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This CO2-recovery process set to enhance EDR.
Mitsubishi Heavy Industries, Ltd. (MHI
; Tokyo, Japan ;
edlinks.che.com/7368533) is marketing a new process that captures carbon
dioxide from flue gas (FG) for enhanced oil recovery (EOR). The KM-CDR
process uses a proprietary amine-based solvent (KS-1) in a packed column to
absorb and regenerate CO2 with less energy than conventional CO2-recovery
processes and with "far less" solvent loss, thereby reducing the
operating costs and increasing the effciency of CO2 capture, says MHI.
The
KM-CDR process was developed in cooperation with Kansai Electric Power Co. (Osaka, Japan;
CE, January 2004. p.13), and MHI has since
delivered several commercial plants to a variety of chemical companies
throughout the world. In 2005, MHI also established a strategic alliance
with Shell EP International Ltd. (Rijswijk, Netherlands) to cooperate in the promotion of
CO2 recovery from industrial sources for EOR projects at oil
fields in the Middle East.
By
injecting pressurized CO2 into a reservoir (diagram), a
supercritical phase, which is miscible with oil, is formed. This decreases
the viscosity, and thus increases the flowability of the oil. MHI estimates
that 10% more of the original oil in place (OOIP) can be recovered oil by EOR
with CO2 (tertiary EOP). Only 30-40% of the OOIP is recovered by conventional oil recovery methods, which
utilize the well's natural pressure (primary recovery) or by pressurizing the
well with oil, water or gas (secondary EOR), says MHI. The company expects to
recover 4 bbl of oil per metric ton of CO2 injected, so a
10,000-m.t./d KM-CDR plant operating at a nearby natural-gas-fired power
plant can potentially recover 40,000 bbl/d of oil.
Presently, the amount of oil produced by EOR is only
about 0.3% of total oil production, and most of the CO2 used is
derived from gas fields at a cost of about $20-30/m.t. However, the CO2
cost is expected to increase due to limited availability. MHI says EOR
projects using CO2 captured by the KM-CDR process will become
feasible if the price of CO2 can be linked with incremental oil
recovery, say, $1015 for the CO2 needed to recover 1 bbl/d of
oil, especially when oil prices stay above $40/bbl.
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