Increasing the production efficiency, and reducing the material costs are generally the main goals, both when planning for the improvement of an already existing process, and when developing a brand new one. Process development involves the planning, testing, supervising and optimizing of the procedures, techniques and workflows of a certain process.
Trials and pilot plants
There are generally a few different steps in developing a new process. First off, laboratory trials are planned, tested and optimized to ensure satisfactory reaction conditions and product yields. This often includes testing of different materials, solvents, and reaction settings, to reach suitable results. The process is later moved over to a pilot plant for pre-commercial production runs, and further large-scale process optimization. This will offer a chance to study the set-up in a situation resembling the final process. In this step, parameters can be adjusted to ensure a maintained quality of the process at a larger scale. During these two initial phases it is also common to test out partially or complete automation of the process, as well as the incorporation of new tools and technological solutions. After the process has been tested and optimized for satisfactory results, it is ready to be moved on to production.
Rotating bed reactors
SpinChem offers help with the development of your heterogeneous processes, from bench-top screening, to full-scale production. Due to the generic design of the SpinChem® rotating bed reactor (RBR), the technology is fully scalable, and performs just as well in liquid phase volumes of a few millilitres (MagRBR), as in several thousand cubic metres of solution (ProRBR). If the existing set-up makes it impractical to use the RBR in-tank for batch processing, SpinChem offers other solutions, such as flow systems, where the RBR is used in a separate vessel connected to the main tank. The SpinChem® RBR can also be used in connected systems of reactor vessels, where the RBR is used in one or more of these vessels.
The efficient mass transfer achieved with the RBR, along with the fact that the solid phase is not exposed to mechanical forces or pressure, makes for quick and clean reactions. Downstream processing is cut to a minimum as there is no need for filtering of solid phase resin or debris from the reaction solution. This makes the SpinChem® RBR a very cost and resource efficient alternative both in research and production.
SpinChem’s fields of expertise include chemistry, engineering, experimental design, solid phase materials, and fluid flow simulations. Through rapid in-house prototyping, testing, simulating, analysis and optimization, SpinChem is able to develop clever, custom-made solutions to fit your processes and applications.
Time lapse video illustrating how an externally connected rotating bed reactor (RBR) can pump and process large liquid volumes by the convective flow created by the spinning RBR. The concept enables handling of volumes at least 10-100 times larger than the external vessel, thus facilitating installation of RBR technology into existing plant equipment.
Conditions: A water filled (2 L) connected system consisting of a tank (1 L) to which an external flower baffled vessel (200 mL) was connected via pipes (24.6 mm ID). A SpinChem® rotating bed reactor (RBR) S221 filled with activated carbon (28 mL, 20-50 mesh) was placed in the external vessel and rotated at 1000 rpm adsorbing dissolved methylene blue (40 mg) within 14 minutes.
Accelerated video showing the removal of methylene blue from 50 L volume of liquid, by adsorption onto activated carbon in a production scale rotating bed reactor (RBR). The decolouration process removed 99.96% of the dye within 10 minutes with a logarithmic decline of concentration as documented by analysis of withdrawn samples.
Conditions: Adsorption of methylene blue (20 g, 400 mg/L) onto activated carbon (7 L, 20-50 mesh) placed in a SpinChem® S511 rotating bed reactor (RBR) operated at 200 rpm within a 38 cm diameter cylindrical reaction vessel containing 50 L water and equipped with three baffles placed along the edges. Samples were withdrawn every half minute and analysed by light adsorption without any need for filtration. The video is shown at 20x speed.
Video showing how a SpinChem® rotating bed reactor (RBR) for use in 20-300 L vessels was charged with solid particles, used for pH neutralization, drained from reaction liquid and finally emptied from solid phase without opening the RBR. This procedure illustrates one approach to using RBR in production scale equipment without opening the reaction vessel.
Conditions: A SpinChem® rotating bed reactor (RBR) S511 was used in a 38 cm diameter cylindrical reaction vessel filled with 60 L water containing phenolphthalein as pH indicator. To this 2 L of ion exchange beads (IRN 99 H+, about 500 µm particle size) were added, followed by 0.5 L NaOH (1 M). During loading and reaction the RBR was spinning at 200 rpm, whereas 50 rpm was used during draining and unloading. The RBR was emptied by spraying water from nozzles in three baffles installed within the reaction vessel.
Computational fluid dynamics simulations is an important tool in the optimization of geometries during development of SpinChem® rotating bed reactor (RBR) products. The image shows velocity vectors in a cross section of the flow around a SpinChem® RBR, in a flower baffled reaction vessel, simulated using ANSYS Fluent software under typical laboratory conditions.
Conditions: The flow was simulated in ANSYS Fluent 17.1 using the steady MRF model at 500 rpm and the SST k-omega turbulence model on a mesh of 0.96 million elements. All dimensions used was identical to the SpinChem® RBR S221 and closely matched the SpinChem® flower baffled reaction vessel V221.
Short video of a coloured dye front moving in a transparent liquid through a pipe connecting an external rotating bed reactor to a larger vessel. The total convective flow rate was calculated to 440 L/h based on linear progression of the dye and assuming steady state turbulent conditions at Reynolds number 7900.
Conditions: A water filled (2 L) connected system consisting of a tank (1 L) to which an external flower baffled vessel (200 mL) was connected via pipes (24.6 mm ID). A SpinChem® rotating bed reactor (RBR) S221 filled with activated carbon (28 mL, 20-50 mesh) was placed in the external vessel and started rotating at 1000 rpm. Maximum velocity (Umax) in the middle of the bottom horizontal pipe was measured by following the movement of methylene blue (1 mL, 40 mg) by means of counting video frames, yielding a linear flow of 0.32 m/s. From the linear flow rate and the kinematic viscosity of water at 20 °C, Reynolds number in the pipe was calculated to 7900, indicating a predominantly turbulent flow for which the velocity profile is represented by U=Umax(1-r/R)1/7, where R is the pipe radius and r is the position from the centre. Numerical integration of this expression over the cross section of the pipe using the quadrature package in SciPy yielded the determined total flow rate. Note that this is an conservative estimate assuming steady state turbulent conditions which might not yet have established shortly after turning on the overhead stirrer. References: Flud mechanics and transfer processes, J.M. Kay, R.M. Nedderman, Cambridge University Press, Cambridge, 1985.