Absorption and Desorption of Carbon Dioxide from Biogas Using Amines

To study the effect of the amino group number of amine on the absorption and desorption performance , monoamine MEA, polyamine EDA and DETA were selected for absorption-desorption-cycle experiments, and the results showed that under the same absorption conditions, polyamines have stronger absorption performance than monoamine, but with effective amine as the absorption evaluation system, increasing the number of amino groups in the molecule could not enhance the absorption capacity of the absorbents, and the effective amine absorption capacity of the three absorbents is MEA>EDA≈DETA. Under the condition of 100°C desorption, the highest desorption efficiency within 90 min is still MEA solution. In addition, compared with DEA and DETA absorbents, the saturation solubility of MEA solution is more sensitive to partial pressure and its cycling stability is stronger.