Development and investigation of integrated solar systems for hydrogen and methanol production

Abstract

Implications of climate change, in particular the negative effects of greenhouse gas (GHG) emissions resulting from fossil fuel combustion, as well as the finite nature of fossil fuels necessitate the implementation of reliable and environmentally benign alternative energy options. This is particularly true for transportation and power generation sectors, which are responsible for the majority of carbon dioxide emissions. Hydrogen is a clean fuel that can be produced from renewable energy via electrolysis and direct photonic energy conversion from sunlight, produces no harmful emissions in combustion, and can be converted to electricity via fuel cells with good efficiency. However, it is challenging to store H2 in a cost and energy efficient manner, and it is not widely available to consumers in comparison to traditional liquid fuels for transportation applications. Storage of H2 produced from solar energy in synthetic fuels is a key step in moving towards an eventual hydrogen economy. By conversion to synthetic fuels such as methanol, hydrogen and solar energy may be directly utilised in current infrastructures as liquid fuels for transportation or in power generation applications. This thesis experimentally investigates clean hydrogen production from solar energy and water using a novel photoelectrochemical water-splitting reactor designed, built, and tested at the Clean Energy Research Laboratory in UOIT. Integrating solar concentration and a spectrum-splitting mirror allows simultaneous photovoltaic electricity generation and direct photonic energy conversion to split water via PEM electrolysis and photoelectrochemical water splitting on the custom built photocathode of the reactor. Case studies are presented for system integration with methanol synthesis from solar energy and anthropogenic carbon capture for environmentally benign fuel production.