Effect of methanol and ethylene glycol on adhesion strength of methane hydrates

doi:10.11949/0438-1157.20241483

Abstract

Abstract:

The wall adhesion strength of methane hydrates serves as a key parameter for evaluating hydrate deposition and blockage risks in pipelines. To investigate this, a self-developed high-pressure visualizable hydrate adhesion strength testing apparatus was employed to measure methane hydrate adhesion strength. Using this system as a reference, the effects of methanol and ethylene glycol were analyzed. The results show that the wall adhesion strength of methane hydrate is controlled by the hydrate content in the adhesion layer, the wall properties and the hydrate's own strength. Under high supercooling, the hydrate adhesion strength on the rough wall is greater. The addition of methanol and ethylene glycol significantly reduced the adhesion strength of methane hydrates, with reductions of 84% and 87% at a concentration of 7%, respectively. The primary mechanism is that thermodynamic inhibitors alter the phase equilibrium temperature, slowing hydrate formation rates, which reduces the hydrate content in the adhesive layer and consequently decreases the effective contact area between hydrate and pipe wall.

Key words: methane hydrate, alcohol, deposition, adhesive strength, flow assurance

摘要：

甲烷水合物壁面黏附强度是评价管道水合物沉积堵塞趋势的关键参数。自行设计了一套高压可视化水合物黏附强度测试装置，测试甲烷水合物壁面黏附强度，并以此为参照体系分析甲醇和乙二醇对其的影响。结果表明：甲烷水合物壁面黏附强度由黏附层中水合物含量、壁面性质和水合物自身强度共同控制，高过冷度下粗糙壁面上的水合物黏附强度更大；添加甲醇和乙二醇显著降低甲烷水合物黏附强度，降低幅度可分别达到84%和87%，主要原因在于热力学抑制剂通过改变相平衡温度减缓了水合物生成速率，降低了壁面黏附层中水合物的含量，减小了水合物与管壁的黏附面积。

关键词: 甲烷水合物, 醇, 沉积, 黏附强度, 流动保障

CLC Number:

TE 53

Chenru ZHOU, Chenwei LIU, Zhiyuan WANG, Minhui QI, Sanbao DONG, Xiangyu WANG, Mingzhong LI. Effect of methanol and ethylene glycol on adhesion strength of methane hydrates[J]. CIESC Journal, 2025, 76(7): 3596-3604.

周臣儒, 刘陈伟, 王志远, 綦民辉, 董三宝, 王翔宇, 李明忠. 甲醇和乙二醇对甲烷水合物黏附强度的影响[J]. 化工学报, 2025, 76(7): 3596-3604.

Figures/Tables 13

Fig.1 Schematic of experimental system of high-pressure hydrate wall adhesion strength

Fig.2 Internal structure of reaction kettle

Fig.3 Schematic of adhesion strength test of hydrate sediment

Fig.4 Baseline test results of hydrate adhesion strength

Fig.5 Schematic of hydrate detachment model on substrate

Fig.6 Variation of hydrate adhesion strength with growth time

Fig.7 Variation of hydrate adhesion strength with subcooling

Fig.8 Results of laser confocal scanning and corresponding contact angle of substrate

Fig.9 Variation of hydrate adhesion strength with roughness

Fig.10 Effect of alcohol concentration on hydrate adhesion strength

Fig.11 Effect of alcohol concentration on hydrate phase equilibrium temperature (pressure is 6.5 MPa)

Fig.12 Effect of methanol (a) and ethylene glycol (b) concentrations on hydrate growth morphology

Fig.13 Effect of hydrate formation pressure on hydrate adhesion strength (alcohol concentration is 3%)

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