Glossary - Introduction to Carbon Capture and Sequestration - page 558

Heat of adsorption
The heat that is released if we adsorb a gas in a solid adsorbent.
See also heat of desorption.
Heat of desorption
The negative of the heat of adsorption or absorption. The heat of adsorp-
tion is the heat that is released if we adsorb a gas in a solid, or the heat
of absorption in the case of absorption in a liquid.
See also heat of adsorption.
Henry coeffi cient
See Henry constant.
Henry constant
Henry constant or coeffi cient gives the solubility or adsorption of a gas in
a liquid or solid. The defi nition of the Henry coeffi cient differs from one
application to another, as do the units.
Hockey stick curve
The famous curve that shows the average global temperature over the
years. The fl at part indicates a constant temperature and in recent years
an upward trend is observed.
Hydraulic fracturing (“fracking”)
The ability to create high-permeability vertical fractures. It is the basis for
the relatively new approach to extracting hydrocarbons.
See also fracking.
Hydrostatic pressure
The equilibrium pressure due to gravity alone; most fl uids in sedimentary
basins are at this pressure.