Environmental assessment of alternative methanesulfonic acid production using direct activation of methane

In this paper we present a comparative life cycle assessment of two processes for the industrial production of methansulfonic acid. The conventional multi-step process for the production of methansulfonic acid is based on the reaction of methanol and hydrogen sulfide to form methanthiol which is used to produce dimethyldisulfate. The dimethyldisulfate reacts further with nitric acid to form methanesulfonic acid. A newly developed process presents the possibility to form methanesulfonic acid directly from methane and sulfur trioxide in a single step at mild conditions. Thus this process enables for the first time the production of a high value chemical through direct activation of methane on an industrial scale. The cradle-to-gate life cycle assessment conducted with the ReCiPe Method revealed that this direct process has a total environmental impact that is 3 times lower than that of the conventional process. The differences resulted from lower energy requirements and alternative reactants used in the direct process. The results therefore demonstrate the potential for methane extracted from natural gas as a greener alternative to oil as a chemical feedstock in the medium term. (C) 2018 Published by Elsevier Ltd.