Modeling and experimental investigation of renewable energy and ammonia-based systems for carbon capturing and useful outputs

Abstract

This thesis work focuses on developing ammonia-based carbon capturing systems that produce useful chemical outputs to offset the energy penalty typically imposed by implementing a carbon capture retrofitting to a power plant. These systems have been investigated through models that are based on exergy and economics tools. The motivation, and the objectives of this work are mentioned. Next, a thorough literature review of the topic of ammonia-based carbon capture systems is provided here to identify the gaps in knowledge. This review concluded that there is a significant lack in experimental investigations of ammonia-based carbon capture systems that are powered by renewable energy sources. Also, the direction of future carbon capture systems is moving towards co-producing of useful and valuable chemicals to offset the costs of operating such systems. By knowing this, renewable energy and ammonia-based carbon capturing systems that produce ammonium bicarbonate are developed and described. Thermodynamic models of the present carbon capturing systems are established using the energy and exergy tools. After that, exergoeconomic models are explained for these systems. Results of the simulation work show that the use of an electrochemical ammonia synthesizer has 13.3% lower energy requirements compared to the use of a proton-exchange membrane electrolyzer and the Haber-Bosch process for ammonia synthesis. The cost of producing ammonium bicarbonate is almost 16% of the market price of this chemical commodity. This indicates that the developed carbon capturing system are financially feasible to produce monetary value.