Scale Up
Process scale up & Process development
Key Benefits Include:
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Dynamically visualise and validate process conditions at different scales
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Confirm process models at different scales
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Identify turbulent / stagnant regions
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Determine process end point by scanning multiple points in process volume
Introduction
New processes are usually developed at lab-scale in small volumes. Under these conditions reaction conditions are approximately the same throughout the vessel. When processes are scaled up to pilot scale or full production at plant scale, vessel volumes are increased by orders of magnitude and homogenous reaction conditions can no longer be assumed.
This leads to different zones or regions in reaction vessels having different process conditions and can be particularly important in exothermic reactions.
Process scale up can often then lead to different reaction conditions occurring than in the original process design, which in turn leads to reduced yields or quality issues through side reactions producing by products.
There are a range of scale up rules (such as mixing power per unit volume, matching impeller tip speeds), however these are rules of thumb and do not always hold true, for example with many non-Newtonian fluids.
Developing an understanding of design space and process modelling through CFD or other modelling tools can often help with process scale-up. However very often such models need validation.
Solution
Process scale up is one of the key areas where process tomography can offer significant advantages. For example the 8-plane p2000 can deliver 2,500 measurements at different locations in a vessel several times per second.
This information can be used to:
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validate process conditions
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confirm process models
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visualise a process and determine the extent to which process conditions vary
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identify turbulent and stagnant regions to inform placement of sensors
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determine process end points.
Where a process envelope is being developed (such as through QbD or as part of a PAT strategy), process tomography can be an important tool in increasing process understanding.
