Relationship Between Viscosity and CO2 Loading in Aqueous and Non-Aqueous Amine Solvents

Amines are used as solvents to capture carbon dioxide both in coal-fired power plants and in the natural gas industry.  As amines absorb carbon dioxide, the molecules interact to form either carbamate-ammonium salts (for primary and secondary amines) or bicarbonate-ammonium salts (for tertiary amines).  These salts greatly increase the viscosity of the solvents, making them less useful and harder to process.  Although amines are frequently used in industry, little research has been done to quantify this relationship.  This study examines the relationship between viscosity and carbon dioxide loading for several amines at various percentages in water.