Technologies and Approaches of CO 2 Capture

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1 Southwest Regional Partnership Project Technologies and Approaches of CO 2 Capture Liangxiong Li, Brian McPherson, Robert Lee Petroleum Recovery Research Center New Mexico Institute of Mining and Technology, Socorro, NM 87801

2 Acknowledgement DOE: Southwest Regional Partnership on Carbon Sequestration, Phase II. DOE: Funding through the NPTO in NETL under Contract No. DE-FC26-00BC15326.

3 Outline Specific Feature of CO 2 Capture from Power Plant. Reviews of Technologies for CO 2 Capture Characteristics of absorption and adsorption based separations Membrane separation technologies State-of-the arts separation technologies Current status of CO 2 capture Our Approach Cost-effective CO 2 capture from flue gas by produced water extraction Zeolite membranes Hydrotalcite zeolite composite membranes Conclusions

4 1. Specific Feature of CO 2 Capture from Power Plant Post-combustion Pre-combustion

5 1.1 Typical CO 2 Concentrations in Process Streams? Power plant CO 2 concentration, vol/% Power Plant Flue Gas, Post-combustion CO 2 capture Coal fired boiler 14 Natural gas fired boiler 8 Natural gas combined cycle 4 IGCC, Pre-combustion CO 2 capture Coal gasfication 40 Natural gas oxidation 24 Others Blast furnace gas Oil refineries and petrochemical plant 8 Thambinmuthu et al., 2002

6 2. Reviews of Technologies for CO 2 Capture Technologies Advantages Challenges Absorption Based Aqueous chemical absorbents Mature technology High COE and corrosion Glycol (Selexol) Commercial product High COE and require low T Aqueous ammonia High-value byproduct Low T requirement (80 o F) Metal organic frameworks High capacity Expensive and high sensitivity Ionic liquid High T and capacity Expensive and high viscosity Membrane Based H 2 selective membrane Favorable for W GS High pressure operation Pd metal membrane High separation factor High cost and sensitivity Zeolite membrane Molecular sieve Sensitive to H 2 O vapor Lithium oxide membrane High temperature Low separation factor Others { Hydrates Hybrids process High pressure operation Low T, High viscosity High-value by product Low capacity

7 2.1 Characteristics of Absorption and Adsorption Flue gas CO 2 1. Chemical absorption 2. Physical absorption 3. Solid Physical adsorption Scrubber Regenerator Regeneration High capacity Low regeneration temperature Low solvent circulation rate Low solvent degeneration rate, kg/ton CO 2 Low corrosion rate

8 2.2 Membrane Separation Technologies 1. CO 2 selective membranes 2. Membranes reactor for CO shift and H 2 /CO 2 separation CO 2 (H 2 ) H 2 (CO 2 ) Polymeric-metallic, LANL Polymer, INEEL Alumina, ORNL Pd membrane, LANL Silica membrane, ECN Zeolite membrane, Univ. of Cincinnati, SNL H 2 ionic transport O 2 ionic transport, pervoskite, Eltron CO 2 ionic transport Solution-diffusion Adsorption-diffusion Ionic diffusion

9 2.3 State-of of-the Arts Separation Technologies T=200 o C P=15 Psi N 2 (~70%), CO 2 (~12%) Contaminant, <1% 1. Aqueous Chemical Sorbents 2. Glycol (Selexol) 3. Aqueous Ammonia 4. Metal Organic Frameworks Post-combustion T=400 o C P=950 Psi H 2 (~60%), CO 2 (~40%) Pre-combustion High-temperature membranes (1) polymeric-metallic membranes (2) porous ceramic membranes (3) ionic conductive membranes Ionic liquid

10 2.4 Current Status of CO 2 Capture Technologies CO 2 capture by chemical absorption is a commercial process. Current research focuses on: Modification of conventional chemical absorbent to enhance the capture c capacity and reduce the regeneration energy. Development of novel type of absorbent and adsorbent including ionic i liquid and metal organic framework. Design more efficient contactor for high CO 2 capture capacity and low energy consumption. Membrane technology for CO 2 capture is under development, especially for high temperature CO 2 separation. Polymeric-metallic metallic composite membranes Molecular sieve zeolite membranes Ionic conducting membranes Hydrotalcite/zeolite composite membranes

11 3. Our Approach 1. Integrated system for cost-effective CO 2 capture by produced water extraction 2. Molecular sieve zeolite membranes 3. Hydrotalcite zeolite composite membranes

12 3.1 Cost-Effective CO 2 Capture from Flue gas by Produced Water Extraction 14% Mole fraction of CO2, % 12% 10% 8% 6% 4% 2% 0% >96.7% Inlet gas DI water Produced water Outlet gas CO 2 bubbles after depressured

13 3.2 High Temperature CO 2 Separation by Microporous Inorganic Membranes Current status: 1) Polymeric membranes, T<150 C. (Lin et al., 2006, Science) 2) Polymer-metallic composite membranes, relative low flux and unknown high pressure separation performance. 3) Inorganic membranes, low separation factor. (Chung et al., 2005) Requirements for novel inorganic membranes: 1) Pore diameter < 1 nm to inhibit Knudsen diffusion and increase the selectivity. 2) Preferential CO 2 adsorption to maximize the permeability and selectivity. H 2 : nm N 2 : nm CO 2 : nm CO: nm

14 3.3 Zeolite Membranes MFI Molecular sieve zeolites: Crystal: excellent chemical, mechanical, and thermal stabilities. Sub-nanometer pores suitable for molecular separation. Pore dia. ~ 0.56 nm 2 µm FAU 2 µm + S i = [ x i [ x /(1 i x /(1 i x )] i permeate )] feed Pore dia. ~ 0.74 nm

15 MFI-Type Zeolite Membranes µm Permeance, 10-8 mol/m 2.s.Pa CO 2 N 2 SF Separation factor (SF) Temperature, o C 0 Zeolite layer Substrate 2 µm ZSM-5 (MFI) membrane Pore size 0.56 nm P s = D s 2ε λran A dθ dp

16 FAU-Type Zeolite Membranes NaY (FAU) membrane Pore size 0.74 nm 1 µm 2 µm Tubular and disc membranes Tubes: Pall Corp.

17 CO 2 Separation by Zeolite Membranes T=25 C: α CO2/N2 = 60, Ps= 10-8 mol/m 2.h.Pa 1. Separation factor decreases with increase of temperature 2. Separation factor and gas permeance decrease at existence of water vapor

18 3.4 Hydrotalcite Zeolite Composite Membranes Zeolite nucleation 500 nm Clay coating 1 µm Clay/zeolite Membrane

19 Characteristics of Hydrotalcite Composite Membranes Cross-Section of SEM Image TEM Image Characteristics: (1) High CO 2 absorption capacity at temperature above 400 o C (2) Enhanced CO 2 chemical absorption at existence of water vapor

20 4. Conclusions CO 2 can be captured using existing technologies and deep reduction in gas emission can be achieved. The challenges include: High operation cost, $/t CO 2 No full-scale demonstration for deep understanding and accurate evaluation Near term plan includes integrated system for economical CO 2 capture and modification of conventional technologies for efficient and costeffective separations. Long term plan focuses on the novel material and process developments, Polymer metallic composite membranes High temperature microporous ceramic membranes Metal organic frameworks Ionic liquids for high temperature IGCC

21 Thanks!!!