Task 4

Modelling and Optimization of a Concentrated Solar Power Plant with Ca-Looping Integration for Thermochemical Energy Storage

🕒 27 months

Objectives | Development of a comprehensive simulation model for a concentrated solar power (CSP) plant with Calcium-Looping (CaL) integration for thermochemical energy storage (TCES) that will be embedded on the integrated model for CaL-TCES for CO₂ capture in a cement plant to be developed in Task 5.

Task Description | A dynamic model for the integrated CSP-CAL-TCES process will be built. It will include units for the solar calciner, carbonator, reservoirs for CaO, CaCO₃ and CO₂, as well as for the heat exchanger network. Individual models for each unit will be developed, tested, and then coupled together into a single integrated model to simulate and optimize process design and operation. Pinch-analysis will be used to optimize heat integration. Results from task 2 regarding the decay of CaO conversion with the number of cycles will be crucial to the definition of some process details and operating conditions.
The operation mode will be cydic. During daytime, solar power will provide the required energy to achieve fast calcination of the CaCO₃ in the calcinator at temperatures near 900°C. The resulting CaO and CO₂ will then be stored and, when needed, combined in the carbonator to produce CaCO₃ that will be stored and used in a new cycle when solar power is available. The energy released at this stage may then be used to generate electricity. Heat integration will also focus on recovering the sensible heat of the streams that would be lost during storage at ambient temperature, improving the efficiency of the process.
Details on calcinator operation are still to be defined, but the use of a pure CO₂ atmosphere, which would result in a pure CO₂ outlet stream will be investigated. The carbonator could then work under a pressurized pure CO₂ atmosphere at temperatures near to 875°C, with a gas turbine being used to directly turbinate the CO₂, increasing the thermal to electric efficiency, as proposed by Chacartegui.
The accomplishment of this task will be achieved by careful selection of the individual component models, correlations and kinetic data from those reported in the literature and adopting additional assumptions and characterizations.
The modeling activities will be carried out in gPROMS software, that allows dynamic simulation of highly complex. The optimization of the heat exchanger network will be conducted in GAMS software.

Results | Obtain an integrated equation based model that will be used for process simulation and optimization of a CSP-CaL-TCES system.