TY - JOUR

T1 - Composite “LiCl/MWCNT” as advanced water sorbent for thermal energy storage

T2 - Sorption dynamics

AU - Grekova, Alexandra D.

AU - Gordeeva, Larisa G.

AU - Lu, Zisheng

AU - Wang, Ruzhu

AU - Aristov, Yuri I.

N1 - Publisher Copyright: © 2017

PY - 2018/3/1

Y1 - 2018/3/1

N2 - Sorption heat storage (SHS) is a promising technology towards efficient use of renewable energy sources. Composite materials based on hygroscopic salts have a high potential for SHS in term of the heat storage capacity. Recently, a new sorbent “LiCl confined to Multi-Wall Carbon NanoTubes (MWCNT)” with enhanced storage capacity (1.7 kJ/g) has been suggested for SHS. This work addresses the dynamic study of water sorption on this material under operating conditions of a daily heat storage cycle. The study consists of three parts: (1) shaping the LiCl/MWCNT composite as grains (GP) and pellets with (PB) and without a binder (PP); (2) water sorption dynamics under conditions of the selected SHS cycle; (3) evaluation of the specific power achievable. Various configurations of the adsorbent bed were tested, namely, the loose grains GP placed on a metal support, and the pellets PB and PP glued to the support. The dynamic curves of water sorption obey an exponential equation. The PB configuration ensured a maximal specific power of 11.2 kW/kg (at 70% conversion) during the heat storage stage. During the heat release stage, the specific power is lower (5.4 kW/kg), probably due to a kinetic hindrance attributed to solid-solid transformation during the decomposition of LiCl·H2O complex towards the anhydrous salt. The high specific power along with the large heat storage capacity make the LiCl/MWCNT composite a promising new candidate for SHS.

AB - Sorption heat storage (SHS) is a promising technology towards efficient use of renewable energy sources. Composite materials based on hygroscopic salts have a high potential for SHS in term of the heat storage capacity. Recently, a new sorbent “LiCl confined to Multi-Wall Carbon NanoTubes (MWCNT)” with enhanced storage capacity (1.7 kJ/g) has been suggested for SHS. This work addresses the dynamic study of water sorption on this material under operating conditions of a daily heat storage cycle. The study consists of three parts: (1) shaping the LiCl/MWCNT composite as grains (GP) and pellets with (PB) and without a binder (PP); (2) water sorption dynamics under conditions of the selected SHS cycle; (3) evaluation of the specific power achievable. Various configurations of the adsorbent bed were tested, namely, the loose grains GP placed on a metal support, and the pellets PB and PP glued to the support. The dynamic curves of water sorption obey an exponential equation. The PB configuration ensured a maximal specific power of 11.2 kW/kg (at 70% conversion) during the heat storage stage. During the heat release stage, the specific power is lower (5.4 kW/kg), probably due to a kinetic hindrance attributed to solid-solid transformation during the decomposition of LiCl·H2O complex towards the anhydrous salt. The high specific power along with the large heat storage capacity make the LiCl/MWCNT composite a promising new candidate for SHS.

KW - Composite sorbent “salt/matrix”

KW - Lithium chloride

KW - Multiwall carbon nanotubes

KW - Sorption thermal energy storage

KW - Water vapor

KW - HIGH-TEMPERATURE

KW - SOLAR-ENERGY

KW - Composite sorbent "salt/matrix"

KW - OF-THE-ART

KW - ADSORPTIVE HEAT TRANSFORMATION

KW - SALT

KW - DENSITY

KW - POROUS MATRIX

KW - SYSTEMS

KW - ADSORBENT

KW - NH2-MIL-125

UR - http://www.scopus.com/inward/record.url?scp=85038216008&partnerID=8YFLogxK

U2 - 10.1016/j.solmat.2017.12.011

DO - 10.1016/j.solmat.2017.12.011

M3 - Article

AN - SCOPUS:85038216008

VL - 176

SP - 273

EP - 279

JO - Solar Energy Materials and Solar Cells

JF - Solar Energy Materials and Solar Cells

SN - 0927-0248

ER -