Computational fluid dynamics (CFD) software from ANSYS provides detailed flow predictions for equipment design, troubleshooting, and scale up. Using FLUENT software helps to understand and optimize the fluid mechanics that drive mixing, separation, heat transfer, chemical reactions and related operations in your process. The integration of the FLUENT CFD package with Aspentech‘s process simulator Aspen Plus enables the use of CFD models as a blocks in an Aspen Plus flowsheet. APECS has also been demonstrated with other CO-compliant process simulators including Aspen HYSYS and gPROMS.

Benefits achieved

APECS provides significant benefits for the improvement of processes for the chemical, petrochemical, pharmaceutical and power industries. Process simulation can now be performed with more accurate models using consistent physical properties and reaction kinetics. Further, the detailed analysis of equipment using CFD technology provided by ANSYS now includes the process context including recycles and simplifies the collaboration of CFD and process analysts. APECS can automate the creation of reduced-order models (ROMs) from a set of CFD cases to provide an accurate yet efficient representation of equipment performance in the process flowsheet. By combining and blending the strengths of multiple methods, APECS manifests the concept of “hybrid simulation”, providing analysts more flexibility in the trade-off between model fidelity and computational cost.

APECS has been developed since 2001 under funding from the US Department of Energy (DOE) and the UK Department of Trade and Industry (DTI). The combined FLUENT/Aspen Plus solution was successfully applied at ALSTOM Power for the modeling of conventional coal power plant as well as for a natural gas combined cycle power plant. DOE’s National Energy Technology Laboratory is using integrated simulations to analyze zero-emission power systems that involve IGCC technology.

NETL has regularly held workshops on APECS such as the one organized in 2009 in Pittsburgh where the different partners involved in the project exposed their achievements.


Zitney S.E. and SYAMLAL M. (2002), “Integrated Process Simulation and CFD for Improved Process Engineering“, Computer Aided Chemical Engineering, vol. 10(C), pp. 397-402.

Zitney S.E. (2005), “CAPE-OPEN Integration for Advanced Process Engineering Co-Simulation”. Presented at the 2nd Annual U.S. CAPE-OPEN Meeting, May 25-26, Morgantown, WV.

Zitney S.E. (2005), “Advanced Process Engineering Co-Simulation of the FutureGen Power and Hydrogen Production Plant“. Proc. of the AIChE 2005 Annual Meeting, October 30-November 4, Cincinnati, OH.

Zitney S.E. (2006), “CAPE-OPEN Integration for CFD and Process Co-Simulation”, Proc. of the AIChE 2006 Annual Meeting, 3rd Annual U.S. CAPE-OPEN Meeting, November 12-17, San Francisco, CA.

Zitney S.E.(2007), “Using Process/CFD Co-Simulation for the Design and Analysis of Advanced Energy Systems“. Presented at 2007 Aspen Engineering Suite (AES) User Group Meeting, April 10-11, Houston, TX.

Zitney S.E. (2007), “Computational Research Challenges and Opportunities for the Optimization of Fossil Energy Power Generation Systems”, Proc. of the 32nd International Technical Conference on Coal Utilization & Fuel Systems, June 10-15, Clearwater, FL.

Zitney, S. E. (2007). “Use of CAPE-OPEN standard in US–UK collaboration on virtual plant simulation”. In Presented at the AIChE 2007 Annual Meeting, 4th Annual U.S. CAPE-OPEN meeting, November 4–9, Salt Lake City, UT.

Zitney S.E., Widman J. Munteanu S., Jain A. (2009), “Co-Simulation for Advanced Process Design and Optimization“. Presented at 2009 Aspen Wordwide User Conference, May 4-7, Houston TX.

Zitney S.E. (2009), “Advanced Co-Simulation for Computer-Aided Process Design and Optimization of Fossil Energy Systems with Carbon Capture,” FOCAPD 2009, Eds. M. M. El-Halwagi and A. A. Linninger, June 7-12, Breckenridge, CO, pp. 185-202, CRC Press, Taylor & Francis, ISBN 978-1-4398-0912-9.

Zitney S.E. (2010), “Process/Equipment co-simulation for design and analysis of advanced energy systems“, Computers and Chemical Engineering, Volume 34, pp. 1532-1542.

Guenther C., Williams K, Snider D and Clark S. (2010), “Accelerating Commercialization and Deployment of Advanced Gasification Technology Through Multiphase Modeling“. Presented at Gasification Technologies Conference, October 31-November 3, Washington, DC.

Subramanyan K., Diwekar U., Zitney S.E. (2011), “Stochastic modeling and multi-objective optimization for the APECS system“, Computers and Chemical Engineering, Volume 35, Issue 12, pp. 2667-2679.