The Power of Membranes: Unlocking a Sustainable Energy Future
As the world grapples with the challenges of climate change, energy security, and sustainable development, innovative technologies are emerging to transform the energy sector. One such game-changer is membrane technology, which is revolutionizing the way we generate, store, and use energy. In this blog, we will look into the importance of membrane applications in energy and explore examples from around the world.
What are Membranes?
Membranes are semi-permeable barriers that separate substances based on their size, shape, and properties. They facilitate the movement of materials like ions and gases while preventing the flow of undesired materials. Membranes can be made of metals, plastics, ceramics and composites and they are important to fields such as biology, energy, water treatment, chemical engineering, and materials engineering.
In the context of energy and energy systems, membranes play a crucial role in various applications, including fuel cells, energy storage, hydrogen production, carbon capture, water treatment, and gas separation.
Fuel cells: Fuel cells are electrochemical devices that convert chemical energy from fuel into electrical energy. Fuel cells employ membrane technology like proton exchange membrane or anion exchange membrane for their operation. The membranes are very important in the device as they serve as electrolyte barriers which allow selective ions to pass through while blocking the passage of other ions and gases.
In the Proton Exchange Membrane Fuel Cell, hydrogen gas is supplied to the anode to be reduced into hydrogen ions and electrons. The electrons flow through an external circuit to generate electricity while the hydrogen ion selectively passes through the membrane to the anode where it combines with oxygen gas and electrons to form water.
Energy Storage: Energy storage devices like batteries make use of membranes in their role of converting chemical energy into electrical energy. The membranes control the movement and separation of ions.
In lithium-ion batteries, there exists a porous separator membrane that allows the movement of lithium-ion between the cathode and anode during the processes of charging and discharging.
In redox flow batteries, membranes allow the selective movement of ions between electrolyte tanks and also prevent mixing of the electrolytes. This exchange of ions enables the electrochemical reactions that lead to the storage and release of electrical energy.
Hydrogen production: The production of hydrogen gas is a very important process that is vital in the energy sector. Hydrogen gas is a fuel that does not exist freely in large quantities and as such, it is produced from water and other organic compounds. In hydrogen production, membranes are very important in enabling separation and purification of hydrogen gas.
In hydrogen production by water electrolysis, proton exchange membranes are employed. Water is first oxidized at the anode to produce oxygen gas, hydrogen ions, and electrons. The membrane allows the selective movement of the hydrogen ions from the anode to the cathode while blocking the movement of oxygen gas. The hydrogen ions are reduced at the cathode to produce hydrogen gas which is collected and stored. The purity of the hydrogen gas collected is high and this is due to the membrane’s blockage of oxygen gas from moving to the anode.
Carbon capture: Some industrial processes in the energy and chemical sector release carbon dioxide and other gases like nitrogen as by-products. Carbon dioxide has harmful effects on the environment and needs to be captured or removed from the environment. Membrane-based carbon capture is one method used in the control of carbon dioxide which employs membranes in its operations.
Selective separation membranes and facilitated transport membranes are two membrane types which separate carbon dioxide from the other gases based on their gas properties such as their solubility and diffusivity difference. These membranes allow the selective movement of carbon dioxide through it while leaving the other non-hazardous gases behind.
Water and wastewater treatment: Membrane-based water treatment is useful in the removal of contaminants and heavy metals from water. Renewable energy sources such as solar energy can be integrated with the membranes to efficiently purify the water.
Wastewater generated from industrial processes is treated using membrane-based water treatment which traps contaminants and heavy metals in order to make the water safe for reuse or for other processes.
Global Examples of Membrane Applications in Energy
The world has seen the great importance obtained from membrane application in the field of energy. Various countries have set-up plants and industries based on the membrane technology in energy and some of which are as follows:
In Ghana, a number of companies operate from the application of membrane science and technology. Some of them include the Bui Power Authority's Hydroelectric Power Plant, Accra Sea Water Desalination Plant at Nungua, Kosmos Energy and Safe Water Network’s Modular Ultrafiltration Plant in Beyin in the Western Region, Maji River Solution’s solar powered water purification system in the Volta Region, and others. Research groups from educational institutions like the Kwame Nkrumah University of Science and Technology have researched the generation of electricity from wastewater using microbial fuel cells containing membranes.
In other countries, a lot has been done in relation to membrane technology. Saudi Arabia has invested into a lot of Reverse Osmosis Desalination Plants which use membranes, Denmark has also done the same in biogas technology using membranes, as well as Hydrogen fuel cell vehicles by Japan. South Africa has the Wits and Solar Desalination Plant which use membranes, Tanzania also has the Renewable Energy-Powered Membrane Systems, and Namibia with the Bethanie Solar Desalination Plant. There are several other developments that have come about as a result of membrane science and technology.
The Future of Membrane Applications in Energy
As the world transitions to a low-carbon economy and sustainable development, membrane technology will play an important role in the energy sector. Advancements in membrane materials, design, and fabrication will improve the performance and efficiency of systems in energy generation and storage. The affordability of membranes is of great concern and as such, there is the need to design membranes with low-cost materials which work effectively. In terms of sustainability, more research should be conducted to ensure membranes are designed to mitigate climate change.
Conclusion
Membrane technology is a powerful tool in the quest for a sustainable energy future. From water treatment to energy generation and storage, membranes are transforming the energy world. As Ghana and the world continue to address energy challenges, it is essential that we make good use of the potential of membrane technology to create a more sustainable, efficient, and equitable energy future for all.
Cover Photo Credit: Created by Hasan Idrees via ChatGPT 4o PLUS
