ULB 4MAT (Ecole polytechnique de Bruxelles) Thermochemical heat storage (TCS): results from SoTherCo project and future prospects

Transcription

1 ULB 4MAT (Ecole polytechnique de Bruxelles) Thermochemical heat storage (TCS): results from SoTherCo project and future prospects Pierre D Ans (ULB), Marc Frère (UMons), Gilbert Descy (Besol, Rochefort) Innovation Meeting 23/06/2015 p. 1 Presentation and goals FP7 ( ) Partners: Besol (leader), UMons, ULg, ULB, Univ. Versailles, CNRS, Austrian Inst. Technol., CEA. Problem addressed: the residential heating demand does not match the heat production by solar collectors need for lossless seasonal storage Heating demand low consumption house: kWh/m².year Collected heat, kwh/25m² solar collectors En. Sol directe [kwh] En. Sol stockable [kwh] Innovation Meeting 23/06/2015 p. 2 1

2 Proposed solution summer S.xH O S. x yh 2O S: salt 2 winter yh O(g) CaCl, SrBr, MgSO,MgCl,..., physisorbe nt, Innovation Meeting 23/06/2015 p. 3 The ideal storage material: Δm, mg Reacts with water in right conditions: Cycling loading lift Results - materials Temperature, C Compact Heat storage density (kwh/m³) Reversible Cycling loading lift after multiple cycles 30 C T adsorption: T min for space-heating in winter 80 C T desorption (solar collectors) Working fluid: water Low temperature source: ground T evaporator=10 C p (H 2 O) = 1250 Pa Easy to manufacture at low cost Low environmental burden Adapted to the desired reactor Innovation Meeting 23/06/2015 p. 4 2

3 Results - materials Salts hydrates alone: expected reactions summer CaCl2.6H 2O(s) CaCl2 (s) 6H2O(g) winter In reality, poorer performance due to deliquescence! Heat storage density 784 kwh / m³ hexahydrat e summer SrBr2.6H2O(s) SrBr2.H 2O(s) 5H2O(g) H r H r J / mol salt winter J / mol salt Heat storage density 629 kwh / m³ hexahydrat e Solution Solid state Innovation Meeting 23/06/2015 p. 5 Results - materials Physisorbents alone: (Permyakova et al.) MIL160(Al) with no host: Weight, % Time, h Heat storage density : 123 kwh/m³ Innovation Meeting 23/06/2015 p. 6 3

4 The ideal storage material: Results - materials Salt hydrates: Heat storage density Physisorbents: Porosity available Stability Studied composites: SG-CaCl 2 SG-SrBr 2 MIL101(Cr)-CaCl 2 Impregnation protocole Hydrates in physisorbents High salt content Morphological stability High heat storage density Innovation Meeting 23/06/2015 p. 7 Results - materials Example with SG-CaCl 2 : (salt at 43 %) 0.4 g/g of water exchanged per cycle kwh/m³ Sorption isotherms Behavior and storage density interpreted by: 2 CaCl2.2H 2O(s) 5.5H2O(g) Ca (aq) 2Cl (aq) 7.5H2O(l) Salt in solution inside the porosity! Marginal contribution of the matrix Innovation Meeting 23/06/2015 p. 8 4

5 Example with SG-CaCl 2 : Excellent reversibility Results - materials Innovation Meeting 23/06/2015 p. 9 Concept nr.1 Composite storage and reactor integrated Heat exchangers = bed support -Economically not viable -Slow kinetics Innovation Meeting 23/06/2015 p. 10 5

6 Concept nr.2 Storage and reaction separated Fluidised bed +Enhanced kinetics +Low pressure drop -High volume -Particule size and wear critical -Vibrations -Auxiliary power (motors) Innovation Meeting 23/06/2015 p. 11 Concept nr.2: design and construction at (Rochefort) Innovation Meeting 23/06/2015 p. 12 6

7 Concept nr.2: integration at Ulg (Arlon) Innovation Meeting 23/06/2015 p. 13 Concept nr.2: examples of tests: 2.1 kg/batch Innovation Meeting 23/06/2015 p. 14 7

8 Concept nr.2: examples of tests: 2.1 kg/batch Heat storage density from the lab is reproduced! Innovation Meeting 23/06/2015 p. 15 Concept nr.3 : Separated storage Reaction phase: fixed bed After reaction: vertical evacuation of bed +No vibration +Quasi constant power +Less particles wear -Some more pressure drop Innovation Meeting 23/06/2015 p. 16 8

9 Concept nr.3 : design and construction at Open loop integration: Tested with success at CEA-Ines Innovation Meeting 23/06/2015 p. 17 Results economics and environment Raw data: (w/o impregnation process) Material SG CaCl 2 SrBr 2 /T Price per kwh produced, 20 years: SG-CaCl 2 SG-SrBr 2 kwh/20 years /kwh Residual value after 20 years? Reduction if multiple cycles per year Cost reduction by upscaling (SG, SrBr 2 )? LCA results in brief (ULB) 1 kwh produced and stored, compared to benchmarks (gas, heat pump) Impact2002+ Minor contribution of the reactor Main contribution of SG Strong dependence on the conditions of use: Favor higher sorption Favor more cycles (100) Values below 100 g CO 2 eq./kwh can be obtained. Innovation Meeting 23/06/2015 p. 18 9

10 Partners competencies After 8 year cooperation, broad expertise in thermochemical heat storage: Materials for TCS: from lab scale synthesis to upscaling (UMons, ULB, University of Versailles) Reactors for TCS: Design and optimization (UMons, Besol) Compatibility of materials (ULB, Besol) Reactor production and upscaling (Besol) Integration in buildings (Besol, ULg, CEA). LCA (ULB) Innovation Meeting 23/06/2015 p. 19 4MAT Future prospects Going beyond TRL6-7 Real scale testing Previous project assumed solar thermal energy. Future project should rely on other heat sources: Waste heat Heat pumps Excess power from the electricity grid Funding? Should include Walloon partners Open to Brussels partners Innovation Meeting 23/06/2015 p

11 Thank you for your attention Innovation Meeting 23/06/2015 p. 21 System configurations Closed loop Open loop Innovation Meeting 23/06/2015 p

12 System configurations Open loop Performance function of ambiant moisture Variable thermal power Simple! Adapted to low power Heat storage density ~200 kwh/m 3 Closed loop Need of a low temperature heat source Additional solid consumption if poor heat source Produced power<distributed power Thermal power: constant Independent on interior conditions Innovation Meeting 23/06/2015 p