(317a) Summary Results of Epri's Engineering and Economic Case Studies of Post Combustion Capture Retrofit Applied to Various North American Host Sites

Summary Results of EPRI's Engineering and Economic
Case Studies of Post Combustion Capture Retrofit Applied to Various North American
Host Sites.

Dr.
Desmond Dillon¹, Robert Chu² and Dr. Gerald Choi²

¹The Electric Power Research
Institute, EPRI, Palo Alto, Ca, USA

² Nexant Inc, San Francisco, Ca, USA

Abstract

With
more than 300 GW of installed coal-fired plants in the US, accounting for about
half of all electricity being generated domestically, it is anticipated that the
existing coal fleet would need to be retrofitted for CO₂ capture in
order to significantly reduce greenhouse gas emissions to acceptable levels. 
Amongst the available and developing capture technologies of pre-combustion,
oxy-combustion and post-combustion capture (PCC), the latter is viewed as a
viable and commercially available technology for existing plant retrofit
application.   

However,
retrofitting PCC to an existing coal fired plant presents significant challenges
in itself. Key issues arise such as:

·        
Limited space for new plant equipment

·        
Limited heat available for process integration

·        
Limitations of the existing steam turbine

·        
Cooling water limitations

·        
Replacement power considerations

·        
Complicated pipe routings.

With an
objective to better understand these factors and quantify their effect, the
Electric Power Research Company (EPRI) of California USA, recently completed a
series of detailed economic and engineering studies examining the feasibility
of retrofitting post combustion capture (PCC) to existing pulverised coal (PC)
and/or circulating fluidized-bed (CFB) power plants, for five different North
American ?host? sites. 

To
effectively undertake this study EPRI assembled a Retrofit Team with
engineering consultants of Nexant Inc. and architect engineers of Bechtel Power Corporation of
Frederick, Maryland.  Nexant's expertise in process plant economic optimization
was complimented with Bechtels practical knowledge and experience in power
plant retrofit costing, design and build. 

The
sites selected for the study included:

·        
Edison
Mission Groups 1500 MW Powerton Station, operated by Mid West Generation in
Pekin, Illinoi, USA

·        
Intermountain
Power Agencies 950 MW Intermountain Generating Station in Delta, Utah USA

·        
Nova Scotia
Powers 320MW (2 x 160MW units) Lingan Generating Station in Nova Scotia, Canada

·        
Great River
Energys 1100MW Coal Creek Station in Underwood, North Dakota, USA

·        
First Energys
176MW CFB Unit at Bayshore Generation Station in Oregon, Ohio, USA

Each of the host sites offered a unique combination of unit
sizes and ages, planned emissions control systems, fuel types, steam conditions,
boilers, turbines, and cooling systems.  Collectively, they represented a
critical sample of five different types of existing coal-fired plants within
the North American fleet. The data from these ?real world? sites provided a
broad insight into generalized cost and performance impact estimates for a
variety of power plant configurations.

Specifically the studies:

• Assessed  the most practical CO₂ capture efficiency configuration based on the existing site constraints
• Determined the space required for the CO₂ capture technology and the interfaces with the existing systems
• Estimated performance and costs for the post combustion CO₂ capture and compression plants
• Assessed the features of each plant that materially affect the cost and feasibility of the retrofit

The paper will give a summary overview of the studies.