Absorption and desorption rates of carbon dioxide with monoethanolamine and piperazine

Abstract

CO2 absorption/desorption was measured in a wetted wall column at 40 and 60 ∘C with 7, 9, 11, and 13 m monoethanolamine (MEA) and 2, 5, 8, and 12 m piperazine (PZ) at various CO2 loadings. 8 m PZ has about a 75% greater CO2 capacity than 7 m MEA. CO2 absorption and desorption is 2–3 times faster with PZ than with MEA at equivalent CO2 partial pressure. The CO2 flux normalized by the liquid side partial pressure driving force, kg, for both MEA and PZ is practically independent of temperature and amine concentration over the range of these experiments when represented as a function of the equilibrium partial pressure at 40 ∘C. Normalized flux decreases a factor of 10 as the equilibrium partial pressure at 40 ∘C increases from 100 to 10 000 Pa.