Abstract We investigated the effect of mixtures of commercial nonionic surfactants Sintanol ALM-7 (A7), Sintanol ALM-10 (A10), Surfynol 465 (S6), Surfynol 485 (S8), and well-known kinetic hydrate inhibitor Luvicap 55W (sample P) on nucleation and growth of sII gas hydrate. The ramp method (cooling at a constant rate of 1 °C × h−1) was employed to determine hydrate onset temperature and subcooling of individual and mixed samples. The dosage of reagents varied within 0.25–1.0 mass% range. A7 and A10 were tested at concentrations of 1.6∙10−4–2.5∙10−3 mass% (about or lower than CMC) as well. All surfactants were found to be weak antinucleators of gas hydrates. The inhibition performance of the surfactants was significantly lower in comparison with Luvicap 55W. We observed that ethoxylated fatty alcohols (A7 and A10) at low concentrations demonstrated a hydrate-inhibiting action at nucleation and growth stages. The Luvicap 55W – surfactant mixtures were tested as KHIs with a total dosage of 0.5 mass%, and in the ratio of 1:1, 1:2, and 1:5. Several mixed samples (1:1 P + A10), (1:2 P + A10), (1:2 P + S6) have demonstrated the same or higher efficacy in inhibition of hydrate nucleation than pure KHI. The results obtained indicate the presence of a synergistic effect of kinetic inhibition of gas hydrate with mixtures of the polymer and ethoxylated nonionic surfactants. Among the mixtures, the best results were obtained for the sample (1:2 P + S6). Surfynol 465 is characterized by high solubility in water, low foaming (compared to other surfactants), and lower cost than vinyl lactam-based KHI. Thus, the Surfynol 465 is a promising synergist for the vinyl lactam polymeric KHI and allows reducing the dosage of the expensive polymer.

中文翻译：

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水溶性聚合物、非离子表面活性剂及其混合物存在下的气体水合物成核和生长

摘要 我们研究了商业非离子表面活性剂 Sintanol ALM-7 (A7)、Sintanol ALM-10 (A10)、Surfynol 465 (S6)、Surfynol 485 (S8) 和众所周知的动力学水合物抑制剂 Luvicap 55W（样品P) 关于 sII 气体水合物的成核和生长。斜坡法（以 1 °C × h-1 的恒定速率冷却）用于确定单个和混合样品的水合物起始温度和过冷度。试剂的用量在 0.25-1.0 质量％范围内变化。A7 和 A10 也在 1.6∙10−4–2.5∙10−3 质量％（约或低于 CMC）的浓度下进行测试。发现所有表面活性剂都是气体水合物的弱抗成核剂。与 Luvicap 55W 相比，表面活性剂的抑制性能显着降低。我们观察到低浓度的乙氧基化脂肪醇（A7 和 A10）在成核和生长阶段表现出水合物抑制作用。Luvicap 55W - 表面活性剂混合物作为 KHI 进行测试，总剂量为 0.5 质量％，比例为 1:1、1:2 和 1:5。几个混合样品 (1:1 P + A10)、(1:2 P + A10)、(1:2 P + S6) 在抑制水合物成核方面表现出与纯 KHI 相同或更高的功效。获得的结果表明存在气体水合物与聚合物和乙氧基化非离子表面活性剂的混合物的动力学抑制的协同效应。在混合物中，样品 (1:2 P + S6) 获得了最好的结果。Surfynol 465 的特点是在水中溶解度高，泡沫少（与其他表面活性剂相比），并且成本低于乙烯基内酰胺基 KHI。因此，