CCS research by the Hydrates and ices laboratory

Assembling a large autoclave for high pressure tests in a cold room.

Preparing to pressure test seabed equipment at low temperatures.

Led by Dr Christopher Rochelle as part of the Hydrates and ices laboratory.

The hydrates and ices laboratory collaborates with other fluid processes researchers such as Keith Bateman in the hydrothermal laboratory.

The hydrates and ices laboratory focusses on colder conditions — -20 °C to +20 °C — using freezers and incubators. Experiments typically replicate temperatures and pressures typical of the seabed of deep seas or below permafrost.

This laboratory investigates the formation of CO2 hydrate in deep-water sediments, and its relationship with pore fluids and mineral grains. This has application to sub-surface storage, including:

  • the storage of CO2 as a liquid with a hydrate cap, above a relatively shallow reservoir
  • the formation of CO2 hydrate as a secondary trapping mechanism in the unlikely event of CO2 migration out of a much deeper reservoir

The formation of CO2 hydrate in cool, moderately deep-water marine sediments is a fairly novel method for underground CO2 storage, but offers certain advantages in terms of geochemical trapping mechanisms. The conditions and reactions we study are quite different to those in more conventional CO2 storage schemes, where conditions are warmer and where free CO2 exists as a supercritical fluid.

Hydrates are a subgroup of a range of compounds called clathrates and have water molecule 'cages'. A wide range of gases and low boiling point liquids can fit in the cages, including methane and carbon dioxide. They are usually white, ice-like solids that are stable at low temperatures and high pressures (e.g. deep oceans or below permafrost in polar regions).

Projects that involve this laboratory:

  • ECO2 (Sub-seabed CO2 Storage: Impact on Marine Ecosystems) — an EC framework 7-suppoted project considering the impact of leaking CO2 on cool marine sediments
  • commercially-funded projects investigating the stability of hydrates in marine sediments