Aminosiloxane having double absorption sites with low viscosity for efficient SO2 capture

Abstract

The viscosity and absorption capacity are important factors in evaluate the performance of SO2 absorbent, but it is not an easy task to balance the contradiction between them. Herein, we designed and synthesized a novel aminosiloxane (3-diethylaminomethyl-1,1,3,3-tetramethyl-disiloxyalkyl methyl)-diethylamine (DTDA) with double absorption sites. This absorbent has low viscosity before and after absorption, with 3.41 mPa·s and 180.00 mPa·s at 303.15 K, respectively. The absorption capacities of DTDA can reach 3.42 mol/mol (303.15 K, 1.00 atm) and 1.71 mol/mol (303.15 K, 0.02 atm). The desorption of SO2 can be realized at 363.15 K with good cyclic absorption performance. Moreover, with the introduction of dimethyl silicone oil (DSO), a mixed absorption system (DTDA-DSO) with liquid-liquid phase-change behaviors was obtained. The mixed absorption system not only shows better thermal stability but also needs lower thermal desorption energy consumption. The excellent absorption performance of DTDA-DSO system makes them have great potential in the field of SO2 capture and could provide strong support for their industrial application.