A novel characterization of furfural-extract oil from vacuum gas oil and its application in solvent extraction process

Abstract

Solvent extraction is highly efficient process for removing the toxic polycyclic aromatic hydrocarbons (PaHs) from vacuum gas oil (VGO) to produce eco-friendly processing oil. In this work, we established a model which can predict both the PCA content and hydrocarbon composition of extraction product. Commercial furfural-extract oil (FEO) from vacuum gas oil was used to obtain liquid–liquid equilibrium data using solvent extraction under the condition of extraction temperature 323K–353K, solvent–oil ratio 1:1–4:1. The effect on the PaHs distribution and polycyclic aromatics (PCA) content was studied. A novel characterization was stated by dividing the oil into eight model-molecules based on the GC-FI TOF/MS and 1H NMR data. The construction of eight molecules including paraffin, naphthene, one to five ring aromatics and sulfur containing polycyclic aromatics was determined by hydrocarbon composition and the H atom distribution, and the UNIFAC groups could be calculated directly. The PCA content was also correlated well with hydrocarbon compositions. This model has advantage of using only one set of adjustable interaction parameter between furfural group and sulfur-containing group. The modeling results showed the calculated yields, hydrocarbon composition and PCA content fitted well with the experimental data, indicating that the model with new characterization method has some predictive ability on the solvent extraction process in this work.