Design and Testing of Kinetic Hydrate Inhibitors
Master thesis
Permanent lenke
https://hdl.handle.net/11250/3166902Utgivelsesdato
2024Metadata
Vis full innførselSamlinger
Sammendrag
The formation of gas hydrates, which restrict pipeline flow and delay oil and gas transport, is a challenge in the oil and gas industry. A chemical prevention method is the deployment of Kinetic Hydrate Inhibitors (KHIs) in the pipeline. KHIs delay hydrate formation and nucleation, allowing a safe operational window before hydrates start to form.
This thesis focuses on the synthesis of a brand new class of KHIs, polyvinyl amine oxides, and the testing of its KHI performance. There is an industrial need for commercially available alkylated amine oxides that can be synthesized in large quantities and have good KHI properties. Additionally, KHI performance tests are performed for the class poly(2-dialkylamino-2-oxazoline)s, received by the Hoogenboom group in Belgium.
The Slow Constant Cooling (SCC) method with high-pressure rocking cells was used as the primary performance test method. The test gas was Synthetic Natural Gas (SNG) or methane. Supplemental isothermal tests were carried out for the polyvinyl amine oxides.
The synthesis of the polyvinyl amine oxides showed that the polyvinyl dibutyl amine oxide (PVAmBu2O) had the best KHI performance, likely resulting from the butyl groups and the amine oxide group. However, the synthesis needs refinement to obtain a reproducible product.
The SCC tests showed that some PVAmBu2O polymers performed better with increasing concentrations. Lower polymer molecular weight yielded the best performance. The addition of iBGE, nBGE, DPBGE and 3 wt.% NaCl improved the performance in SNG. Antagonistic effects by iBGE and nBGE were observed in the methane tests. A 2-degree Celsius onset temperature was obtained in the methane tests, indicating a potential for the polymer to be utilized in methane systems. In addition, the polymers outperformed PVCap in both test gases, indicating a new promising product that can be used in SNG and methane systems.
Isothermal tests revealed induction times of 2192 min (SNG) and 1068 min (methane) with a chemical blend of 5000 ppm PVAmBu2O and 5000 ppm nBGE. An unusual double pressure drop was observed in the SNG test.
The tests on the poly(2-dialkylamino-2-oxazoline)s showed similar performance to PVCap in SNG and methane. Synergism was obtained with iBGE, nBGE, DPBGE, and 3 wt.% NaCl while antagonistic effects were observed with TiPeAO and TiPeAB. In contrast, iBGE addition into the methane led to poorer performance.