De-risking hydrogenation:

Since hydrogen gas is highly flammable, precise control of pressure and temperature is vital for safe and effective reactions, as well as for mitigating potential impurities that may form. Chemists can leverage parallel reactions and design of experiments (DoE) software to optimise these conditions early on, then employ automated systems that monitor these conditions in real-time as a reaction occurs.

The method of hydrogen gas introduction, such as headspace pressurisation or hollow agitator, can affect mass transfer and reaction efficiency. Uneven gas dispersion or inefficient hydrogen usage can occur if the most appropriate method is not used for a particular scale or process. Tools like Dynochem can be used to evaluate gas-liquid mass transfer during scale-up and aid in selecting the most effective method for gas delivery. 

Catalysts determine reaction selectivity and rate, making it critical to rapidly identify the optimal one. Parallel reactor systems, paired with DoE, are particularly useful for this process, allowing chemists to quickly and efficiently test a wide range of catalysts. This speeds up development while also ensuring the effectiveness of the chosen catalyst at a larger scale. 

Hydrogenation reactions become more hazardous and challenging to work with as they scale, making it imperative to proactively prepare for scale-up. One way to circumvent scale-up challenges is by harnessing lab-scale equipment that closely mimics that which will be used as the project scales, reducing risk and supporting ongoing optimisation. In addition, conducting mass transfer modelling and mixing studies early on and using specialised scale-up software like Dynochem aid de-risking the process. 

In addition to a general scale-up assessment, thorough hazard evaluation studies are imperative for implementing the right engineering controls and avoiding the health and safety risks that hydrogen gas can bring. Establishing standard operating procedures for charging, reaction processing, and post-reaction handling, as well as ensuring all team members are properly trained on potential risks, is crucial for safely handling hydrogenations. The flammability of hydrogen and the pyrophoric nature of many catalysts make proactive safety planning essential, and controls like hydrogen detection and pressure release systems can aid in eliminating risk as the process scales. 

Contaminants in reactors can deactivate catalysts, which unnecessarily wastes material, extends project timelines, and introduces additional risks. Strict cleaning and conditioning protocols between runs are imperative to eliminate impurities that could impact future reactions and ensure continued catalytic efficiency.

Once the reaction is complete, removal of catalysts and other potential byproducts is important to ensure purity and effectiveness. Carbon filtration and scavengers can be used to isolate catalysts and other byproducts. Once processing is complete, any precious metal catalysts used should be evaluated to ensure that they are recovered and recycled where possible, improving the environmental sustainability and economics of the process. 

Stability testing to define safe hold points is important to ensure ongoing product quality and compliance in processing, storage and transport. Conducting stress tests helps to identify optimal conditions under which the product remains stable.