A contract chemical manufacturing plant worker

For contract chemical manufacturers, there is something very tantalising — and at times somewhat terrifying — about the word “scaling up”. It’s no easy task to take a process that’s magic in the lab and scale it up to industrial production. The is a thing all contract manufacturers should work through, but much harder than juicing chemicals up into a reactor. The path from the lab to commercial production is steeped in technical and logistical hurdles, and it could not be more important.

So, let’s get down to business by learning some of the biggest contract manufacturer obstacles during this critical stage and their success.

Complexity of Scaling Chemical Reactions

The first (and perhaps the most obvious) obstacle is the fundamental difference between small-scale lab production and large-scale production. Chemists, in their labs, make things using small amounts of stuff, exact measurements and controlled circumstances. It’s a sensitive process, in which all variables are calibrated for optimal performance.

Yet on the factory floor, these lab-perfect lab dynamics don’t always translate well. The reaction that happened in a 1-litre flask, with no trouble, could fail miserably in a 1,000-litre reactor. Heat balance, mixing rates and mass flow all change completely with scaling. Reactions well regulated in the laboratory can quickly accelerate or slow down too fast on a larger scale, leading to lower yields, impurities or even runaway reactions that are life-threatening.

Heat and Mass Transport: Staying Ahead of the Reaction

Temperature and mass transfer is probably one of the largest issues when it comes to scale. In the lab, it’s not hard to keep the temperatures and stirring rates steady enough that reactants flow easily together. Then you go to industrial production, and it’s much more difficult to maintain that control.

Consider heat transfer, for instance. With a small flask, heat travels rapidly and evenly through the solution. But, in a big reactor, heat doesn’t necessarily go through as well. Some parts of the solution can be too hot and side reactions will result or the mixture will go into breakage, while other parts can be too cold and slow the reaction down.

At a higher scale, mass transfer, as the motion and combination of molecules, becomes too. It is difficult to get the reactants mixed uniformly, and all reaction products into contact with one another, especially with high volume. That’s why the reactors at larger scale tend to have more elaborate mixing equipment to ensure that things flow uniformly through the entire reaction.

Variability of Raw Materials: The Consistency Conundrum

Another major challenge for scale-up is consistency in raw materials. Chemists have traditionally produced excellent, well-calculated chemicals in the lab. But when transitioning to industrial production, selecting raw materials on a mass scale introduces inaccuracies that were never a concern for smaller runs.

Other sources, subtle variations in purity, or even transport and storage conditions can influence these elements’ reaction behaviour. This variation can create an unreliable product — some batches of the product work just fine, and others don’t. Controlling this variation in raw material is key for contract producers, as it ensures that each batch is of the same high quality.

Supply Chain Stability: Where Everything Comes Together

And, speaking of raw materials, even the supply chain is a challenge. Scaling production involves importing many more chemicals, and those chemicals will change hands as markets shift, regulators or even geopolitics change.

For contract manufacturers, supply chain management is a balance between the continuous flow of raw materials without having to overstock or hit a bottleneck. It can mean closely aligning with suppliers, planning for the long term, and sometimes even developing secondary sourcing models to protect against disruption.

Continuous Quality Control at Scale

Quality control (QC) is important in every production line, but scale-up makes the process even more urgent—and difficult. Quality control in the laboratory can be as simple as experimenting with a few samples to check they are in accordance with expectations. But with production at scale, QC becomes more stringent.

With bigger batch sizes, more variation or error can get through, and contract manufacturers have to tighten up quality control. This can include in-line testing methods, which allow the customer to observe the product while it is forming, rather than at the end of production. And when caught early enough, they are able to fix issues without having to scrap a batch and have to redo it all over again.

Process Optimisation: Targeting Performance Fine-Tuning for Efficiency

Commercial manufacturing is all about efficiency. Even the tiniest inefficiencies in the laboratory become costly in large scale. For example, if you’re getting a reaction a little longer than planned in the lab, that might be fine, but if you’re manufacturing at scale, those extra hours lead to increased energy costs, production times, and lower throughput.

It’s about optimising processes. Subcontractors have to fine-tune the process to achieve the maximum yield, minimal waste, and shorter time-to-production. This involves frequently tuning reaction times, temperatures and concentrations so that it hits the sweet spot in which the process is efficient, smooth and stable.

Working within Environmental and Safety Regulations

With lab to commercial scale, environmental and safety requirements become increasingly crucial. In some respects, chemical production creates a huge environmental footprint, from waste to emissions. These effects are amplified on a large scale and contract producers will need to ensure they adhere to national and international regulations like REACH in Europe or environmental laws of other countries.

Furthermore, security is of paramount importance. Some reactions that are perfectly safe at the laboratory scale, can be harmful on a commercial scale if the temperature, pressure or other variables are more challenging to control. For contract manufacturing, risk assessments and safety controls should be strictly followed to ensure the safety of workers and the planet.

The Science and Art of Growing Up

Upscaling from the lab to production is the tricky and essential aspect of contract chemical manufacturing. It involves careful science, engineering and logistics. From heat transfer to raw material acquisition, each element needs to be managed so that the process is safe and effective while retaining high-quality final product.

Scaling successfully is the market’s true differentiation for contract chemical manufacturing. It’s chemical process engineering for manufacturing, and it’s the road to commercial success if done right. So if scaling up seems scary, it’s also where opportunity awaits, where laboratory innovation could find its way into the world at scale.

By Neil Kelvin

I'm writer specialising in the manufacturing sector of the UK.