What’s the BIG deal with industrial evaporation?

Scaling up from laboratory evaporation to industrial evaporation is not as BIG of a task as it sounds if you follow a few guidelines. In this post, I explore how different parameters must be altered as you scale up from small to large volumes of solvent. And I give you a reason why you should use laboratory evaporation before industrial evaporation. Think you already know it all yourself? Read on to find out.

I was at a steak house the other day and the waiter did a fantastic job convincing me that I would indeed need the 350 g steak and the 250 g just won’t do. I try to eat as small amounts of meat as possible, but it just smelled so good that I let him convince me. I upped my order, but this was maybe not in the best interest of my stomach or the environment.

There are times though where you have to go big or go home. For example, you might be doing wonderful experiments on a lab scale in the research lab, but often someone comes along to take what you are doing and replicate it on production scale.

I’ve already touched upon similar topics with how to use thin layer chromatography to scale up to flash chromatography and how to use analytical chromatography to upscale to prep HPLC. So why don’t I give rotary evaporation a turn now?

Upscaling from lab rotary evaporation to industrial evaporation might sound challenging, but there are some tips that can help you simplify the process.

For one, once you go from small volumes to big volumes, or from the laboratory evaporation to the industrial evaporator , you can keep several of your process parameters the same. The physical behavior of solvents is independent of their volume.

Therefore, settings such as vacuum, bath temperature and cooling are identical on both small and large Rotavapors.

One parameter you would have to alter when changing over to industrial evaporation is the rotation speed. The laboratory-scale evaporator has a typical speed of 280 rpm, whereas the industrial evaporator has a rotation speed of 150 rpm.

What kind of an output can you expect from industrial evaporation compared to laboratory evaporation? Well, with a lab-scale evaporation, you can evaporate amounts in the range of 3L Ethanol/h. If you keep all your parameters the same, but increase the size of the evaporation flask, you can expect to double your evaporation rate.

If you are really trying to reach a high evaporation rate with the lab rotary evaporator, for example by using an HP condenser, you might achieve rates of 4.5 L/h. With the same conditions and an industrial evaporator, you can probably evaporate about 3 times as much.

Another parameter you should consider is the fill level. On a lab scale evaporator, you can fill up to 2.5 L in the evaporation flask. An industrial evaporation flask can handle the astonishing amount of 13 L when tilted. These high volumes of solvent, plus additional heating power and cooling power, greatly contribute to boosting the performance of the industrial evaporation.

The laboratory rotary evaporator is incredibly useful for performing feasibility studies and testing applications before purchasing or using an industrial evaporator.

With the smaller system, you can characterize behaviors such as foaming, you can determine the right temperature for the heating bath and chiller, or you can find the ideal vacuum setting. Then you can transfer these parameters to your industrial evaporator.

One feature that can further simplify transfer between the lab-scale and industrial-sized evaporator is the interface. If the interface can control both of your rotary evaporators, then changing between the two systems and upscaling your work is made even easier.

For a video on the topic of scaling up from small to large volumes, check out this link:

And if you are already using industrial evaporator, you might benefit from seven tips on how to optimize your industrial evaporation performance. This is certainly a topic for a future blog post!

I hope I supersized your knowledge on how to scale up from laboratory evaporation to industrial evaporation. I would hate to leave you starving for more, but hey, the thirst for knowledge is hard to quench. Keep on coming back to the blog to feed your curiosity.

Till next time,

The Signature of Bart Denoulet at Bart's Blog