Regeneration of Mono-ethanolamine Solution After Biogas Purification by Electrical Heating with Assisted Ultrasonic Wave

Abstract

© 2018 Springer Science+Business Media B.V., part of Springer Nature High CO2composition in biogas decreases biogas heating value and low gas temperature is obtained. CO2separation with mono-ethanolamine (MEA) absorption is one effective method for biogas purification due to its low operating pressure and low methane loss. In addition, the used MEA solution could be regenerated with 80–100 °C heating and in this study, the regeneration of used MEA solution after biogas purification was carried out by electrical heating with assisted ultrasonic wave. The used MEA solution was regenerated for 75 min by electrical heating to a temperature of 70–98 °C and compared with the combination of electrical heating at 70–90 °C with 20 kHz ultrasonic wave. The solution pH value was the indicator to show the CO2status in the solution after regeneration and the suitable pH value should not be lower than 10 similar to the new solution. The results showed that the regeneration of the used MEA solution by electrical heating with assisted ultrasonic wave could reduce the electrical energy for the regeneration and increase the CO2absorption efficiencies in the next cycle with low energy consumption.