[Truncated] This thesis aims to explore two questions crucial to the advancement of hydrate research and the development of novel kinetic hydrate inhibitors (KHIs): 1. What causes the observed stochastic nature of hydrate formation? 2. How do KHIs affect (a) hydrate formation (b) hydrate growth and (c) agglomeration?
The experiments described in this work were performed using three different tools: a High‐ Pressure Lag Time Apparatus (HP‐ALTA), a HP‐Video Cell and a Micromechanical Force Apparatus (MMF).
The HP‐ALTA is a recently developed tool capable of capturing large distributions of hydrate formation temperatures in significantly shorter times compared to traditional techniques. As the HP‐ALTA can be operated in either a constant subcooling or linear cooling mode, it was first important to establish the relationship between the data collected in both modes. Although both modes provide equally useful data, the linear cooling mode allowed significantly faster data collection, and so was used in all subsequent experiments. Data collected using the linear cooling mode was in the form of distributions of hydrate formation temperatures. The hydrate formation temperatures refer to the temperature range at which hydrate formation was detected using the HP‐ALTA. Different hydrate systems were found to have different distribution widths. The possible reasons behind these variations were explored by modelling the gas concentrations in the aqueous phase. By modifying the expressions for the driving force in aqueous solutions of hydrate‐forming systems derived by Kashchiev and Firoozabadi, the minimum supersaturation driving force required for 90 % methane 10 % propane mixed gas and CO2 hydrate formation in quiescent systems was then estimated. The performances of six different KHIs were then compared quantitatively.
|Qualification||Doctor of Philosophy|
|Publication status||Unpublished - Mar 2014|