Export to Refworks Export to EndNote Email
Report an Issue

Enhanced geothermal systems (EGS) with CO2 as heat transmission fluid--A scheme for combining recovery of renewable energy with geologic storage of CO2 [electronic resource].

Published:
Berkeley, Calif. : Lawrence Berkeley National Laboratory, 2009.
Oak Ridge, Tenn. : Distributed by the Office of Scientific and Technical Information, U.S. Dept. of Energy.
Additional Creators:
Lawrence Berkeley National Laboratory and United States. Department of Energy. Office of Scientific and Technical Information
Access Online

Availability

I Want It

Finding items...

Restrictions on Access:
Free-to-read Unrestricted online access
Summary:
It has been suggested that enhanced geothermal systems (EGS) may be operated with supercritical CO₂ instead of water as heat transmission fluid (D.W. Brown, 2000). Such a scheme could combine recovery of geothermal energy with simultaneous geologic storage of CO₂, a greenhouse gas. At geothermal temperature and pressure conditions of interest, the flow and heat transfer behavior of CO₂ would be considerably different from water, and chemical interactions between CO₂ and reservoir rocks would also be quite different from aqueous fluids. This paper summarizes our research to date into fluid flow and heat transfer aspects of operating EGS with CO₂. (Chemical aspects of EGS with CO₂ are discussed in a companion paper; Xu and Pruess, 2010.) Our modeling studies indicate that CO₂ would achieve heat extraction at larger rates than aqueous fluids. The development of an EGS-CO₂ reservoir would require replacement of the pore water by CO₂ through persistent injection. We find that in a fractured reservoir, CO₂ breakthrough at production wells would occur rapidly, within a few weeks of starting CO₂ injection. Subsequently a two-phase water-CO₂ mixture would be produced for a few years,followed by production of a single phase of supercritical CO₂. Even after single-phase production conditions are reached,significant dissolved water concentrations will persist in the CO₂ stream for many years. The presence of dissolved water in the production stream has negligible impact on mass flow and heat transfer rates.
Report Numbers:
E 1.99:lbnl-1949e
lbnl-1949e
Other Subject(s):
Note:
Published through SciTech Connect.
05/01/2009.
"lbnl-1949e"
World Geothermal Congress 2010, Bali, Indonesia, April 25-29, 2010.
Pruess, K.; Spycher, N.
Earth Sciences Division
Funding Information:
DE-AC02-05CH11231
View MARC record | catkey: 14131104