Convert Batch Reactor to Flow Reactor for CO2 Reduction and Ammonia Synthesis

Abstract

Fertilizer is mass-produced and used worldwide in agriculture. A key ingredient in fertilizer is ammonia, which is highly energy-intensive to produce on an industrial scale due to the high temperatures and pressures required (400-500 C, 150-250 bar) . This 1 thermally-driven process typically requires significant fossil fuel use. The greenhouse gas emissions from ammonia production alone contribute to 2% of annual global emissions . 2 Alternatives to the traditional thermally-driven Haber-Bosch process used to generate ammonia have been studied extensively, and using a light-driven photothermal process is a promising strategy. However, the use of this process for ammonia production must be investigated and better understood in order to make it more feasible for use in industry . 3 This project works towards creating an understanding of the photothermal catalysis process and reactor design, with the end goal of improving the reaction yield for ammonia synthesis. Currently, a batch reactor is used to perform photothermal reactions, including CO2 reduction and ammonia synthesis, in the Dasgupta lab. Batch reactors involve introducing reactants at the start of the reaction, followed by monitoring the gas composition with respect to time. On the other hand, flow reactors allow for the continuous introduction of reactants, generally allowing for more rapid data collection and analysis. Additionally, using a flow reactor in lieu of a batch reactor can decrease the downtime between stages of a reaction. In the synthesis of chemicals such as ammonia, flow reactors are more industrially relevant than batch reactors. Testing using the lab-scale flow reactor is an important step prior to the eventual design and implementation of a pilot-scale reactor. Designing the new flow reactor setup was my task.