(5an) Back to the Future – a New Generation of Chemical Reaction Engineering Challenges

Onsite conversion of biomass, dissolution reactions in small-scale flows, and membrane science all include emerging challenges that chemical reaction engineering fundamentals can tackle. Furthermore, these research topics show potential for impacting science and education over the next decade. Onsite conversion of biomass from second and third generation feedstock to chemical products would help address transportation and storage issues that reduce efficiency. Modular, meso-scale processing units could potentially overcome this challenge, but require understanding chemical mechanisms, engineering catalysts, and creating novel unit operations. Dissolution reactions remain an important class of chemical transformations that impact our lives. Drug delivery, feedstock conversion (e.g., solid waste and forest residues), and synthetic chemistry applications can take advantage of accurate kinetics and mechanisms. The use of small-scale flow systems to elucidate this knowledge is limited by a lack of strategies for handling solid particulates, which presents tremendous opportunity for new insight. Finally, membrane science is on the brink of a revolution by potentially impacting energy, environmental (including water sustainability), and biological problems that demand robust and more efficient materials. Next generation membranes include novel hybrid materials that meet application requirements yet are efficiently manufactured. Nevertheless, new science is needed to continue moving this field forward. These emerging challenges warrant a multifaceted approach, which includes interdisciplinary collaboration, partnerships with industry and academia, and integration of modern problems into our curriculum.

Current research work at the Massachusetts Institute of Technology concerns application of microchemical systems for discovery and development. Over the past decade, microchemical systems have evolved from simple devices for basic chemistry (e.g., microreactors) to more complex systems for multi-step synthesis. Early studies using microreactors revealed the many advantages of chemical synthesis in small-scale flows such as enhanced heat and mass transfer characteristics, safer synthesis of dangerous compounds, isolation of air and moisture sensitive chemistry, and reduction of hazardous waste. Optimized reaction conditions and rapid experimentation also add value to the technology by shortening product development life cycles. These reasons and others have provoked recent interest in continuous-flow synthetic chemistry using microchemical systems. Nevertheless, small-scale continuous-flow chemistry is not without challenges. Efficient separations and handling solids are two challenges facing discovery and development with microchemical systems. These topics will be presented and discussed.