© 2007 chevron and john zink company, llc


Session 10Session 10Thursday, December 7, 8:00Thursday, December 7, 8:00--9:309:30

NOx Reduction Implementation TechnologyNOx Reduction Implementation Technology

PlantPlant--wide NOx Reduction Strategies:wide NOx Reduction Strategies:ChevronChevron ––John Zink ExperienceJohn Zink Experience

Ed Shepherd, Chevron (Richmond, CA)Ed Shepherd, Chevron (Richmond, CA)JimJim SeeboldSeebold, retired from Chevron (Richmond, CA), retired from Chevron (Richmond, CA)

Chuck Baukal, John Zink (Tulsa, OK)Chuck Baukal, John Zink (Tulsa, OK)


Factors to Consider

•Existing & future permitted NOx levels•Existing equipment emissions performance•Capital & operating costs•Complexity & reliability•Emission credits costs•Planned equipment shutdowns•Future production levels•Future process modifications•Space availability & requirements•Timing•Heating equipment loading (base vs. peaking)•Environmental considerations of any new equipment


NOx Reduction Efficiency

0.006 –0.01590 –97%Selective Catalytic Reduction (SCR)

0.033 –0.08540%Selective Noncatalytic Reduction(SNCR)

0.02555%Flue Gas Recirculation

0.007 –0.0380 –95%Ultra-Low-NOx-Burners (ULNB)

0.0660%Low-NOx Burners (LNB)

0.14Base CaseStandard Burners

ApproximateEmissions(lb/MMBtu)

ApproximateReduction

(%)Technology

Source: M. Bradford et al., Controlling NOx Emissions –Part 1, Chem. Eng. Prog., Vol. 98, No. 3, pp. 42-46, 2002.


NOx Reduction in Process Heaters

Control TechnologyControlledEmissions

PercentReduction

Low-NOx Burners 0.1 –0.3 lb/106 Btu 25-65*

Staged Air Lances Not Available 35-51

Ammonia Injection Not Available 43-70

Urea Injection + Low NOx Burner Not Available 55-70

Selective Catalytic Reduction 20 –40 ppm 65-90

Selective Catalytic Reduction +Low NOx Burner

25 –40 ppm 70-90

*Reductions of up to 90% have been demonstrated.

Source: J. Bluestein, NOx Controls for Gas-Fired Industrial Boilers & Combustion Equipment:A Survey of Practices, Gas Research Institute (Chicago), Report GRI-92/0374, 1992.


NOx Reduction Cost Effectiveness ($/ton)

0 500 1000 1500 2000 2500 3000 3500

Current Generation LowNOx Burners

Fuel Dilution onConventional Burners

Next Generation Low -NOx Burners

SCR + Low -NOx Burners

SCR System

$/Ton NOx Reduced

Source: J. McAdams et al., Minimize NOx emissions cost-effectively, Hydrocarbon Processing,Vol. 80, No. 6, pp. 51-58, 2001.


NOx Reduction RetrofitsCost Impact of Reduction Mandates

•Shape of curveconfirmed in everycapital project we haveeither done or studied

•Significant differencebetween 65% and 85%

•That kind of differenceroughly DOUBLES thecost

•Paying public &stockholders like thelower cost better0

50

100

150

200

0 250 500 750 1000 1500 2000 2500 500065% 85%NOx Reduction

Cost

Major Processing ComplexNOx Reduction ProjectsCost vs. Percent ReductionLeast-Cost Technology Mix


Most cost-effective approach to plant-wide NOx reductionbenefits both consuming public & corporate shareholders

•Negotiate a bubble rule on emissions fromthe entire processing complex

•Try to negotiate a cost-effective overallreduction under the bubble

•Control major sources to the max leavingsmaller sources alone

•Favor ultra low NOx burner retrofits avoidingthe proliferation of smaller SCRs

•But provide at least one huge SCR on amajor source (e.g., boiler house, steammethane reformer) as a “dial”control on totalemissions under the bubble


What we wouldWhat we wouldlikelike NOTNOT to doto do!!

What we wouldWhat we wouldLIKELIKE to doto do!!


35-mm slideconversion coming!ItIt’’s onlys only

moneymoney!!

Why we donWhy we don’’t liket likeSCRs too much . . .SCRs too much . . .


Selective Catalytic Reduction (SCR) System

FlueGas

Flue gascontainingNOX fromanotherprocess

CatalystAmmonia in carrier gas


OK, fine, you may prefer to do burners,but which SCRs make the most sense?

•Really BIG ones …•The bigger the better …•They’re all highly effective …•But the bigger they are the more cost-

effective they become!


5

10

15

20

25

30

35

0 500 1000 1500 2000 2500 3000Fir ing Rat e, mmBt u/ hr

(mmBtu)1/2

Build reallyBuild really BIGBIG SCRsSCRs!!


CapExCapEx OpExOpExNo SCR at the boiler house! …...…….…. ~$10m ~$2m/yr

No SCR at crude unit F1100/F1160! … ~$10m ~$2m/yr

No SCR at hydrogen reformer F355! ... ~$10m ~$2m/yr

Chevron RichmondChevron Richmond’’s NOx Project Highlightss NOx Project HighlightsHuge Savings Accrued to the Shareholders by Inspiring &

Supporting the Development of Extremely Low-NOx Burners

Intense collaboration with burner suppliersIntense collaboration with burner suppliers

Crude unit burners installedCrude unit burners installed onon--thethe--runrunFavorable margins — NONO shutdown contributed torefinery profitability

~$30m~$30m ~$6m/yr~$6m/yr

SavingsSavings


Chevron RichmondChevron Richmond#4 Crude Unit#4 Crude Unit

Ultra Low NOx Burner RetrofitUltra Low NOx Burner Retrofit


180 ppm 0 ppm


180 ppm 14 ppm

© 2007 Chevron and John Zink Company, LLCBefore 180 ppmBefore 180 ppm After 14 ppmAfter 14 ppm

SCR Reduction (92%) at a Burner PriceSCR Reduction (92%) at a Burner Price!!For process heating youFor process heating you DONDON’’TT need a selective catalytic reduction flue gas treatmentneed a selective catalytic reduction flue gas treatment

plant but you reallyplant but you really DODO need burners so why not superneed burners so why not super--low NOx burnerslow NOx burners


Rel

ativ

eN

Ox

Em

issi

on

s

Fuel leancombustion

Fuel richcombustion

Diffusion Flame

Premix Flame

FlammabilityFlammabilityLimitLimit

Region ofStoichiometricCombustion

Design burner toDesign burner tooperate in this regionoperate in this region

The Trick?Deep penetration into the

low-Btu regime whilstmaintaining flame

stability!

ULTRA LEAN PREMIXULTRA LEAN PREMIX


On the other hand, you’ll stillneed at least one monster SCR… whether you like it or not!


……II’’llll KILLKILL youyou !!Be Safe or ...

Free-standing stack lift withmonster low-temperature SCRin the background (on one of two

SMR furnaces) illustrates whywe don’t like SCRs too much…


PrePre--lift Safety Talklift Safety Talk


3 Cell Terrace WallSteam Methane Reformer

228 burners

The other SMR furnace got ultra low NOx burners!


Chevron Richmond Boiler HouseChevron Richmond Boiler HouseNote hills thatNote hills that wouldwould have beenhave been

the central duct supportsthe central duct supportsfor two monster SCRs ...for two monster SCRs ...


Poor ManPoor Man’’s SCR:s SCR:Fuel ConditioningFuel Conditioning!!

“Fuel Induced Recirculation”(FIR) or “Fuel Dilution”

PERF Fuel DilutionConstant Firing Rate

55

60

65

70

75

80

85

90

95

100

105

0 5 10 15 20 25 30 35Nitrogen in Fuel Gas, vol%

NO

x,p

pm

•Reaction rate limited!

•Reduce flame temperature,reduce NOx!

•“Cool”Fuel!

•Ain’t science wunaful?


TThehe BIGBIG IIdea:dea:

““Deep penetration into the low-Btu regime… while still maintaining flame stability!”

ItIt’’s all about making a lows all about making a low--Btu fuelBtu fuelPremixed “FIR”(Fuel Induced Recirculation) Example

One way to do it …

flue gas

fuel gas

primaryair

secondaryair

flameflame


~ 93% NOx Reduction!


DIAL-A-NOX in action !!!

#4 Boiler Sub#4 Boiler Sub--1010 ppmppm DemonstrationDemonstration

~ 98% NOx Reduction!


Recent photograph of an expert alertly seeking breakthrough soluRecent photograph of an expert alertly seeking breakthrough solutions ...tions ...

QuestionsQuestions??

© 2007 chevron and john zink company, llc

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