Evaluation of the U.S. DOE R&D Program to Identify Advanced Solvent Process Configurations for Post Combustion Capture☆

Abstract There are increasing efforts by the United States government and private industry to develop advanced technologies to mitigate anthropogenic carbon dioxide (CO 2 ) emissions that are contributing to global climate change. One very promising approach to reducing greenhouse emissions is to capture and compress CO 2 at a power plant, then transport it to a storage site and inject it for long-term storage in any of a variety of suitable geologic formations. The United States Department of Energy (DOE) is investing in advanced technologies to significantly reduce the cost of capture from pulverized coal, integrated coal gasification combined-cycle, and natural gas fired power systems. The DOE is providing research and development (R&D) funding for over 60 individual projects that are investigating a wide variety of CO 2 separation techniques for these systems, including various approaches utilizing advanced solvents, sorbents, and membranes. Research also includes the development of advanced processes and related components to support these new separation technologies and improve the efficiency of the capture systems. It has become clear that integrating the various advanced processes and components with the advanced separation technologies in different combinations will be necessary to reduce the costs to levels which will make power plants with carbon capture and storage (CCS) competitive with other sources of electric power generation. This study consisted of a systematic a review of seven DOE-supported R&D projects active in 2013 and developing advanced solvent technology systems for post combustion capture from pulverized coal fired power plants. For the solvents sub-program area, each project in the portfolio addresses a single or multiple technologies that comprise one or more components of a complete functioning advanced carbon capture system. The scope of the review focused on identifying the components of the advanced solvents technologies and how the various components could be combined and integrated to further reduce the cost and improve the efficiency of capture. The seven R&D projects selected as part of this study were active in 2013 and are developing/testing six different solvents [i.e., monoethanolamine ((MEA) benchmark), MEA/amine variants, Piperazine (PZ), bio-catalyst/enzyme- catalyzed solvent (carbonic anhydrase –(CA)) with potassium carbonate (K2CO3), and a proprietary amine based solvent]. The projects are also evaluating the use of 17 advanced capture system components (e.g., advanced absorber columns, strippers, intercoolers, compression, heat exchangers, etc.). The approach used in this review was to examine each R&D project and subdivide it into the innovative and unique components or features, and then determine where the individual features could be combined components from other technology systems. Several near-term or second generation technologies were selected and subsequently assembled into various integrated configurations to make complete advanced carbon capture systems. Six conceptual combinations of the technology components were developed to be evaluated for their potential in improving the overall chance of achieving the DOE Program Goals of greater than 90% carbon capture at no more than $40/ tonne of captured CO 2 . Each of the combinations was reviewed with the solvent utilized by the primary or base carbon capture (CC) technology developer. The best combination of additional technology components from other projects was then applied to that solvent technology, while attempting not to substantially impact the process conditions. This allows a reasonable evaluation of the potential benefits without compromising the base solvent process. Six conceptual technology combinations that could have additional benefits by combining the advanced solvents, technologies, and capture processes together were identified. For each combination, a screening evaluation was performed of the various components potential contribution to the combined system improvement in capture efficiency. This evaluation and the estimate of component contributions were based on statements about the technology or component ability to reduce the cost of capture or reduce energy use, as represented by the participant organizations.