Comparative Assessments of PC, NGCC and IGCC Power Plants With and Without CO 2 Capture and Storage. Objectives

Transcription

1 Comparative Assessments of, and Power Plants With and Without CO 2 Capture and Storage Edward S. Rubin, Anand B. Rao and Chao Chen Department of Engineering and Public Policy University Pittsburgh, Pennsylvania Third Annual Conference on Carbon Capture & Sequestration Washington, DC May 4, 24 Objectives Compare the performance and cost of current fossil fuel power systems with and without CO 2 capture and storage (CCS) Pulverized coal combustion () Integrated coal gasification combined cycle () Natural gas combined cycle () 1

2 What s s New Here? We explore a broader range of conditions that influence comparisons among these technologies We highlight the implications of CCS energy penalties on resource requirements, multi-pollutant emissions, and cross-media environmental impacts We use the (publicly available) IECM computer model to systematically evaluate all three systems The IECM is Available At... CO 2 Version (Beta): Contacts: rubin@cmu.edu mikeb@cmu.edu Web Access : www. iecm-online.com Technical Support: PED.modeling@netl.doe.gov 2

3 Case 1: Nominal Assumptions Nominal Case Study Assumptions Parameter Reference Plant (~5 MW) Fuel Type Net HHV Efficiency (%) Capacity Factor (%) Fuel Cost, HHV ($/GJ) CCS Plant (~5 MW) CO 2 Capture System Amine Amine CO 2 Removal (%) 9 9 Pipeline Pressure (MPa) Geologic Storage Option Aquifer Aquifer 2 x 7FA Supercritical Nat. Gas 2%S Bit Also: fixed charge factor =.148; all costs in constant 22 US$ Texaco quench 2%S Bit Shift+Selexol Aquifer 3

4 CO 2 Emission Rates (kg/mwh MWh) Ref. Plant 818 with CCS Cost of Electricity (COE) (Levelized $/MWh) Ref. Plant +capture + transport & storage EOR Storage

5 Cost of CO 2 Avoided ($/tonne CO 2 ) 7 capture transport + storage EOR Storage Case 2: Effects of Fuel Price and Plant Dispatch 5

6 Differences in Total Variable Operating Cost ($/MWh MWh) (Includes fuel, chemicals, utilities, wastes and byproducts) Plant Fuel Price $1.27/ MBtu $1.27/ MBtu $2.5/MCF $4.5 $6.5 Ref. Plant (Base case) ~ Implication: Decreasing dispatch of at higher gas prices if coal plants are available Recent Trends for Plants Average Gas Price ($/MBtu) Assumed CF=85% Year Actual= 45% 32% 6

7 Effect of Variable Capacity Factor on Breakeven NG 85%CF COE ($/MWh) Variable CF Constant CF Natural Gas Price ($/MCF) Differences in Total Variable Operating Cost w/ CCS ($/MWh MWh) (Includes fuel, chemicals, utilities, wastes and byproducts) Plant Fuel Price $1.27/ MBtu $1.27/ MBtu $2.5/MCF $4.5 $6.5 CCS Plant (Base case) Implication: Increasing dispatch of 7

8 Cost of Electricity ($/MWh MWh) w/ Differential Capacity Factors $4.5/MCF capture + transport & storage CF = 75% (all cases) 75% 85% 5% Case 3: Effects of Financing & Operation 8

9 Can You Build It? Today, plants are generally more expensive than conventional plants, based on expected COE technology is also perceived as riskier by the financial community, and by many utility companies Several efforts underway to develop more attractive financing and ownership arrangements to facilitate deployment of in the U.S. power market Two New Scenarios for Financing and Operation Unfavorable Higher fixed charge rate of 17.3% (2% risk premium on rates of return) Lower plant utilization (CF=7%) Favorable Lower fixed charge rate of 1.4% (e.g., Harvard 3-Party Covenant) Higher plant utilization (CF=8%) 9

10 Cost of Electricity ($/MWh MWh) for the Two New Scenarios 9 8 Unfavorable 75 8 Favorable Ref. Plant CCS Plant Case 4: CCS Energy Penalty Impacts on Resource Consumption and Multi-media Emissions 1

11 Energy Penalty Defined Commonly defined as the reduction in plant output for a constant fuel input (i.e., plant derating) due to CCS More general definition is based on change in net plant heat rate or efficiency (η): EP = 1 (η ccs / η ref ) Case study energy penalties: = 24%, = 14%, = 15% An Alternative Definition An alternative definition of the energy penalty is the increase in plant inputs per unit of output (EP*): EP* = EP / (1 EP) This measure reflects increases per unit of product for: Plant fuel consumption Other resource requirements Solid and liquid wastes Air pollutants not captured by CCS Upstream (life cycle) impacts 11

12 CCS Energy Penalties Case study energy penalties for current technologies based on EP*: = 31 % = 16% = 18% Increases in Fuel and Reagent Consumption * Increase in Limestone Consumption kg limestone / kwh Increases in Coal and Natural Gas Consumption kg fuel / kwh Increase in Ammonia Consumption kg ammonia / kwh.1 *Based on Illinois #6 coal. 12

13 Increases in Solid Wastes & Plant Byproducts * Increases in Ash or Slag Residues kg ash or slag / kwh 2 *Based on Illinois #6 coal Increases in Desulfurization System Residues kg DeSOx residues / kwh Increases in Air Emission Rates *.2 Increase in SO2 Emission Rate g SO2 / kwh Increase in NOx Emission Rate g NOx / kwh *Based on Illinois #6 coal. 13

14 The Critical Importance of Technology Innovation New or improved technologies for power generation and CO 2 capture can lower the cost of CCS, and significantly reduce adverse secondary impacts by: Improving overall plant efficiency Reducing CCS energy penalties Maximizing co-capture of other pollutants Work in Progress at CMU Incorporate performance and cost models of advanced power systems and CO 2 capture options: Oxyfuel combustion ITM oxygen production Advanced designs Advanced Expand and regionalize transport & storage models Comparative analyses of CO 2 capture options for new and existing power plants Advanced, and systems Repowering or rebuild of existing units Assessments of R&D Benefits 14