"Green synthesis" in chemistry should probably be renamed. "Closed-loop synthesis" is closer to what it's about. The fundamental concept is that you're not pr

"Green synthesis" in chemistry should probably be renamed. "Closed-loop synthesis" is closer to what it's about. The fundamental concept is that you're not producing any waste products or unwanted side reactions, and all the reagents and catalysts are recycled back to their original state at the end of the reaction. This typically involves synthetic routes that start with small molecules and build larger molecules from them in a specific manner (rather than say, cleaving a large molecule and then having to throw away part of it as waste). With something highly reactive like HF acid, it might mean generating the HF from a fluoride salt, using it in the reaction, then converting any leftover HF back to the salt at then end of the process.