Performance Optimization of an Electrolyzer for the Hybrid Copper-chlorine Thermochemical Cycle
Open Access
- Author:
- Larow, Eric George
- Area of Honors:
- Energy Engineering
- Degree:
- Bachelor of Science
- Document Type:
- Thesis
- Thesis Supervisors:
- Serguei Lvov, Thesis Supervisor
Dr. Sarma V Pisupati, Thesis Honors Advisor - Keywords:
- Hybrid
Thermochemical
Cycle
Cu-Cl
Copper Chloride
Electrolyzer
Hydrogen - Abstract:
- A background of electrolyzers and thermochemical cycles for hydrogen production is first given to introduce the Cu-Cl hybrid thermochemical cycle. The research performed on improving performance of the electrolysis step of the Cu-Cl cycle is then presented. This research involved studying the effect of catalyst loading technique, quantifying the effect of reducing catalyst loading from the cathode and anode, quantifying the temperature dependence of cell performance, and observing the effect of anolyte and catholyte flow rate on the overall cell performance. By improving the performance of the Cu-Cl electrolyzer, the proposed Cu-Cl hybrid thermochemical cycle under development is pushed closer to an economically viable technology for producing hydrogen gas efficiently from renewable heat and electricity sources. A 62 % increase in current density at an applied potential of 0.6 V was achieved by switching catalyst application technique from painting to spraying at a loading of 0.8 mg/cm2 platinum. It was found that platinum catalyst was more effective at the cathode than the anode. When sprayed platinum loadings were reduced from 0.8 mg/cm2 on both the cathode and anode, to 0.4 mg/cm2 and 0.1 mg/cm2, respectively, the required amount of platinum catalyst was reduced by 69 % while only decreasing current density by approximately 24 % at an applied potential of 0.6 V. The findings of this research improved Cu-Cl electrolyzer design in terms of catalyst application, therefore improving economics behind proposed projects based on the Cu-Cl hybrid thermochemical cycle. Studies presented in this paper were also included in a transaction paper for the Journal of the Electrochemical Society (Hall et al. 2013).