Bin Lou

Hydroalkylation modification of naphthene-based aromatic-rich fraction and its influences on mesophase development

Naphthene-based aromatic-rich fraction was modified by tetrahydronaphthalene and polyethylene glycol to obtain modified materials which were selected to prepare mesophase pitches by a direct condensation method. The structural composition of modified materials were characterized by simulated distillation (SIMDIS), elemental analysis, Fourier transform infrared spectrometry (FTIR) and 1H nuclear magnetic resonance (1H NMR) spectroscopy. Influences of the naphthenic structures and alkyl chains in modified materials on the formation and development of mesophase structures were investigated by analyzing variations in optical texture, softening point, carbon residue, molecular and microcrystal structure of mesophase pitch. Results showed that the alkyl structures in modified materials treated by tetrahydronaphthalene and polyethylene glycol were mainly naphthenic structures and alkyl chains, respectively. The existence of alkyl structures in modified materials was beneficial for the formation of mesophase with high quality. Moreover, the naphthenic structures had a better improving effect than alkyl chains. Abundant naphthenic structures or an appropriate amount of alkyl chains in feedstock contributed to the preparation of mesophase pitch with large domain structure, low softening point, high carbon residue and ordered microcrystal structure.

Insight into effective denitrification and desulfurization of liquid fuel with deep eutectic solvents: an innovative evaluation criterion to filtrate extractants using the compatibility index

Tremendous attention has been paid to removal of N-/S-containing compounds from liquid fuel due to the necessity of reducing NOx and SOx emissions. In this work, the compatibility index (CI or PCI) was developed as a new criterion to evaluate the removal efficiency (Re) of quinoline, carbazole and dibenzothiophene (DBT) in deep eutectic solvents (DESs). For alkaline quinoline, acid–base extraction was pronounced, and ChCl/mandelic acid was the optimal extractant to achieve a removal efficiency of 99.2 wt% (CI = 0.37). For near-neutral carbazole and DBT, polarity compatible extraction was the predominant mechanism. The highest Re value of 94.9 wt% for carbazole removal was obtained in the ChCl/mandelic acid extractant (PCI = −0.044). DBT was difficult to remove directly because of its low molecular polarity. After adding H2O2, the desulfurization efficiency was found to increase to 99.1 wt% in the ChCl/p-toluenesulfonic acid extractant (PCI = 0.014). Furthermore, experiments with real diesel confirmed that the highest desulfurization and denitrification efficiency was 67.7 wt% and 63.7 wt%, respectively, in ChCl/p-toluenesulfonic acid. The compatibility index developed in this study has the potential to simplify the filtration operation of extractants and to intensify the removal efficiency of N-/S-containing compounds in the category of “green extraction”.

Influence of boiling point range of feedstock on properties of derived mesophase pitch

The composition of raw material was optimized by vacuum distillation. The carbonization behavior of two kinds of raw material was followed by polarizing microscope, softening point, carbon yield and solubility. Two kinds of mesophase pitch have been monitored by X-ray diffraction (XRD), Fourier transform infrared spectrometer (FTIR), elemental analysis and 1H nuclear magnetic resonance (1H-NMR). The analysis results suggested that raw material B (15wt% of A was distillated out and the residue named B) could form large domain mesophase pitch earlier. The shortened heat treat time favored the retaining of alkyl group in mesophase pitch and reduced the softening point of masophase pitch.

Improvements to quality of needle coke by controlled carbonized conditions

In this study, the selected aromatic-rich fraction derived from hydrocracking tail oil was carbonized and further improvement in the quality of resultant coke was achieved by promoting temperature at the solidification stage. In comparison with conventional process carried out isothermally and isobarically, the coupling analysis between formation and subsequent uni-axial orientation of mesophase textures during the controlled process was systematically discussed on the basis of the mutual relevance among mesophase texture evolution, gas evolution rate and solidification rate of intermediates. The results show that on the premise that formation of bulk mesophase, appropriate rate of gas evolution at a right time of solidification contributes to fine produces fine fibrous mesophase aligned uni-axially and less pores. Moreover, the intermediates with solidification index of 2∼6 are suitable for deformation induced by gas evolution.In this study, the selected aromatic-rich fraction derived from hydrocracking tail oil was carbonized and further improvement in the quality of resultant coke was achieved by promoting temperature at the solidification stage. In comparison with conventional process carried out isothermally and isobarically, the coupling analysis between formation and subsequent uni-axial orientation of mesophase textures during the controlled process was systematically discussed on the basis of the mutual relevance among mesophase texture evolution, gas evolution rate and solidification rate of intermediates. The results show that on the premise that formation of bulk mesophase, appropriate rate of gas evolution at a right time of solidification contributes to fine produces fine fibrous mesophase aligned uni-axially and less pores. Moreover, the intermediates with solidification index of 2∼6 are suitable for deformation induced by gas evolution.

Influence of carboxyl anion on the dissolution of chitosan in cholinium-based ionic liquids

Chitosan can be applied in because of its excellent antimicrobial activity and abundant bio renewable and biodegradable resource. To better utilize this kind of native polysaccharide, it is still necessary to develop an efficient chitosan solvent system. Tn present study, 6 kinds of novel choline carboxylate ionic liquids (ILs) were developed. The solubility of chitosan in these H2O-ILs with different molar ratio were measured at 25 °C. The effect of the carboxylate anion of the ILs on chitosan solubility was estimated and found that the solubility of chitosan in the H2O-IL increased with the increasing of alkyl chain length in the anion. Moreover, the H2O-IL solution would not able to dissolve chitosan because the proton H was alternated by employing NH2 or OH group. The H2O-[Ch][CH3CH2CH2COO] (Rmol=6:1) solvent system exhibits highly efficient capacity for the dissolution of chitosan, and the solubility of chitosan reached up to 20.8 wt.%. From NMR measurement, these results could be explained by the possible interaction between carboxylate anion and chitosan and the strong hydration of the carboxyl group in the IL, suggesting that anionic structure have a significant impact on the dissolution of chitosan in the H2O-IL solvent system. Altogether, these results would provide an important evaluation indicator for screening the most suitable solvent system of chitosan.Chitosan can be applied in because of its excellent antimicrobial activity and abundant bio renewable and biodegradable resource. To better utilize this kind of native polysaccharide, it is still necessary to develop an efficient chitosan solvent system. Tn present study, 6 kinds of novel choline carboxylate ionic liquids (ILs) were developed. The solubility of chitosan in these H2O-ILs with different molar ratio were measured at 25 °C. The effect of the carboxylate anion of the ILs on chitosan solubility was estimated and found that the solubility of chitosan in the H2O-IL increased with the increasing of alkyl chain length in the anion. Moreover, the H2O-IL solution would not able to dissolve chitosan because the proton H was alternated by employing NH2 or OH group. The H2O-[Ch][CH3CH2CH2COO] (Rmol=6:1) solvent system exhibits highly efficient capacity for the dissolution of chitosan, and the solubility of chitosan reached up to 20.8 wt.%. From NMR measurement, these results could be explained by the po...