Separation and characterization of biofuels in the jet fuel and diesel fuel ranges by fractional distillation of organic liquid products

摘要

In this paper, we investigated the fractional distillation on bench scale of four organic liquid products (OLPs) obtained by thermal-catalytic cracking of crude palm oil using 5%, 10%, 15%, and 20% (w/w) sodium carbonate as the catalyst. The main objective of this work was to obtain biofuels similar to fuels derived from petroleum such as jet fuel and diesel fuel. Thus, the fractionation experiments were carried out at atmospheric pressure and in two distillation temperature ranges, 160-245 degrees C and 245-340 degrees C, obtaining two distilled fractions denominated green jet fuel and green diesel, respectively. The distilled fractions (biofuels) have been physical-chemical characterized by Officials AOCS and ASTM Methods regarding specific gravity at 20 degrees C, kinematic viscosity at 40 degrees C, corrosiveness to copper, acid value, saponification value, refractive index, and distillation curve. The chemical composition of distilled fractions has been determined by GC-MS. The results of the fractionation of the OLPs show that sodium carbonate is an excellent catalyst regarding yield and selectivity for the production, firstly of green diesel and secondly of green jet fuel. Most physical-chemical properties of green jet fuel and green diesel fractions are within limits established by ANP No. 37 for conventional jet fuel [aviation kerosene (QAV-1/JET A-1)] and ANP No. 65 for commercial diesel (diesel S10), respectively. The experimental distillation curve of the green jet and green diesel fractions are similar to the standard distillation curve of aviation kerosene and diesel S10, respectively. Results from GC-MS analysis revealed that the size of the hydrocarbon chains constituting the green jet fuel (C-10-C-15) and green diesel (C-14-C-17) fractions obtained in the present study are in agreement with the length of the chains of hydrocarbons established for aviation kerosene and diesel S10, respectively. In parallel, the increase of catalyst in the thermal-catalytic cracking process improved the yield, selectivity, physical-chemical properties and chemical composition of both biofuels. Therefore, the results presented in this paper indicate that green jet fuel and green diesel fractions can be used as a partial or total substitute for aviation kerosene and diesel S10, respectively.