Development and analysis of novel photoelectrochemical reactor for solar based clean hydrogen production

In the scope of this thesis, a photoelectrochemical hydrogen production reactor is comprehensively investigated by using experimental and numerical analyses methodologies. In this regard, the primary objective of this study is to develop a new photoelectrochemical reactor enabling solar-based hydrogen production in an environmentally benign manner. The unique conic-mesh structural design of the working electrode adapted to provide a passive solar-light tracking characteristic to the system enhancing the solar light absorption throughout daylight time. In sequence, electrodeposition and sol-gel dip coating techniques are practiced fabricating a copper oxide semiconductor as a working electrode and a titanium dioxide-coated electrode in counter. The new reactor concept is experimentally tested for various conditions through physical electrochemical tests including open circuit potential, linear sweep voltammetry, cyclic voltammetry and PWR potentiostatic tests for the characterization of the photoactive electrode. Energy and exergy efficiencies and hydrogen production rates are evaluated for various experimental conditions including with and without light cases. The developed photoelectrochemical hydrogen production reactor is also numerically simulated and comprehensively analyzed by using electrochemical, thermodynamic, life cycle analysis, scale-up analysis, and optimization techniques. The highest hydrogen production rate corresponding to 4.48 μg H2/s at near atmospheric conditions (25 oC temperature and 101.3 kPa pressure) is obtained with the applied external bias of 2.25 V, where the reactor operates under artificial solar light with an intensity of 1000 W/m2. The produced photocurrent density is determined to be 1.81 mA/cm2, corresponding to a photo-conversion efficiency (ABPE) of 1.84%. For these operational conditions, the energetic and exergetic efficiencies of the reactor are evaluated as 0.866% and 0.878%, respectively. Without light case, the PEC reactor acting as an electrolyzer operates with energetic and exergetic electrolysis efficiencies of 56.51% and 54.38%, respectively. The comparative life cycle assessments resulted that the global warming potential of the photoelectrochemically produced hydrogen is the lowest corresponding to a value of 1.052 kg CO2 eq per kilogram produced hydrogen. From the scale-up analysis, the levelized cost of the photoelectrochemically produced hydrogen is evaluated as $3.47 per kilogram of H2.

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

2023

Author dc:creator

• Karaca, Ali Erdogan

Advisor dc:contributor.advisor

• Dincer, Ibrahim

Language dc:language.iso

en

Handle dc:identifier.uri

https://hdl.handle.net/10155/1875

OAI identifier oai:identifier

oai:ontariotechu.scholaris.ca:10155/1875