Abstract:

Monoethanolamine (MEA) has been widely used as a CO₂ absorbent in flue gas CO₂ capture, but the high energy consumption of CO₂ regeneration has brought huge economic challenges to the large-scale development of this technology. Adding a solid catalyst to the absorbent can reduce the energy barrier of the regeneration reaction and increase the CO₂ desorption rate, ultimately achieving rapid desorption at lower temperatures. This paper used natural mineral nano basalt as a catalyst to enhance the CO₂ capture performance of MEA solution. Firstly, the differences of CO₂ absorption and desorption performances between the addition of basalt and the blank experiment were compared. Then the physical and chemical properties of the basalt catalytic reaction process were explored using characterization techniques such as X-ray Diffraction (XRD), X-ray Photoelectron Spectroscopy (XPS), Fourier Transform-Infrared Spectroscopy (FTIR), N₂ Temperature-Programmed Desorption (N₂-TPD), Pyridine Adsorption-Infrared Spectrometry (Py-IR), and NH₃ Temperature-Programmed Desorption (NH₃-TPD). Finally, the catalytic mechanism of basalt in the MEA solution was proposed. The experimental results showed that basalt rock powder had the ability to provide protons and accept electrons with the presence of Brønsted acid sites, Lewis acid sites and Lewis base sites on its surface. Under 100℃ conditions, compared with the blank experiment, its CO₂ cyclic absorption capacity increased by 5.0%, CO₂ desorption rate increased by 76.5%, and sensible heat decreased by 11.9%. Therefore, basalt rock powder can be used as a composite catalyst for CO₂ capture improvement in MEA solution.

Key words: carbon dioxide, basalt, absorption-desorption, energy consumption, catalyst

摘要：

单乙醇胺（MEA）作为CO₂吸收剂已被广泛用于烟气CO₂捕集，但是高CO₂再生能耗给该技术的大规模发展带来了巨大的经济挑战。向吸收剂中添加固体催化剂可降低再生反应能垒，提高CO₂解吸速率，最终实现在较低温度下的快速解吸。本文采用天然矿物质——玄武岩石粉作为催化剂强化MEA溶液捕集CO₂性能。首先对比了添加玄武岩与空白MEA溶液的CO₂捕集性能差异；接着采用X射线衍射、X射线光电子能谱、傅里叶红外、氮气物理吸附、吡啶红外、氨气程序升温脱附等表征技术探究了玄武岩催化反应过程的物化性质；最终，提出了玄武岩催化反应机理。实验结果表明，玄武岩石粉表面存在Brønsted酸位、Lewis酸位和Lewis碱位，具有提供质子和接受电子的能力。100℃条件下，与空白实验相比，其CO₂循环吸收容量提高了5.0%，CO₂解吸速率最大提高76.5%，显热降低11.9%。因此，玄武岩石粉可作为CO₂解吸催化剂用于强化MEA溶液捕集CO₂性能。

关键词: 二氧化碳, 玄武岩, 吸收-解吸, 能耗, 催化