OPEN A NEW PATHWAY FOR NEXT GENERATION ENERGY STORAGE IN CSP TOWER PLANTS, TECHNOLOGICALLY FEASIBLE, ECONOMICALLY VIABLE AND SUSTAINABLE
SOCRATCES CONCEPTUAL SCHEME
Concentrating Solar Power (CSP)
System concentrates the sun rays to convert the solar radiation to high temperature thermal energy. Among the CSP power technologies, solar tower systems result the most appropriate for this purpose since the high temperature required.
Solar energy is provided to the calciner reactor to carry out the CaCO3 decomposition (calcination). The calcination requires temperatures above 900ºC to achieve sufficiently fast reaction if calcination takes place a pure CO2 atmosphere.
Once calcination occurs, the CO2 and CaO streams produced are passed through a heat exchanger network to take advantage of their high temperature to preheat the CaCO3 particles entering the calciner.
CO2 is compressed up to ~ 75 bar, in order to avoid unreasonably large storage volumes, previously to be storage at ambient temperature. Solids (CaCO3 and CaO) are storage either at high or low temperature at ambient pressure. The storage system allows a fully decoupled operation of charge and discharge phases for long periods.
When energy is needed, a certain amount of CaO and CO2 are sent separately to the carbonator. Both streams are passed through a heat exchanger network to be preheated.
In the carbonator reactor, CaO solids and CO2 reacts according the reverse reaction, the carbonation, releasing the stored energy at high-temperature. The CaCO3 produced is either storage or sent to the calciner for a new cycle.
The heat released by the carbonation is used to produce electricity by means a power cycle. Among the possibilities, by using a CO2 closed Brayton cycle may be reached an efficiency above 45%.
IMPROVEMENT IN THE RELIABILITY AND CSP PLANTS LIFETIME WHILE DECREASING OPERATION AND MAINTENANCE COSTS, HENCE CREATING NEW BUSINESS OPPORTUNITIES
EXPECTED RESULTS DURING THE SOCRATCES PROJECT
Prototype demonstration of capacity for energy storage.
Successful calcination at prototype scale by means of flash calcination technology.
Successful carbonator design with possibility for the scale-up. Integration of high temperature carbonator (>750ºC) and Stirling engine for power production.
Successful solids conveying and control system management.
SOCRATCES is an integral and multidisciplinary approach where different knowledge areas are involved: thermal systems, electronics engineering, solar energy, control, physics, chemistry, power generation, materials, reactors, LCA, etc. It integrates multidisciplinary R&D groups, SMEs and companies in an equilibrated structure where all the required skills for the adequate development of the project are fully covered.
The consortium comprises all the involved fields and assures the fulfilment of the full value chain within the project with R&D groups and companies. Each one of these has a different role and their commercial and industrial experience will facilitate and enhance the exploitation of the results.
In addition, Associations and Stakeholders offer the opportunity for wide dissemination of the project and will link the consortia with the relevant industries in Europe.