Isolation of guaiene from crude and distillate patchouli oil extracted by molecular distillation

Guaiene is one of the components of sesquiterpenes that affects the patchouli oil fragrance. It is commonly used in the pharmaceutical industry and is also used as a flavoring and fragrance agent in the food industry. The objective of this study was to obtain the highest content of guaiene and to investigate the effect of the isolation stage by the molecular distillation process. Crude and distillate fraction patchouli oil samples were introduced into the molecular distillation system. The process conditions applied were first-stage and second-stage molecular distillation. Parameters observed were in terms of chemical composition and color. Results obtained the highest content of a-guaiene in the patchouli oil fraction distillate provided by second-stage molecular distillation (23.53%). However, the highest content of A-guaiene was revealed in second-stage molecular distillation residues (33.15%) of patchouli oil fraction distillate samples. The chromaticity value of the second stage distillate was yellow while the residue was yellow-red, respectively.

Method for producing low-viscosity marine fuel oil

Low-viscosity marine fuel oil that is obtained from the products of residual raw materials and middle distillate fractions of oil is intended for use in ship engines instead of a diesel fuel. A real-world application of this new composition is of great importance A proposed new composition of low-viscosity marine fuel oil is created by compounding a mixture of oil distillates in accordance with the following parameters. The oil distillate mixture should contain a vacuum distillate fraction 420-490°C, a vacuum distillate fraction 350-420°C and a straight-run diesel fraction 180-350°C taken in certain ratios. This study presents the new fuel composition and its technical advantages over previous analogues. The benefits include improvements in the coking properties and storage stability due to the stability in the pour point indicator.

Investigation on Component Separation and Structure Characterization of Medium-Low Temperature Coal Tar

Two medium-low temperature coal tars (MLCTs) derived from the pyrolysis of low-grade bituminous coal were separated into 11 narrow fractions by true boiling distillation. The primary property and chemical composition analysis of MLCTs and their distillate narrow fractions were investigated at the macroscopic and molecular level by gas chromatography-mass spectrometer (GC-MS) and proton nuclear magnetic resonance (1H NMR). The two MLCTs show obvious characteristics of medium-low temperature coal tar, including a high H/C, high-oxygen and nitrogen, low-sulfur, low-density, and low viscosity. As the boiling point increases, the molecular weight of each distillate fraction increases continuously. Meanwhile, the yield of each distillate fraction increases gradually, except for the 270–300 °C distillate fractions. The oxygen content in the 170–230 °C distillate fractions is much higher than that of the other distillate fractions. The dominant groups of compounds in the MLCTs were saturates, aromatics, and resins, and the resin content was above 24.5 wt%. The molecular composition of the below 170 °C fractions mainly consists of benzene, toluene, and xylene, and the main phenolic compounds in the 170–230 °C distillate fraction are low-rank phenols, such as phenol, cresol, and xylenol. Although the macroscopic properties of the MLCT-Z and MLCT-S were quite similar, the molecular composition, the group composition and hydrogen distribution in each MLCT and its narrow distillate fractions are still different. The present work has contributed to our present understanding of the composition of MLCTs and to the guiding of the efficient processing of MLCTs.