Benchtop Euler Wheel for Kinetic Hydrate Inhibitor Screening: Comparison to Rocking Cells

摘要

A new type of high-pressure instrument dubbed the Euler wheel has been used for the testing of kinetic hydrate inhibitors (KHIs). The acrylic top of the wheel allows for observations of the fluids and hydrate formation through the entire loop. A series of four to six experiments on each KHI was carried out at an active dosage of 2500 ppm and an initial pressure of 40 bar using the constant-cooling method. The results were compared to KHI tests carried out in steel rocking cells. The rankings between the two types of instruments were found to be very similar. However, the best KHIs did not cause a pressure drop due to hydrates in the wheel, even at the minimum experimental temperature (0.7 degrees C), which represents a fairly high subcooling (Delta T = 14.3 degrees C). Further tests were therefore conducted at a lower concentration of 1000 ppm KHI, which helped to determine a clearer ranking of the best KHIs. The fluid movement in the wheel is closer to laminar flow, whereas the flow in rocking cells is more turbulent. This suggests that the lower turbulence in the wheel is the reason for the lower onset temperatures observed in the wheel. Thus, the type of fluid flow encountered in the field can impact the performance of KHIs.