Pre-SCR Injection Of Sodium Sorbents

Transcription

1 Pre-SCR Injection Of Sodium Sorbents Cornelia Cretiu Technical Development Engineer SOLVAir NAFTA EUEC San Diego, CA March 6, 2018 Soda Ash & Derivatives

2 Presentation Outline The SOLVAY Group Pre-SCR Injection Why and How Power Plant 1, Trona Results Power Plant 2, Sodium Bicarbonate Results Takeaway 2

3 WE ARE A WORLD LEADER IN THE CHEMICAL INDUSTRY 140 industrial sites 1 27,000 employees 1 58 countries occupational accidents at major R&I centers 1 Group sites per million hours worked underlying results (audited figures) 2. MTAR: Medical Treatment Accident Rate 2, net sales 1 EBITDA 1 billion of million of 5.85 Kg Greenhouse gas intensity CO 2 eq. per EBITDA 3

4 We offer and continuously develop competitive and sustainable environmental solutions used for air emissions control, through a range of products, services, technologies and treatment systems. 4

5 Pre-SCR Injection: WHY cost savings Small Size <150 MW $100k-$150k Potential Savings Medium Size 150 MW-600 MW $150k-$750k Potential Savings Large Size 600 MW-1300 MW $750k-$1,200k Potential Savings 5

6 Power Plant #1 - Summary Medium size boiler Pre-SCR injection for improved efficiency, cost savings Increased heat rate of the whole system Measure of success: Less than 5 ppm SO 3 at SCR exit 6

7 HOW: Setup of Testing Power Plant #1 Clean flue gases Sodium based sorbent injection Test NH 3 Regular Sodium based sorbent injection ESP HCI SCR DeNO X Heat recovery Wet FGD Combustion SO X Raw flue gases Fly Ashes Residual Sodium Chemicals Stack Reduce min operating temperature of SCR Maintain low SO 3 through SCR to air heater Potentially reduce heat rate ~2% 7

8 Baseline SO 3 Concentrations Trona Before AH Clean flue gases Sodium based sorbent injection HCI NH 3 SCR DeNO X Heat recovery ESP Wet FGD Combustion SO X Raw flue gases Fly Ashes Residual Sodium Chemicals Stack ppm ppm ppm ppm Acceptance: 5 ppm as measured in point 1 at Low Load and point 2 at Full Load 8

9 Power Plant #1 - Injection Test Plan Use existing system on site to inject material Week 1: Test three different sorbents to determine best option - Normal Trona, D 90 =100µm - Fine Trona, D 90 =50µm - (Sodium Bicarbonate (SBC), D 90 =25µm) Week 2: use winning sorbent for acceptance criteria testing Criteria Less than 5 ppm SO 3 entering SCR will significantly reduce SCR min operating temperature - SCR inlet SO 3 only measured at min load with NH 3 shut off Less than 5 ppm entering AH allows for ~1% heat rate reduction from shutting off SA steam coils 9

10 SO 3 Removal Rate SO 3 -Sorbent Stoichiometry Milled Trona yielded the best SO 3 removal 10

11 Acceptance Criteria #1: SCR Inlet SO 3 Concentration at Minimum Load Milled Trona resulted <1.5 ppm SO Load 11

12 Acceptance Criteria #2: SCR Outlet SO 3 Concentration at Full Load Milled Trona met the 5ppm SO 3 acceptance level 12

13 Power Plant #2 - Summary Large size boiler Pre-SCR injection for improved efficiency Increased heat rate of the whole system is secondary Measure of success: Increased SO 2 removal and assess dispersion method efficiency 13

14 Setup of Testing Power Plant #2 Clean flue gases Sodium based sorbent injection Test HCI NH 3 SCR DeNO X Regular Sodium based sorbent injection Heat recovery ESP Combustion SO X Raw flue gases Fly Ashes Residual Sodium Chemicals Stack Assess SO 2 removal Assess various dispersion devices Improve capture of SOx in addition to HCl 14

15 Power Plant #2 - Injection Test Plan Use existing system on site to inject material, two DSI systems from both existent units but testing only on Unit 1 The DSI system of Unit 2 was connected to the hot side of Unit 1 pre- SCR, injection point taking advantage of the existing static mixers The DSI system of Unit 1 remained connected on the cold side after the AH Criteria Finely milled sodium bicarbonate d90<22um Possibility of going 0-10 tons per hour on both sides hot and cold Testing done while burning 100% PRB 15 15

16 Performance Hot side injection with regular lances before the existing static mixers was best 16

17 SO 2 Removal Rate vs. Injection Rate Hot side injection with regular lances before the existing static mixers was best 17

18 Path Forward The long term effects, if any, to the SCR were not studied, short term no negative effects were seen To prevent any seepage in the pores of the catalyst, the permanent heating system in place is activated to keep the catalyst warmer than the dew point at all times The high removal of sulfates increases sulfate content in the runoff water from the landfill, which needs to be addressed with better treatment 18

19 Takeaway High removal >95% of SOx was achieved with sodium sorbents Pre-SCR dry sorbent injection can be used to improve heat rate of power plants and allow lower minimum operating conditions when idling Milling Trona from D90 100µm to 50µm improves its efficiency up to 40% Increased efficiency = $$$ Savings 19

20 DISCLAIMER: All technical advice and recommendations provided, if any, are intended for use by persons having the appropriate education and skill. Solvay Chemicals, Inc. and its affiliates shall not be liable for any use or non-use of such advice and/or recommendations. Users of our products are solely responsible for the design, construction and operation of their own facilities Benoit Verdickt, Business Manager benoit.verdickt@solvay.com Marilyn Treacy, Commercial Manager marilyn.treacy@solvay.com Michael Atwell, Sales Development Manager michael.atwell@solvay.com Marco Riccio, Sales Development Engineer marco.riccio@solvay.com Cornelia Cretiu, Technical Development Engineer cornelia.cretiu@solvay.com