The effects of a new promoter on the growth kinetics of methane hydrates were investigated using a visualized constant-pressure autoclave. The experimental results show that when the 1#, 2# and 3# unit promoter was compounded at a ratio of 2 : 1 : 1, the induction time was shortened greatly from 30 h to 0.64 h compared to the no promoter situation. Meanwhile, there was a larger amount of hydrate formation, and final hydrate volume fraction was 83.652%. Then, the hydrate formation characteristics under different additive dosages (500 ppm, 1000 ppm, 2000 ppm, 5000 ppm) and different subcooling degrees (2.5 °C, 3.5 °C, 4.5 °C, 5.5 °C, 6.5 °C) were investigated. The new promoter at these 4 concentrations could effectively shorten the induction time. And the higher the concentration, the smaller the induction time (0.22 h at 5000 ppm). It was also found that gas consumption and hydrate production rate increased first and then decreased with increasing promoter dosage. Finally, the optimal dosage was determined to be 2000 ppm, at which the induction time was shortened to 0.52 h, and the final hydrate volume fraction was 85.74%. Under the dosage of 2000 ppm and the subcooling degree of 6.5 °C, the shortest induction time (0.29 h) and the maximum formation rate (20.950 ml h⁻¹) were obtained among all the experimental conditions in this work. Moreover, the greater the subcooling degree, the faster the hydrate nucleation, and the shorter the induction time. However, if the subcooling degree was too high, a hydrate layer formed rapidly at the gas–liquid interface in the autoclave, which would hinder hydrate formation and lead to the reduction of hydrate volume fraction to 60.153%. Therefore, a reasonable selection of the proportioning of promoters, dosage of the promoter and formation temperature could significantly promote the formation of hydrates. The findings in this work are meaningful to hydrate associated applications and can provide useful references for the selection of hydrate promoters.

Using electrochemical measurements, the corrosion inhibition performance of pyridine bromide ionic liquid corrosion inhibitors on low carbon steel was evaluated under different concentrations and alkyl chain lengths of anions. The optimal process conditions were obtained: at 25 °C, in a 1 M HCl corrosion medium, the 1-dodecyl-3-methylpyridine bromide ionic liquid ([C₁₂Py]Br) exhibited the best corrosion inhibition effect, with maximum inhibition rates of 94.1%. The study mechanism showed that the adsorption process was a mixed adsorption dominated by chemical adsorption. Surface analysis (SEM/EDS, XPS) and quantum chemistry results verified that [C_nPy]Br could form a protective film on the surface of low carbon steel and inhibit its corrosion. In addition, molecular dynamics simulations were used to analyze the adsorption behavior of corrosion inhibitor molecules on the Fe(110) surface, and the formation sequence of bond and non-bond interactions in the Fe corrosion inhibitor molecular system on the Fe(110) surface was obtained, which was consistent with the experimentally determined corrosion inhibition efficiency. The radial distribution function (RDF) showed that the adsorption mode of the corrosion inhibitor on the metal surface was a mixed adsorption dominated by chemical adsorption and supplemented by physical adsorption.

The sulfur compounds in diesel can cause environmental pollution. As the main component of the sulfide compounds in diesel, dibenzothiophene (DBT) must be removed previously. In this study, 1-alkyl-3-methyl imidazole ionic liquids (ILs) bromic [C_nmim]Br (n = 4, 6, 8, 12) were prepared. The phenylalanine, histidine, glycine, tryptophan were used as anions to displace the Br⁻¹ of [C_nmim]Br through ion exchange resin to get the amino acid ionic liquids for deep removal of DBT from model oil in the presence of H₂O₂. The results show that the desulfurization of 1-octyl-3-methyl phenylalanine imidazole ionic liquid [C₈mim]Phe is higher than that of [C₈mim]His, [C₈mim]Gly, and [C₈mim]Trp. The effect of temperature, the volume ratio of H₂O₂/model oil, and time on desulfurization of [C₈mim]Phe combined with H₂O₂ was studied. The response surface analysis was used to seek the optimal desulfurization process parameters of the [C₈mim]Phe combined with H₂O₂. Repeated experiments of DBT removal by [C₈mim]Phe combined with H₂O₂ from model oil were conducted under the optimized conditions. The desulfurization of [C₈mim]Phe combined with H₂O₂ was declined from 97.4% to 93.4% after 8 recycle times. Meanwhile, the oxidation-extraction desulfurization mechanism of [C₈mim]Phe combined with H₂O₂ was confirmed by Fourier transform infrared spectroscopy (FT-IR) and liquid chromatography-mass spectrometry (LC-MS).

The sulfur compounds in gasoline will cause air pollution and acid rain. As the main component of the sulfide compounds in gasoline, dibenzothiophene (DBT) is is difficult to remove. To solve this problem, magnetic imidazole ionic liquids (MILs) with different carbon chain alkanes [C_{4, 6, 8}min]Br/FeCl₃ were developed to improve the extractive desulfurization performance. Furthermore, Cetyltrimethylammonium bromide (CTAB) was added, in combination with MILs to achieve a higher removal rate of DBT in gasoline. The results show that CTAB combined with MILs has a better removal effect on DBT. The mechanism of CTAB combined with MILs gasoline desulfurization was analyzed.