PURPOSE: To obtain sulfonated compounds with low degree of color development and with high rate of sulfonation, by carrying out the sulfonation of organic compounds with SO3 gas while feeding SO3 dividedly and regulating the temperature of a reaction surface between each feeding site independently.
CONSTITUTION: In continuous sulfonation by the contact of roganic compounds in the state of a liquid thin film with SO3 gas diluted with an inert gas, SO3 gas is dividedly fed to different sites against a flowing-down direction on a reaction surface, and the temperatures of the reaction surface between each feeding site and the adjacent reaction surface are independently regulated. In an example, organic compounds are fed through an inlet 9, and SO3 gas is fed through eacg inlet 5, 6, 7 of SO3 feeding pipes 1, 2 and 3 and fed into a reaction column through gas-feeding inlets 12, 11 and 10. The temperature of each reaction stage is regulated by heat exchangers 15-18.
EFFECT: Local heat generation and side reactions due to locally excess SO3 gas are suppressed, and conditions suitable for each reaction condition can be selected.
MATSUKAWA HARUYOSHI
SUGI ETSUO
YADA KAORU
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