Greenhouse Gas Mitigation & CO2 Storage Prof. Jenn-Tai Liang Chemical & Petroleum Engineering Department The University of Kansas Capture, purification, reuse & storage of CO2 Costs of Capture: Highly location, technology, energy costs, etc. dependent. Estimated cost of capture: US$23 ~ $53/t.* * Herzog, MIT 2006 Capture, purification, reuse & storage of CO2 Costs of Transportation & Storage: Highly location, method, energy costs, etc. dependent. Estimated cost: US$2.92 ~ $4.86/t.* * Herzog, MIT 2006 Capture, purification, reuse & storage of CO2 Opportunity Cost: Estimated opportunity cost for substantial capture & storage activity: US$25 ~ $35/t.* * Herzog, MIT 2006 Capture, purification, reuse & storage of CO2 Is geological storage safe? With careful site selection and characterization, it is generally considered safe to store CO2 in geological formations. Capture, purification, reuse & storage of CO2 Issues with storage in other countries: Increased costs and risks of leakage during transportation. Global carbon credit trading not established. Difficulties in monitoring & verification. Geologic Sequestration Oil & Gas Reservoirs – – – – Enhanced oil recovery* Enhanced gas recovery in gas condensate reservoirs* Depleted oil & gas reservoirs Reservoir pressure maintenance* Saline Aquifers Coal Beds – Enhanced coal bed methane recovery* * income generating Geologic Sequestration Near-term, low-volume implementation: Store high purity CO2 in local hydrocarbon reservoirs or saline aquifers. Suitable for industries producing high purity CO2. Geologic Sequestration Long-term, large-scale implementation: Store CO2 in deep saline aquifers. Takes decades to build expensive infrastructures for capture and transportation. Geologic Sequestration Key issues: Costs associated with the CCS. Storage capacity of venues selected. Containment longevity. Monitoring & verification Geologic Sequestration Cost issues: CCS is expensive. Needs income generating potential for industries to implement. Carbon tax credits or government subsidy required for large-scale implementation. Geologic Sequestration Storage-capacity issues: Requires good geologic model. Need reservoir simulation for CO2 movement and trapping. – Simulation must couple flow, phase, geochemical, geomechanical models. Storage capacity estimates must be conservative and Monte Carlo simulation should be used to address uncertainties. Geologic Sequestration Monitoring issues: Monitoring strategy should be site specific and risk based: – Risk profile differs in different geological formations. Seismic Pressure Vegetative stress Eddy covariance and flux accumulation chamber Best developed monitoring methods: – – – – Geologic Sequestration Verification issues: Detection limit and precision of measurements must be established to insure accurate and cost-effective inventory accounting. Methods for establishing detection limit: – Fraction of background CO2 flux – Prescribed CO2 flux – Specified CO2 emission per year – Percent of CO2 will be injected Where should Taiwan be heading? Learn from others first (do not reinvent the wheel): CCS Consortia: – – – CO2NET, CO2NET3, CO2ReMoVe (EU-funded consortia) CCP, GCEP (Industry-funded consortia) GEODISC, CO2CRC (Australia) Weyburn project – CO2 EOR (EnCana) Salah project – Saline formation (BP) Sleipner project – CO2-rich gas reservoir (Statoil) Nagaoka pilot (RITE of Japan) Frio Brine pilot (Texas BEG) Commercial Projects: – – – Pilot projects: – – Where should Taiwan be heading? Things can be done “NOW”: Survey suitable geological formations for CO2 storage. Gain site assessment experience using wellcharacterized CPC gas reservoirs: – – – – – use Monte Carlo simulation to estimate storage capacity, use reservoir model to simulate long-term CO2 trapping and movements, establish risk profile and develop monitoring strategy, evaluate sub- and above-surface monitoring methods, estimate costs. Where should Taiwan be heading? Roles of industries, government, and academia: Oil and gas industry, geological surveys, and academia need to work together to identify sites that can be used to store CO2 safely, near permanently, and cost effectively. Government should sponsor pilot demonstration projects to validate findings from feasibility studies. Where should Taiwan be heading? Roles of industries, government, and academia: Government should sponsor outreach program through education, forums to gain public support. The outreach program should address the status of current technological developments and the risks involved in CCS. Including NGOs’ views in an objective fashion is crucial to gaining public acceptance.