Stephanie Freeman January 10 th , 2007

1. Degradation of ROC16, a Novel Amine Solvent Stephanie Freeman January 10th, 2007 Rochelle Group University of Texas at Austin – Dept. of Chemical Engineering

2. Presentation Outline • Introduction to ROC16 • CO2 Solubility • Solid-Liquid Equilibrium of ROC16 • Volatility of ROC16 • Capacity and Viscosity • Comparison of Kinetics • Oxidative Degradation with Metals • Thermal Degradation • Conclusions and Current Issues • Future Work on ROC16

3. Introduction to ROC16 • ROC16 is a novel amine solvent recently patented by the Rochelle Group • The Rochelle group is currently investigating ROC16 as an viable alternative to 7 m MEA

4. Hilliard (2007) CO2 Solubility in ROC10 at 40°C PCO2 = 7.5 kPa PCO2 = 0.75 kPa

5. Hilliard (2007) Solubility of ROC20 At a loading of ~0.22, ROC20 is soluble at ambient temperature

6. Hilliard (2007) Solubility of ROC16 (cont.) Current optimized absorber loadings

7. Hilliard (2007) Expected Volatility at 40°C

8. Kinetics: ROC16 vs. 7 m MEA • Comparison at 60°C, PCO2* = 1 kPa • kg’ = 1.5x10-9 kmol/m2-Pa-s, 7.0 m MEA(a) • kg’ = 2.7x10-9 kmol/m2-Pa-s, ROC04 (b) • kg’ for ROC16 was estimated • Aboudheir (2003) • Cullinane (2005) Rate of ROC16 is roughly 2X faster than 7 m MEA

9. Oxidative Degradation - Methods • Low gas flow experiments • 100 mL/min 98% O2 / 2% CO2 • Analysis using Anion and Cation IC to detect: • Organic acids (formate, acetate, etc.) • Inorganic ions (nitrite and nitrate) • Amides (through formate production) • Amines • Not yet testing for: • Amino Acids • Aldehydes

10. Oxidative Degradation - Results

11. Thermal Degradation - Methods • Degradation of ROC20 studied at 135°C and 150°C • Loadings of α=0.3 and α=0.4 • Stainless steel bombs used • Amine concentration analyzed by: • Cation IC • Acid pH titration

12. Thermal Degradation over 5 weeks

13. Conclusions Advantages of ROC16 over MEA • Faster rates of absorption (Cullinane 2005) • Higher capacity for CO2: • CapROC16 = 1.44 mol CO2 / kg solution • CapMEA = 0.84 mol CO2 / kg solution • Negligible oxidative degradation (w/o Cu2+) • Negligible thermal degradation (potentially greater stripper P and T) • Comparable heat of absorption • Comparable volatilities

14. Conclusions (cont.) Issues that Need to be Addressed • Increased viscosity decreases diffusion • Precipitation with loss of CO2 loading or over-loading • Feasibility of onsite loading of ROC16 • Narrow solubility range • Volatility management

15. Conclusions (cont.) Potentially Intractable Obstacles • Pseudo-polymerization of ROC16 • Rapid increase in viscosity • Trigger unknown • Anomalous gas/liquid behavior • Oxidation experiments with either Fe/Cr/Ni or Cu produced some kind of “foam”

16. Future Work on ROC16 • Additional degradation experiments with higher concentrations of Cr, Ni, and Fe • Obtain rate data for ROC16 • Further study phase equilibrium behavior of ROC16 • Investigate pseudo-polymerization • Develop plausible onsite loading procedures • Determine true extent of foaming

17. Questions?