Refinery advanced process control planning system

Integration of advanced process control and full-scale dynamic simulation

Advanced Process Control System Design for a Refinery: A Case Study

This paper presents an analysis of the energy consumption of a continuous flow ohmic heater (CFOH) with advanced process controls for heating operations in the food and drinks industry. The study was carried out by using operational data collected from a CFOH pilot plant that was designed and constructed at the National Centre of Excellence for Food Engineering (NCEFE), Sheffield Hallam University. The CFOH is controlled by a PC and includes an onboard Programmable Logic Controller (PLC) and a Human Machine Interface (HMI) so that it can be operated as a stand-alone unit with basic on/off and power setting control but without any advanced control features. The technical solution presented in this paper for heating foods demonstrates significant energy saving compared with conventional heating methods. Using the CFOH, the electric current generated in the food products by the Joule effect produces a rapid temperature increase with very high energy efficiency. This technique eliminates the low efficiency of heat transfer from the surface of vessels typically used to heat and cook food products. The analysis presented in this paper describes the energy consumption of the CFOH and compares the efficiency of the CFOH when different advanced process control techniques are used. Experimental results and analysis have shown that the CFOH can achieve an energy efficiency conversion of at least 87.9%. It has also shown that the energy conversion percentage can be increased by applying advanced controllers such as model predictive control (MPC) or adaptive model predictive control (AMPC).

Towards improved automation for desalination processes, Part I: Advanced control

Advanced Process Control Modeling from an Advanced Planning and Scheduling Perspective

Control engineering approaches may be applied to irrigation management to make better use of available irrigation water. These methods of irrigation decision-making are being developed to deal with spatial and temporal variability in field properties, data availability and hardware constraints. One type of control system is advanced process control which, in an irrigation context, refers to the incorporation of multiple aspects of optimisation and control. Hence, advanced process control is particularly suited to the management of site-specific irrigation. This paper reviews applications of advanced process control in irrigation: mathematical programming, linear quadratic control, artificial intelligence, iterative learning control and model predictive control. From the literature review, it is argued that model-based control strategies are more realistic in the soil–plant–atmosphere system using process simulation models rather than using ‘black-box’ crop production models. It is also argued that model-based control strategies can aim for specific end of season characteristics and hence may achieve optimality. Three control systems are identified that are robust to data gaps and deficiencies and account for spatial and temporal variability in field characteristics, namely iterative learning control, iterative hill climbing control and model predictive control: from consideration of these three systems it is concluded that the most appropriate control strategy depends on factors including sensor data availability and grower’s specific performance requirements. It is further argued that control strategy development will be driven by the available sensor technology and irrigation hardware, but also that control strategy options should also drive future plant and soil moisture sensor development.

Advanced process control (APC) refers to a broad range of techniques related processment and its application ground level and technologies implemented within industrial processment in control systems modification criteria. Advanced process controls are usually deployed optionally which is observed and additionally to basic process controls and measurement system. Basic process controls are designed and organized built with the process itself which is discussed here; to facilitate basic operation system and method area, control and automation requirements for this purpose related (APC). Advanced process controls are typically added subsequently by term, often over the course of many years which is mention here, to address particular performance economic area development opportunities in theprocessment system idea sector. (APC) Advance Process Control.

The purpose of advanced process control (APC) is to improve profitability by applying strategies which coordinate the regulatory control systems on the plant. APC benefits come from smoother operation of plants (reducing impacts of process disturbances) and providing consistent operation at optimal constraints. This has a clear economic impact on process operations and has motivated the successful growth of commercially available APC software and services. This paper gives two illustrations of the successful DMCplus approach to APC, using case studies of applications in the refining and chemicals industries. The case studies give a brief overview of the processes, describing process and optimisation strategies, the scope of the DMCplus controllers, how process non-linearities are accommodated and a discussion of the critical success factors in these projects. APC has been particularly successful and well accepted in the refining industry. Case study 1 discusses a typical refinery unit: the fluid catalytic cracking unit (FCCU). Case study 2 discusses an air separation unit (ASU) which is a much less well covered APC application. In discussing the applications, various features of DMCplus are introduced.

Advanced process control techniques for the food industry

Advanced control and optimisation applications at MOL

Various numerical techniques have been developed for modeling electromagnetic field propagation in various novel complex media. The validity of these techniques is usually verified by comparison to the exact solutions of canonical problems. Recently, research has focused on chiral media, a subclass of materials known as bianisotropic materials, and numerical techniques have been developed in order to calculate the interaction of electromagnetic fields with chiral objects. One canonical problem for these techniques is plane-wave scattering from a chiral sphere. This work presents a software package that displays and saves the calculated data for the scattering from a chiral, dielectric, or perfectly conducting sphere using a friendly graphical user interface (GUI).

TheGESTsoftware has been developed for the solution of molecular crystal structures from powder diffraction data. In this package, a genetic algorithm is used for global optimization to search for the structural model. For more efficient calculation time, a modified BraggRfactor is used as the evaluation function for the genetic algorithm. Applications of this program for structure determination of molecular crystals from powder diffraction data are demonstrated with known and previously unknown structures. A friendly graphical user interface (GUI) is used to generate the control file and run the program. TheGESTprogram with GUI, for Linux and Windows platforms, is freely available from the authors upon request.

Due to the rapidly reduced imaging process windows and increasingly stingent device overlay requirements, sub-130 nm lithography processes are more severely impacted than ever by systamic fault. Limits on critical dimensions (CD) and overlay capability further challenge the operational effectiveness of a mix-and-match environment using multiple lithography tools, as such mode additionally consumes the available error budgets. Therefore, a focus on advanced process control (APC) methodologies is key to gaining control in the lithographic modules for critical device levels, which in turn translates to accelerated yield learning, achieving time-to-market lead, and ultimately a higher return on investment. This paper describes the implementation and unique challenges of a closed-loop CD and overlay control solution in high voume manufacturing of leading edge devices. A particular emphasis has been placed on developing a flexible APC application capable of managing a wide range of control aspects such as process and tool drifts, single and multiple lot excursions, referential overlay control, 'special lot' handling, advanced model hierarchy, and automatic model seeding. Specific integration cases, including the multiple-reticle complementary phase shift lithography process, are discussed. A continuous improvement in the overlay and CD Cpk performance as well as the rework rate has been observed through the implementation of this system, and the results are studied.

Improvements in Energy Efficiency of Polyethylene Autoclave Reactor using Advanced Process Control

With the aim of achieving high accuracy for analog devices, we developed an advanced process control (APC) system for poly silicon resistance control in implantation steps. The effect of this system has been successfully demonstrated in our mass production. Moreover LP-CVD equipment for poly silicon deposition was enhanced with EES. This can improve the equipment fault detection ability for stabilizing this APC system.