Absorption of CO₂ : - by Ammonia

Abstract:

In this diploma work, the absorption of CO₂ in different liquid solutions was studied by gas absorption in a randomly packed column. To characterize the absorption a few experiments with SO₂ absorption were made.The report has resulted due to the large amounts of carbon dioxide released into the atmosphere, mainly from fossil-fired power plants. To reduce these emissions, carbon dioxide can be separated from flue gas by different techniques such as CO₂ absorption with ammonia. The work consists of a theoretical and a laboratory part of measurements and calculations. In the experimental part a system of absorption and associated test equipment was constructed. Different liquid solutions of pure water, potassium carbonate solution and ammonia in various concentrations were used to catch carbon dioxide by countercurrent absorption. Also SO₂ was absorbed in the potassium carbonate solution to determine the gas film constant. The absorption efficiency of CO₂ ranged from a few percent in the experiment with water to up to 7% with potassium carbonate solution. The CO₂ absorption of ammonia varied with concentration and gave a separation of between 12 and 94%. Ammonia tests were made at both 10 and 20 °C. In general, a higher CO₂-capture at 20 °C was obtained as confirmed by theory.