Developments in calcium/chemical looping and metal oxide redox cycles for high-temperature thermochemical energy storage: A review

Abstract

Energy storage is one of the most critical factors for maximising the availability of renewable energy systems whilst delivering firm capacity on an as-and-when required basis, thus improving the balance of grid energy. Chemical and calcium looping are two technologies which are promising from both the point of view of minimising greenhouse gas emissions and because of their suitability for integrating with energy storage. A particularly promising route is to combine these technologies with solar heating, thus minimising the use of fossil fuels during the materials regeneration steps. For chemical looping, the development of mixed oxide carrier systems remains the highest impact research and development goal, and for calcium looping, minimising the decay in CO2 carrying capacity with natural sorbents appears to be the most economical option. In particular, sorbent stabilisers such as those based on Mg are particularly promising.In both cases, energy can be stored thermally as hot solids or chemically as unreacted materials, but there is a need to build suitable pilot plant demonstration units if the technology is to advance. Highlights Calcium and chemical looping can potentially be deployed at commercial scale within the next two decades. Both technologies have the potential for energy storage, either by means of sensible heat stored in solids or as chemical energy. A critical requirement for such development is construction and testing of suitable pilot and demonstration plants. Both technologies can be combined with solar power to offer particularly attractive systems with thermochemical energy storage.

Techno-Economic and Environmental Evaluations of Decarbonized Fossil-Intensive Industrial Processes by Reactive Absorption & Adsorption CO2 Capture Systems

“…The innovative calcium looping method was selected as decarbonization technology for the fossil-intensive industrial applications based on the following reasons: it represents a promising technology in reducing the CO 2 capture energy and cost penalties, possibility to use the spent sorbent (deactivated calcium sorbent) within the main process, sorbent lower cost and large availability, etc. [14]. For this decarbonization technology, the conceptual design is presented in Figure 2.…”

“…technology in reducing the CO2 capture energy and cost penalties, possibility to use the spent sorbent (deactivated calcium sorbent) within the main process, sorbent lower cost and large availability, etc. [14]. For this decarbonization technology, the conceptual design is presented in Figure 2.…”

“…Combined cycle power using one M701G2 gas turbine Super-critical power plant [17] 290 bar/582 Plant capacity: 1 Mt/y cement 95% NOx removal yield by selective catalytic reduction unit 98-99% SOx removal yield by wet desulphurization unit Coal-based heat and power unit for ancillary energy consumptions Decarbonization unit employing a chemical scrubbing system [19] Methyl-diethanol-amine (MDEA) aqueous solution 50% wt. Absorption/desorption columns: 42-55 • C/115-125 • C 90% flue gas decarbonization rate (pre-and post-combustion) Solvent regeneration: thermal using LP steam at 140-150 • C Decarbonization unit employing a Ca-based sorbent system [19] Natural limestone as calcium-based sorbent Carbonation/calcination reactors: 540-615 • C/825-975 • C 90% flue gas decarbonization rate (pre-and post-combustion) Oxy-fuel combustion system to provide heat for sorbent regeneration Power consumption for oxygen production unit: 200 kWh/t CO 2 conditioning unit [14] Four compression stages with 120 bar final pressure at plant gate Moisture removal by gas-liquid absorption using Tri-Ethylene-Glycol (TEG) CO 2 composition (volume percentages): >95% CO 2 , <2000 ppm CO, <200 ppm H 2 O,<50 ppm H 2 S, <4% other gases…”

Developing Oxygen Carriers for Chemical Looping Biomass Processing: Challenges and Opportunities

“…We also note the recently published reviews on oxygen carrier formulation for various chemical looping applications. [24][25][26][27] These reviews have comprehensively captured the recent advances in the development of oxygen carriers for the conversion of gaseous and liquid hydrocarbon fuels to heat and, or functional chemical products. However, we identify an outstanding need to complement the existing literature and to establish a comprehensive understanding of the structural-functional relationship of OCs used in CLBP.…”

Background and Strategies for Identification and Design of Materials for Thermochemical Energy Storage and Conversion

“…Although some reaction systems are presented which contain costly noble metals copper or platinum, others seem quite reasonable for further investigations, since the operating temperature range is in a reasonable frame from around 205 °C for MgO2/MgO up to around 880 °C for BaO2/BaO. Some calcium-based reaction systems are also considered for implementation in chemical looping processes [39].…”