TY - JOUR

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

AU - Grekova, Alexandra D.

AU - Gordeeva, Larisa G.

AU - Aristov, Yuri I.

PY - 2017/9

Y1 - 2017/9

N2 - Sorption heat storage (SHS) is a promising technology towards efficient use of renewable energy sources. Materials based on hygroscopic salts and their hydrates have a high potential for SHS in term of heat storage capacity. This work addresses the study of the novel composite water sorbent based on expanded vermiculite impregnated with LiCl, specified for two particular SHS cycles, namely seasonal and daily heat storage in winter. The paper consists of two parts: (i) preparation of the LiCl/vermiculite composite and study of its texture, phase composition, as well as equilibrium and dynamics of water sorption; and (ii) evaluation of the potential of the new sorbent for the selected SHS cycles. The results obtained show that the salt, dispersed inside the vermiculite pores, reacts with water molecules, forming the crystalline hydrates LiCl·nH2O (n = 1, 2). The heat storage capacity of the LiCl/vermiculite reaches 2.3 (224 kW h/m3) and 2.6 kJ/g (253 kW h/m3) for seasonal and daily SHS cycles at the charging temperature 75–85 °C, that exceeds the appropriate values for common and innovative adsorbents suggested for SHS. This demonstrates the high potential of the new composite for SHS and promotes the broader implementation of this emerging technology.

AB - Sorption heat storage (SHS) is a promising technology towards efficient use of renewable energy sources. Materials based on hygroscopic salts and their hydrates have a high potential for SHS in term of heat storage capacity. This work addresses the study of the novel composite water sorbent based on expanded vermiculite impregnated with LiCl, specified for two particular SHS cycles, namely seasonal and daily heat storage in winter. The paper consists of two parts: (i) preparation of the LiCl/vermiculite composite and study of its texture, phase composition, as well as equilibrium and dynamics of water sorption; and (ii) evaluation of the potential of the new sorbent for the selected SHS cycles. The results obtained show that the salt, dispersed inside the vermiculite pores, reacts with water molecules, forming the crystalline hydrates LiCl·nH2O (n = 1, 2). The heat storage capacity of the LiCl/vermiculite reaches 2.3 (224 kW h/m3) and 2.6 kJ/g (253 kW h/m3) for seasonal and daily SHS cycles at the charging temperature 75–85 °C, that exceeds the appropriate values for common and innovative adsorbents suggested for SHS. This demonstrates the high potential of the new composite for SHS and promotes the broader implementation of this emerging technology.

KW - Composite sorbent “salt/matrix”

KW - Expanded vermiculite

KW - Lithium chloride

KW - Sorption thermal energy storage

KW - Water vapor

KW - SILICA-GEL

KW - SOLAR-ENERGY

KW - Composite sorbent "salt/matrix"

KW - LOW-TEMPERATURE HEAT

KW - ADSORPTIVE HEAT TRANSFORMATION

KW - CHILLERS

KW - SYSTEMS

KW - ADSORBENT

KW - OPTIMIZATION

KW - SORPTION PROPERTIES

KW - CYCLE

UR - http://www.scopus.com/inward/record.url?scp=85021636950&partnerID=8YFLogxK

U2 - 10.1016/j.applthermaleng.2017.06.122

DO - 10.1016/j.applthermaleng.2017.06.122

M3 - Article

AN - SCOPUS:85021636950

VL - 124

SP - 1401

EP - 1408

JO - Applied Thermal Engineering

JF - Applied Thermal Engineering

SN - 1359-4311

ER -