Luciene da Silva Castro, et. al. International Journal of Engineering Research and Applications www.ijera.com ISSN: 2248-9622, Vol. 11, Issue 12, (Series-II) December 2021, pp. 12-31 www.ijera.com DOI: 10.9790/9622-1112021231 12 | Page Use of Alternative Materials to Produce Lithium Silicate for CO 2 Capture Luciene da Silva Castro* Alexandre Carvalho Bertoli**, Ana Paula de Carvalho Teixeira ** , Rochel Montero Lago ** , Vanessa de Freitas Cunha Lins * * Programa de Pós-Graduação em Engenharia Química, Universidade Federal de Minas Gerais, Avenida Presidente Antônio Carlos, 6627, Escola de Engenharia, Campus Pampulha, Belo Horizonte, Minas Gerais – Brazil. ** Departamento de Química do Instituto de Ciências Exatas, Universidade Federal de Minas Gerais, Avenida Presidente Antônio Carlos, 6627, Campus Pampulha, Belo Horizonte, Minas Gerais – Brasil. e-mail:lucienecasttro@hotmail.com; bertolialexandre@yahoo.com.br; anapct@ufmg.br; rochel@ufmg.br; vlins@deq.ufmg.br. ABSTRACT The development of efficient and low-cost materials for carbon dioxide capture is currently an important technological challenge. Among several materials used for CO 2 capture, lithium silicate has been proved an important alternative for several applications. The present work reviews the use of different available and low- cost mineral and waste silica sources to prepare lithium silicate. The main natural silica sources mapped were halloysite, vermiculite, kaolinite, sepiolite, wollastonite, serpentinite, diatomite, and quartz whereas the main potential wastes were slag, fly ash and rice husk ash. Based on several aspects compared for the different sources, e.g., silica content, the preparation methods, and the CO 2 capture efficiencies and a critical analysis suggested that depending on the location, cost, and availability different silica sources may stand out as a more promising source. Keywords: CO 2 capture; lithium silicate; mineral; silica; waste. --------------------------------------------------------------------------------------------------------------------------------------- Date of Submission: 10-12-2021 Date of Acceptance: 24-12-2021 --------------------------------------------------------------------------------------------------------------------------------------- I. INTRODUCTION Fossil fuel utilization and anthropogenic activities are mainly responsible for dioxide carbon emissions (CO 2 ) in the atmosphere, one of the main responsible gases for climate change [1]. In this scenario, technologies involving Carbon Capture and Storage (CCS) and Carbon Capture and Utilization (CCU) [2]–[4] have received much attention in the last years. In the CCS technology, the captured CO 2 is transferred to a suitable local for long-term storage and in the case of CCU, the captured CO 2 is transformed into a product [5]. Capture technologies are usually divided into three groups: post-combustion, pre-combustion, and oxyfuel [3]. In pre-combustion technology, CO 2 is separated from other gases in an intermediate step [6], [7]. In the oxyfuel process, the fuel is burnt in almost pure oxygen resulting in high temperature and CO 2 high concentration (about 80%). In post- combustion, the capture is carried out after combustion with air, obtained carbon dioxide, normally in low concentration. Among these techniques, post-combustion is the most used [7]– [9]. The most common post-combustion separation processes are absorption, membrane separation, adsorption, cryogenic separation, and chemical looping combustion (CLC) [10]. There are different kinds of materials that can be used for CO 2 capture, for example zeolites, carbon, MOFs (metal-organic frameworks), COFs (covalent organic frameworks), and silicates [11]. One of the most interesting material for CO 2 capture is the lithium silicate [12]. II. LITHIUM SILICATE (Li 4 SiO 4 ) FOR CO 2 CAPTURE Lithium silicate is an important material for CO 2 capture due to its high CO 2 capture capacity (theoretical value: 367 mg CO 2 /g Li 4 SiO 4 ), excellent cyclic (until 50 cycles [13]) and thermal stability [14] [15] with relatively low regeneration temperature (> 700 ° C) as compared with CaO. It also shows the possibility of using available and low-cost raw materials for its production [16]–[20]. RESEARCH ARTICLE OPEN ACCESS