS & C), London and the British Comparative Thromboplastin were tested on fresh normal and coumarin plasmas, and on three series of freeze-dried plasmas. One of these was made from coumarin plasmas and the other two were prepared from normal plasmas; in each series, one plasma was normal and the other two represented different degrees of coumarin defect.Each thromboplastin was calibrated against NIBS&C rabbit brain 70/178, from the slope of the line joining the origin to the point of intersection of the mean ratios of coumarin/normal prothrombin times when the ratios obtained with the two thromboplastins on the same fresh plasmas were plotted against each other. From previous evidence, the slopes were calculated which would have been obtained against the NIBS&C “research standard” thromboplastin 67/40, and termed the “calibration constant” of each thromboplastin. Values obtained from the freeze-dried coumarin plasmas gave generally similar results to those from fresh plasmas for all thromboplastins, whereas values from the artificial plasmas agreed with those from fresh plasmas only when similar thromboplastins were being compared.Taking into account the slopes of the calibration lines and the variation between laboratories, precision in obtaining a patient’s prothrombin time was similar for all thromboplastins.

Dry chip feedrate control using online chip moisture

TAPPI Journal ◽  
2018 ◽  
Vol 17 (05) ◽  
pp. 295-305
Author(s):  
Wesley Gilbert ◽  
Ivan Trush ◽  
Bruce Allison ◽  
Randy Reimer ◽  
Howard Mason
Keyword(s):  
Production Rate ◽  
Control Strategy ◽  
Rate Control ◽  
Near Infrared ◽  
Dry Mass ◽  
The Other ◽  
Process Variability ◽  
Moisture Sensor ◽  
Feedback Control Strategy ◽  
And Control

Normal practice in continuous digester operation is to set the production rate through the chip meter speed. This speed is seldom, if ever, adjusted except to change production, and most of the other digester inputs are ratioed to it. The inherent assumption is that constant chip meter speed equates to constant dry mass flow of chips. This is seldom, if ever, true. As a result, the actual production rate, effective alkali (EA)-to-wood and liquor-to-wood ratios may vary substantially from assumed values. This increases process variability and decreases profits. In this report, a new continuous digester production rate control strategy is developed that addresses this shortcoming. A new noncontacting near infrared–based chip moisture sensor is combined with the existing weightometer signal to estimate the actual dry chip mass feedrate entering the digester. The estimated feedrate is then used to implement a novel feedback control strategy that adjusts the chip meter speed to maintain the dry chip feedrate at the target value. The report details the results of applying the new measurements and control strategy to a dual vessel continuous digester.

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