Author:

Jon Isley, Senior Director – Process Technology, Fluor Canada

Carbon capture is a mature technology solution at the forefront of energy transition options to mitigate greenhouse gas emissions from large industrial emitters. Carbon capture is an efficient option for new and existing industries to meet progressing regulations while at the same time leveraging Canada’s natural resources, existing infrastructure, and capacity to sequester carbon dioxide in very close proximity to where fossil fuels are available.  

Carbon capture from post-combustion flue gas has been practiced commercially for several decades. Beginning in the 1980s to the early 2000s, there was a robust market for food-grade carbon dioxide which provided economic incentives for development and commercialization. As the world became more concerned with carbon dioxide’s impact on climate change, industries expanded carbon capture applications to higher pressure sources, which over time, has changed market conditions and made capturing carbon dioxide from lower pressure sources less economically attractive. With the latest combination of government regulations and incentives that target greenhouse gas emission goals for 2030, the carbon capture focus is now shifting to large industrial emitters. Implementing commercially proven technologies on a broad scale will play a substantial role in meeting the established goals under the targeted timelines.

One such commercially proven carbon capture technology is Fluor’s Econamine FG PlusSM (EFG+). In 1989, Fluor kicked-off development of what became the EFG+ technology after acquiring rights to the original Econamine solvent from Dow. Fluor’s first commercial application was on a gas turbine exhaust on the Natural Gas Combined Cycle (NGCC) power plant at Bellingham, Massachusetts. The Bellingham plant had continuous commercial operation from 1991 to 2005 before the NGCC was shut down for reasons unrelated to technical performance. Nonetheless, the plant logged more than 120,000 hours of carbon capture operation over 14+ years and demonstrated an on-stream factor over 98% during later operating years.

The Bellingham plant kickstarted second generation amine-based carbon capture technology by becoming a development platform for process design optimization, energy efficiency and solvent maintenance and formulation studies. The process improvements pioneered at Bellingham created the foundation for what EFG+ technology has become today. Since the Bellingham plant design, the EFG+ process now includes several additional technological advancements which set it apart from other amine-based CO2 capture technologies. These advancements are:

• Patented 2-Stage direct contact cooler (US 9,346,007)
• Patented multi-celled gas processing (US 9,333,456)
• Patented absorber intercooling (US 6,800,120)
• Lean vapor compression
• Improved solvent formulation
• Low pressure-drop packing
• Patented heat integration methods (US 9,320,985 and US 9,314,732)
• Advanced solvent maintenance system

In one specific example using operating experience gained at Bellingham and on several other EFG+ units installed on a variety of flue gas types, Fluor developed the proprietary Solvent Maintenance System. This system is designed to maintain the circulating solvent in pristine condition by continuously removing degradation products as well as contaminants known to catalyze their formation. Solvent maintenance is key to maintaining trouble-free operation in the presence of oxygen, improving both solvent hygiene and performance, and significantly reducing solvent losses compared to more conventional thermal reclaiming systems. This system dramatically improves the environmental signature of the EFG+ carbon capture process by:

• Significantly reducing the solvent degradation rate, and therefore both the solvent consumption and waste production, and
• Reducing emissions associated with volatile degradation products including ammonia and aldehydes.

Proper solvent maintenance avoids significant issues that have been reported by other carbon capture technology applications. When carbon capture solvents degrade, the unwanted byproducts can cause corrosion, foul equipment, and significantly reduce carbon capture performance including capture rate and onstream availability. Loss of performance means loss of revenue or incentives for carbon capture, plus increased costs in downtime, maintenance, solvent make-up costs and byproduct solvent waste disposal costs. Poor solvent performance can thus jeopardize a carbon capture project’s justification and cannot be understated as a project risk. The proven ability to handle solvent degradation is a key differentiator of a reputable and proven commercial scale carbon capture offering. 

The development of EFG+ offers the latest generation carbon capture technology for large industrial emitters. EFG+ has been successfully demonstrated in commercial applications with over 30 plants built over the past three decades, with gases derived from a spectrum of applications and fuel sources. Fluor has leveraged decades of experience and development effort to incorporate innovations, improving efficiency and performance. These improvements have positioned EFG+ to be one of the best solutions available and actionable today to tackle Canada’s emission targets.

Figure 2 – Block flow diagram of the Bellingham project:

Figure 3 – DCC and Absorber Views: