(355b) Ammonia Production at Milder Conditions for Distributed Manufacturing | AIChE

(355b) Ammonia Production at Milder Conditions for Distributed Manufacturing


Malmali, M. - Presenter, Texas Tech University
Nowrin, F. H., Texas Tech University
Lin, B., Texas Tech University
Hrtus, D., Texas Tech University
Fotsa, Y., Texas Tech University
Ammonia produced via the well-known Haber-Bosch (HB) process is one of the most important innovations of the 20th century. In the conventional process, reactants are produced through steam reforming of natural gas. Once produced, hydrogen and nitrogen react at high temperatures (400–500 °C) and high pressures (150–300 bar) in the HB reactor to produce ammonia. High temperature is needed to accelerate reaction kinetics while high pressure is required to increase the single-pass conversion. The HB process is critical to sustain the food production, as it is an indispensable ingredient of nitrogen fertilizers. Not only a fertilizer, ammonia is recently proposed as an indirect form of hydrogen storage because of its high hydrogen density (17.8 wt.%) and the viability of long-term storage and delivery.

Distributed “green” ammonia produced with hydrogen from water electrolysis and nitrogen from air has been considered as an alternative to the fossil fuel-based ammonia production. To realize the idea of distributed ammonia manufacturing, designing optimized small-scale HB process that operates at milder conditions is on demand. In this presentation, I will discuss two strategies to reduce the pressure and temperature requirements. First, the idea of replacing the phase-changing condensation with high-temperature absorption will be discussed that can lead to reducing the operating pressure by a factor of ten (10-20 bar). I will then discuss the design of better catalyst materials that can reduced the reaction temperature to 300 °C.