No abstract

The hydrogen economy is accelerating technological evolutions toward highly efficient hydrogen production. In this work, the catalytic performance of NiO/NaCl for hydrogen production via autothermal reforming of ethyl acetate and water is further improved through lanthanum modification, and the resulted 3%-NiLaO /NaCl catalyst achieves as high as 93% H selectivity and long-term stability at 600 °C. The promoting effect is caused by the strong interactions between lanthanum and NiO/NaCl, by which LaNiO and a novel LaOCl phase are formed. The key role of LaOCl in promoting low-temperature hydrogen production is highlighted, while effects of LaNiO are well known. The LaOCl (010) facet possesses high adsorption capacity toward co-chemisorbing ethyl acetate and water. LaOCl strongly interacts with ethyl acetate and H O in the form of hydrogen bonding and coordination effect. The interactions induce tensions inside ethyl acetate and H O, activate the molecules, and hence decrease the energy barrier for reaction. In situ Fourier transform infrared spectroscopy (FTIR) reveals that LaOCl along with NaCl enhances the adsorption ability of NiO/NaCl. Moreover, LaOCl improves the dispersion of Ni species in NiO-LaNiO -LaOCl nanosheets, which possess abundant active sites. The effects together promote hydrogen evolution. Furthermore, the NiLaO /NaCl catalyst can be easily reborn after deactivation due to the water solubility of NaCl.

Water-in-waxy crude oil emulsions with different water cuts were prepared with three different stirring speeds. The droplet size and distribution of the dispersed phase were determined by measuring the droplet diameter with trinocular biomicroscopy. The effects of the droplet size and distribution of the dispersed phase, water cut, and coldfinger temperature on wax deposition for water-in-waxy crude oil emulsions were studied experimentally using the coldfinger apparatus. The results show that the three influencial factors, including the coldfinger temperature, water cut, and droplet size and distribution, have a significant effect on wax deposition for the twophase oil-water system. In addition, 24 test results referring to different test conditions have been analyzed statistically. The significance analyses of influencial factors have been accomplished by using the F-test method from the data obtained from variance analysis. The results show that, for water-in-waxy crude oil emulsion, the influence degree on wax deposition in order is the coldfinger temperature, water cut, and the droplet size and distribution. At the end of the experiments, the samples of wax deposits collected from the coldfinger experiments were analyzed using high-temperature gas chromatography (HTGC) to determine the percentage of iso-alkanes, n-alkanes, and total wax in the deposits. The results of this study provide a reference and an insight for the further study on the two-phase oil-water wax deposition in flow loop and actual pipelines and should be of significant interest to develop a reliable prediction model in the future.