Hydrate Formation from Gaseous CO2 and Water

• Published in: Environmental science & technology Vol. 33; no. 9; pp. 1448 - 1452
• Main Authors: Morgan, James J, Blackwell, Veronica R, Johnson, Don E, Spencer, Dwain F, North, Wheeler J
• Format: Journal Article
• Language: English
• Published: Washington, DC American Chemical Society 01.05.1999
• Subjects: Applied sciences; Atmospheric pollution; Carbon dioxide; Earth, ocean, space; Economics; Exact sciences and technology; External geophysics; Other pollution sources in industry; Physical and chemical properties of sea water; Physics of the oceans; Pollution; Prevention and purification methods; Water; Laboratory study; Cost minimization; Hydration; Pollution prevention; Carbon dioxide; Operating mode; Dissolution; Waste disposal; Greenhouse gases; Storage; Chemical reaction; Upgrading; Ocean; Air pollution; Gas hydrates; Hysteresis; Aquaculture; Seawater
• ISSN: 0013-936X; 1520-5851
• DOI: 10.1021/es980736k

Economics of creating CO2 hydrate on a large scale favor use of gaseous rather than liquid CO2 as input to the production process. We accordingly studied systems using deionized water and CO2 gas to reduce formation pressures and costs of hydrate production to the greatest extent possible. Three research avenues were explored:  utilization of hysteresis effects, use of dissolved Snomax (a protein from the bacterium Pseudomonas syringae), and development of a continuous flow reactor (cfr) utilizing vigorous mixing of water and CO2 gas. Hysteresis effects produced pressure reductions of 14−50%. We demonstrated a method of transferring benefits from the hysteresis effect to a CO2 water mixture that had not yet undergone hydrate formation. Snomax at 10 ppm by weight produced about a 5% reduction in hydrate formation pressure. We designed and operated a prototype cfr with partial success at producing CO2 hydrate. The hydrate phase diagram is based on hydrate decomposition pressures and should not be used as an indicator of formation pressures.