Image of a researcher scaling up from a round bottom flask to a large scale jacketed lab reactor

A reaction that works is not the same as a process that scales.

Most chemists have seen this happen: a reaction performs well at small scale, but behaves differently when transferred to a larger vessel. Yield drops, impurities appear, selectivity changes or an exotherm becomes harder to control.

Often, these problems have not appeared suddenly. They were already present, but hidden by the small-scale workflow.

When developing a process, it is important to look beyond whether the chemistry “works”. Confident scale-up depends on understanding and controlling the reaction environment from the earliest practical stage.

What can affect scale-up?

Several factors that may seem manageable at small scale can become critical during process development.

Temperature control
Hotplates, heating mantles and ice baths can give limited control over the true process temperature. At larger scale, heat removal becomes more difficult and exotherms can become more significant. Internal temperature measurement, active cooling and controlled temperature ramps help reveal and manage these risks earlier.

Mixing
Magnetic stirring is convenient, but it is not always representative of larger-scale processing. Overhead stirring, scalable impeller design and consistent vessel geometry can help chemists generate data that is more relevant for scale-up.

Data capture
Manual observations and end-point measurements only tell part of the story. Real-time data logging helps chemists understand what is happening throughout the reaction, making it easier to compare runs, transfer knowledge and reproduce results.

Reagent additions
At small scale, additions are often carried out manually. At larger scale, addition rate can directly affect safety, selectivity and reproducibility. Pump-controlled dosing, especially when linked to process temperature, can turn addition strategy into an effective control tool.

Designing for scale-up earlier

Representative, controllable workflows can help chemists identify hidden variables before they become larger-scale problems.

Systems such as the Mya 4 Reaction Station, Reactor-Ready jacketed reactors and AVA Reaction Control Software support this by enabling controlled temperature, scalable stirring, automated data logging and feedback loops.

For example, in one customer application, an exothermic addition was controlled using AVA software linked to a jacketed reactor, pump and circulator. The pump automatically paused when the process temperature rose above the defined limit, then restarted when the temperature returned to the acceptable range. This helped maintain control of the reaction during scale-up.

In another case, a design of experiments workflow was repeated using Mya 4 with active cooling, overhead stirring and full data logging. This improved consistency at small scale and provided enough process understanding to support successful scale-up to 100 L, avoiding a lengthy reformulation stage.

Better understanding, lower risk

Scale-up confidence comes from understanding the reaction environment, not just the reaction outcome.

By controlling temperature, mixing, additions and data capture earlier in development, chemists can build more reproducible workflows, reduce risk and make better decisions before committing time and material to larger-scale work.

To hear the full discussion and see the customer examples in more detail, watch the webinar on demand: Designing Reactions for Confident Scale-up.

You can also book a 1-2-1 online demonstration with one of our experts to discuss how controlled reactor workflows could support your process development.