DOE Pulse
  • Number 353  |
  • January 2, 2012

Initiative aims to speed carbon capture technology

Carbon Capture Simulation Initiative

Carbon Capture

Simulation Initiative

The Carbon Capture Simulation Initiative (CCSI) is a partnership among five DOE national laboratories (NETL, Lawrence Berkeley, Lawrence Livermore, Los Alamos, and Pacific Northwest), industry, and various academic institutions that are working together to develop state-of-the-art computational modeling and simulation tools to accelerate the commercialization of carbon capture technologies from discovery to development, demonstration, and ultimately, widespread deployment at hundreds of power plants. CCSI is part of DOE/NETL's comprehensive carbon capture and sequestration (CCS) research program, part of the President's plan to overcome barriers to the widespread, cost-effective deployment of CCS within 10 years.

Taking promising new power plant technologies from concept to commercial scale normally would take 20-30 years in order to manage the overall risk of the scale-up process. Science-based models developed as part of CCSI will be used in conjunction with pilot-scale data to allow larger steps to be taken earlier with greater confidence, thereby reducing the time and expense required for achieving commercial deployment of carbon capture technology.

The CCSI Toolset will incorporate commercial and open-source software currently in use by industry as well as new software tools developed by the Partnership to fill identified technology needs. It will consist of models for particle and device scale simulation, process synthesis and design, and plant operations and control, all of which build on a common set of basic data. The software will be linked by a web-based framework that will allow scientists and engineers at the CCSI sites to incorporate uncertainty quantification, risk analysis, and decision making using the capabilities and specialized software existing on computers at the various national labs.

Modeling and Simulation of Solid Sorbent Carbon Capture Systems

Designing a carbon capture system requires understanding how a solid sorbent material interacts with flue gas to adsorb carbon dioxide and how that carbon dioxide can then be removed so CO2 can be pressurized and sent for utilization or storage. Significant work remains to define and optimize the reactors and processes needed for successful sorbent capture systems, but it appears that solid-sorbent-based post-combustion capture will have a lower energy penalty than current amine-based solvent systems. Therefore, the CCSI partnership has decided to initially focus on solid-sorbent-based, post-combustion capture technology.

NETL researchers are developing new predictive models that can be used to help design, analyze, and optimize solid sorbent processes. Two new models have been developed recently. One is a multi-stage fluidized bed reactor in which the flue gas bubbles through two beds of solid sorbent particles. As the flue gas interacts with the particles, CO2 is adsorbed, generating significant amounts of heat. One of the benefits of a fluidized bed reactor is that the heat can be removed very efficiently. Another model is a moving bed regenerator in which the solid sorbent is heated as it falls through a series of heat exchange tubes. As the sorbent is heated, it releases CO2. The regenerated sorbent is then sent back to the adsorber for reuse, completing the cycle. Based on the results of these simulations, even more detailed simulations are being conducted, which consider the internal geometry and flow patterns.

Uncertainty Quantification

Uncertainty quantification (UQ) is now recognized as an essential component of the computational investigation of complex, multi-physics, multi-scale system behavior. UQ is the study of the accuracy and reliability of scientific inferences and is used to provide confidence measures that can be used by decision makers working with simulations, such as those that will be produced by CCSI. CCSI is leveraging the significant advances and expertise from the DOE National Nuclear Security Administration (NNSA) Advanced Simulation and Computing (ASC) Program and the Office of Science Advanced Scientific Computing Research (ASCR) Program. The main objective of these efforts will be to develop a set of computational tools for UQ to be integrated into current simulation software.

Uncertainty quantification methods were recently demonstrated at NETL for the CCSI Industry Advisory Board. This analysis allowed us to determine not just the solvent flow required to capture 90% of the CO2 from a flue gas stream but also the effects of uncertainties associated with mass transfer coefficients and equilibrium constants on the accuracy of the overall determination.

Integration Framework

To manage local and remote execution of simulations and the passing of data between CCSI components, we are developing a web-based framework. Workflow software will coordinate and track the activity. This design will allow the UQ software to run a large number of simulations that test alternative designs using different input combinations and then integrate the results, even though the software packages may be running on multiple machines at different sites. It will also provide web-based interfaces for monitoring the software and test results.

CCSI is leveraging existing component interchange standards and formats (such as CAPE-OPEN, ActiveX/COM, and SOAP) to interconnect the framework and software tools. The integration framework was recently demonstrated at NETL by connecting UQ tools developed at Lawrence Livermore National Laboratory with a process simulation developed at NETL via the internet using a web-based gateway.

Submitted by DOE’s National Energy Technology Laboratory