Hydrogen Production from Seawater : New System by Researchers

Hydrogen Production from Seawater : New System by Researchers

Here’s an article posted in Sci-Tech Daily

According to the article,

Double-membrane system: The innovation lies in the implementation of a bipolar, or two-layer, membrane system for extracting hydrogen from seawater. This design effectively controls the movement of ions, particularly chloride, which can interfere with the hydrogen extraction process.

Efficient hydrogen production: The study demonstrates a method for efficiently producing hydrogen gas from seawater using electrolysis. By utilizing the double-membrane system, the researchers successfully separate hydrogen and oxygen gases from seawater while preventing the formation of harmful byproducts like bleach and chlorine.

Potential for scalability: The research not only advances the understanding of seawater-to-hydrogen conversion but also provides insights into designing stronger membranes for various applications. Additionally, future improvements in electrode and membrane materials could enhance scalability, making this technology more viable for energy-intensive sectors like transportation.

The process of extracting hydrogen from seawater, as developed by the team of scientists from SLAC National Accelerator Laboratory, Stanford University, University of Oregon, and Manchester Metropolitan University, involves a sophisticated double-membrane system and electrolysis. Here’s a detailed breakdown of the process:

1. Seawater Intake: Seawater is funneled into the system as the starting material. Seawater contains various ions, including hydrogen ions (protons), hydroxide ions, sodium ions, chloride ions, and other impurities.
2. Bipolar Membrane System: The heart of the innovation lies in the bipolar membrane system. This system comprises two layers of membranes with specific properties:
   • The first membrane layer allows only positive hydrogen ions (protons) to pass through while blocking other ions.
   • The second membrane layer allows only negative ions, such as chloride, to travel through, effectively mitigating harmful chloride reactions.
   • The first layer also contains negatively charged groups fixed to the membrane, further preventing the movement of unwanted negatively charged ions like chloride.
3. Electrolysis: Once the seawater passes through the bipolar membrane system, it enters the electrolysis phase. Electrolysis involves using electricity to drive a chemical reaction, in this case, the separation of hydrogen and oxygen from water molecules. Specifics of the electrolysis process include:
   • Application of electricity to drive the electrolysis reaction.
   • Protons (H+) from seawater move through the first membrane layer to the reaction site, where they interact with a negatively charged electrode.
   • At the electrode, protons are converted into hydrogen gas (H2), which is collected as the desired end product.
   • The second membrane layer prevents harmful chloride ions from reaching the reaction site, ensuring the safety and efficiency of the process.
4. Product Collection: Hydrogen gas produced during the electrolysis process is collected as the primary product. This hydrogen gas can be utilized as a low-carbon fuel for various applications, including fuel-cell electric vehicles and energy storage for electric grids.
5. Byproduct Management: One significant achievement of this process is the prevention of harmful byproducts like bleach and chlorine, which can occur due to the oxidation of chloride ions. The design of the bipolar membrane system effectively mitigates these undesired reactions, ensuring the safety and environmental friendliness of the process.
6. Research Implications: In addition to hydrogen production, the research contributes to a better understanding of ion movement through membranes. This knowledge can inform the development of stronger membranes for various applications, including the production of oxygen gas through electrolysis.

Interestingly, we have some other posts related to this content:

Green Hydrogen From Seawater Using Catalysts: UH researchers develop a catalyst for converting seawater to green hydrogen, a game-changer for regions with limited freshwater access.

Green Hydrogen from Seawater Using PEM Electrolyzer by Fraunhofer ISE: Fraunhofer Institute for Solar Energy Systems (Fraunhofer ISE) has presented a green hydrogen production technique via proton exchange membrane (PEM) electrolyzer, employing seawater.

Double-Membrane Electrolysis: A New Method for Producing Hydrogen Directly from Seawater – A new method called double-membrane electrolysis enables the extraction of hydrogen directly from seawater, operating without creating toxic by-products like bleach and chlorine.