Investigations on bio and natural gas conditioning and separation via gas hydrate formation under the use of surface active materials (promoters)

• Main Author: Filarsky, Florian
• Other Authors: Schrader, Thomas
• Format: Doctoral or Postdoctoral Thesis
• Language: English
• Published: 2019
• Subjects: ddc:540; Fakultät für Chemie » Organische Chemie; Gas hydrates > Promoter > Separation; permafrost
• Online Access: https://doi.org/10.17185/duepublico/70583; https://nbn-resolving.org/urn:nbn:de:hbz:464-20191023-122022-3; https://duepublico2.uni-due.de/receive/duepublico_mods_00070583; https://duepublico2.uni-due.de/servlets/MCRFileNodeServlet/duepublico_derivate_00070544/Diss_Filarsky.pdf

Gas hydrates are solid crystalline inclusions of guest molecules in water. In nature, due to high pressures and low temperatures, they can be found in deep sea or permafrost areas where water molecules form cage-like structures in which stabilizing guest molecules are centered inside. The guest molecules are e.g. lower hydrocarbons or carbon dioxide. Former research was mainly focused on the exploitation of natural gas hydrate deposits and the prevention of gas hydrate formation in gas pipelines. Along with the growing knowledge on gas hydrate properties, new applications are conceivable. Nowadays, efficient gas storages, desalination units, gas separation processes etc. are thinkable. In the coming decades, the relevance of natural and biogas will rise due to the decline of conservative fossil fuels like crude oil. Currently, both gases need to be conditioned with a high cost and energy effort. The presented thesis follows the attempt to solve these problems by developing an energy saving gas hydrate separation process. Therefore, the gas hydrate formation behavior in presence of diverse kinetic and thermodynamic promoter mixtures is extensively investigated under different conditions and the separation efficiency evaluated. Surface active substances are tested and a promoting coating for reactors and particles is designed. A multitude of reactor designs is developed, operated and optimized with regard to an improved, targeted gas hydrate formation. Furthermore, first-time feasibility studies are performed proving a successful development of a promoting coating, a combined biogas production with subsequent gas hydrate separation, and a gas hydrate absorption process. Additionally an Excel Tool© is developed for the prediction of gas hydrate equilibria. Supported by simulations, the promising results of this thesis result in economic considerations revealing the vast energy and cost saving potential of a gas hydrate separation process applicable for bio and natural gas conditioning. Further, a pilot plant is ...