Development of seawater electrolysis with low-cost membranes for sustainable cement production and pretreatment

Membrane electrolysis is an electrochemical process that uses ion-exchange membranes (IEMs) to selectively migrate ions and recover valuable resources from seawater. Despite its advantages, its application in large-scale industrial processes like cement production has been limited by the high costs and low mechanical durability of traditional IEMs, such as AEMs and CEMs. These membranes are susceptible to fouling, oxidation, and corrosion, which reduce their efficiency and lifespan, making the process less viable for industrial scalability. In this research, a novel approach utilizing ultrafiltration (UF) membranes, typically employed in filtration processes, is proposed as a cost-effective alternative to traditional AEMs and CEMs in seawater electrolysis. UF membranes, known for their superior mechanical strength and lower cost, are used to selectively separate calcium (Ca2+) and magnesium (Mg2+) ions from seawater, precipitating them as calcium hydroxide (Ca(OH)2) and magnesium hydroxide (Mg(OH)2), respectively. These hydroxides can then be calcined into calcium oxide (CaO) and magnesium oxide (MgO), which are key raw materials for Portland cement production. Compared to the conventional process of producing cement from limestone, which releases substantial carbon dioxide (CO2) emissions due to high-temperature calcination, this method significantly reduces CO2 emissions. By sourcing Ca2+ and Mg2+ directly from seawater and eliminating the need for mining and processing of limestone, the overall carbon footprint of Portland cement production is greatly minimized. This makes the process not only more environmentally sustainable but also economically feasible due to the use of low-cost UF membranes and renewable seawater resources. Furthermore, the integration of UF membrane electrolysis with membrane distillation (MD) demonstrates additional benefits, such as improved water recovery rates and reduced scaling of desalination membranes. The simultaneous recovery of freshwater and valuable resources like lithium further enhances the process’s potential for sustainable seawater resource utilization. UF Membrane electrolysis also presents a promising approach as a direct pretreatment technology for impurity removal from seawater. It demonstrates the capability to achieve an efficient removal rate of up to 99% for divalent ions. Furthermore, the removal of boron and bromide can be effectively facilitated through precise pH regulation. In conclusion, this thesis demonstrates the feasibility of UF membrane electrolysis as a low-cost, scalable solution for decarbonized cement production, with additional applications in seawater desalination and valuable resource recovery from seawater through hybrid processes. The findings offer a significant advancement in the development of sustainable technologies for industrial applications, offering new prospects for maximizing the efficient utilization of seawater resources.

Author dc:creator

• Chen, Qian

Statement dc:rights

• info:eu-repo/semantics/embargoedAccess
• The author owns the copyright in this thesis including all reproduction and reuse rights for the work. The work may not be altered without the permission of the copyright owner. Attribution is essential when quoting or paraphrasing from this thesis.
• © 2025 Qian Chen
• au.edu.uts.lib/cph

Language dc:language.iso

en_US

Handle dc:identifier.uri

http://hdl.handle.net/10453/190104

OAI identifier oai:identifier

oai:opus.lib.uts.edu.au:10453/190104