Flue Gas Mercury Removal Using Carbon- Polymer Composite Material

Transcription

1 Flue Gas Mercury Removal Using Carbon- Polymer Composite Material X. Sean Lu, Zach Xu, Steve Stark, Richard Gebert, W.L. Gore &, Inc. Tom Machalek, Carl Richardson, Jennifer Paradis, URS Corporation Ramsay Chang, Electric Power Research Institute Brandon Looney, Marcus Mathews, Southern Company EUEC January 31 February 2, 2011, Phoenix, AZ

2 Outline Introduction Lab tests Field demonstrations Summary W. L. Gore &

3 Introduction Activated carbon for flue gas Hg removal: Carbon injection: low Hg capacity, fly ash contamination Stationary carbon bed: saturation by SOx or other acid gases, frequent bed regenerations Gore s carbon-polymer composite (CPC) tape material: Activated carbon (chemically treated) and fluoropolymer composite tapes Applied in stationary bed configurations Much less potential to be saturated by SOx or other acid gases, therefore, no frequent bed regenerations are required W. L. Gore &

4 Introduction Gore s carbon-polymer composite (CPC) material (continued): Flue gas conditions: low temperature ( < 100 o C) and humid ( > 50%RH) SOx and other acid gases are converted into aqueous acid solutions and expelled to the CPC tape s outer surfaces, then collected Hg can be fixed on the carbon surfaces with high capacity ( > 1.0wt%) due to the low operating temperatures; therefore, long-term operation before sorbent saturation by mercury CPC tapes can be made into modular forms with reasonably low pressure drop US patent: 7,442,352 B2 (2008) by Lu & Wu

5 Introduction Typical Stationary Carbon Bed Applications Flue gas SOx, Hg Clean air Adsorption mode By high temp heating A system to collect & treat SOx Carbon column Acid Solution Regeneration mode Or by water washing A system to treat dilute H2SO4 solution, < 2% acid

6 Lab Tests SOx and Hg removal - convert SOx into sulfuric acid solution

7 SO2 Removal Efficiency (%) W. L. Gore & Lab Tests SOx and Hg removal - convert SOx into sulfuric acid solution (continued) CPC tape Regular carbon Test conditions: 900ppm SO2 6mg/m^3 Hg 4cmx7cm tape 300sccm flow 65C 65% RH Time (day)

8 Hg Removal Efficiency (%) Lab Tests SOx and Hg removal (continued) High mercury removal efficiency & capacity 100 Test Test Conditions: Condition: 200sccm, 900ppm 6mg/m^3, SO2, 65%RH, 6.0mg/m^3 67C, 1.8 Hg, gram 65%RH, sample 65C Time (hour)

9 Lab Tests Mercury removal with parallel plate arrangement by URS Flow Out Mercury: mg/m^3 SO2: 50 ppmv Temperature: 140F (60C) RH: 50% Gas flow: 0.8cfm Total CPC tape: 3.8 x 23 (two strips) Plastic back Gore CPC tape ¼ Flow In

10 Lab Tests Mercury removal with parallel plate by URS (continued) URS model simulations: Stabilized Hg removal efficiency = 80% Stabilized Hg removal Eff. = 82%

11 Mercury Content on Tape (ppmw) Lab Tests Mercury removal with parallel plate by URS (continued) - Distribution of Hg on CPC tape after URS testing 600 Hg content on carbon tape after URS BT test Tape-2 Tape Distance from Inlet (inch)

12 Small scale field demonstrations Plant Yates Demonstration (I) Parallel Plate (March July 2010) The demonstrations were jointly carried out by Gore, EPRI, URS, and Southern Company Tests were done at Southern Company s Plant Yates power station Slip stream flue gas was taken after limestone wet scrubber (from stack) Temperature: ~123F (51C) Humidity: 100% Flow Rate: 5.0cftm (5ft/second linear velocity) Carbon tape: 4-strips of 5in x 5ft Testing date: March 26, April 21, May 20, July 13, and July 30, 2010

13 Plant Yates Newnan, Georgia W. L. Gore &

14 Small scale field demonstrations (continued) We are here!

15 Small scale field demonstrations (continued) Inlet port Outlet port Venturi meter Stack CPC tapes Blower Adjustable valve Tent Analytical equipments Floor

16 Percent Removal (%) Small scale field demonstrations (continued) Hg & SO2 Removal 100% 90% 80% 70% Total Hg Removal - 5acfm, 10ft SOx Removal 60% 50% 40%? 30% 20% 10% 0% Temperature Excursion Test Period (Days of Operation)

17 Small scale field demonstrations (continued) W. L. Gore &

18 Small scale field demonstrations (continued) Plant Yates Demonstration (II) Sorbent Module (Aug. - present) The demonstrations were jointly carried out by Gore, EPRI, URS, and Sothern Company Tests were done at Southern Company s Plant Yates power station Slip stream flue gas was taken after limestone wet scrubber (from stack) Temperature: ~123F (51C) Humidity: 100% Flow Rate: 13.0 and 24.7acfm (5 and 9.5ft/second linear velocities) Carbon tape: 6 deep, 3.8 diameter cylindrical modules (8 modules) Testing date: July 31, Aug. 30, Sept 16, Oct 26, Nov. 29

19 Small scale field demonstrations (continued) Flue Gas Inlet Sampling Ports Six Modules CPC Tape module Eight Modules Liquid Collector/Drain

20 Pressure Drop, inch H2O Small scale field demonstrations (continued) 4" Diameter CPC Roll Pressure Loss - roll inside PVC pipe 1.0 Field Data Lab Data Velocity, fpm

21 Mercury Removal Small scale field demonstrations (continued) Hg Removal 100% 90% 80% 70% 60% 50% 40% Total Hg Removal - Six Modules Total Hg Removal - Eight Modules 30% 20% 10% Plant Outage System Offline 0% Operation Time (Days) W. L. Gore &

22 Mercury Removal (%) Small scale field demonstrations (continued) Linear Gas Velocity - 5.0ft/s Linear Gas Velocity - 9.6ft/s Three-modules Six Modules Eight Modules

23 SO2 Removal Efficiency (%) Small scale field demonstrations (continued) SO2 Removal Operating Time (day) SO2 Removal - six modules SO2 Removal - eight eifht modules

24 Summary A unique sorbent material, carbon polymer composite material (CPC), has been developed for flue gas mercury and other contaminates removal The CPC material is deployed in a stationary sorbent bed applications, and the sorbent bed does not require a frequent regeneration process Field demonstration tests have shown that the CPC bed is effective for Hg/SOx removal (in coal-fired power plant after a wet scrubber) for long-term (4-5 months without requiring frequent regeneration or maintenance processes) We will perform a preliminary engineering economic analysis is to assess the feasibility of retrofitting the CPC to the existing power plant and cost, and conduct a medium scale field demonstration this year, and a full-scale field demonstration afterward W. L. Gore &