Low pressure process for the preparation of methanedisulfonic acid alkali metal salts

A process for producing methanedisulfonic acid potassium salt which comprises heating an aqueous solution of about two molar equivalents of potassium sulfite to a temperature of from about 60° C. to about 90° C.;

• adding about one molar equivalent of dibromomethane to the aqueous potassium sulfite solution at a temperature of from about 60° C. to about 90° C.;
• and then separating the resulting methanedisulfonic acid potassium salt from the reaction solution.

A process for producing an alkyldisulfonic acid which comprises heating an aqueous solution of about two molar equivalents of an alkali metal sulfite to a temperature of from about 60° C. to about 90° C.;

• adding about one molar equivalent of a dihaloalkane to the aqueous alkali metal sulfite solution at a temperature of about 60° C. to about 90° C.;
• separating the resulting alkyldisulfonic acid alkali metal salt from the reaction solution;
• and then reacting the alkyldisulfonic acid alkali metal salt with an ion exchange polymer.