Transformations of thiophene compounds under catalytic cracking conditions

[Display omitted] ► Reduction of the sulfur content in catalytic cracking gasoline. ► Transformations of various organosulfur compounds in catalytic cracking conditions. ► Different hydrocarbons as hydrogen donors. ► Impact of acid–base properties of the additives to the cracking catalysts on sulfur content reduction. A method for in situ reduction of the sulfur content in catalytic cracking gasoline is reported. A comparison of thermal and catalytic transformations of sulfide and thiophene sulfur is presented. Main transformations of various organosulfur compounds are demonstrated. The effect of [H]-donor activity of hydrocarbons on conversion of thiophene sulfur into hydrogen sulfide is revealed. The impact of acid–base properties of the additives to the cracking catalysts on sulfur content reduction in the liquid products is examined in detail (TPD-NH3, 27Al NMR, CO2 adsorption). The choice of optimal qualitative composition of a modifying additive for reducing the sulfur content in catalytic cracking gasoline is substantiated.