Life cycle analysis of the solar thermochemical energy storage scheme SOCRATCES

Abstract

Background: SOCRATCES is an environment-friendly thermochemical solar energy storage scheme based on calcium-looping [1]. It involves capturing of solar energy using an endothermic splitting of calcium carbonator into calcium oxide and carbon dioxide, and a subsequent exothermic combination of these two products to reproduce calcium carbonate in a cyclic process [2]. The life cycle analysis of this concept, which has generated substantial interest in recent years, is extremely important in its holistic assessment [3]. Methods: The methodology followed was based on the international standards ISO 14040:2006 and 14044:2006, considering three different scales – the pilot plant in Seville, Spain [1] and two industrial-scale sizes with 10 and 100 MW. The data for calculating the environmental impact was compiled by the consortium involved in the project SOCRATCES (EU GA 727348) and the previously developed deliverables [4] in the project. Additional information that was not covered during the work of the project was taken from different literature resources. For the calculation of the LCA, the software Umberto® LCA+ was utilized. Results: The results showed that the technology is comparable to alternative energy storage approaches in terms of the environmental impact assessment. It is located in the lower region of CO2-Eq output per kWh produced electricity and has significantly lower toxicity impact. When the eco-efficiency factor is brought into consideration, it emerged that the technology is considerably superior to competing alternatives, which comes from the higher storage time compared to other technologies. Conclusions: The Stirling engine appears to be a sound choice, in terms of conversion efficiency, at comparatively low temperatures, to be integrated with an exothermic reactor, at least at small-scale applications.

Thermochemical energy storage in barium carbonate enhanced by iron(iii) oxide

“…15,17,18 In Spain the largest CaL TCES prototype to date is being constructed, with an output power of 1 MW th . 19 However, it is based on the CaL process and thus may require constant replacement of limestone (CaCO 3 ) due to its limited cyclability. 20 Recent work shows that TCES in either the dolomite (CaMg(CO 3 ) 2 ) or limestone systems shows that cycling stability can be improved by naturally occurring impurities.…”

Review of Thermochemical Technologies for Water and Energy Integration Systems: Energy Storage and Recovery

“…Thermochemical technologies (TCT) are a set of sorption and reaction-based components and systems having the ultimate objectives of improving the operation and the sustainability of industrial processes and energy systems [1]. For sustainability promotion, TCTs may be implemented with the aims of improving energy use and water use, and reduce the emissions of liquid or gas pollutants, overall promoting the eco-efficiency of industrial units [2,3]. The role of TCTs is, thus, as improvement measures, similar to heat recovery [4] and wastewater treatment [5].…”

“…Within system retrofitting research, thermochemical technologies have a fundamental role for water and energy integration systems (WEIS), namely, in the form of alternative thermal energy storage (TES) [6] and wastewaterto-energy (WWtE) [7]. TCTs present overall efficiencies to their counterparts [2], which is substantially notorious in the case of TES [8]. In the case of wastewater-to-energy, TCTs are particularly relevant for green hydrogen production [9].…”