Environmental benefits of methanesulfonic acid. Comparative properties and advantages
This paper reviews some chemical and physical characteristics of methanesulfonic acid and the short-chain alkanesulfonic acids in general. The aqueous solubility of metal methanesulfonates, the conductivity of aqueous methanesulfonic acid (MSA) solutions and the low toxicity of MSA all make MSA(aq) an ideal electrolyte for many electrochemical processes, especially those involving tin and lead. Aspects of aqueous process effluent treatment, acid recovery and metal alkanesulfonate salt preparation are also environmentally favorable. Emphasis in this paper is given to rationalizing the rapidly growing commercial preference for MSA(aq) as an electrochemical electrolyte, especially with respect to the substitution of MSA for HBF4 in the electroplating of Sn/Pb solder. Economic aspects of MSA are also considered.