Non-Aqueous Solvents for Post-Combustion CO 2 Capture

Transcription

1 Center RTI International for Energy Technology Non-Aqueous Solvents for Post-Combustion CO 2 Capture RTI International Luke Coleman, Marty Lail, Steven Reynolds, Markus Lesemann, Raghubir Gupta BASF Christian Riemann, Kumar Sugavanam, Sean Rigby, Georg Sieder, Todd Spengeman, Torsten Katz May 18, st Post-Combustion Capture Conference (PCCC1)Abu Dhabi

2 RTI International RTI International Research budget >$750MM 13% average annual growth over the last 10 years. One of the worlds leading research organizations: >4,200 professionals in more than 40 countries High-quality scientific staff with tremendous breadth Over 130 different academic disciplines Mission: To improve the human condition by turning knowledge into practice

3 Center for for Energy Energy Technology Technology RTI Center for Energy Technology Program Areas Advanced Gasification Syngas Conversion and Clean Fuels CO 2 Capture and Conversion Biomass Conversion and Biofuels Objective: Development of new energy technologies from laboratory bench to full-scale commercialization Scale Production Industry 3 Core Competencies Catalyst, sorbent and solvent development Reaction engineering Process design and optimization Bench-scale and prototype testing Pilot Bench University Engineering and Technology Unit Basic Science Developmental Commercial Technical Maturity Access to Mission-Oriented Federal Programs

4 BASF The world s leading chemical company Sales 2010: 63,873 million Income from operations (EBIT) 2010: 7,761 million Employees at yearend 2010: 109,140 Gas Treatment Leading provider of gas treatment solutions Customer focused solution provider +300 industry references Innovation driven business unit Gas treating excellence BASF The Chemical Company 4

5 Project Team: U.S. Department of Energy ARPA-E Novel Non-Aqueous CO 2 Solvent-based Capture Process CO 2 IMPACCT Program Inventor of novel, non-aqueous CO 2 solvent chemistry Novel solvent synthesis and formulation, solvent screening and evaluation, and process design and simulation efforts Objective: Develop novel non-aqueous CO 2 scrubbing solvents and capture process that could substantially reduce the parasitic energy load and corresponding increase in Cost of Electricity (COE) for post-combustion CO 2 capture Funding: $2.75 M ($2.2M ARPA-E) Performance Period: July 2010 June 2013 Global leader in gas treatment solutions Extensive experience in the design, engineering, and servicing of acid-gas removal systems Guide solvent evaluation and process design to focus efforts on solving technical challenges to commercialization Process Performance Targets Power Performance Reboiler Duty < 2.0 GJ th /tonne CO 2 Plant Efficiency Point Loss < 7 points Economic Indicators Increase in COE < 50% Cost of CO 2 Avoided < $45/tonne CO 2 5

6 Overview of the State-of-the-Art Amine Solvents Basis: 450 MW e Coal-fired Power Plant Parasitic Cost of CO Cost [$/ton CO Solvent Energy 2 removed] 2 Removed [%] Power Capital Operating [$/ton CO 2 ] 30 % MEA KS State-of-the-Art Current state-of-the-art technologies are estimated to be ~85% in ICOE Current DOE post-combustion research target for increase in COE (ICOE) is 30-35% R&D Focus: Largest contributor to ICOE is Power Consumption Reboiler Duty Assumed $80/MWh 1. Rochelle, G. T. (2009). "Amine Scrubbing for CO 2 Capture." Science 2009, 325, Abu-Zahra, M. R. M.; Niederer, J. P. M.; Feron, P. H. M.; Versteeg, G. F. International Journal of Greenhouse Gas Control I 2007, 135. ICOE Breakdown Capital Operating Power 7

7 Reboiler Heat Duty R&D Opportunity qq RR = CC PP(TT RR TT FF ) MM ssssss 11 + HH αα MM CCOO22 xx VV,HH22 OO pp HH 22 OO 11 + HH aaaaaa,ccoo 22 ssssss pp CCOO22 MM CCOO22 MM CCOO22 Sensible Heat Heat of Vaporization Heat of Absorption Solvent C p [J/g K] h abs [kj/mol] h vap [kj/mol] X solv [mol solvent/ mol solution] α [mol CO 2 / mol solvent] Reboiler Heat Duty [GJ/tonne CO 2 ] MEA (30%) Lower Energy Solvent System All aqueous systems have similar properties such as high heat capacities, heats of absorption and vaporization, and high dilutions Reboiler heat duties are similar and can only be improved by lower heats of absorption or increase in concentration of amine. RTI s Approach: Non-aqueous, organic-based solvent systems More suitable physical and chemical properties Alternative reaction pathways to conventional carbamate and bicarbonate chemistry 8

8 RTI s Approach to Non-aqueous Solvents Potential Reaction Pathways Non-aqueous reactions offer lower energy reaction pathways Reactions are reversible at low temperatures Achieve high dynamic CO 2 loadings CO 2 Non-aqueous solvents have low specific heat capacities and low solvent dilutions Diverse group of nitrogenous bases 9

9 Challenges facing Non-Aqueous CO 2 Solvents RTI s Non-Aqueous Solvents Easily Separate from Aqueous Phase Water accumulation and involvement in the CO 2 capture mechanism Non-aqueous reaction pathway must be essentially exclusive in the presence of water (no selectivity for rxns involving H 2 O) Solvent systems with low water solubility form separate liquid phase Solvent viscosity Solvent viscosity affects rate of CO 2 capture and column dimensions Solids formation in rich solvent Solids can accumulate in packing or other undesirable areas in the process Foaming Many aqueous and non-aqueous solvents foam when purged with gases 10

10 Automated, Multi-cycle Solvent Evaluation System Saturator Gas Metering and Switching CO 2 Analyzer Condenser Chiller Reactor Multi-Cycle Testing With High-Fidelity Flue Gas Automated batch recycling of solvent Continuous cycling between absorption and regeneration conditions ~ 150 ml solvent volume Temperature controlled, atmospheric pressure reactor Simulated flue gas including CO 2, H 2 O, O 2, and SO 2 (balance N 2 ) Automated data analysis 11

11 Automated CO 2 VLE and Reaction Calorimeter Automated Gas Switching Automation, Control, and Acquisition 12 Batch Charge Vessel Calorimeter / Equilibrium Cell Capabilities CO 2 Partial Pressure CO 2 Loading Relationship (Vapor-liquid Equilibrium) Heat of CO 2 Absorption (Reaction Calorimetry) Specific Heat Capacity Vapor Pressure Heat-balance reaction vessel

12 Center for Energy Technology Screening Results of RTI s Novel Non-aqueous CO 2 Solvents CO 2 Loading [gco 2 /Lsolvent] Peak Regeneration Temperature [ C] Loading Temperature A B C D E F G H I J K L Aq. MEA Non-Aqueous Solvent System Screened a broad array of nonaqueous solvent families Summary of Results: Low regeneration temperatures 40 to 110 C High CO 2 loading capacities 60 to 163 g CO 2 / L solvent Identified promising candidate solvents systems that have higher loadings and lower regeneration temperatures than conventional aqueous-amine solvents 13

13 CO 2 Absorbed [grams] Multi-cycle Testing with High-fidelity Flue Gas Representative Non-aqueous Solvent Absorption: Temperature: 30 C Flue Gas Composition: 14%CO 2, ~3 % H 2 O, 4% O 2, 50 ppm SO 2, Balance N 2 Regeneration: Temperature: Ramp to 80 C Gas Composition: N 2 Purge Cycle Number Summary of Results: Stable CO 2 loading and regeneration temperature in presence of water Not degraded by water 14

14 Water Accumulation is a Major Hurdle for Non-aqueous Systems RTI s Non-Aqueous Solvents: Are selective for non-aqueous reaction pathways in the presence of water Have low water solubility and therefore form a separate liquid phase in the presence of water Have low regeneration temperatures allowing use of lower quality steam 15 Phase Separation

15 Lowering Power Load and ICOE Solvent C p [J/g K] h abs [kj/mol] h vap [kj/mol] x solv [mol solvent / mol solution] α [mol CO 2 / mol solvent] Reboiler Heat Duty [GJ/tonne CO 2 ] MEA (30%) Lower Energy Solvent System 1.45* 30* * 0.6* *Experimentally measured data Beneficial Characteristics Lower specific heat capacity (C P ) Lower heat of absorption ( h abs ) Lower solvent dilution (Increasing x solv ) Increased CO 2 working capacities ( α) Challenges Lower absorption T for optimal capture Water accumulation due to condensation or desiccation of water from flue gas Evaporative losses in absorber Degradation by flue gas contaminants (O 2, SO 2 ) Cost of solvents

16 Technology Development Plan Current Project Efforts Previous Work Current Project Future Development Yr TRL Proof of Concept/Feasibility Laboratory Validation Comprehensive solvent screening Identify promising solvent systems Determine thermodynamic and physio-chemical properties for novel systems CO 2 capture process modeling Develop comprehensive process model Evaluate novel process configurations and integration schemes Compare performance with conventional solvent systems 17

17 Technology Development Plan Next Stage of Project Previous Work Current Project Future Development Yr TRL Relevant Environment Validation Prototype Testing at Power Plant Bench-scale testing to assess solvent performance Continuous flow, 10 kg/day CO 2 capture unit operated using simulated flue gas Long term (1,000 hours) performance stability testing with high-fidelity flue gas Collect process and scale-up data to support simulation and pilot-scale unit design efforts CO 2 capture process modeling Update process models Techno-economic analysis Preliminary engineering design package for a pilot unit 18

18 Summary RTI s Non-Aqueous Solvent have potential to significantly lower ICOE Significantly lower energy penalty Potential for lowering operating costs Project Status Nearing completion of Year 1 of the project Identified several promising non-aqueous solvents exhibiting Reboiler heat duties ranging from 2.0 to 2.5 GJ th /tonne CO 2 Evaluating process configurations, solving process challenges Designing continuous bench-scale unit RTI s CO 2 Capture and Conversion Program Team 19