Mario Hoernicke, Katharina Stark ABB Corporate Research Ladenburg, Germany, firstname.lastname@example.org, email@example.com; Daniel Schmitt ABB Process Automation, Energy Industries Mannheim, Germany, firstname.lastname@example.org; Christian Schmitz B&R Industrie-Elektronik GmbH Bad Homburg, Germany, email@example.com; Polyana da Silva Santos Evonik Industries AG Marl, Germany; Lukas Bittorf, Norbert Kockmann TU Dortmund University Dortmund, Germany; Manfred Eckert Merck Darmstadt, Germany
Modular design approaches have been shown to bring substantial benefits to an astonishing variety of products and processes – from uninterruptible power supplies to software engineering, and much in between. Chemical and pharmaceutical processes, in particular, profit from modularization as it helps them overcome the challenges posed by the rapidly changing production environments that are characteristic of these industries →01. As well as catering for production capacity and product type changes, modular plants deliver a faster time to market and save time during engineering and commissioning (up to 50 percent in both cases) .
To exploit the advantages of process modularization, new process automation communication and control structures are required. Here, ABB is a leader and is recognized in the community as a standardization driver. Moreover, ABB has developed modular plant engineering prototypes. To ensure these prototypes perform well under real-world conditions, they must be tested in industrial applications.
It made sense, therefore, for ABB, in 2017, to join a third-party-funded enterprise: the ENPRO-ORCA project . In this project, plant owners and automation system vendors jointly develop pilot applications. Within these pilots, the engineering prototypes can be tested. The pilot applications also allow the project participants to systematically validate the VDI/VDE/NAMUR 2658 standard upon which much of the modularization work is based. ABB’s project partners are the TU Dortmund University, Evonik and Merck.
The project’s findings so far have been very positive and to fully appreciate them, a basic description of modular process automation architecture is helpful.
Modular process automation architecture
Modular production plants are, unlike conventional plants, assembled from predefined, pretested process modules called process equipment assemblies (PEAs)  – sometimes referred to as packaged units or skids. PEAs fulfill a dedicated process function, such as tempering, and can be used in multiple applications. PEAs are described using the Module Type Package (MTP) standard, which is a vendor-neutral description of PEAs. For the automation of PEAs, a prototype of ABB’s Module Designer is used that accommodates ABB and B&R automated PEAs. With this prototype, the automation engineering of the modules can be performed and the resulting automation system, eg, based on ABB Freelance, can be automatically generated. In addition, the Module Designer can automatically generate the corresponding MTP.
MTPs allow PEAs to be integrated into a supervisory control system: the process orchestration layer (POL) . ABB’s Extended Automation System 800xA is used as a POL. For engineering the pilots, a prototype of the ABB Orchestration Designer is used. From the Orchestration Designer, all parts required for the runtime are automatically generated in System 800xA and can immediately be used for supervisory control .
Every PEA has its own intelligence, often a programmable logic controller (PLC) or embedded or distributed control system controller . The controller exposes the functions of the PEA using OPC UA. Functions are abstracted from the process device, eg, a valve, into so-called services. Services are controlled from the POL and execute the process functions provided by the module. A tempering module might, therefore, provide a service called “Tempering,” which receives a start command and the setpoint for the required temperature so that the PEA internally executes the required functions of the devices.
The basic concepts, ie, integration using MTPs and service-based process design, have already been tested; it has been shown that modularization of process functions is possible. First concepts, architectures and prototypes have been developed by ABB for a modular automation system. Projects and previous initiatives  defined the automation system for modular plants and provided prototypes and demonstrators. The pilots described in this article are based on the previously developed prototypes [6,4].
Several pilot applications were created in cooperation with ABB’s customers Merck and Evonik, and the Laboratory of Equipment Design at the TU Dortmund University (Germany) developed a laboratory pilot →02 – 03. Only the laboratory pilot will be discussed in detail here.
TU Dortmund University (Distillation)
The pilot application at the TU Dortmund University is an existing laboratory environment that has been modularized by automating modules with a controller, providing an MTP for each of them and integrating them into the POL.
The distillation plant consists of five PEAs: distillation, feed, two thermostats and an analysis module. The analytical PEA is optional and can be used, for example, to determine continuously the concentration of the distillate or bottom product stream. The two thermostats and the feed PEA are required to operate the distillation, but can also be replaced by any other PEA that fulfills the same function (heating/cooling or dosing). The distillation PEA as well as the feed PEA are each equipped and automated using PLCs.
The thermostats have an embedded control system. The analysis PEA is independently equipped with all necessary functionalities by the manufacturer of the software suite. For the other PEAs, the MTPs are provided by the PLC vendor. All PEAs can, therefore, be easily integrated into ABB’s POL.
The services provided by the individual PEAs developed in this project are used to operate the system from the POL. Different services are available from each PEA. The feed PEA, for example, provides a dosing function via the service “Dose.”
The analysis PEA provides an “Analyze” service, in which Raman spectrograms are continuously recorded and then evaluated against a concentration of a component. This concentration value is communicated by the analysis PEA through System 800xA to the other PEAs, so that a module-to-module communication is achieved.
For each service, procedures specifying how the service should be executed are defined.
Usage of the laboratory plant
The distillation PEA is used to separate a mixture of substances into high- and low-boiling components with the highest possible purity. The basic operations required in this plant for this purpose, such as heating, level control, control of the spinning belt speed and similar further operations, can be combined and encapsulated automatically in a “Distilling” service using a few operator specifications. Procedures are provided for startup and shutdown of the plant, which ensures automatic plant operation →04.
The Distilling service provides different procedures depending on how the user wants to operate the plant – for example, manually or automatically. In the “distilling_automatic” procedure, for instance, the operator has only to specify a heating capacity and desired head temperature (without analysis PEA) or head concentration (with analysis PEA). The distillation PEA then automatically and continuously adapts to this specification without operator influence.
The automatic “OP_testing” service enables a characterization of various unknown materials that, compared to a tray or packed column method, is 30 to 70 percent faster and uses 40 to 80 percent less material.
Lessons from the other pilot sites →02 expanded the team’s experience in modularization for processes:
Namur pilot case study
The Namur case study was delivered from the Namur working groups (Namur is an international user association of automation technology and digitalization in process industries) as a reference for the technological implementation and modeling of the MTP. In modular automation, the pilot is used as a reference example for the concept and prototypes; for ABB, it is the in-house testbed for new technology development in automation engineering and modular production. Additionally, the pilot is used as a testbed for the pilot applications, since PEAs can easily be added to the demonstrator and the automation of PEAs, import of MTPs and PEA-to-PEA communication can be tested.
After Namur’s seven PEAs are engineered using the Module Designer, the plant topology is developed using Orchestration Designer →05-06.
The Merck distillation pilot plant consists of a complex PEA that implements all the functionalities required to operate distillation. In this PEA, it is possible to show how services can be called from other services within the PEA and from the POL to demonstrate that a larger process can be realized at the PEA level. The PEA is “intramodular safe” and plant standalone operation is possible. Both manual control and automatic control via a recipe have been validated. Thus, it is shown that this technology is suitable for process automation, while important knowledge and experience were gained for the future operation of modular plants.
In a close cooperation between Evonik, WAGO and ABB, HMI visualization, PEA tags, services and service-based recipe control were implemented and tested in this pilot →07. The services can be controlled manually via the POL, as well as via the recipe control (engineered in Orchestration Designer). PEA-to-PEA communication for analog and binary signals is prototypically implemented and tested.
The tests with the ABB POL prototype show that it is possible to store and load different plant topologies and, thus, switch PEAs within a modular plant by a few commands within minutes. As a result, use cases such as planning a new project and function changes are validated for ABB’s POL based on System 800xA in an existing plant.
A second Evonik pilot plant consists of six PEAs and represents the first time that PEAs suitable for productive use are presented instead of a laboratory setup. Here, ABB’s POL was validated for use cases such as services and PEA-to-PEA communication and module- spanning control loops to reach the same functionality as existing plants.
A future of modularization
All pilot applications returned very positive results and it was demonstrated that the orchestration of modules using MTP works. The requirements of the pilots were met and the feasibility of MTP and modular automation was proven. All tag interfaces for equipment control and monitoring, services and service parameters have been successfully tested. The sequences for automatic operation were implemented and tested with positive results. In addition, cross-module control was successfully implemented and tested in the Evonik pilot plant.
MTP and the modular plant concept is a future standard as well as a potential game-changer for the process industry that addresses time-to-market and flexibility challenges →08. ABB is leading MTP development, implementing the latest standards and presenting a recipe engine based on the service concept and process orchestration for modules from different suppliers.
Now that the feasibility of fully modular production plants is proven, the next step is to leverage the immense potential of this technology for conventional plants.
Acknowledgment: The authors were partially supported by the ORCA project, funded by the German Government Ministry for Business and Energy (BMWi) (support code 03ET1517E, B, H, I) as part of the ENPRO program.
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