Effective Removal of Phenylamine, Quinoline, and Indole from Light Oil by β-Cyclodextrin Aqueous Solution through Molecular Inclusion

The use of an aqueous solution of β-cyclodextrin (β-CD) as a molecular inclusion agent to simultaneously remove basic nitrogen (phenylamine and quinoline) and nonbasic nitrogen (indole) compounds, which are the main organic nitrogen compounds in light oil, is reported for the first time. The influence of various factors on the denitrification process, including the mass concentration of β-CD, the denitrification time, the volume ratio of β-CD aqueous solution to oil, the operation temperature, the presence of aromatic hydrocarbons and sulfides in light oil, and the regeneration performance were investigated, and the optimized denitrification conditions were obtained. Both the basic nitrogen and nonbasic nitrogen compounds were effectively removed by β-CD aqueous solution, which is obviously superior to the current non-hydrodenitrification methods. Furthermore, the structures of the inclusion complexes of β-CD with phenylamine, quinoline, and indole were studied by UV absorption, 1H NMR, and Fourier transf...