ABSTRACT
Lithium-based sorbents are considered as promising candidates for post-combustion carbon capture because of their superior stability compared to CaO. In the present study, Li4SiO4 powders were synthesized by Solution Combustion Synthesis (SCS) technique using LiNO3 as lithium source, TEOS as silicon source and citric acid as the fuel. CO2 sorption tests were carried out for the synthesized samples and, powder prepared at 650°C during 4 h, which has 17 µm of particle size, 5.2 m2 g−1 of specific surface area, 85.2% Li4SiO4 phase purity with 97 nm of crystallite size showed a sorption performance as 29.5 wt% CO2 uptake value, in thermobalance test under 92 vol% CO2 (N2 balance) gas concentration at 600°C. The sample had a CO2 uptake value of 21.4 wt% under 20 vol% CO2 concentration which was chosen to simulate industrial off-gas conditions. Also, the same sample showed a good cyclic durability during the sorption/desorption tests. The sample maintained its cyclic CO2 uptake capability range between 21 and 24 wt% for 15 cycles.
Acknowledgement
Kagan Benzesik also acknowledges the TİNÇEL Foundation for the financial support for his research visit to Instituto de Carboquimica, Zaragoza, Spain.
Disclosure statement
No potential conflicts of interest was reported by the authors.
Statement of novelty
Li4SiO4 is a critical material for both CCS technologies and fusion reactors. Conventionally and commercially, Li4SiO4 is synthesized via solid-state synthesis. This technique requires very high energy consumption to heat up the reactant materials (Li2CO3 and SiO2) resulting in synthesized powders having very large particle size and crystallite size. Combustion synthesis methods provide synthesized ceramic powders with low energy requirement and in nano-size. With this study, Li4SiO4 powders as solid sorbent for post-combustion carbon capture were synthesized via solution combustion technique and CO2 uptake characteristics were fully investigated. The sorbent showed a sorption performance as 29.5 wt% CO2 uptake value, in thermobalance test under 92 vol% CO2 (N2 balance) gas concentration at 600°C.