The synergetic effect of a range of different solvents on the kinetic hydrate inhibitor (KHI) performance of poly(N-vinylcaprolactam) (PVCap) has been investigated. The equipment used was a high-pressure (76 bar) rocking cell apparatus using slow constant cooling (approximately 1 °C/h from 20.5 °C) and a synthetic natural gas mixture forming structure II hydrate. The synergetic effect was investigated by adding 5000 ppm of a range of alcohols, glycol ethers, and ketones to a solution of 2500 ppm of PVCap (M_w = 10 000 g/mol). For many of the additives, the ranking of the synergetic effect can be explained with reference to the size, shape, and hydrophobicity of the main alkyl group (“tail”) in the molecule as well as the presence of a glycol ether group. Among all of the solvents investigated, the best synergetic effect was achieved by 4-methyl-1-pentanol. When 5000 ppm of 4-methyl-1-pentanol was added to 2500 ppm of PVCap, no hydrate formation occurred down to the minimum test temperature of 3 °C (subcooling at ca. 16.3 °C) in 15 parallel experiments compared to 10.4 °C for pure PVCap. Predictions for improved glycol ether synergists are given.

中文翻译：

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改进的聚（N-乙烯基己内酰胺）的动力学水合物抑制剂性能的溶剂增效剂

研究了多种不同溶剂对聚（N-乙烯基己内酰胺）（PVCap）的动力学水合物抑制剂（KHI）性能的协同作用。所使用的设备是使用缓慢恒定冷却（从20.5°C到大约1°C / h）的高压（76 bar）摇室设备，以及形成结构II水合物的合成天然气混合物。通过将5,000 ppm的一系列醇，乙二醇醚和酮添加到2500 ppm PVCap（M _w= 10000 g / mol）。对于许多添加剂而言，协同作用的等级可以参考分子中主要烷基（“尾部”）的大小，形状和疏水性以及乙二醇醚基团的存在来解释。在所有研究的溶剂中，最佳的协同作用是通过4-甲基-1-戊醇实现的。在15个平行实验中，当将5000 ppm的4-甲基-1-戊醇添加到2500 ppm的PVCap中时，在最低测试温度3°C（约16.3°C过冷）下，没有水合物形成发生，最低温度为3°C C为纯PVCap。给出了改进的乙二醇醚增效剂的预测。