Powerful permanent magnets
Permanent magnets — materials that create their own persistent magnetic field — are frequently used in most types of electronics, turbines, engines and motors. Currently, nearly all powerful permanent magnets require rare-earth elements (REEs), such as neodymium or samarium. A new permanent-magnetic material eliminates the need for REEs and their associated environmental and supply-chain risks, instead relying on abundant substances like iron and nitrogen. Through their Clean Earth Magnet® technology, Niron Magnetics (Minneapolis, Minn.; www.nironmagnetics.com) has demonstrated its novel magnet-production technology at the pilot scale, and plans to open a full-scale manufacturing facility in Sartell, Minn., which will significantly scale up production.
“The process begins with the creation of precisely engineered iron oxide nanoparticles, which undergo a specialized reduction process that results in iron nitride nanoparticles. The final step involves aligning the magnetic particles and compacting them under high pressure to form dense permanent magnets,” explains Frank Johnson, CTO of Niron Magnetics.
Currently, the company operates out of their commercial pilot plant in Minneapolis, which has a capacity of 5 tons/yr of REE-free magnets, but the new plant is expected to produce 1,500 tons/yr by 2026. “Companies like General Motors, Volvo, Samsung and Stellantis have invested in Niron’s technology. These partnerships are extremely important for developing applications that leverage iron nitride’s unique magnetic properties, enabling manufacturers to reduce their reliance on rare-earth materials while maintaining high performance standards,” adds Jonathan Rowntree, CEO of Niron Magnetics.
Additionally, says Rowntree, Niron’s magnets are made with iron nitride, which “boasts the highest theoretical magnetization of any known material,” while also providing superior thermal stability when compared to traditional rare-earth-based magnets.
Desalination advances
Water scarcity is a growing global concern that is driving increasing efforts to conserve, re-use and treat water. Desalination of seawater is a known technology to combat water shortages, but it is an energy-intensive process. Solar-powered evaporation can be a more energy-efficient desalination process, as demonstrated by researchers from the University of South Australia (UniSA; www.unisa.edu.au). The salt in seawater, however, limits the achievable evaporation rate. Studies reportedly found seawater evaporation rates to be about 8% lower than those for pure water.
Professor Haolan Xu, a materials science researcher at UniSA, in collaboration with researchers from China, has developed a simple strategy to overcome this limitation. The team was able to achieve seawater evaporation rates 18.8% higher than for pure water by introducing common clay minerals into a floating photothermal hydrogen evaporator. According to the researchers, the hydrogen evaporator maintained its performance for months after immersion in seawater. The mineral materials used in the process included halloysite nanotubes (HNTs), bentonite (BN), zeolite (ZL) and montmorillonite (MN) in combination with carbon nanotubes (CNTs) and sodium alginate (SA) to form a photothermal hydrogel.
“The key to this breakthrough lies in the ion exchange process at the air-water interface,” Xu says. “The minerals selectively enrich magnesium and calcium ions from seawater to the evaporation surfaces, which boosts the evaporation rate of seawater. This ion-exchange process occurs spontaneously during solar evaporation, making it highly convenient and cost-effective.”
This work has been published in the journal Advanced Materials.
High-pressure H2 production
Clyde Hydrogen Systems (Glasgow, Scotland; www.clydehydrogen.com), a spinout company from the University of Glasgow’s School of Chemistry, has announced the successful production of hydrogen at pressures exceeding 100 bars using its scaled-up catalytic hydrogen generator. The company’s technology uses a decoupled electrolysis process that includes an electrochemical reductor that generates a reduced mediator solution and a catalytic hydrogen generator that produces high-pressure hydrogen gas. The business is on track to deliver a fully integrated pilot system by late 2025.