Shokri Abolfazl, Shahhosseini Shahrokh, Bazyari Amin
School of Chemical, Petroleum and Gas Engineering, Iran University of Science and Technology, Tehran, Iran.
Sci Rep. 2024 Oct 2;14(1):22905. doi: 10.1038/s41598-024-74203-z.
Carbon dioxide capture has become an important issue in reducing atmospheric heat these days. In this study, adsorption of carbon dioxide by aerogel Gamma Alumina-Metatitanic Acid has been investigated and optimized. Morphological and structural analyses such as BET, FESEM, FT-IR, and XRD have also been conducted. In addition, Response surface methodology has been applied in order to achieve the optimal conditions, using a five-level Central composite design. The highest amount of adsorption, 12.874 (mmol/g), was recorded at a temperature of 20 (°C), pressure of 7 (bar), and 25 (%wt) of Metatitanic Acid. This was approximately 11.46% and 4.84% higher than those of mesoporous MgO and 4Azeolite, respectively. Regeneration of the adsorbent was also studied at different temperatures and process durations. Metatitanic acid, as a catalyst, reduces the temperature and regeneration time of the adsorbent by creating active sites and surface hydroxyl groups. It also lowers the required activation energy and enhances the thermal conductivity of the composite material. The optimal result was achieved at a temperature of 100 (°C) and a duration of 30 (min). Finally, isothermal and thermodynamic experiments were conducted to establish the most accurate predictive model and conditions, including Enthalpy, Entropy, and Gibbs free energy. The results indicate that the Freundlich model aligned well with the laboratory findings. Additionally, the negative values of Enthalpy, Entropy, and Gibbs free energy suggested that the adsorption process was physical, exothermic, and spontaneous.
如今，二氧化碳捕集已成为降低大气热量的一个重要问题。在本研究中，对气凝胶γ-氧化铝-偏钛酸吸附二氧化碳进行了研究和优化。还进行了诸如BET、场发射扫描电子显微镜（FESEM）、傅里叶变换红外光谱（FT-IR）和X射线衍射（XRD）等形态和结构分析。此外，采用五级中心复合设计，应用响应面方法以实现最佳条件。在温度20（℃）、压力7（巴）和偏钛酸含量25（%重量）的条件下，记录到最高吸附量为12.874（毫摩尔/克）。这分别比介孔氧化镁和4A沸石的吸附量高出约11.46%和4.84%。还研究了吸附剂在不同温度和处理时间下的再生情况。偏钛酸作为催化剂，通过产生活性位点和表面羟基来降低吸附剂的温度和再生时间。它还降低了所需的活化能并提高了复合材料的热导率。在温度100（℃）和时间30（分钟）时获得了最佳结果。最后，进行了等温及热力学实验，以建立包括焓、熵和吉布斯自由能在内的最准确预测模型和条件。结果表明，弗伦德利希模型与实验室结果吻合良好。此外，焓、熵和吉布斯自由能的负值表明吸附过程是物理的、放热的且自发的。
