Influence of alkylaromatic hydrocarbons on the efficiency of linear alkylbenzene sulfonic acid synthesis

- The impact of aromatics and isoalkanes on alkylbenzene sulfonic acid formation was studied.
- Deactivation of Pt-catalyst caused by its coking was researched.
- The effect of highly viscous component formed from alkyl aromatics on sulfonation process was assessed.
- Mathematical model of sulfonation process considering process unsteadiness was developed.
- The yield and quality of ASA were improved.

ASA is the main ingredient of many commercial formulations for industrial and domestic synthetic detergents. Studying the work of the technological equipment that is used for manufacturing of the linear ASA allow us to conclude that alkylaromatic hydrocarbons in the product flow to hydrogenation reactor have significant impact on all technological stages. The aim of this work was to estimate the quantitative impact of alkyl components on ASA manufacturing efficiency and to improve the performance of the main equipment. The performed infrared (IR) and gas chromatography-mass spectrometry (GC-MS) analysis of the linear alkylbenzenes (LAB) and ASA samples indicate that the viscous components are tetralines and sultones as a part of unsulphonated matter. The developed mathematical model was used to reveal the following results and regularities of equipment modes: if the hydrogen/feedstock molar ratio at dehydrogenation stage equals 6/1, it is less optimal due to coke formation and requires increasing water supply. An increase of aromatics content in alkylation product flow leads to an increase in HF flow rate to the regeneration column. The optimal SO3/LAB molar ratio increases along with content of aromatics in raw materials. The developed model of sulfonation process predicts the duration of reactor inter-washing period.