Beyond the Reaction:
An Integrated Approach to Process Scale-Up
Over the last two decades, laboratories around the world have successfully created new metal-organic frameworks (MOFs) for a variety of applications — making them more stable, reliable, and practical, as well as unlocking new possibilities for addressing global challenges. But despite these advancements, many labs still only produce grams at a time. NuMat is changing the MOF landscape by innovating advanced manufacturing processes to scale production from grams to tons using standard chemical production equipment.
NuMat goes beyond the reactor to address the full set of challenges posed by the scale-up process, including:
Optimizing each MOF for synthesis using pilot units for reaction, washing, and activation
Recovering waste based on economic efficiency
Forming MOFs to fit specific, application-driven requirements
Scaling MOFs requires more than just larger vessels — it requires a full consideration of downstream production and supporting infrastructure, including for safety, compliance, and quality control. NuMat’s innovative workflow is creating a new era for MOF-enabled products in key sectors, including microelectronics, defense, life-science, and emerging technologies.
Today, NuMat is producing MOFs in commercially scale quantities through a highly integrated workflow, from high-throughput experimental discovery to application development to prototype testing and product launch. Our dedicated team of process engineers brings unique expertise in scaling and forming materials.
While each MOF is intricate and unique, different groups of MOFs have common properties that enable scale-up processes specifically adapted to them. NuMat has extracted these generalizable principles that can be applied and replicated across MOFs to scale them to commercial levels. Key to the process is setting up pilot units for:
Each unit is optimized to suit the individual MOF. For the synthesis of the MOF itself, the NuMat team adjusts process variables to optimize yield, surface area, particle size, particle size distribution, and particle circularity. Kinetic studies on multiple small-scale reactions allow for systematic analysis of the interacting variables to create the optimal reaction within stainless steel reactors.
The washing and separation process units are scaled to match the reactor output.
This requires the design of vessels with scalable adaptations of lab-scale workflows. Throughout this process, attention must also focus on health, safety, and environmental compliance, while also minimizing facilities costs.
Key to achieving this balance is reducing reaction times. Each hour of reaction time comes at a cost of thousands for labor and equipment depreciation. By speeding up reaction times through pressure and temperature controls, along with facility-level engineering management and automated tools, the NuMat’s team of expert engineers is able to create more efficiency at lower cost.
NuMat takes a holistic approach to the production process — iteratively and quantitatively assessing a range of considerations that affect performance, cost, and efficiency. A major issue in creating MOFs is use of solvents, which is a major cost driver. NuMat has developed ways to reuse reagents in commercial-scale MOF production. This is part of our full economic model.
In many cases, the best economic option is to recover solvents after washing and reuse them in MOF production. Factors that influence this decision include the type of MOF, the volumes being produced, and environmental considerations.
NuMat has set up a robust infrastructure for making such economic decisions within a solid framework that complies with safety and other regulations.
Once MOFs are synthesized, they must be formed to suit the specifications of their intended application. NuMat has a state-of-the-art formation applications lab and team dedicated to optimizing a number of techniques that result in different materials forms, from granules and pellets to hockey puck-like discs.
Material formation is a common challenge in MOF production as MOFs have a wide range of mechanical, thermal, and chemical stability when compared to other adsorbents. As a result, significant know-how is required to maintain material performance when using industrially relevant formation techniques. NuMat has innovated new methods to form MOFs that achieve specific performance requirements.
The proper formation of MOFs requires tight control of particle size and distribution to optimize mass transfer characteristics. Any formation process must optimize for adsorption capacity and saturation at the pore level for each application. Choosing the ideal formation technique requires a thorough understanding of the technical requirements of a given application.
Such a consideration is especially important in pressure-swing adsorption, in which the mass transfer rate of the sieve controls cycle time and affects bed size factor; the faster the mass transfer, the smaller the bed size. Decreasing particle size speeds up mass transfer but increases pressure drop. To circumvent this pressure drop, sieve materials are formed into pellets with macroporous interparticle voids. NuMat has devised a number of formation options to handle various such scenarios in which pressure drop may influence MOF performance.
NuMat has produced single-crystal particle sizes ranging from 1 micron to 2 millimeters with narrow particle size distribution. This includes techniques to mechanically form MOF materials with little to no loss in surface area.
In cases where mass transfer rate and pressure drop are critical to system performance, NuMat has developed macroporous MOF-polymer beads using techniques developed for ion exchange resins. In this technique, MOFs are blended with polymers, allowing the full exploitation of MOF surface area.
Toward a Predictive Process
Creating an integrated workflow for scaling up MOFs to commercial levels involves significant engineering, scientific, and manufacturing expertise. Although commercial off-the-shelf equipment is used, advanced kinetic, computational and other work is necessary. Safety and compliance are also a major consideration.
Scaling requires constant re-evaluation of safety risks. Many safety items that are irrelevant on the lab scale become primary drivers at commercial volumes. Examples include asphyxiation risk of inert gas, explosion risk of powder drums, and flammability risk of solvent transfer. In developing its commercial-scale operations, NuMat has identified such risks and designed a facility to address them that is compliant with relevant regulatory codes.
Moving forward, the primary scientific hurdles that remain to making the MOF scaling process even more robust is a fuller understanding of the kinetics that underlie how MOFs are synthesized. NuMat is a leader in developing
optimized reactors for synthesis. The engineering team is continually working to improve understanding to make the field more predictive.
NuMat continues to work at the leading edge of MOF production, creating large volumes of high-value, high-performance materials to address a variety of commercial challenges.