Gas Hydrate Growth Kinetics

• Main Author: Meindinyo, Remi-Erempagamo Tariyemienyo
• Other Authors: Svartås, Thor Martin
• Format: Doctoral or Postdoctoral Thesis
• Language: English
• Published: University of Stavanger, Norway 2017
• Subjects: petroleumsteknologi; gass; varmeoverføring; VDP::Technology: 500::Rock and petroleum disciplines: 510::Petroleum engineering: 512; Gass; Arctic
• Online Access: http://hdl.handle.net/11250/2431863

PhD thesis in Petroleum engineering Gas hydrate thermodynamics and phase equilibria is already well established. However, some knowledge gaps still need to be filled in gas hydrate growth kinetics, in relation to new gas hydrate based technologies in gas separation and storage; as well as in the modeling of gas hydrate growth from the mechanisms of intrinsic kinetics, mass transfer, and heat transfer. Our findings from this work contribute valuable insights to the ongoing discussion on gas hydrate growth kinetics. New technologies in gas separation and storage require fast and efficient gas hydrate formation rates. In line with this, we have investigated the effect of parameters that may be optimized to give rapid gas hydrate growth rates, such as; temperature, water content, stirring rate, and reactor size on gas hydrate growth kinetics. This was carried out in two studies, in the first one, the growth rate was estimated directly from gas consumption rates in normal milliliters per minute [NmL/min]; while the second study was an extension of the first with the growth rate normalized by the water content (volume of water) in the cell. In line with this investigation, we have employed the correlation for the average bubble diameter from literature, based on isotropic turbulence theory for estimating the average bubble size; for analysis of the dispersion parameters of the system. The results from these studies reveal the following: 1. For the temperature: increased subcooling increases gas hydrate growth rates. Increased subcooling in this case gives a direct reflection of the effect of increased driving force. 2. For the water: increased water content gave poorer gas-liquid dispersion and thus slower gas hydrate growth rates. 3. For stirring: increased stirring increased the growth rate up to a threshold stirring rate beyond which further increase in the stirring rate did not increase the gas hydrate growth rate. This was linked to negligible heat and mass transfer effects beyond the threshold stirring rate. ...