PURPOSE: To circulate and use I2 and SO2 as a whole, by reacting an aqueous solution of sulfurous acid with excess I2 to give a sulfuric acid solution and an aqueous solution of hydrogen polyiodide, reacting part of the latter with CH3OH to give CH3I, and reacting the resultant CH3I with the rest to give CH4.
CONSTITUTION: An aqueous solution of sulfurous acid is reacted with excess I2 to give a sulfuric acid solution and an aqueous solution of hydrogen polyiodide separated into two liquid phases, and the aqueous solution of the hydrogen polyiodide is then partially reacted with methanol in the liquid phase at 20W250°C to give CH3I while recovering I2. The resultant CH3I is then reacted with HI gas separated from the rest of the aqueous solution of the hydrogen polyiodide by the distillation in the vapor phase the hydrogen polyiodide by the distillation in the vapor phase at 200W600°C to give CH4 while recovering I2. On the other hand, concentrated sulfuric acid in a concentration close to the azeoptropic composition with water is separated from the sulfuric acid solution by distillation to separate from the excess water, and thermally decomposed at 700W 1,000°C as a vapor-phase catalytic reaction to afford O2 while recovering SO2.
EFFECT: One mole CH4 is obtained from one mole CH3OH with thermal energy at 1,000°C or below.
SATOU SHIYOUICHI
KONUKI KAORU
NAKAJIMA HAYATO
IKEZOE YASUMASA
