METHOD OF PREPARING SODIUM ALKYLBENZENE SULPHONATE Russian patent published in 1998 - IPC

FIELD: chemical industry. SUBSTANCE: present invention describes method of preparing high-quality sodium alkylbenzene sulfonate by sulfonation of alkylbenzene with mixture of inert gas with sulfur trioxide prepared by thermal desorption from oleum followed by neutralization of sulfonic acid with sodium hydroxide. Thermal desorption of sulfur trioxide from oleum is carried out using inert gas, one portion of which is admitted into desorption column from below in counterflow to oleum running down, and other portion of inert gas is admitted into sulfurator in amount so that sulfur trioxide concentration in sulfurizing gas is from 5 to 10%. Inert gas flow rate in desorption column varies from 0.3 to 0.45 m/s. Temperature is maintained within 80 to 120 C at oleum desorption stage, and temperature of sulfurizing gas at sulfurator inlet is regulated by inert gas strean within 40 to 60 C. Two inert gas streams are first passed through oleum for drying purposes. EFFECT: more efficient preparation method. 4 cl