Investigation of new KOH and NaOH thermochemical cycles for hydrogen production and carbon capturing

Hydrogen production and carbon dioxide removal are two of the critical pieces to achieve ultimate sustainability target. This study develops and investigates four new versions of NaOH and KOH thermochemical cycles to combine hydrogen production and carbon dioxide removal in an integrated and synergistic manner. The sodium hydroxide and potassium hydroxide thermochemical cycles are considered as the base cycles to produce hydrogen by using a nonequilibrium reaction. The proposed new 4-step and 5-step version thermochemical cycles incorporated with carbon capture, are investigated from the energy and exergy perspectives of thermodynamics. Also, these newly developed versions are assessed from techno-economic and environmental perspective in order to reveal the economic feasibility and environmental impact of these cycles. In addition, optimization studies are carried out for the newly proposed versions in order to determine the optimum parameters to carry out the reactions to improve the source utilization and maximize the hydrogen production and carbon removal. Furthermore, newly developed four versions are comparatively assessed with already available two versions of NaOH and KOH thermochemical cycles, in order to see the changes from thermodynamic, chemical, and economic aspects. Calculations showed that heat to hydrogen conversion can be carried out up to 50.36% and 77.09% of energy and exergy efficiencies with the newly developed versions. Significant environmental benefits demonstrated that a kg of hydrogen can be generated between 2 and 2.4 kg of carbon dioxide emissions without carbon capture and up to 19.8 kg of carbon dioxide removal with carbon capture.

Name thesis:degree_name

Doctor of Philosophy (PhD)

Discipline thesis:degree_discipline

Mechanical Engineering

Grantor

University of Ontario Institute of Technology

Year dc:date.issued

2024

Author dc:creator

• Temiz, Mert

Advisor dc:contributor.advisor

• Dincer, Ibrahim

Language dc:language.iso

en

Handle dc:identifier.uri

https://hdl.handle.net/10155/1908

OAI identifier oai:identifier

oai:ontariotechu.scholaris.ca:10155/1908