Used as a catalyst in esterification and transesterification reactions, particularly in the production of biodiesel. It offers high efficiency in converting free fatty acids and triglycerides into fatty acid methyl esters with minimal side reactions. Its strong acidic nature makes it suitable for industrial processes requiring acid catalysis without metal contamination. Also applied in organic synthesis for sulfonation and as a proton source in selective chemical transformations. Stable in aqueous solutions, it allows for easy handling and dosing in continuous processes.