Conversion of alkanes under single pulse of hydrodynamic cavitation. I. Behavior of C₁₃–C₁₅ alkanes

Abstract

There are many different methods of petrochemical raw materials activation. This article discusses hydrocarbons mechanoactivation that helps to increase the yield of the key products. This effect shows itself most clearly in the n-alkanes distribution. The main purpose of this study is to attempt to learn whether the energy of a single pulse of cavitation occurring in a disintegrator DA-1 is enough for the destructive transformation of n-alkanes with the number of carbon atoms in the molecule less than 15 and for the formation of compounds with low molecular weights. It was shown that the total decrease in the concentration of reactants (monomethyltridecane, n-tridecane and n-pentadecane) is completely compensated by the higher content of n-tetradecane in the mixtures. The content of iso-alkanes, n-tridecane and n-pentadecane decreased. Other compounds did not appear in the mixtures after the impact of a single pulse of cavitation. It was shown that the energy of a single pulse of hydrodynamic cavitation released in DA-1 is insufficient for the large-scale break of the bonds between the secondary carbon atoms in the chains of C₁₃–C₁₅ alkanes (mostly n-tetradecane, the content of which in the mixture was greater than 97%) and for the diffusion of radicals from the “cage” with the formation of compounds with low molecular weights. A similar effect can be expected especially in respect of n-alkanes having a fewer number of carbon atoms. A possible mechanism of the reversible isomerization reaction in the studied system is discussed in this article.

Keywords

• the c₁₃–c₁₅ alkanes, cavitation, mechanical stresses, isomerization, cracking, free radicals, recombination, a random event, possibility.