Thermal Driving Demonstration of Li₄SiO₄/CO₂/Zeolite Thermochemical Energy Storage System for Efficient High-Temperature Heat Utilizations

Abstract

Thermochemical energy storage (TcES) system using lithium orthosilicate/carbon dioxide (Li 4 SiO 4 /CO 2) reaction was developed for recovery and utilization of high temperature thermal energy generated from high temperature industrial process. Li 4 SiO 4 /CO 2 TcES packed bed reactor (LPR) and zeolite packed bed reactor (ZPR) were developed as thermal energy storage and CO 2 reservoir. Both reactors, LPR and ZPR, were connected by flexible tube and thermal driving operation of TcES system was demonstrated. For lithium orthosilicate packed bed reactor, tablet forms of Li 4 SiO 4 named K-tablet was developed and used in this study. Li 4 SiO 4 carbonation (thermal energy output process) and lithium carbonate (Li 2 CO 3) decarbonation (thermal energy storage process) were conducted sequentially with specific condition. All experimental results showed similar tendency; a middle temperature in the Li 4 SiO 4 packed bed reactor rapidly increased and decreased at the initial time of carbonation and decarbonation respectively. From kinetic analysis, it was confirmed that the developed K-tablet reacted around 80% and a thermal energy output density of LPR was estimated 331-395 kJ/L-packed bed, 759-904 kJ/L-material. The thermal driving demonstration of Li 4 SiO 4 /CO 2 /Zeolite TcES system shows high possibility to utilize surplus heats in low-carbon ironmaking system efficiently.

Additive Effect on Lithium Silicate Pellets for Thermochemical Energy Storage

“…Especially for its utilization as a high temperature TcES, reactivities of Li 4 SiO 4 under high concentrations of CO 2 needs be investigated. In our previous work, the reactivity enhancement of K 2 CO 3 was also con rmed with Li 4 SiO 4 pellets at 600-700°C (Kim et al, 2019a(Kim et al, , 2019b. However, the reactivities of Li 4 SiO 4 with di erent ratios of K 2 CO 3 additives had not been completed under high concentrations of CO 2 .…”

Lithium compounds for thermochemical energy storage: A state-of-the-art review and future trends

“…The composites incorporate materials that form a matrix to contain the salt and enhance cycle stability, thermal conductivity, and promote the heat and mass transfer. For instance, common composites using lithium salts are; activated carbon (AC) mixed with expanded natural graphite treated with sulfuric acid (ENG-TSA) [69,70], expanded graphite (EG) [71][72][73], activated alumina (AA) [74], expanded vermiculite (EVM) [75], Wakkanai siliceous shale (WSS) [76], silica gel (SG) [77], vermiculite (VM) [78][79][80], silica-alumina (S-AA) [81], zeolite (13X-Z, NaY-Z, Z) [82][83][84][85], graphene oxide (GO) [86]. In this sense Yu et al [69,70] developed a new type of consolidated composite sorbent using activated carbon (AC) as the porous matrix to harbour the LiCl salt.…”

“…The results revealed that LiOH•H2O/13X-Z presented the lowest apparent activation energy (21.5 kJ/mol) and the highest heat storage density 1949 kJ/kg (3 times higher than the pure LiOH). In a different research, Kim et al [83], studied the reaction of Li4SiO4/CO2 for recovery and utilisation of the high-temperature produced from industrial processes. To do this, two reactors (Li4SiO4/CO2 packed bed reactor (LRP) and zeolite packed bed reactor (ZPR)) were developed as TES.…”

Development of Metal Supported SOEC for Carbon Recycling Iron Making System

“…To establish a carbon cycle system, CO 2 is reduced with non-fossil primary energy, and carbon resources such as carbon monoxide (CO) are recycled and reused. It is necessary to establish a rational CO 2 resource recycling and energy reduction technologies such as CO 2 electroreduction, [7][8][9] recycling of plastic waste, 10,11) utilization of scrap metal, [12][13][14] and waste heat recovery 15,16) in this system. To establish the iACRES, we have been studying CO 2 reduction technology using solid oxide electrolysis cells (SOECs).…”