one-A is a creative hotspot for ideas and concepts relating to all fields of process plant engineering. With inquisitive minds and motivated staff, we develop new solutions and optimize existing technologies.
“The way of one-A“ – a way that leads straight to the top in the fields of microreaction technology, cellulose technology and other technology areas. Build your successful future together with one-A!
Microreactors are process reactors operated in continuous mode and characterized by high selectivity and fitness for extreme process conditions.
The benefits of micro-size reactors are based on the same process principles that are also applicable for all other reactors and can be put down to their small radial dimensions.
The benefits of microstructures resulting from better mixing and more precise heating allow for very high reaction speeds. In addition, also more severe process conditions can be achieved in microreactors. A pressure increase will also lead to an increase in the boiling temperature, thus allowing for higher process temperatures. Higher temperatures in turn also increase the reaction speed.
That way, syntheses that take several hours in batch production can be completed within just a few seconds/ minutes in a microreactor. This reduces the reactor volume required for the reaction and increases the space-time yield. At the same production volume, microreactors as significantly smaller.
space-time yield STY = mass flow rate m / reactor volume V
Microreactors are operated in continuous mode and benefit from the advantages resulting therefrom: narrow residence time distribution, easier quality control, constant process conditions, efficient heat utilization, shorter downtimes, fewer start-up and shut-down operations and, as a result, longer service life of equipment / pumps.
The reaction of two substances in different phases is not only limited by the reaction speed, but also by the mass transfer coefficient kL and the specific phase boundary area aV. The product of aV*kL gives the characteristic size for reactions in multi-phase flows. An increase in the phase boundary interface and/or the specific surface by way of microstructures promotes multi-phase reactions.
The smaller the hydraulic diameter, the larger the specific surface area:
Specific surface area = surface/volume
Example tube ….
The amount of heat to be dissipated in a reaction is defined by the volume of the reacting substrate. The smaller the reactor, the larger the specific surface area (see above) available for heat transfer. This allows a significantly more precise heating / cooling and thus an optimal temperature selection.
Heat transfer = heat transmission coefficient * surface area * temperature gradient
Diffusion describes the undirected, random motion of particles that contributes to mixing. The diffusion time increases with the square of the diffusion path. In a microreactor, the diffusion time amounts to only a few seconds whereas, in a tank with a diameter of several meters, it amounts to several hundred hours making it no longer relevant under such circumstances.
With the right choice of flow rates and mixing elements, it is possible to achieve Bodenstein / Peclet numbers from 4 to over 100, thereby obtaining a sufficient back-mixing or an almost ideal plug flow reactor.
Produce only the volumes you actually need. Fast start-up and shut-down will allow you to produce your product in the exact quantity required within the shortest times. Less waste – an economic and ecological gain!
Produce your product where you need it. Microreactors are significantly smaller than batch reactors and can be easily transported from A to B.
Small reactor volumes minimize the risk of toxic chemicals.
The risk of explosion is avoided by staying below the maximum experimental safe gap. Due to the small reactor volume no major damage will occur even in a “worst case” scenario.
Due to the small scale of the microreactor system a scale-up by numbering-up is simple and safe.
New synthesis routes, substitution of polluting chemicals and higher yields will render your process more efficient and also more eco-friendly.
We will be pleased to put our know-how to your service!
one-A’s modular microreactor represents the solution of choice for the scale-up of microstructured processes from laboratory to commercial scale.
The simple structure comprising meander-shaped tubes in heating channels offers maximum flexibility. The selection of different tube diameters and particularly corrosion-resistant materials allows adapting the reactor to your individual process needs.
The tubes and heating channels are combined in plates that can be individually heated and cooled. Special tube connections allow for the feed and discharge of any given number of substance flows.
That way, you can adjust several temperature levels and integrate several process steps in one reactor. Preheating, mixing, reacting and quenching can be easily combined in one reactor. The metal structure allows operating at pressures and temperatures that go well beyond the usual standards.
one-A offers more! In line with this motto we are also offering our customers other solutions besides microreactors for the complete engineering, utilities, electrical & instrumentation, safety analysis, CE marking, and many more. We would be pleased to advise you.
Every reaction is different and therefore also the optimal reactor for that reaction is different.
one-A’s microreactor is unrivalled in terms of modularity. Still, some applications may require an entirely different approach. one-A commands a wealth of process expertise and experience in the manufacture of microstructured reactors, different heating systems as well as in conveying media with atypical substance characteristics.
Conducting tests under controlled and clearly defined process conditions allows gaining scientific insights about the process and is therefore helpful for process optimization.
The flexible adjustment of different test conditions allows for a quick screening and thus for a fast process development. If production is then conducted in microstructured equipment, too, the time saved can significantly curb the time to market.
Time and again, engineers are faced with challenges when using microstructured equipment on a commercial scale because a scale-up results in a loss of the micro-effects. The beneficial micro-effects can be easily transferred to commercial scale by means of numbering-up or equaling-up.
- Nitration reactions
- Nitroaldol reactions
- Suzuki-Miyaura cross-coupling reactions
Generation of nanoparticles with extremely narrow particle size distribution
Hydrolysis reactions at elevated temperatures
The Lyocell technology represents an eco-friendly process for transforming the most varied natural cellulosic raw materials into fibers, filaments and films. These in turn are processed in the textiles industry. Moreover, cellulosic products are also used for technical applications and in the packaging industry.
Lyocell products are characterized by many advantages:
The challenge of the Lyocell technology lies in the efficient transformation of the raw cellulose material into a spinnable solution.
These and other questions will be answered by one-A on the basis of their decade-long experience in the cellulose business, specifically in the Lyocell technology. one-A Engineering offers the complete production process on the basis of proprietary developments and own patents. one-A Engineering’s Lyocell staple fiber technology is available in the range from 1.0 to 6.7 dtex at different staple lengths and can be processed to yarns either as individual fiber or in fiber mixes using OE or ring spinning systems.
Apart from their outstanding properties, the Lyocell products in particular also offer economic and ecological benefits. With an almost completely closed solvent loop, the process presents itself as an extremely eco-friendly and cost efficient solution.
The raw material used for the production of Lyocell fibers is cellulose originating from tree plantations, i.e. a renewable resource.
The solvent used for cellulose treatment is amine oxide which transforms the cellulose directly into a highly viscous, spinnable solution.
Amine oxide is a strongly hygroscopic substance available as an aqueous solution with a concentration of 50-60%. The N-O group is strongly polar with the highest electron density on the oxygen atom. NMMO is produced at a commercial scale by oxidation of methyl morpholine with hydrogen peroxide.
This composition allows the N-O group to build hydrogen bonds. Cellulose can thus be dissolved in large quantities.
The dissolution quality depends on a series of parameters which include:
After the filtration step, the solution is spun to a tow, washed and then the solvent is removed. The tow is in a next step cut to staple fibers and dried.
Key characteristics of this process are that renewable resources are used as raw materials for fiber production, on the one hand, and that the solvent is treated and recycled at almost 100%, on the other.
As a consequence, the process is characterized by few residues in the waste water and by zero air pollution. The main aspect here is that the solvent is not classified as hazardous.