Microwave-Assisted Synthesis of Zeolite A from Metakaolinite for CO₂ Adsorption

The global demand for energy and industrial growth has generated an exponential use of fossil fuels in recent years. It is well known that carbon dioxide (CO₂) is mainly produced, but not only from fuels, which has a negative impact on the environment, such as the increasing emission of greenhouse gases. Thus, thinking about reducing this problem, this study analyzes microwave irradiation as an alternative to conventional heating to optimize zeolite A synthesis conditions for CO₂ capture. Synthesis reaction parameters such as different temperatures (60-150 °C) and different time durations (1-6 h) were evaluated. The CO₂ adsorption capacity was evaluated by CO₂ adsorption-desorption isotherms at 25 °C and atmospheric pressure. The results showed that the synthesis of zeolite A by microwave irradiation was successfully obtained from natural kaolinite (via metakaolinization), reducing both temperature and time. Adsorption isotherms show that the most promising adsorbent for CO₂ capture is a zeolite synthesized at 100 °C for 4 h, which reached an adsorption capacity of 2.2 mmol/g.