Site items in: Content by Author Paul Dauenhauer

Optimizing absorption to improve Haber-Bosch synthesis
Presentation

Ammonia absorber columns offer an alternative separation unit to replace condensation in the Haber-Bosch synthesis loop. Metal halide salts can selectively separate ammonia from the reactor outlet gas mixture and incorporate it into their crystal lattice with remarkably high thermodynamic capacity. While the salts’ working capacity can be limited and unstable when they are in their pure form, the capacity is stable and can be high when using a porous silica support. Here, we discuss optimal conditions for uptake and release of ammonia. The production capacity (ammonia processed per unit absorbent and per unit production time) depends on processing parameters…

Ammonia Absorbents with High Stability and High Capacity for Fast Cycling
Presentation

Ammonia absorption is an alternative separation to condensation in ammonia production. Metal chloride salts selectively incorporate ammonia into their crystal lattices with remarkably high capacity. Regeneration and stability of these salts are further improved by dispersing them onto a porous silica support. Here, we discuss the optimal preparation methods of supported metal halides, as well as optimal conditions for uptake and release of ammonia. The metal halide salt particle size, support particle size, support composition and preparation methods are optimized for material stability, speed of uptake and release, and maximum ammonia capacity. An automated system was used to rapidly screen…

Potential Strategies for Distributed, Small-Scale Sustainable Ammonia Production
Presentation

Potential Strategies for Distributed, Small-Scale Sustainable Ammonia Production Alon McCormick*, Ed Cussler, Prodromos Daoutidis, Paul Dauenhauer, Lanny Schmidt, Chemical Engineering and Materials Science; Roger Ruan, Doug Tiffany, Bioproducts and Biosystems Engineering; Steve Kelley, Humphrey School of Public Affairs; Mike Reese, West Central Research and Outreach Center, University of Minnesota