(3cn) Design, Control and Estimation of New Energy Systems: Application to Energy Efficient IGCC Plants with Carbon Capture

In the recent years, incentives on the efficient and sustainable use of fossil fuels and on the use of renewable sources of energy have risen again in the United States and worldwide. These incentives are largely motivated by high energy costs dictated by oil prices in the international market and the strong environmental concerns associated with carbon dioxide (CO₂) emissions to the atmosphere that are released during the combustion of fossil fuels and are linked to global climate change. The use of process systems engineering tools, such as process modeling, control, design and optimization, may be the key to allow the implementation of the next generation of technologies that enable the efficient and sustainable use of the current major energy sources. However, process systems engineering approaches for new energy systems are still scarce. My research will contribute with novel applications of existing process systems tools and the development of new tools for the improvement of new energy systems. In this poster, I will focus on the application of systems tools to coal-based Integrated Gasification Combined Cycle (IGCC) plants with carbon capture for electricity generation, but other systems of interest include biorefineries, coal and biomass-based gasification plants for the production of power, chemicals and liquid fuels.

Regarding the application of interest, IGCC plants have emerged recently as a more efficient technology for coal-based electricity generation when compared to conventional pulverized coal-fired power plants. IGCC units also allow the mitigation of CO₂ emissions as they enable CO₂ capture at different positions of the process flowsheet. Designing new energy efficient coal-based plants for power generation that minimize the amount of CO₂ emissions is one of the great current engineering challenges, especially now that a few IGCC demonstration projects with carbon capture are under development in the U.S. [1].

Regarding the tools of interest, my research will explore the use of process operability concepts [2, 3] to design new energy efficient process units. Process operability both permits the verification of a current process design limitations and enables the consideration of control objectives at the design stage. This fact is important because once the design is fixed, process control will not be able to overcome its inherent limitations. Individual units will be studied first, followed by their energy integration. Process integration increases the overall plant efficiency, but results in several dynamics and control challenges such as nonlinearities and time-scale separation in the process model, and the requirement of transitions due to the change in targets and operating conditions. The implementation of model-based controllers and state estimation algorithms [4] will be investigated to facilitate the operation of new energy systems in a constrained, fluctuating and integrated environment.

As an example of the application of process systems engineering tools to a unit in the IGCC flowsheet, I will present my current research results on membrane reactors for carbon capture in IGCC units [5].

References

[1] Anthony N. Zinn. CCPI and ICCS demonstration projects. In 2010 NETL CO₂ Capture Technology Meeting, Pittsburgh, PA, September 2010.

[2] Fernando V. Lima and Christos Georgakis. Input-output operability of control systems: the steady-state case. J. Proc. Cont., 20:769-776, July 2010.

[3] Fernando V. Lima, Zhenya Jia, Marianthi Ierapetritou, and Christos Georgakis. Similarities and differences between the concepts of operability and flexibility: the steady-state case. AIChE J., 56:702-716, March 2010.

[4] Fernando V. Lima and James B. Rawlings. Nonlinear stochastic modeling to improve state estimation in process monitoring and control. AIChE J., 57:996-1007, April 2011.

[5] Fernando V. Lima, Prodromos Daoutidis, Michael Tsapatsis, and John J. Marano. Modeling and Optimization of Membrane Reactors for Carbon Capture in IGCC Units. To be Presented at AIChE Annual Meeting, Minneapolis, MN, October 2011.