A group of chemists has developed a new method for creating important fluorochemicals that bypass the dangerous byproduct hydrogen fluoride (HF) gas. The findings, published in Science, can achieve a large impact on improving the safety and carbon footprint of a growing global industry. The article is titled “Fluorochemicals from fluorspar via a phosphate-enabled mechanochemical process bypassing HF.”
Fluorochemicals are a group of chemicals with many important applications—including polymers, agrochemicals, pharmaceuticals, and the lithium-ion batteries of smartphones and electric vehicles—with a $21.4 billion global market in 2018. Currently all fluorochemicals are generated from the toxic and harmful gas) hydrogen fluoride process (Ho-F) hydrogen fluoride. Despite strict safety regulations, HF emissions have occurred many times in the past decades, sometimes with fatal accidents and harmful environmental effects.
To develop a safer method, a group of chemists at the University of Oxford together with colleagues from the Oxford spin-out FluoRok, University College London, and Colorado State University, took inspiration from the natural biomineralization process that forms teeth and bones. Typically, HF itself is produced by reacting with a crystalline mineral called fluorspar (CaF2) with sulfuric acid under harsh conditions, before it was used to make fluorochemicals. In the new method, fluorochemicals are produced directly from CaF2completely bypassing the production of HF: a breakthrough that chemists have been looking for for decades.
In the novel method, solid-state CaF2 activated by a biomineralization-inspired process, which mimics the way calcium phosphate minerals are formed biologically in teeth and bones. The team is grounded in CaF2 with powdered potassium phosphate salt in a ball-mill machine for several hours, using a mechanochemical process that evolved from the traditional way we grind spices with a pestle and mortar.
The resulting powdered product, called Fluoromix, enabled the synthesis of more than 50 different fluorochemicals directly from CaF2 , with up to 98% yield. The method developed has the potential to streamline the current supply chain and reduce energy requirements, helping to meet future sustainability targets and lower the industry’s carbon footprint.
Happily, the solid-state process developed is as effective as acid grade fluorspar (> 97%, CaF2) as it contains synthetic reagent grade CaF2. The process represents a paradigm shift for the production of fluorochemicals worldwide and led to the creation of FluoRok, a spin-out company focused on the commercialization of this technology and the development of safe, sustainable, and cost-effective fluorinations. The researchers hope that this study will inspire scientists around the world to provide disruptive solutions to challenging chemical problems, with the hope of benefiting society.
Calum Patel, from the Department of Chemistry, University of Oxford, and one of the lead authors of the study, says, “Mechanochemical activation of CaF2 with a phosphate salt is an exciting invention because this seemingly simple process represents a very effective solution to a complex problem; however, big questions about how it reacts remain. Collaboration is key to answering these questions and advancing our understanding of this new, unexplored area of fluorine chemistry. Successful solutions to big challenges come from multidisciplinary approaches and skills, I think the work really captures the importance of that.
Lead author Professor Véronique Gouverneur FRS, from the Department of Chemistry, University of Oxford, who conceived and led this study said, “The direct use of CaF2 for fluorination is a holy grail in the field, and a solution to this problem has been sought for decades. The transition to sustainable methods for the production of chemicals, with reduced or no harmful effects on the environment, is now a high priority objective that can be facilitated by ambitious programs and a general rethinking of current manufacturing processes.
“This study represents an important step in this direction because the method developed in Oxford has the potential to be implemented everywhere in academia and industry, reduce carbon emissions, for example, by shortening supply chains, and offer more reliability due to the fragility of global supply chains.”
More information:
Calum Patel et al, Fluorochemicals from fluorspar with a phosphate-enabled mechanochemical process that bypasses HF, Science (2023). DOI: 10.1126/science.adi1557. www.science.org/doi/10.1126/science.adi1557
Provided by the University of Oxford
Citation: Nature inspires breakthrough achievement: Hazard-free production of fluorochemicals (2023, July 20) retrieved 20 July 2023 from https://phys.org/news/2023-07-nature-breakthrough-hazard-free-production-fluorochemicals.html
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