The hydrate formation rate is the key to the implementation of solid gas storage and transportation technology by the hydrate method. As a MOF material with strong hydrothermal stability, ZIF-8 has been proved to play a significant role in promoting the nucleation and growth of hydrate. However, the growth kinetics promotion mechanism and growth law of methane hydrate in the ZIF-8 promoter system have not been clarified at present. Therefore, the growth kinetics experiment of methane hydrate in the ZIF-8 promoter system was carried out in a high-pressure visualization reactor to systematically study the effects of the ZIF-8 concentration, undercooling degree, and pressure on the growth law of methane hydrate. The experimental results showed that: (1) the concentration of ZIF-8 had a significant shortening effect on the induction period of methane hydrate. With the increase in the ZIF-8 concentration, the induction time of methane hydrate was shortened from 5.85 h to 0.85 h. The methane gas consumption showed a gradually increasing trend at first, and then with the reaction going on, a dense hydrate film was formed at the gas–liquid interface, which increased the mass transfer resistance, resulting in the increase in the methane gas consumption gradually becoming stable. There were four stages in the growth process of hydrate, namely rapid formation, slow formation, secondary formation, and end formation and the optimal dosage of ZIF-8 promoter exists, and the optimal critical specific content was 0.02 mg mL⁻¹. (2) With the increase of undercooling, the induction time of methane hydrate decreased significantly, and the increase in the methane consumption also showed an increasing trend at first and then decreased. (3) With the increase of the system pressure to 7 MPa, the induction time of methane hydrate decreased from 1.02 h at 6 MPa to 0.2 h at 7 MPa, and the decrease rate was 80.8%, which was mainly due to the presence of “OPEN GATE” in the ZIF-8 accelerator. With the increase of the system pressure, the pore opening of the ZIF-8 material increased, the adsorption of methane increased, and the nucleation and growth of methane hydrate were promoted.

中文翻译：

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ZIF-8纯水体系中甲烷水合物生长动力学研究

水合物的形成速度是水合物法实施固体气体储运技术的关键。ZIF-8作为一种具有强水热稳定性的MOF材料，已被证明在促进水合物的成核和生长方面具有显着的作用。但目前尚不清楚ZIF-8助剂体系中甲烷水合物的生长动力学促进机理和生长规律。为此，在高压可视化反应器中进行了ZIF-8助剂体系中甲烷水合物的生长动力学实验，系统研究了ZIF-8浓度、过冷度、压力对甲烷水合物生长规律的影响。 . 实验结果表明：(1)ZIF-8浓度对甲烷水合物的诱导期有明显的缩短作用。随着ZIF-8浓度的增加，甲烷水合物的诱导时间从5.85 h缩短到0.85 h。甲烷耗气量起初呈逐渐增加的趋势，随后随着反应的进行，在气液界面形成致密的水合物膜，增大了传质阻力，导致甲烷耗气量逐渐增加。变得稳定。水合物的生长过程分为快速生成、缓慢生成、二次生成和末端生成四个阶段，存在ZIF-8促进剂的最佳用量，最佳临界比含量为0.02 mg·mL 甲烷水合物的诱导时间由 5.85 h 缩短至 0.85 h。甲烷耗气量起初呈逐渐增加的趋势，随后随着反应的进行，在气液界面形成致密的水合物膜，增大了传质阻力，导致甲烷耗气量逐渐增加。变得稳定。水合物的生长过程分为快速生成、缓慢生成、二次生成和末端生成四个阶段，存在ZIF-8促进剂的最佳用量，最佳临界比含量为0.02 mg·mL 甲烷水合物的诱导时间由 5.85 h 缩短至 0.85 h。甲烷耗气量起初呈逐渐增加的趋势，随后随着反应的进行，在气液界面形成致密的水合物膜，增大了传质阻力，导致甲烷耗气量逐渐增加。变得稳定。水合物的生长过程分为快速生成、缓慢生成、二次生成和末端生成四个阶段，存在ZIF-8促进剂的最佳用量，最佳临界比含量为0.02 mg·mL 这增加了传质阻力，导致甲烷气体消耗量的增加逐渐趋于稳定。水合物的生长过程分为快速生成、缓慢生成、二次生成和末端生成四个阶段，存在ZIF-8促进剂的最佳用量，最佳临界比含量为0.02 mg·mL 这增加了传质阻力，导致甲烷气体消耗量的增加逐渐趋于稳定。水合物的生长过程分为快速生成、缓慢生成、二次生成和末端生成四个阶段，存在ZIF-8促进剂的最佳用量，最佳临界比含量为0.02 mg·mL^-1。(2)随着过冷度的增加，甲烷水合物的诱导时间明显减少，甲烷消耗量的增加也呈先增加后减少的趋势。(3)随着系统压力增加到7 MPa，甲烷水合物的诱导时间从6 MPa时的1.02 h下降到7 MPa时的0.2 h，下降率为80.8%，这主要是由于存在ZIF-8 加速器中的“OPEN GATE”。随着系统压力的增加，ZIF-8材料的开孔率增加，对甲烷的吸附增加，促进了甲烷水合物的成核和生长。