WASHINGTON, DC - Conversion Gas Imports, LLC
(CGI) of Houston, Texas, recently reported its findings
on the "Bishop Process" to the Department of Energy -- a
novel method of unloading and re-gasifying liquefied
natural gas (LNG) directly from ocean tankers for
storage in underground salt caverns. Initial indications
are that a salt cavern-based LNG terminal can be built
at about half the cost and twice the capacity of a
conventional liquid tank terminal.
The action follows Secretary of Energy Spencer
Abraham's meeting in June with the National Petroleum
Council (NPC), during which he heard their
recommendations on engaging consumers in smart energy
use and on increasing natural gas supplies, which
currently remain tight as prices continue to rise.
Secretary Abraham had earlier called upon the NPC to
host a meeting later this year to discuss natural gas
supplies, but felt the situation needed more immediate
attention. He also has also called for a Global Natural
Gas Summit, to be held later this year.
"The Bishop Process, if proven successful, has the
potential to significantly increase world LNG trade and
provide a highly secure, economical and flexible way to
expand LNG imports and augment the nation's energy
supply," Secretary Spencer Abraham said. "CGI's report
couldn't have come at a more advantageous time. My
meeting last month with the National Petroleum Council
raised concerns about natural gas supplies in the United
States. Innovative ideas such as the Bishop Process
could make all the difference."
Liquefied natural gas -- natural gas that has been
transformed to a liquid by cooling it to minus 260
degrees Fahrenheit -- currently is unloaded from
ocean-going tankers and stored in above-ground storage
tanks that are specially designed to hold the LNG before
it can be re-gasified.
The Bishop Process entails receiving LNG directly
from an offshore tanker, pressurizing and warming it to
40o F, and then injecting the natural gas into
underground salt caverns for storage, thereby
effectively eliminating the need to build expensive
above-ground cryogenic storage tanks, while
simultaneously increasing the storage capacity potential
of LNG imports.
The process is considered a success based on its use
of a novel low cost seawater heat exchanger. Traditional
heat exchangers, which use natural gas to heat the LNG,
cannot keep up with tanker offloading rates at marine
terminals. CGI's unique high volume, high-pressure heat
exchanger enables shorter unloading times. In addition,
ship unloading can be accomplished miles from the
storage caverns, providing further security and siting
flexibility.
The CGI feasibility study comes on the heels of
Federal Reserve Chairman Alan Greenspan's recent
testimony before the House Energy and Commerce
Committee, calling for an expanded ability to import
more LNG in an effort to stabilize the United States'
market for natural gas.
Ultimately, the Bishop Process could enable the
development of LNG receiving and storage facilities that
are faster and less expensive to build, and have higher
storage and "take away" capability than today's tank
terminals.
Salt locations suitable for storage in proximity to
significant natural gas distribution systems have been
found both onshore and offshore in many LNG importing
areas of the world. In the United States, there are over
1000 salt caverns being used for hydrocarbon storage and
delivery, including the Strategic Petroleum Reserve's
four sites.
Before industry moves forward in constructing a LNG
receiving facility based on the Bishop Process, field
tests are required to determine the critical elements
needed to reach operational success. NETL, CGI and
several industry partners are currently working to
define the procedures and costs for these tests.
Critical elements to be addressed include:
- Engineering and evaluating a method to moor and
offload a LNG ship offshore;
- Designing, constructing, and testing a LNG pump
capable of creating cavern injection pressures and
flow capacities that provide for acceptable ship
discharge times; and
- Designing, building, and testing a heat exchanger
that will economically warm the LNG at high pressures
and high volumes.
Total cost of the feasibility study was $168,450, of
which DOE provided $134,750 and CGI contributed $33,700.
The
Final
Report [PDF-15MB]
on this project can be accessed at:
http://www.netl.doe.gov/technologies/oil-gas/index.html.
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