It is a major aim of the CoPIRIDE project to provide theEuropean chemical industry with technical solutions whichenable the application of intensified, continuous processes.Process intensification is an acknowledged possibility toreduce the production costs of chemicals and thus toincrease competitiveness. Amongst others, process intensi-fication can be achieved as result of the application ofNovel Process Windows like accelerating reactions by usinghigher temperatures or concentrations. Also the develop-ment and use of catalysts is a way to increase productivity.However, all this needs adequate reactors which allow forhandling the increased requirements with respect to heatand mass transfer.

Microreactors have a huge potential to control even highlyexothermic and fast reactions due to their high ratio of sur-face to volume and small channel dimensions. They are alsowell suited for the application of highly active heterogeneouscatalysts. To date, microstructured reactors are broadlyapplied in lab scale and in numerous cases up to pilot andproduction scale for the intensification of chemical processes.Currently available techniques are well elaborated to enablethe commercial manufacture of laboratory reactors in smallseries and of pilot reactors.

However, there is still a lack of appropriate and costeffi-cient manufacturing techniques applicable for microstruc-tured devices which are suited for the high throughputs ofproduction scale. Currently, metal and especially stainlesssteel plates are microstructured using wet chemical etchingor mechanical machining processes. Both techniques arecomparatively expensive, limited in size and less suited foran economic mass production.

In CoPIRIDE, these restrictions will be overcome using anew manufacturing approach in which microstructuring byroll embossing plays a central role. Furthermore, a reactor

manufacturing strategy is followed which enables achievinga large variety of different reactor modules based on a smallnumber of manufacturing tools and steps. This allows theadaptation of the reactor design to a broad range of pro-cess needs like throughput, residence time, reaction condi-tions like pressure and temperature, heat and mass transfer,involved phases, and use of heterogeneous catalysts. Sizeand composition of the reaction modules can be varied bychanging the structured width, the length and number ofplates. The appropriate joining technology of the stackedplates can be chosen, e.g. laser welding, vacuum brazing.

Whereas vacuum brazing gives high pressure stability, wide-ly independent of size, it is not possible to insert a catalystprior to brazing, due to the high temperatures applied.However, laser welding with its controlled heat input allowsfor catalyst insertion prior to welding, but the achievedpressure stability depends on the device size. Combinationof different reactor modules opens additional flexibility.

The advanced development status of such modular micro-structured reactors made by using the new manufacturingtechniques is demonstrated by their implementation inpilot plants. These encouraging results base on joint effortsof Wetzel Company (roll embossing), Laserzentrum Schorcht(laser cutting and welding), and IMM (coordination, reac-tor concepts and design, vacuum brazing).

For further details, please see also the reports of theCoPIRIDE partners in this newsletter.

Modular microstructured reactors based on newmanufacturing techniques

Intensified Processing Gateways in Future Plants

Issue September 2012 Page 5

Vacuum brazed (left) and laser welded (right) reactor modules comprising plates microstructured by roll embossing, threefold modular test reactor (mid).

Dipl.-Ing. Ulrich Krtschil, Institut für Mikro-technik Mainz GmbH, acts as Technical ProjectManager and leads Work Package 3 (ModularMicroreactor Design, Fabrication, and Testing).As a chemical engineer, he had three decadesexperiences from work in industry before he joined IMM in 2004.

Extract from CoPIRIDE Newsletter No. 3

The WETZEL Processing Group is one of the most accomp-lished and innovative groups of companies in the printingand embossing industry. The headquarters of the group is atWETZEL GmbH in Grenzach-Wyhlen/Germany. Another sub-sidiary, WETZEL Sp.z.o.o. located near Warsaw in Poland,supplies the central European market with printing forms.Along with rotogravure cylinders and flexographic sleeves,WETZEL also manufactures embossing rollers and embossingmachines which are used in various industries including thepackaging, furniture, aerospace and automotive sectors aswell as for decorative and architectural applications in theconstruction industry.

As part of various research and development projects, amulti-functional test line was installed at WETZEL inGrenzach-Wyhlen.

As well as the special coating applications and the previousembossing applications, this system was used as the basisfor developing an efficient rotary embossing process formanufacturing micro-structured stainless steel strip in theongoing CoPIRIDE research project. These structured platesare, in turn, used in microreactors deployed in the chemicalindustry.

The trial system called “APOLLO” has all of the technologiesneeded to develop new application technologies close tothe production line as well as to test the requirements ofthe new functional surfaces for the manufacture of microre-actors using new manufacturing methods.

Combining digitalisation processes with the most modernengraving processes and the latest laser technology hasenabled WETZEL to produce technical functional surfacesand engrave the finest microstructures in surfaces.

The production of micro and nano structures (e.g. thesophisticated skin resembling that of a shark with a special3D effect or the lotus flower or light refraction effects)were researched in various projects for renowned clients inthe same way as the use of ultra-fast phenomena.

In particular re-creating bionic surfaces on rotary tools canbe tackled with the new laser technology.

The ability to test the transfer of the functional surfaces to different materials (such as stainless steel, aluminium,copper, plastics, films, cardboard, paper etc.) on the testline is the basis of a new complete process chain for thepossible market launch.

During the course of the CoPIRIDE project, WETZEL GmbHexploited its extensive technical know-how to develop themanufacturing process for micro-structuring the process-relevant reactor plates made from stainless steel strip,together with the innovative and reproducible structureparameters for this. Different to the previously used reactorplates which were produced in line with present-day tech-nology using conventional etching technology, at WETZELthe manufacturing process is examined by means of rollersin a special embossing calender which was modified/re-developed as part of the CoPIRIDE project. This in-housedeveloped embossing calender was incorporated in the“APOLLO” test line in order to also test the required com-plete manufacturing process from coil to coil.

The focus here was on the standardisation and developmentof the efficient manufacturing process for microstructuredreactor plates from small batches through to mass produc-tion.

“Made by WETZEL” stands for efficient manufacture of tech-nical functional surfaces using rotary embossing technology.

Intensified Processing Gateways in Future Plants

Page 6 Issue August 2012

Microstructuring of technical functional surfaces on stainless steel strip (metal plates)

by means of efficient rotary embossing

Michael Streuber, Wetzel GmbH, has broadexperience of embossing technology and rol-ling process engineering and is withinCoPIRIDE task leader of Workpackage 3.2 (newmanufacturing techniques by roll embossingand soldering)

Extract from CoPIRIDE Newsletter No. 3

The main task for Laserzentrum Schorcht Company within

the CoPIRIDE project is the development of an industrial

laser welding technology for microstructured stacked platereactors comprising thin plates of less than 0.2 mm. Thisincludes the development of an appropriate method forstacking different frames as well as thin flat and corrugatedplates prior to the laser welding. These laser-welded stackscan be used, for example, as heat exchangers or modules ofmicrostructured reactors. In addition to the developmentand provision of the technology, Laserzentrum SchorchtCompany is particularly interested in the economics of themanufacturing process. Here the goal is limiting the manu-facturing time, e.g. maximizing the speed of laser welding,whilst ensuring high quality.

The Laserzentrum Schorcht Company offers contract manufacturingin laser materials ranging from technological development to full pro-duction. The equipment consists of 12 laser systems whereof four arealso used for laser cutting.

For example, large and small heat exchangers, ball bearings with adiameter of 3 mm, or surgical instruments were laser welded andoften afterwards labelled. Laser cutting of any contour in tubes upto 2.60 m long and up to a 400 mm in diameter, flat bed cutting upto 1.50 x 3.00 m and especially micro-cutting are provided.

For this reasons, an advanced fibre laser is applied. Thisplant (Figure 1) is equipped with very fast linear motors, pro-viding accelerations and velocities of 10 m/s and 10 m/s,respectively. The accuracy of the axes is about 5 µm. Thefibre laser has 2000 W of power and two changeable fibreswith different core diameters.

In principle, laser welding of stacked plate devices con-sisting of conventionally, e.g. mechanically or wet-chemi-cally etched, micro-structured plates is an established tech-nology. However, laser welding of the comparatively thinplates of microstructured reactors based on the new manu-facturing techniques developed within CoPIRIDE is challen-ging and requires further development. Thus, initial weldtests with thin plates were carried out and the achieved weldseam quality was investigated (see Figure 2). In a next step,simple stacks of plates microstructured by roll embossing ofonly 0.15 mm thick high-grade steel strips were weldedapplying the determined best suited welding parameters.With these experiences, several varieties and sizes (up to60 mm structured width) of microreactors comprising platesmicro-structured by roll embossing were stacked and joinedby laser welding (see Figures 3 and 4). Currently, laser weldedreactors comprising roll embossed plates with 150 mm micro-structured width are in manufacture. A further enlargementof the reactor dimensions is planned.

Dipl. Phys. Peter Schorcht studied Physics in nonlinear optics at theFriedrich Schiller University Jena. He was involved in the develop-ment of different lasers, before he founded his own company, theLaserzentrum Schorcht GmbH, in 1995.

Dipl. Ing. Peter Weimar studied precision engineering at theUniversity of Applied Sciences Jena. Within the LaserzentrumSchorcht, he is responsible for projects of laser material processingrequiring highest precision and acts as project manager. InCoPIRIDE, he is also the task leader for large-size laser weldedmicroreactors.

Laser welding for stacked plate reactors

Intensified Processing Gateways in Future Plants

Issue September 2012 Page 7

Figure 2: First welding tests with two thinplates

Figure 3: Laser welded reactor comprisingroll embossed plates

Figure 4: Two stacked foam microreactorsin different sizes

Figure 1: P. Schorcht (left) and P. Weimar (right) in front of thefibre laser system inspecting a CoPIRIDE reactor

Extract from CoPIRIDE Newsletter No. 3