CAPE-OPEN – Aspen Plus based mathematical modeling for integrated simulation of an entrained bed gasifier and gases purification
Systematic methods and tools for managing the complexity
Tools Integration - CAPE Methods & Tools (T4-10P)
Keywords: Process simulation, coal gasification, CAPE-OPEN, software components, interoperability
The CAPE-OPEN (CO) interface standards were developed to allow process modeling components to be used in any compliant process modeling environment [1]. The CO standards provide a suitable environment for this purpose, they enable the generation of modules which are easy to plug and use from different simulation platforms. These last features allow them to be portable, thus facilitating their straightforward integration to different simulation schemes [2] and enhancing the potential of simulation to deal with complex systems modeling, validation, operation and optimization.
The increase in the prices of oil and natural gases has motivated the growing interest towards coal conversion technologies such as gasification. Moreover, the implications of the strict environment laws regarding the climate change and greenhouse effect has made the power producing companies to look for alternative and cleaner solutions in order to reduce their pollutant gas emissions. Nowadays gasification is a commonly used technology for extracting the energy from coal and solid waste. These materials are gasified producing a gas mainly composed of carbon monoxide and hydrogen, which is utilized in gas turbines of Integrated Gasification Combined Cycle (IGCC) systems for power production. Such systems are quite complex to model and usually lack of detailed integrated models which could improve their flexibility and performance.
Within the different types of gasifiers contemplated in IGCC systems, entrained bed reactors achieve the highest gasification rates. These reactors operate with feed and blast (air/steam) in co-current flow with extremely short residence time and high temperatures and pressure. This type of gasifier generates product gas at high temperature and lowest heating value with the highest oxygen consumption.
In this work a mathematical model of an entrained bed gasifier unit has been developed for enhanced synthesis gas production. The gasification model is divided into three different stages: devolatilization/pyrolysis and volatile combustion, gasification and combustion. The conversion reactions take place sequentially. Mathematical simulations are necessary to help finding out feasible operating conditions of the process to achieve better process performance.
Matlab and Visual Basic are tested as tools for modeling. In developing the model mass, moment and energy balances will be considered. Temperature, concentration and velocity profiles were obtained along the reactor height from literature [3] and are used as data for validation. The proposed gasification model improves the understanding of the process and can be used as an accurate predictive tool at the optimization stage. The models integration with purification units is done in Aspen Plus, thus providing the basic model connectivity in terms of first principle calculations, as well as detailed purification steps modeling.
Acknowledgements:
Financial support received from the European Community projects (MRTN-CT-2004-512233; RFC-CR-04006; INCO-CT-2005-013359) and the Generalitat de Catalunya with the European Social Fund (FI grant) is fully appreciated.
References:
[1] Martin Barrett Jr, W. and Yang Y. “Development of a chemical process modeling environment based on CAPE-OPEN interface standards and the Microsoft .NET framework”. Computers and Chemical Engineering, 30 (2005) 191–201.
[2] L. Pérez, A. O. Domancich, G. E. Vazquez and N. B. Brignole, “A CAPE-OPEN compliant simulatin module for an ammonia reactor unit”. 2nd Mercosur Congress on Chemical Engineering, (2005).
[3] Govind R. and Shah J. “Modeling and simulation of an entrained flow coal gasifier”. Aiche Journal, 30, vol.1, 79-92, (1984).
Presented Thursday 20, 13:30 to 14:40, in session Tools Integration - CAPE Methods & Tools (T4-10P).
