Project

ARCO-CRYSTAL: Adaptive Robust Predictive Control of Continuous Slug Flow Cooling Crystallization

Subject area	Chemical and Thermal Process Engineering Automation, Control Systems, Robotics, Mechatronics, Cyber Physical Systems
Term	since 2022
Funding	Deutsche Forschungsgemeinschaft (DFG)

Project description

Cooling crystallization is a widely used technology to produce a particulate product with desired quality attributes such as particle size and its distribution. Batch operation is currently still the standard for industrial crystallization. Continuous crystallizers are promising in terms of lower investment, operating costs, better control, and higher flexibility, especially for specialty chemicals or active pharmaceutical ingredients (API) with low production volumes. There are a large number of products in this category as, for example, more than 90 % of APIs are crystalline organic compounds with a small production rate of 250 to 1000 kg/a. Small-scale continuous crystallization faces some important challenges that are addressed in this project, such as the extremely small flow rates (10-100 ml/min) that are often associated with undesirable fouling or the difficulty to perform online measurements that allow autonomous high performance operation. Innovative tubular crystallizers have been developed to enable these small flow rates, including the slug flow crystallizer. Here, crystallization takes place in a small tube through a segmented air/liquid flow with high process and material efficiency. However, the challenge of fouling remains here as well. In addition, due to the lack of process analytical technologies for real-time small-scale applications and the current low availability of model-based methods for continuous crystallization, fully autonomous operation is not possible, which prevents the applicability of small-scale continuous crystallization in the industrial field. Therefore, the main goal of ARCO-CRYSTAL is to achieve autonomous process control of continuous slug flow cooling crystallization that enables precise narrow particle size distribution and high process yield while preventing unwanted fouling. To achieve this within the project, the following objectives will be pursued: (1) develop an online measurement of particle size distribution and fouling detection, (2) develop a process model, including a physics-based population balance model for particle size distribution and a data-based model for fouling, and (3) implement a model predictive control algorithm that accounts for uncertainties and process constraints. The main outcome of this interdisciplinary project will be the demonstration of an adaptive and robust process control strategy at the laboratory facility, supported by novel sensor technologies to ensure autonomous operation.

Researchers

Location & approach

By car

The campus of TU Dortmund University is located close to interstate junction Dortmund West, where the Sauerlandlinie A 45 (Frankfurt-Dortmund) crosses the Ruhrschnellweg B 1 / A 40. The best interstate exit to take from A 45 is “Dortmund-Eichlinghofen” (closer to South Campus), and from B 1 / A 40 “Dortmund-Dorstfeld” (closer to North Campus). Signs for the university are located at both exits. Also, there is a new exit before you pass over the B 1-bridge leading into Dortmund.

To get from North Campus to South Campus by car, there is the connection via Vogelpothsweg/Baroper Straße. We recommend you leave your car on one of the parking lots at North Campus and use the H-Bahn (suspended monorail system), which conveniently connects the two campuses.

The Laboratory of Process Automation Systems is located at Building G2 on the North Campus. Find more information here.

By train

TU Dortmund University has its own train station (“Dortmund Universität”). From there, suburban trains (S-Bahn) leave for Dortmund main station (“Dortmund Hauptbahnhof”) and Düsseldorf main station via the “Düsseldorf Airport Train Station” (take S-Bahn number 1, which leaves every 15 or 30 minutes). The university is easily reached from Bochum, Essen, Mülheim an der Ruhr and Duisburg.

You can also take the bus or subway train from Dortmund city to the university: From Dortmund main station, you can take any train bound for the Station “Stadtgarten”, usually lines U41, U45, U 47 and U49. At “Stadtgarten” you switch trains and get on line U42 towards “Hombruch”. Look out for the Station “An der Palmweide”. From the bus stop just across the road, busses bound for TU Dortmund University leave every ten minutes (445, 447 and 462). Another option is to take the subway routes U41, U45, U47 and U49 from Dortmund main station to the stop “Dortmund Kampstraße”. From there, take U43 or U44 to the stop “Dortmund Wittener Straße”. Switch to bus line 447 and get off at “Dortmund Universität S”.

The Laboratory of Process Automation Systems is located at Building G2 on the North Campus. Find more information here.

The H-Bahn (Suspended Monorail System)

The H-Bahn is one of the hallmarks of TU Dortmund University. There are two stations on North Campus. One (“Dortmund Universität S”) is directly located at the suburban train stop, which connects the university directly with the city of Dortmund and the rest of the Ruhr Area. Also from this station, there are connections to the “Technologiepark” and (via South Campus) Eichlinghofen. The other station is located at the dining hall at North Campus and offers a direct connection to South Campus every five minutes.

The Laboratory of Process Automation Systems is located at Building G2 on the North Campus. Find more information here. The building is within 5min walking distance of the H-Bahn Station "Dining Hall at North Campus".

Map

The facilities of TU Dortmund University are spread over two campuses, the larger Campus North and the smaller Campus South. Additionally, some areas of the university are located in the adjacent “Technologiepark”.

Site Map of TU Dortmund University (Second Page in English).