(269a) A Comprehensive Investigation of CO2 Absorption and Desorption Performance Using Novel Amine Solvents

Extreme weather events caused by global warming are now occurring more frequently. Global warming, resulting from greenhouse gas emissions, has gained significant attention. Among these gases, CO₂ is the primary contributor to global warming. The 2023 CO₂ emissions report from the International Energy Agency (IEA) indicates that global energy-related CO₂ emissions rose by 1.1% in 2023, increasing by 410 million tonnes to reach a new record high of 37.4 billion tonnes. Therefore, it is essential to develop CO₂ capture, storage, and utilization (CCUS) technologies to address the challenges of global warming and climate change resulting from increasing CO₂ emissions.

Among post-combustion carbon capture technologies, the absorption of CO₂ using alkanolamines is the most reliable, widely applied, and well-developed method. Alkanolamine solutions react rapidly with CO₂ and efficiently extract it from a gas mixture; notably, they can be reused multiple times after thermal regeneration. Aqueous 5 M ethanolamine (MEA) has been extensively researched and tested for CO₂ absorption from sizable stationary emission sources, serving as a benchmark for all Carbon Capture and Storage (CCS) processes. However, using aqueous MEA has significant drawbacks, such as amine degradation, equipment corrosion, and particularly the high energy demand for solvent regeneration, which accounts for approximately 60-70% of the total operating cost of the amine scrubbing process. This high cost hinders its widespread application on an industrial scale. There is an urgent need to develop energy-efficient solvents to address the limitations of CO₂ capture using aqueous MEA.

In this work, the CO₂ absorption and desorption performance of various novel amine solvents, including blended solvents and biphasic solvents, is studied and compared with that of the benchmark aqueous 5M Monoethanolamine solvent. The objective of this study is to experimentally examine the equilibrium CO₂ loading, initial absorption and desorption rates, cyclic capacity, and heat duty for the solvent regeneration of various novel solvents, and compare them with those of conventional solvents (such as MEA). The screening experiments have been conducted in a glass round-bottom flask, a condenser, and a temperature-controlled water bath. The absorption performance of various novel solvents is quantified in terms of absorption capacity and absorption rate.

However, the regeneration performance is assessed by quantifying the rate of CO₂ desorption and cyclic capacity and monitoring energy consumption throughout desorption experiments conducted at a controlled temperature of 373 K. The amine degradation rate and its effect on corrosion are also studied. All the results have been compared with the results of the benchmark MEA solvent. The performance of the novel solvent shows better performance than that of conventional MEA for CO₂ capture.

Keywords: Carbon Capture, Blended Amine, Regeneration Performance

References:

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