Lianjing Mao,Xiaolong Zhou,Tianyu Zheng,Xiao Li,Xiufang Wang,Zhiyu Zhao,Wei Sun,Pengrui Zhang,Jinhe Sun
The metal ion extraction process is usually accompanied by the removal of coordinated water molecules and the change of water content in the extraction phase. However, hierarchical methodologies on water research are incredibly sparse, restricting a thorough knowledge of the extraction mechanism. It was clarified the diversity of water occurrence forms in the extraction phase and quantitative relationship between water, Li + and crown ether based on the (B12C4/B15C5/B18C6-[EMIm][NTf 2 ])-LiNTf 2 solvent extraction system. While the complexation mechanism between hydrated Li + and crown ether was discussed carefully. Firstly, it demonstrated that the water content of the extraction phase: B18C6 > B15C5 > B12C4. Secondly, the water in the extraction phase is mainly collected by solvent and crown ether, with the latter catching water primarily via Li + coordination and weak interactions. In the end, focusing on the water captured by the crown ether through Li + coordination, slope analysis and DFT calculations found that Li (H 2 O) 4 + was removed three water molecules to complex with B12C4 or B15C5, whereas B18C6 tends to remove two water molecules. It is precious for a thorough grasp of the mechanism and procedure of Li + extraction by crown ethers. What’s more, it offers novel strategies for investigating water content and transfer mechanisms in extraction systems.
Yongcheng Huang,Yaoting Li,Xudong Han,Jiating Zhang,Kun Luo,Shangsheng Yang,Jiyuan Wang
In this paper, biodiesel was used to upgrade bio-oil by extracting the high-quality fuel fractions in bio-oil through solvent extraction . After the extraction, the upper layer blends of biodiesel and the high-quality bio-oil components, also called the “extraction phase liquid”, was obtained and denoted as EPBB. Firstly, Thermogravimetric (TG) and Fourier transform infrared (FTIR) analyses indicated that the light components originally in bio-oil, such as alcohols, ethers, ketones and carboxylic acids were extracted from bio-oil to biodiesel and formed the EPBB. Then the fuel properties of EPBB were measured at different temperatures. The results showed that the density of EPBB was higher, while its viscosity, surface tension and lower heating value (LHV) were lower than those of biodiesel. Accordingly, EPBB revealed better atomization and evaporation characteristics as compared to biodiesel. Finally, the engine performance of EPBB was tested on an unmodified direct-injection diesel engine. When compared with biodiesel, the ignition delay of EPBB was longer, the premixed combustion duration was longer, while the total combustion duration was shorter. The fuel economy of EPBB was comparable to that of biodiesel, and the NOx, soot, CO and UHC emissions of EPBB were all lower than those of biodiesel.