# CIBO - EP

A Meeting Mar ch 17, 2014

1

# Ag enda - Subpart DDDDD F ocus • Coal fir ed boiler C O emissions r elativ e t o co mpliance and MA

TS appr oach • St artup/shut down re quir emen ts and major issues • Po te ntial impact and in te ntions re lative t o UPL application and r emand • Re mand - re co nsider ation - co mpliance concerns 2

# CO DDDDD vs. MA TS • Essen tially no dif

fe re nce in non - dio xin orga nic HAP emissions fr om coal fir ed ICI boilers co mpar ed t o E GU boilers

– Basic combus tion methods, fuels, operation ar e similar r elative to non - dio xin orga nic HAP emissions

– To ta l emissions as TPY ar e much higher for E GU coal fir ed boilers than fo r ICI coal fir ed boilers 

## • Ye t DDDDD imposes C O limits wher eas MA TS uses work pr actice appr oach 3

# Issues with Boiler MAC T C O Appr oach • Concerns with asserting con tinuous co mpliance under all oper ating conditions

– CO emissions ar e known to v ary with operating conditions and fuel quality (e.g., especially mois tur e and fines with s to ke rs ) ov er time

– 30 da y r olling a ve ra ge for CEMS ma y not cov er issues 

## • Some boilers with inher en t design limit ations that impact C O emissions 4

# Da ta Ava ilability • EP A made publicly ava ilable the following:

– Utility MA

TS pr oposed rule dated Ma y 3, 2011 • Incorpor ating a work pr actice appr oach to addr ess non dio xin orga nic HAP



## – Re sults of the EP

A pilot scale Multipollut an t Con tr ol R esear ch F acility tes ting r efer enced in the MA TS pr oposed rule 

## • Both ar ose aft er the close of commen t period fo r the June 4, 2010 Boiler MA CT Pr oposed Rule (Augus t 23, 2010) 5

# Indus trial Coal Boiler HCHO vs CO

6

# EG U Coal Boiler HCHO vs CO

7

# Combined ICI Coal Boiler and E GU Coal

Boiler Da ta

89

# Conclusions • A w ork practice appr oach as used for MA TS co al fired boiler s is equally applic able t o ICI c oal fired boiler s • Bec ause the MA

TS wo rk practice appr oach was fir st noticed aft er co mmen t closing for the 2010 Boiler MACT Pr oposed rule, that appr oach was not a va ilable fo r public c ommen t on the Boiler MACT rule • Therefor e, the w ork practice appr oach for c oal fir ed boiler non dio xin org anic HAP should be open for EP A r ec onsider ation and included within EP

A’ s r ec onsider ation of non - dio xin org anic HAP emissions and CO limits • This appr oach wo uld retain all issues relative to c oal fired ICI boiler CO within the rec onsider ation pr ocess and not split it between Court R eview Brie fs and rec onsider ation

– Re sulting in a mor e coher ent and efficient re gula tory/leg al pr ocess • EP A c ould ev aluate a mix of work practices as an alt ernative to CO limits

– Pe riodic tune - ups with ongoing continuous O2 monitoring

– O2 trim systems, which pr ovide continuous combustion optimiz at ion 10

# St artup/Shut down Issues

11

# Oper at ional Pr oblems • As discussed in CIBO (and others’) r ec onsideration petitions, ther e ar e major problems with the final rule sta rtup/shut down approach • EP A’ s MA TS appr oach using per cen t load and time is re asonable

– 25% load for 4 hour s following a cold start would work for a high per cen t of ICI units

– Those with r emaining issues could be allowed to work out a unit - specific pr ocedur e with the permitting authority 

### • Ex amples of pr oblems and r ec ommended solutions provided separate ly & summariz ed in following slides • These issues need t o be addr essed soon in the re co nsideration process - ther e ar e serious concerns at the r egulat ed sour ces whether additional pr ovisions need to be provided 12

### Scenario - sta rtup on clean fuel, eng ag e non - lis te d controls prior to adding solid fuel Con tr ols - An y • Po te nt ial compliance issue

– Clean fuel a va ilability

– CO issue with tr ansition fr om g as/liquid to solid • 30 da y a verage depends on compliance margin 

### • Sugg es te d solution

– Expand clean fuel lis t • Additionally

, include all other Gas 1 fuels; biodiesel; fuels meeting HCl, Hg , TSM by fuel analysis; other clean fuels per permitting authorities

– Provide adequa te “sta rtup” time t o cover transition fr om s tartup fuel to primary solid fuel per slides below 13

### Scenario - St artup on solid fuel Con tr ols - Dry • Po te nt ial compliance issues

– Need adequa te flue g as temper at ur e and low enough O2 prior to ESP energiz at ion

– Need time within “sta rtup” period for combus tion unit firing primary fuel(s) and all e xe mpted air pollution contr ols to reach stable conditions

– Need “sta rtup” definition to accommodate units with heat or s team upon main fuel ignition

– Differ entiate between cold start (more time) & hot restart (less time) 

### • Sugg es te d solutions

– Include ESP s in T

able 3, item 5 - exe mpted contr ols to be s tarted as ex peditiously as possible

– End sta rtup when boiler/PH has continuously maintained ≥25% of maximum output at normal output conditions for 4 hr fo r cold sta rt/1 hr fo r hot re sta rt and all contr ol devices in s table oper at ion

– OR boiler/PH oper at ing abov e minimum oper at ionally s table output flow rate /pr essur e fo r minimum time per site - specific sta rt - up plan 14

### Scenario - St artup on solid fuel Con tr ols - We t • Po te nt ial compliance issues

– Need time within “sta rtup” period for combus tion unit firing primary fuel(s) and all e xe mpted air pollution contr ols to reach stable conditions

– Differ entiate between cold start (more time) & hot restart (less time)

– Could ha ve problems meeting 30 da y ro lling CO CEMS limit if inadequa te “sta rtup” period is allowed 

### • Sugg es te d solutions

– End sta rtup when boiler/PH has continuously maintained ≥25% of maximum output at normal output conditions for 4 hr fo r cold sta rt/1 hr fo r hot re sta rt and all contr ol devices in s table oper at ion

– OR boiler/PH oper at ing abov e minimum oper at ionally s table output flow rate /pr essur e fo r minimum time per site - specific sta rt - up plan 15

### Scenario - St artup on solid fuel Con tr ols - Dry or Wet • Po te nt ial compliance issues

– Need to addr ess units that shar e common contr ol device and s tartup sequentially or when one unit is s tarting up and one or mor e units is alr eady in normal oper at ion

– Could ha ve problems meeting 24 hour block opacity limit or 30 da y ro lling CO CEMS limit if inadequa te “sta rtup” period is allowed 

### • Sugg es te d solutions

– Sequential s tartup: End s tartup when the las t boiler/PH to s tart has continuously maintained ≥25% of maximum output at normal output conditions for 4 hr fo r cold sta rt/1 hr fo r hot re sta rt and all contr ol devices in s table oper at ion

– OR when the las t boiler/PH is oper at ing abov e minimum oper at ionally sta ble output flow r ate/pressure for minimum time per site - specific sta rt up plan

– Non - sequential s tartup: The boiler/PH initiating s tartup wo uld get a sta rtup period with end of s tartup depending on hot/cold sta rtup 16

### Scenario - Unit begins s ta rtup, re aches minimum sta ble load, but equipmen t pr oblem r esults in “failed s ta rtup” Con tr ols - An y • Po te nt ial compliance issues

– All of the abov e 

### • Sugg es te d solutions

– Ensur e entire period is consider ed s tartup, ev en if r each the minimum load thr eshold

– 4 hour period mus t be continuous • To allow for re covery fr om decr ease in temperatur es, etc., to stable conditions • Wo uld not be able to continually cycle in and out of the startup period • Once 25% load is r eached for some time period, it becomes a hot r estart
17

### Scenario - Lose solid fuel feed; dela y or lack of auxiliary fuel; wet fuel can incr ease O2 and trip ESP , which trips fuel; fuel feed pr oblems causing interruptions Con tr ols - We t • Po te ntial c ompliance issues

– “Shutdown” not completed if unit continues to supply useful output until fe ed is r es tored • Not normal operation and not always malfunction
– Ma y be issue with 30 - da y C O CEMS limit depending on compliance margin and length of event • Sugg ested solutions

– “Shutdown” definition to accommodate return of fuel prior to total loss of ste am/heat output • Cannot be forced to take unit totally down before reinitiating startup • End of period would be a hot restart with startup work practices applying
– Re vise t o r ead: “Shut down ends when ther e is **both** no steam or heat being supplied **and** no fuel being combusted in the boiler or process heater; **or** when s ta rtup is initiated by r eintroducing fuel t o the boiler or pr ocess heater after fuel feed has been halt ed.” 18

### Scenario - Lose solid fuel feed; dela y or lack of auxiliary fuel; wet fuel can incr ease O2 and trip ESP , which trips fuel; fuel feed pr oblems causing interruptions Con tr ols - Dry • Po te ntial c ompliance issues

– “Shutdown” not completed if unit continues to supply useful output until fe ed is r es tored • Not normal operation and not always malfunction
– ES P trip is r equir ed upon Master Fuel Trip

– Ma y be issue with 24 hour block opacity limit or 30 - da y C O CEMS limit depending on compliance margin and length of ev ent • Sugg ested solutions

– “Shutdown” definition accommodate return of fuel prior to total loss of ste am/heat output • Cannot be forced to take unit totally down before reinitiating startup • End of period would be a hot restart with startup work practices applying
– Re vise t o r ead: “Shut down ends when ther e is **both** no steam or heat being supplied **and** no fuel being combusted in the boiler or process heater; **or** when s ta rtup is initiated by r eintroducing fuel t o the boiler or pr ocess heater after fuel feed has been halt ed.”

– Include E SP s in T

able 3, item 6 exempted APCs not r equir ed to be oper ated during a shut down 19

### Scenario - Pe r the “shutdown” definition, shutdown begins upon halting fuel feed t o the boiler/PH; fuel can s till be burning in the boiler/PH Con tr ols - An y • Po te nt ial compliance issues

– Curr ent definition: • “Shutdown means the cessation of operation of a boiler or pr ocess heater for an y purpose. Shutdown begins either when none of the steam fr om the boiler is supplied fo r heating and/or pr oducing electricity , or fo r an y other purpose, or at the point of no fuel being fir ed in the boiler or pr ocess heater , whichever is earlier

. Shutdown ends when ther e is no steam and no heat being supplied and no fuel being fir ed in the boiler or pr ocess heater

.”

– This can be interpreted tha t shut down does not begin until no fuel is burning or no s team/heat is being supplied

– In some designs, fuel continues to burn in the unit after fuel feed stops 

### • Sugg es te d solution

– Clarify tha t “fuel being fir ed” in this case means fuel being fed to the combus tion unit 20

### Scenario - Mor e than 1 unit v en ts t o a wet contr ol device; 1 unit shuts down and other(s) re main oper ating Con tr ols - An y • Po te nt ial compliance issues

– We t scrubber pr essur e drop can depend on flow thr ough the scrubber

– With fewer units oper at ing , oper at ing par ameter limits established during the performance test with both units in oper at ion ma y not be achiev able 

### • Sugg es te d solution

– Unsur e how to address in the rule • Submit alternate monitoring r equest and establish differ ent operating scenarios?

– e.g., alternate oper ating limits with fewer units in operation
– Similar issue t o use of g as fuel firing in a solid fuel fir ed boiler wher e emission contr ols ar e not needed 21

# Pa th F orw ar d • EP A in te ntions to addr ess s ta rtup/shut down issues? • An y further in fo rmation needed?

22

# UPL Implic at ions • Major concerns with dela ys and pot en tial sta ndar d changes r elativ e t o c ompliance dat es • EP A in te ntions?

23

# Re mand - Re co nsiderat ion - Compliance

Concerns • If an y emission limit changes ar e co nte mplat ed, notice and commen t is re quir ed along with e xt ended compliance timing • Compliance planning and c apit al in ve st men t mus t co nsider all r egulat ory r equir emen ts to gether

– ANY changes upset the pr ocess and cause timing , effort, and cos t pr oblems 24

# Additional discussion?

25