# FCC Issues Startup & Shutdown

EPA Offices

- RTP May 22, 2012 The f ollowing slides were presented by Jeff Sexton of Marathon, based on data obtained from member companies of the FCCU Technical Consenters Team and presented during an API meeting with EPA.2 

# FCC Startup & Shutdown Discussion Topics

 Backend Control Technology Overview

 Technical Concerns & Issues During Startup & Shutdown

 Torch Oil Process Design & Utilization

 Case Studies

– FCC Startup & Shutdown Emissions

 FCC Startup & Shutdown Process Dynamics

 Advocacy Recommendation3 

# FCC Emission Control Technology Options

FCC Regenerator Expander WH/CO Boiler

4th stage (FSS) 

### TSS SCR Wet Gas Scrubber LoTOx Scrubber SNCR

Torch Oil ESP

DFAH 

# Sketch shows most types of FCC flue gas emission control technology options. Technology selection is

unit specific. A particular FCC would not use all of these technologies.4 

# Technical Concerns & Issues
– Startup & Shutdown
 Provisions for Torch Oil Use

 Increased CO Emissions



##  Provisions for Start

- Up Of CO Boiler

 Increased CO Emissions During Boiler Commissioning



##  Provisions for Start

- Up Of SCR Unit

 Increased NOx While Commissioning SCR and Increasing Temperature

 Bypass During Unit Start

- Up to Minimize Catalyst Accumulation



##  Provision for Start

- Up of LoTOx Unit

 Need Sulfites to Absorb Excess Ozone (only after feed

- in)



##  Provisions for Start

- Up Of ESP Unit

 Do Not Energize Until After Stable Operation Based Upon Safety

 Increased PM Emissions Until ESP Is Energized



##  Provisions Transitory Operations ( Hot Standby )

 Prolonged use of torch oil to minimize temperature cycles and start

- up time

 NOTE: Hot Standby can result either from an unplanned shutdown, or from a planned shutdown of limited time duration. Either scenario provides data that illustrates the effects of torch oil on CO emissions since it is the use of torch oil (and not the reason for shutdown) that increase CO emissions.5 

# FCC Startup & Shutdown Discussion Topics

 Backend Control Technology Overview

 Technical Concerns & Issues During Startup & Shutdown

 Torch Oil Process Design & Utilization

 Case Studies

– FCC Startup & Shutdown Emissions

 FCC Startup & Shutdown Process Dynamics

 Advocacy Recommendation6 

# Torch Oil Process Design

Retractable Nozzle FEED STEAM7 

# Torch Oil Design

 Torch Oil Distribution

 Typically 1

- 5 distribution points

 Used in Conjunction with DFAH

– gas burner8 

# Torch Oil Distribution9 

# FCC Startup & Shutdown Discussion Topics

 Backend Control Technology Overview

 Technical Concerns & Issues During Startup & Shutdown

 Torch Oil Process Design & Utilization

 Case Studies

– FCC Startup & Shutdown Emissions

 FCC Startup & Shutdown Process Dynamics

 Advocacy Recommendation10 

# Case Study
– FCC Unit Trip & Restart (Unit A2 with Baghouse)

% ppm ppm ppm % fb:ai24c fb:ai25c fb:ai26c fb:ai23c fb:ai27c O2 CO NOx SO2 PM 2/5/2012 15:00 2.224893 0.041363 14.37988 12.17822 4.220494 2/5/2012 16:00 9.815133 646.0181 4.611854 7.822043 4.076272 2/5/2012 17:00 10 1000 2.463162 4.532601 4.393805 2/5/2012 18:00 10 1000 1.663704 7.346815 4.315623 2/5/2012 19:00 10 1000 0.525491 9.9804 4.427371 2/5/2012 20:00 10 1000 1.268489 6.878176 4.363206 2/5/2012 21:00 10 1000 2.240567 6.583831 4.641382 2/5/2012 22:00 10 1000 2.319089 6.083542 4.73274 2/5/2012 23:00 10 1000 4.374256 5.38329 5.282178

2/6/2012 0:00 10 1000 1.277679 2.760265 5.189806 2/6/2012 1:00 10 990.8149 32.74268

- 1.12886 6.451317 2/6/2012 2:00 10 612.9687 38.50444 1.17072 6.745082 2/6/2012 3:00 10 282.9718 42.66721 3.526949 6.402687 2/6/2012 4:00 9.625029 248.479 44.20884 4.237224 6.244692 2/6/2012 5:00 6.305254 175.9361 46.05983 4.068154 5.561254 2/6/2012 6:00 3.440695 18.86569 31.3849 1.040237 5.103787 2/6/2012 7:00 2.340538 28.34961 23.29546 2.139952 4.801994 2/6/2012 8:00 2/6/2012 9:00 

# Unit Trip

(loss of instrument air)



# Feed

- In Example of Unit Trip and Restart

– This particular case was caused by loss of Instrument air causing a Safety Instrumented System to activate. The operator responded by introducing torch oil to maintain regenerator temperatures and was able to re

- introduce feed ~10 hours later. Duration of restart will depend on many factors. . CO emissions remained high during the restart period (at CEMS maximum span) due to use of torch oil. The high resultant CO is from torch oil usage and would be the same for either a planned or unplanned shutdown11 

# Case Study
– FCC Unit Start
- Up After TAR (Unit A4 with FGS)

O2 CO NOx SOx 3/14/2012 0:00 10.01 34.73 0.47 0.25 3/14/2012 1:00 10.01 67.35 0.56 0.25 3/14/2012 2:00 10.01 175.26 2.71 0.25 3/14/2012 3:00 10.01 374.89 0.67 0.25 3/14/2012 4:00 10.01 318.17 0.47 0.25 3/14/2012 5:00 8.71 298.89 0.47 2.43 3/14/2012 6:00 6.26 268.93 0.48 14.81 3/14/2012 7:00 10.01 630.74 1.22 0.25 3/14/2012 8:00 10.01 1027.66 0.69 0.25 3/14/2012 9:00 10.01 1027.66 0.48 0.25 3/14/2012 10:00 10.01 1027.66 0.47 0.25 3/14/2012 11:00 10.01 1027.66 0.46 0.25 3/14/2012 12:00 10.01 1027.66 0.47 0.76 3/14/2012 13:00 10.01 1027.66 0.47 17.56 3/14/2012 14:00 10.01 888.85 0.47 33.19 3/14/2012 15:00 10.01 973.17 0.53 56.76 3/14/2012 16:00 10.01 286.34 4.09 72.43 3/14/2012 17:00 10.01 1027.39 0.47 62.10 3/14/2012 18:00 10.01 1028.08 0.48 64.21 3/14/2012 19:00 8.44 860.67 22.08 87.50 3/14/2012 20:00 2.18 118.21 54.32 195.33 3/14/2012 21:00 2.38 172.64 54.50 22.34 3/14/2012 22:00 1.48 60.97 47.73 7.33 3/14/2012 23:00 1.30 41.13 42.38 14.75

3/15/2012 0:00 1.33 32.10 40.86 5.00 3/15/2012 1:00 1.39 33.89 40.94 0.67 3/15/2012 2:00 1.09 40.38 32.79 0.25 

# Feed

- In Example of Unit Restart After TAR

– This data shows emissions during a unit restart after a maintenance turnaround . Duration of restart will depend on many factors. CO emissions remained high during the restart period (at CEMS maximum span) due to use of torch oil . Again this illustrates that any feed out condition of the FCCU (whether planned or unplanned) which necessitates the use of torch oil to either maintain or reheat the regenerator bed temperatures will have increased CO emissions. SEE CLJ BOLDED COMMENT ADDED BELOW12 

# Case Study
– FCC Unit Trip & Restart (Unit A3 with ESP)

o2 CO Nox SO2 Opacity Torch Oil % PPM PPM PPM % BPD 10/15/2010 8:00 2.95 92 107 6 6.47 0 10/15/2010 9:00 2.82 86 106 6 6.28 0 10/15/2010 10:00 2.79 77 105 6 6.13 0 10/15/2010 11:00 2.72 77 104 6 5.88 0 10/15/2010 12:00 3.55 175 107 5 6.34 0 10/15/2010 13:00 6.41 356 55 2 17.64 0 10/15/2010 14:00 10.00 219 9 3 14.73 52.12 10/15/2010 15:00 10.00 822 26 7 19.20 96.10 10/15/2010 16:00 10.00 1000 35 11 22.55 98.55 10/15/2010 17:00 10.00 1000 48 15 14.95 83.67 10/15/2010 18:00 10.00 1000 34 11 14.87 66.60 10/15/2010 19:00 10.00 113 11 5 10.18 9.93 10/15/2010 20:00 10.00 9 6 3 3.97 7.85

11/18/2010 9:00 10.00 1000 26 22 14.41 183.50 11/18/2010 10:00 10.00 915 21 24 12.98 159.67 11/18/2010 11:00 3.17 445 28 34 14.46 174.65 11/18/2010 12:00 3.68 222 91 77 17.53 128.03 11/18/2010 13:00 4.59 323 103 7 18.34 72.15 11/18/2010 14:00 3.21 42 107 18 17.96 181.85 11/18/2010 15:00 4.61 180 114 14 21.33 111.31 11/18/2010 16:00 5.12 601 114 1 21.54 0 11/18/2010 17:00 4.31 648 117 2 12.69 0 11/18/2010 18:00 3.84 511 116 3 3.72 0 11/18/2010 19:00 3.94 683 114 3 3.68 0 11/18/2010 20:00 2.96 258 109 5 2.78 0 11/18/2010 21:00 3.96 577 104 3 3.25 0 

# Unit Trip

Feed

- In

Example of Unit Trip and Restart

– This particular case was caused by loss of power causing a Safety Instrumented System to activate. The operator responded by introducing torch oil to maintain regenerator temperatures and was able to re

- introduce feed ~10 hours later. Duration of restart will depend on many factors. CO emissions remained high during the restart period (at CEMS maximum span) due to use of torch oil. The high resultant CO is from torch oil usage and would be the same for either a planned or unplanned shutdown

. SEE CLJ BOLDED COMMENT ADDED BELOW13 

# Case Study
– FCC Unit Trip & Restart (Unit A1 with TSS)

0 100 200 300 400 500 600 700 800 900 1000

0 20 40 60 80 100 120CO (ppm); SOx (ppm)NOx (ppm); Opacity (%); O2 (%) NOx Opacity O2 CO SOx Shutdown 10/1 10:45 PM Start Up 10/4 12:12 AM 

### Example of Unit Trip and Restart

– This particular case was caused by a unit upset causing a Safety Instrumented System to activate. The operator responded by introducing torch oil to maintain regenerator temperatures and was able to re

- introduce feed ~61 hours later. Duration of restart will depend on many factors. In this example, other equipment problems Delayed feed

- in. CO emissions remained high during the restart period (at CEMS maximum span) due to use of torch oil. The high resultant CO is from torch oil usage and would be the same for either a planned or unplanned shutdown

.
SEE CLJ BOLDED COMMENT ADDED14 

# Case Study
– FCC Unit Trip & Restart (Unit A1 with TSS)

0 100 200 300 400 500 600 700 800 900 1000

0 20 40 60 80 100 120CO (ppm); SOx (ppm)NOx (ppm); Opacity (%); O2 (%) NOx O2 Opacity CO SOx Shutdown 12/11 10:30 AM Start Up 12/15 1:30 PM



### Example of Unit Trip and Restart

– Same example as previous case study. Only exception is opacity spiked during this restart. A technician reported the opacity meter beam was not aligned with its receiver due to thermal expansion. Ambient temperature was very cold. CO emissions remained high during the restart period due to use of torch oil. Restart took 99 hours.15 

# Case Study
– FCC Unit Trip & Restart (Unit A6 with LoTox + FGS)

0.0 200.0 400.0 600.0 800.0 1000.0 1200.0 1400.0 1600.0 1800.0 2000.0

- 5.00 0.00 5.00 10.00 15.00 20.00 25.00 30.00 35.00CO (ppm); SOx (ppm)NOx (ppm); Opacity (%); O2 (%) NOx Opacity O2 CO SOx ESD @3:39 Feed in @ 21:30



### Example of Unit Trip and Restart

– This particular case took 18 hours to restart. LoTOx was not operational during this period to minimize ozone slip without Any sulfites in scrubber liquor. CO emissions remained high during the restart period due to use of torch oil.16 

# Case Study
– FCC Unit Trip & Restart (Unit A5 with COB+FGS+SNCR)

0.0 100.0 200.0 300.0 400.0 500.0 600.0 700.0 800.0 900.0 1000.0

- 50.00

0.00 50.00 100.00 150.00 200.00 250.00CO (ppm); SOx (ppm)NOx (ppm); Opacity (%); O2 (%) NOx Opacity O2 CO SOx Unit Shutdown Feed In



### Example of Unit Trip and Restart

– This particular case took 9 hours to restart. CO emissions were controlled with use of torch oil since this unit had a CO Boiler and was able to maintain operation during restart. Not all CO Boilers are maintained on

- line during restart due to safety concerns.17 0.0 100.0 200.0 300.0 400.0 500.0 600.0 700.0 800.0 900.0 1000.0

0.00 50.00 100.00 150.00 200.00 250.00 300.00 350.00CO (ppm); SOx (ppm)NOx (ppm); Opacity (%); O2 (%) NOx Opacity O2 CO SOx Unit Shutdown 

# Case Study
– FCC Unit Shutdown (Unit A5 with COB+FGS+SNCR)

Example of Unit Shutdown

– CO emissions were controlled with a CO Boiler. Not all CO Boilers are maintained on

- line during shutdown due to safety concerns.18 

# Case Study
– FCC Unit Shutdown (Unit B1 with TSS+PRU+ESP)

Example of Unit Shutdown

– CO emissions collected with temporary analyzer with higher span than CEMS to collect higher CO values during shutdown. Note CEMS is at maximum span of 1000ppm but actual CO emissions were above 3000ppm as a result of the need to use of torch oil to maintain regenerator bed temperature19 

# Case Study
– FCC Unit Shutdown (Unit B1 with TSS+PRU+ESP)

Example of Unit Shutdown

– Same unit as previous slide. Data shows other emissions.20 

# Case Study
– FCC Unit Startup (Unit B1 with TSS+PRU+ESP)

Example of Unit Startup

– CO emissions collected with temporary analyzer with higher span than CEMS to collect higher CO values during startup. Note CEMS is at maximum span of 1000ppm, and CO emissions from analyzer hit the maximum span of 5000ppm as a result of the need to use of torch oil to heat up the regenerator bed temperature prior to feed introduction21 

# Case Study
– FCC Unit Startup (Unit B1 with TSS+PRU+ESP)

Example of Unit Startup

– Same unit as previous slide. Data shows other emissions.22 

# Case Study
– FCC Unit Startup From Hot Standby (Unit B1)

0 200 400 600 800 1000 1200

0 20 40 60 80 100 120

2/2/12 12:00 2/3/12 0:00 2/3/12 12:00 2/4/12 0:00 2/4/12 12:00 CO Emissions (ppm) Feed (MBPD) Torch Oil (BPH) 

### FCU Hot Standby

- CO emissions

Total FCU Feed (MBPD) Torch Oil SE Nozzle (bph) CO Rolling 1hr Average (ppm) 

### Example of Unit Startup

– CO emissions were high (at CEMS maximum span) due to use of torch oil to maintain regenerator bed temperatures prior to feed Introduction. The high resultant CO is from torch oil usage and would be the same for either a planned or unplanned shutdown23 

# Case Study
– FCC Unit Startup (Unit C1 with ESP

- prior to 2010 and FGS post 2010)

Startup Jan 2010 May 2009 Sep 2008 Nov 2007
60 Day Period After Startup
Stack NOx, ppmvd Period Average 111 101 84 65 Maximum Daily 253 154 171 159 Stack CO, ppmvd (1) Period Average 21 38 36 32 Maximum Daily 255 572 717 541 Regenerator Flue Gas CO, ppmvd Period Average 60 80 54 69 Maximum Daily 585 1812 1898 1319 Low-NOx Promoter Injection Period Average, lb/day 59 45 41 32 Cumulative Total, lb 3511 2701 2435 1898
96 Hour Period After Startup
Stack NOx, ppmvd Period Average 137 93 117 53 Maximum Hourly 298 198 222 298 Stack CO, ppmvd (1) Period Average 98 208 207 164 Maximum Hourly 1000 1000 1000 1000 Regenerator Flue Gas CO, ppmvd Period Average 243 576 494 561 Maximum Hourly 5901 5381 4693 9503

Notes (1) Stack CO CEMS maximum range = 1000 ppmvd 

### Example of Unit Startup

– CO emissions collected with temporary CEM to collect higher CO values during startup. CO emissions were high due to use of torch oil. Note that the hourly averages (red circle below) are at maximum span of 1000ppm for the CO CEMS, but the analyzer shows values in the 4500

– 9500 ppm range for a span of 10,000ppm.24 0 2000 4000 6000 8000 10000

0 8 16 24 32 40 48 56 64 72 80 88 96Regen Flue Gas CO, ppmvd

Hour 

### FCC Startups

- Regenerator Flue Gas CO Hourly Average Data

Jan 2010 May 2009 Sep 2008 Nov 2007 

# Case Study
– FCC Unit Startup (Unit C1 with ESP

- prior to 2010 and FGS post 2010)

Example of Unit Startup

– CO emissions collected from 4 different unit start

- ups to show range and variability. A temporary CEM was used to collect higher CO values. CO emissions were high due to use of torch oil.25 

# Case Study
– FCC Unit Startup (Unit C2 with COB + ESNCR + FGS)

0 100 200 300 400 500 600 700 800

0 20 40 60 80 100 120 140Stack CO, ppmvd



### Hour Reference 

### FCC Startup
- Apr12 Stack CO
- Hour Average Data 

# Exceeded 500 ppm CO With COB in Operation Example of Unit Startup

– CO emissions, even with at fired COB in service, can exceed 500ppm on startup. Additionally, not all FCCU’s will start

- up with a COB in service due to safety and plant stability concerns26 

# FCC Startup & Shutdown Discussion Topics

 Backend Control Technology Overview

 Technical Concerns & Issues During Startup & Shutdown

 Torch Oil Process Design & Utilization

 Case Studies

– FCC Startup & Shutdown Emissions

 FCC Startup & Shutdown Process Dynamics

 Advocacy Recommendation27 

# FCC Startup = Process Dynamics

Drawing Removed Since Did Not Get Permission From Licensor28 

# FCC Startup & Shutdown Discussion Topics

 Backend Control Technology Overview

 Technical Concerns & Issues During Startup & Shutdown

 Torch Oil Process Design & Utilization

 Case Studies

– FCC Startup & Shutdown Emissions

 FCC Startup & Shutdown Process Dynamics

 Advocacy Recommendation29 

# Advocacy Recommendations
– Work Practice Standards

 Safety and operability risks for running some flue gas emission control equipment (such as ESP, SCR and SNCR) during FCC startup

 FCC Startup & Shutdown Emissions Are Not Practical to Measure

 FCC startups and shutdowns are generally infrequent

– contribution to long

- term pollutant mass emissions is relative small

 Typical refinery goal is a 4

- 5 year FCC run length



#  PM Testing During S/U Represents Safety Risk & No Coke Burn

 The EPA should consider a technology

- based exemption to any short

term limits during transitory periods associated with startup, shutdown, and hot standby operations. The EPA could accomplish this by requiring facilities to prepare a Startup/Shutdown Plan, outlining the specific steps to be taken to minimize FCCU emissions during this period. The long

- term limits would still need to be met.