Green hydrogen production via water electrolysis represents a viable strategy to decarbonize the global energy economy, as it can address the intermittent issues of solar resources and serve as a fungible energy carrier. Solar-derived water electrolysis requires 45–65 kW h kg⁻¹ H₂ of electricity and ~10 L of deionized water to produce 1 kg of hydrogen. Competing water usage could limit deployment at scale for renewable electrolysis installations in arid, sunny climates. Our recent studies have demonstrated that producing renewable hydrogen using only sunlight and wastewater is a promising approach to reduce water and carbon footprints [1,4]. Additional revenue can be obtained from waste management and by-products recovery (clean water, organics/minerals).

This project will develop a system for raw wastewater management and green hydrogen production. It will allow encompassing the following challenges/tasks:

Activity 1: Identify suitable wastewater feedstocks (e.g., mining wastewater, natural water, seawater) and establish typical compositions.

Activity 2: Develop an appropriate solar driven water treatment process to pre-condition one of these wastewaters for: (a) waste management, such as brine concentration; (b) produce suitable feeds for flow electrolysis cell, such pre-conditioned biomass, deionized water.

Activity 3: Producing renewable hydrogen using the solar driven flow electrolysis cell (a commercial cell or in-house-designed prototype cell), fed by pre-conditioned wastewater.

This work will contribute to a project funded by the Trailblazer Universities Program and be undertaken within the PartCat Research Group (https://www.pcrg.unsw.edu.au/hydrogen-value-chain-solar-reforming-of-waste-organics-for-clean-hydrogen-production). The expected outcome of the thesis project are described below in order of increasing challenge:

1. Re-build a solar driven membrane distillation system (please refer to [2]) to produce deionized water from a synthetic wastewater (such as desalination brine). Then evaluate the performance of an established PV driven commercial electrolyzer system by using the produced deionized water.
2. Develop a multi-stage process for producing clean water and value-added minerals from inorganic wastewater (e.g., selectively remove ions), assembling a flow electrolysis cell and a PV solar system to produce renewable hydrogen.
3. Develop an organic wastewater pre-treatment system (e.g., to digest, or recover, concentrate) and using the pre-conditioned organic biomass molecules to produce renewable hydrogen and value-added chemicals using an in-house prototype electrolyzer.

Suitable for (choose one or more): Chemical Engineers

Suitable for remote completion: No

Level of difficulty (choose one): Challenging

Suggested completion time (choose one): Three Terms (standard enrolment)

Supervisors:

• A/Prof Jason Scott
• Dr. Qiyuan Li
• Dr. Lixue Jiang

Suggested readings/references/more information:

[1]. Li, Q., Jiang, L., Huang, G., Wang, D.-W., Shepherd, J., Daiyan, R., Markides, C.N., Taylor, R.A. and Scott, J.  2023.  A ternary system exploiting the full solar spectrum to generate renewable hydrogen from a waste biomass feedstock. Energy & Environmental Science.

[2]. Li, Q., Charlton, A.J., Omar, A., Dang, B., Le-Clech, P., Scott, J. and Taylor, R.A.  2022.  A novel concentrated solar membrane-distillation for water purification in a building integrated design. Desalination 535, 115828.

[3]. Li, Q., Zhuo, Y., Shanks, K., Taylor, R.A., Conneely, B., Tan, A., Shen, Y. and Scott, J.  2021.  A winged solar biomass reactor for producing 5-hydroxymethylfurfural (5-HMF). Solar Energy 218, 455-468.

[4]. L. Jiang, J. Pan, Q. Li, H. Chen, S. Zhou, Z. Yu, S. Jiang, H. Yin, J. Guan, R. A. Taylor, R. Fisher, G. Leslie, J. Scott, H. Zhao and D.-W. Wang, A holistic green system coupling hydrogen production with wastewater valorisation, EcoMat, 2022, e12254.