• 한국신재생에너지학회:학술대회논문집
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• 2011.11a
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• pp.124.2-124.2
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• 2011

천연의 메탄 하이드레이트를 생산하기 위한 방법으로 몇 가지가 알려져 있으나 최근의 연구 결과로는 감압법이 가장 효과적이며 경제성을 확보할 수 있다고 알려져 있다. 하지만 이 방법을 이용한 메탄 하이드레이트 개발생산 시에는 해리된 물과 가스가 동시에 생산유체로 발생하여 수송되며, 생성수에는 하이드레이트 전구체라고 알려진 미완의 하이드레이트 구조체가 남게 된다. 생산유체는 낮은 해수온도에 노출되어 가스 하이드레이트가 쉽게 재생성될 가능성이 높기 때문에 안정적인 가스 생산과 생산시설의 보호를 위해서는 적절한 가스 하이드레이트 재성성 억제대책이 필요하다. Kinetic 억제제의 적용이 많이 이루어지고 있는 가스전에서의 경험을 바탕으로 투여해 보는 시도를 하고 있지만 sII인 천연가스 하이드레이트에서의 억제효과와 비교하여 저하된 결과가 보고되고 있다. sI과 sII는 메커니즘의 차이로 인해 억제제의 성능이 다르게 나타난다. sI인 메탄 하이드레이트에 대하여 kinetic 억제제의 효과를 살펴보았고 이온성액체를 적용한 효과적인 sI 하이드레이트 억제기법을 보고한다. 또한 기존의 sII 억제제와 혼합하여 시너지효과를 얻을 수 있음을 확인하였다.

• Journal of Ocean Engineering and Technology
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• v.34 no.5
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• pp.342-350
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• 2020

In this study, a hydrate inhibition system is investigated for shallow water gas fields. Mono-ethylene glycol (MEG) injection has been used as a typical method for inhibiting hydrate formation in gas fields; therefore, most offshore platforms are equipped with MEG injection and regeneration processes. A recent application of a kinetic hydrate inhibitor (KHI) has reduced the total volume of MEG injection and hence reduce the operating cost. Experiments are designed and performed to evaluate and verify the KHI performance for inhibiting hydrate formation under shallow water conditions. However, the shut-in and restart operation may require the injection and regeneration of MEG. For this operation, the MEG concentration must be optimized while considering the cost of MEG regeneration. The obtained results suggest that decreasing MEG concentration from 80 wt% to 70 wt% can reduce the life cycle cost (LCC) of MEG regeneration process by approximately 5.98 million USD owing to reduced distillation column cost. These results suggest that the hydrate inhibition system must be evaluated through well-designed experiments and process simulations involving LCC analysis.

• Korean Chemical Engineering Research
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• v.52 no.6
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• pp.814-820
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• 2014

In this work, hydrate inhibition performance of water-soluble polymers including pyrrolidone, caprolactam, acrylamide types were evaluated using torque measurement and high pressure differential scanning calorimeter (HP ${\mu}$-DSC). The obtained experimental results suggest that the studied polymers represent the kinetic hydrate inhibition (KHI) performance. 0.5 wt% polyvinylcaprolactam (PVCap) solution shows the hydrate onset time of 34.4 min and subcooling temperature of 15.9 K, which is better KHI performance than that of pure water - hydrate onset time of 12.3 min and subcooling temperature of 6.0 K. 0.5 wt% polyvinylpyrrolidone (PVP) solution shows the hydrate onset time of 27.6 min and the subcooling temperature of 13.2 K while polyacrylamide-co-acrylic acid partial sodium salt (PAM-co-AA) solution shows less KHI performance than PVP solution at both 0.5 and 5.0 wt%. However, PAM-co-AA solution shows slow growth rate and low hydrate amount than PVCap. In addition to hydrate onset and growth condition, torque change with time was investigated as one of KHI evaluation methods. 0.5 wt% PVCap solution shows the lowest average torque of 6.4 N cm and 0.5 wt% PAM-co-AA solution shows the average torque of 7.2 N cm. For 0.5 wt% PVP solution, it increases 11.5 N cm and 5.0 wt% PAM-co-AA solution shows the maximum average torque of 13.4 N cm, which is similar to the average torque of pure water, 15.2 N cm. Judging from the experimental results obtained by both an autoclave and a HP ${\mu}$-DSC, the PVCap solution shows the best performance among the KHIs in terms of delaying hydrate nucleation. From these results, it can be concluded that the torque change with time is useful to identify the flow ability of tested solution, and the further research on the inhibition of hydrate formation can be approached in various aspects using a HP ${\mu}$-DSC.