Increasing the Selectivity of Synthesis Stages for Linear Alkyl Benzenes

Background: Starting from the mid-20th century, synthetic detergents produced from petrochemical raw materials have become more and more widely used and in many cases have better cleaning characteristics than natural soap. Objective: The purpose of this work was to reveal physical and chemical regularities of C9-C14 hydrocarbons transformations and to increase the selectivity of the steps of synthesis of highly biodegradable linear alkylbenzenes. Method: Based on the thermodynamic analysis performed with use of quantum-chemical modeling, the study has shown how the structure of hydrocarbons affects their properties and reactivity. Results: With use of the results of the mathematical modeling of the main steps of synthesis of linear alkylbenzenes, it was shown that the selectivity of the process can be improved by suppressing the catalyst deactivation by coke during dehydrogenation of alkanes to alkenes. Conclusion: This can be achieved by reducing the hydrogen-rich gas circulation ratio while increasing the H2O supply to the reactor. The stemming decrease in the concentration of dienes in the feedstock allows us to reduce the HF flow rate to benzene alkylation with alkenes.