The negative effects of pilot-scale scaling up
Thread Content
Recently, during experiments to scale up from pilot scale, it was found that when the amount of material used in the pilot tests was increased by 10 times, a significant impact on the product yield became evident. It affects about 4%. I don’t know how to reduce this difference.
Negative effects may arise when scaling up from lab-scale experiments; this is purely within the normal range. It is advisable to make appropriate changes to some parameters to see if there is any improvement.
Here are a few personal opinions: 1. “Increasing the feed amount by 10 times in the pilot test” is not an increase; rather, it is a change in one variable – the feed amount – and it remains within the scope of the pilot test. 2. “Pilot scale-up” refers to the scaling up of production volume and production equipment. 3. The scaling effect, especially that of reactors, arises from the conflict between chemical reactions and mass and heat transfer, and involves many aspects.
You’re not doing any scaling up at all; you’re just replacing a 250ml four-neck flask with a 2500ml one. This doesn’t even qualify as pilot-scale production – scaling up by 10,000 times would be more like it. It’s actually just a test of the process; variations of this kind are normal. It seems that your yield has decreased by 4%, so it’s likely that you haven’t mastered one of the parameters properly, or the conditions used aren’t exactly the same as those in the pilot test. You need to carefully investigate the reasons for this.
Thank you all here. I observed such obvious negative effects even with a 10x magnification test. It’s quite surprising. It is currently being rectified. I hope its negative effects can be reduced
10 times magnification is already considered magnification; there is no requirement for 10,000 times magnification.
Regarding what the original poster said about increasing the feed amount by 10 times, I’m not sure if the size of your equipment has changed. “The impact can be clearly seen from the product yield. It affects about 4%. ”There are many possible reasons. For example, if the amount of material fed in is large and the concentration of the reaction materials is high: 1. It may be affected by the reaction equilibrium. 2. Side effects have increased. 3. The heat transfer requirements are high, and heating or cooling cannot keep up. 4. With a large amount of material, the reaction residence time does not increase accordingly. In short, there are many factors.
“\"The feed rate is increased by 10 times.\" If the reactor and other components are not scaled up as well, the reaction residence time will definitely change.
The reaction should also have a yield range within which all values are acceptable; it’s impossible for the yield of each batch in pilot tests to be exactly the same! Increasing the feed rate – is there a central control system? Is the condition control strict? If the conditions are strictly controlled and there is strict central monitoring, there should not be much difference!
The container size is increased by 6 times, and the feeding amount is increased by 10 times. The control conditions remain unchanged. It is preliminarily determined here that mass transfer and mixing degree have an impact on the yield. As for whether there are any others, I would appreciate advice from those with relevant experience.