The document discusses achieving 100% alternative fuel rates (AFR) and using high sulfur petcoke fuels to produce cement clinker with NOx emissions below 500 mg/Nm3 without selective non-catalytic reduction (SNCR). It outlines fundamental rules and shares case studies where plants achieved these goals. Micro-mixing of oxygen, volatiles, and precise temperature control in the kiln and calciner were critical to ensure proper combustion. Computational fluid dynamics (CFD) modeling helped identify issues like stratification and recommend solutions like increased burner momentum. Maintaining the right operating parameters and combustion fundamentals can allow plants to use more alternative fuels and reduce emissions.

2. 100% AFR and high S petcoke with 500
mg/Nm3 NOx without SNCR
by The CINAR TEAM
Presented by Tom Lowes
at Cemtech Conference Marrakech 12th Feb 2013
Summary
Experience based fundamental practical rules to achieve 100% AFR with a
high S petcoke are outlined; together Plant Cases where it has been done,
with the use of Process Knowledge and experience aided as needed by MI-
CFD, together with the basics of low CAPEX hot reburn retrofits to drop the
contribution of kiln NOx and calciner fuels N to NOx emissions with Plants
cases where it has been done to meet < 500 mg/Nm3 without SNCR

3. 100% AFR and high S petcoke with 500
mg/Nm3 NOx without SNCR
 Not easy to achieve
 Outside experience of most process people
 Need to Understand ( 3W’s):
 Why there is a the Problem?
 Where is it occurring ?
 WHTBD?
 Have the ability to go in side the kiln and calciner and see WHERE the
problem is happening and WHY.
 Then Identify WHTBD via Process Knowledge, MI-CFD simulations
and interpretation of a range of potential solutions
 This paper will give the rules and show how it can be done for little or no
additional CAPEX on 5 of the 130 + Plants Projects that have been done by
the CINAR TEAM as a means of guiding Plants to their own specific
solutions

4. 100% AFR and high S petcoke with 500
mg/Nm3 NOx without SNCR
 Needs
 Avoid excessive build up
 No Significant loss of output
 No increased VOC emission
 Hit NOx targets
 Rules for AFR and Petcoke
 VF < 2
 HM Carbon < 0.1%
 HM Cl < 1%
 Eliminate Kiln and Calciner Stratification
 Need MOT not 3T’s
Combustion in a
 M – Micro mixing
very narrow
 O – Oxygen region
 T – Temperature
 Additional for 500 mg/Nm3
 MOT ++
 i.e. Volatiles and sub stoichiometric RT

5. Case I
An AT Calciner 100% < 5% S petcoke
plus 15% Tyre Shreds
Stopping to dig put the Kiln and Riser
Every 3 weeks

6. CO at @ 5000 ppm
indicative of
Clinker SO3 vs Preheater O2 Volatiles of tdf not
micro mixing with O2
before quenching.
1.4
NOx < 500 mg/Nm3
at 10% O2
1.2 Calculated Clinker SO3 lelvel
So excess HOLDING up in riser
1
and needing stops for digging
Clinker % SO3
0.8
out
Average
WHY?
0.6 VF SO3 13.5
HMSO3 6.0
0.4 CO ppm 4856.3
O2 % 4.9
0.2 NOx ppm 248.0
tdf TSR 15
0
2 2.5 3 3.5 4 4.5 5 5.5 6
%O2
O2 too low need @ 3.5% for petcoke plus tdf a top of riser - @ 6 at
PH and burner mmtm too low at 4 N/MW need 9 N/MW

7. MI - CFD Application to Kiln
O2
stratification
due to too
low a
momentum

8. MI - CFD Application to Kiln
Petcoke Combustion- 5 N/MW
Particle Size: 10
µm
Particle Size: 22
µm
Particle Size: 35 µm
Particle Size: 45
µm
Particle Size: 90 µm
Compare the +45 &
90u burnout on this
slide compared to
next one

9. MI - CFD Application to Kiln - Increased mmtm
Petcoke Combustion – 10 N/MW
Particle Size: 10
µm
Particle Size: 22
µm
Particle Size: 35 µm
Particle Size: 45 µm
Particle Size: 90 µm
Hence the
appropriate mmtm
can overcome +90u
issues

10. Average PH O2
Plant feedback @ 6%
SO3 vs O2
No stoppage for
6
digging out and build
5
up
4
SO3 So can go for 7% S
3
BUT disaster struck
2
R2 = 0,8157
Plant personnel
1
0
changed and lessons
5 5,5 6 6,5 7 7,5 learnt forgotten and
O2 strive for low O2 and
SO3 VS O2 Polynomial (SO3 VS O2)
thinking more output
initial present
Burner mmtm (N/MW) 4,30 7,10
Hot meal SO3 (average ) 6,02 2,91
SO3 sd 2,47 0,89
clinker SO3 (average) 0,53 0,95
SO3 sd 0,26 0,15
VF ( average) 13,48 3,21
Combustion Nox (average) 226 467
CO preheater 0,51 0,14

11. High S Petcoke Trial
12
Target 1.9%
10
SO3 in clinker to
avoid build up
Number of samples
8
6
4
2
0
0.78 0.98 1.18 1.38 1.58 1.78 1.98 2.18
% SO3 in Clinker
Lessons Learnt were forgotten too low PH O2 used on the misconception
more output would be achieved – ran 10 days and then had to shut down to
dig out the build up

12. Case II
A Gas Fired Calciner kiln which is
seeking to do 90% overall TSR from SRF
and Biosolids BUT cannot run for more
than 4 days without stopping for KILN
BALLS or BUILD UP

13. Kiln Balls and Build Up
 Liquid OK at 26%
 A/F and SR not in Kiln Balls Region
 Kiln Burner mmtm low at 5 N/MW compared to TML OFT of 10
N/MW
 MR in both hot meal and clinker << 1
SO3 Na2O eq MR Cl
Clk 0.14 0.56 0.19 0.00
HM 0.35 0.77 0.35 0.98
VF SO3 2.50 VF K2O 5.96
 BUT MI-CFD on the calciner identified probable cause and solution
 It was down to the poor combustion of HiCal (50 ash and 50% C 2%
vols) produced from the SPL of the Aluminium Industry, not
combusting well in the KRD and causing balls via low temperature
melts under reducing conditions (F present with the HiCal)
 Recommended moving it to the TAD

14. Oxygen Profile For HiCal Cases
O2 = 3.4 % O2 = 3.0 % O2 = 3.0 % O2 = 3.0 % O2 = 3.0 %
O2 % O2 %
HiCal Particles are
in Black Colour
Big stratification
of O2 and fuel
Case 11
Case 9 In addition to 16% of
Case 8 32% Stage3 Meal in Case 10 Stage 3, 50% From Stage
16% Stage3 in TA, TA, HiCal velocity Reduced feed (150 13 was also moved to
HiCal velocity 24m/s, 30 deg angle to 100 tph), HiCal Lower Stage 3 in TAD,
Base Case 24m/s (upward) velocity 45m/s HiCal velocity 24m/s

15. Analysis of Simulation Results For HiCal
Base Case 8 Case 9 Case 10 Case 11
16% Stage3
Case in TA, HiCal
32% Stage3 Reduced In addition to 16% of
Meal in TA, feed (150 to Stage 3, 50% From Stage
velocity HiCal velocity 13 was also moved to
24m/s 100 tph), HiCal
24m/s, 30 deg velocity 45m/s Lower Stage 3 in TAD,
angle (upward) HiCal velocity 24m/s
Exit Oxygen % 3.4 3.0 3.0 3.0 3.0
Exit oC 847 840 840 849 865
Temperature
HiCal % 41 99.6 99.3 99.9 99.6
Burnout
Implemented as case 9 to minimise hot spot potential at the same time as
the burner mmtm was increased to 10 N/MW and the Balls and excessive
build disappeared
Simulations showed how 90% TSR could be achieved via the burner and
calciner.
The biggest issue was stratification in the calciner, which caused poor
calcination and burnout in the KRD side of the calciner and a JAMS was
designed and invoked

16. Oxygen Profile
O2 = 3.8 % O2 = 3.4 % O2 = 3.4% O2 = 3.2 % O2 = 3.4 % O2 = 3.2 % O2 = 3.3 %
O2 %
Flow
Stratification
reduces with
JAMS (3& 5%)
Case 16 Case 17 Case 18
Case 14 Case 15
Case 12 Case 13 4.5 & 1.5 tph 50-50% SRF 4.5 & 1.5 tph 50-50% SRF 4.5 & 1.5 tph
4.5 & 1.5 tph SRF 50-50% SRF SRF 3 %JAMS 3%JAMS 5 %JAMS 5%JAMS 5 %JAMS 1jet

17. SRF Particle Trajectories
BO = 94 % BO = 98 % BO = 97 % BO = 99 % BO = 97 % BO = 99 % BO = 98 %
BO %
One JET Jams better than 2 or 4,
50/50 KRD and TA split best
Case 16 Case 17 Case 18
Case 14 Case 15
Case 12 Case 13 4.5 & 1.5 tph 50-50% SRF 4.5 & 1.5 tph 50-50% SRF 4.5 & 1.5 tph
4.5 & 1.5 tph SRF 50-50% SRF SRF 3 %JAMS 3%JAMS 5 %JAMS 5%JAMS 5 %JAMS 1jet

18. Case III
A coal fired calciner at 70% TSR
wishes to go to 100% Calciner TSR
with only 2 secs RT
Current Issues CO and @ 75C
increase in PH outlet temperature

19. 100 % Calciner TSR
 Impossible many would say.
 Calciner far too small at 2 secs RT need at least 6 secs.
 However look at the car development
 1 litre engines now produce the power or 10 litres 50 years ago
 How has the development been done
 Via well customised CFD programmes for Engine combustion for both
diesel and gasoline
 A customised CFD programme – MI-CFD – can do the same for a small
calciner
SO Tune the Engine give it an MOT
 What is the Engine
 Coal and AFR injection, TA , meal and das riser
 The micro mixing or O2 and fuels need to be optimised with respect
combustion and heat transfer to the meal
 The is little point in adding volume at the cold end if
the engine is poorly tuned

20. MI-CFD - Calciner
 Schematic of where the focus needs to be to improve calciner performance
and /or drop NOx. Find the hidden enemy – STRATIFICATION and
ELIMINATE OR EXPLOIT IT!!!!
Adding Calciner Volume is often
proposed to improve calciner
performance, however it is at the
COLD end of the calciner and does
not cost effectively improve
Main body of calciner
performance compared to engine
where more
tuning
combustion and
DAVID beat Goliath with skill and
calcination takes
knowledge, NOT SIZE
place, efficacy
depends on the
Engine Tuning Engine – meal, fuels, burners, kiln
gases and TA
Optimisation and Tuning of this area
Hot Reburn region via MI-CFD makes a calciner perform
below the TA allowing much better in terms of output,
optimised reburn and kcals/kg/AFR and emissions
NHi conversion to N2
and not back to NO

21. Burnout Time - WHITE ANT - for a 250u Particle as a function of O2 and
Temperature K
14 N.B simply adding RT at
the cold end of the
12
calciner without
modifying bottom end
10
does little for burnout
Burnout Time secs
8
6
4
2
0
0 1 2 3 4 5 6
% O2
Significance of 1200 1300 1400 3 secs RT 1100
Temperature and O2
vs RT

22. SLC 100% 7 % S petcoke
Oxygen and petcoke Temperature and Meal
Initially 3 secs
RT, pyro top
added to give 5
secs to run at
100% high S
petcoke
Exit
Exit Temp.
O2 905oC Hot spots where
1.2% Petcoke meal and petcoke
particles’ do not mixed and
trajectories are cause of the Meal
high NOx particles’
Trajectories

23. Replacing
single burner SLC 100% 7 % S petcoke
with 2 burner
down at 60
deg and 75
Petcoke burnout = 95%
m/s
Calcination =90%
Gets 98% BO
Little done below this
and 95% Cal.
level.
at pyro top Calc. %
Generally extending the
BO% calciner volume to
improve performance is
not very cost effective
compared to improving the
early mixing and hence
combustion between TA,
meal and fuel via MI-CFD
without increasing the size
of the calciner.
Petcoke
Plus 93% calcination at
burnout 905 C is not a good
98% calciner.
Meal particles
calcination – 93%

24. 100% Calciner TSR
 CINAR did initially work for this calciner plant to overcome problems of
poor coal burnout and calcination and very bad build up
 This is shown on the next 3 slides, how a low cost modification to the
TA inlets enabled them to overcome the problem and get to @ 70%
calciner TSR with an Engineered Fuel (EF), however the Plant Manager
wanted to get to 100%
 .As the calciner has only 2 secs RT this proved to be difficult for them,
due to CO, less of output and elevated PH outlet temperature and we
were asked again to help
 From simulations of the current operations it was identified that:-
 The EF was being quenched too fast to get a good burnout and its path was
going to the lower O2 regions in the calciner and only burning out to 73%
 Simulations of the EF and coal injection points, plus meal splits and a
venturi a series of recommendations were made to get potential to 100%
TSR

25. Oxygen Mass Fraction [-]
Original
Modified
Original Modified
Burnout % 70 93
Calcination % 70 90

26. The EF releases
Oxygen Profiles / Fuel Trajectories if volatiles fast,
but is then
quenched too
fast by the meal
and then travels
in a low O2
Case Base Case region which
Coal Burnout (%) 99 makes the
EF Burnout % 73 burnout poor
Total Burnout % 81
Calcination 95 Near the walls of
there are oxygen
Coal / O2 EF / O2 rich areas where
available oxygen
would enhance
the burnout
O2 [m/m]

27. EF particles in O2-Meal particles in Temperature
O2
T (C) Currently
being
implemented
Adding a
lower meal
70% inlet
Profuel Axial Sleeve of 100%
EF injectors Profuel

28. Best Case Implementation and Feedback
 Based on the MI-CFD simulations, modification were proposed to
the EF burners, meal split and the installation of the customized
venturi design not only to stop the EF drop out but to improve the
mixing of the O2 with the EF. The predicted change is below
Case 70/30 100%
Coal Burnout (%) 99 -
Eng. Fuel Burnout % 73 84
Calcination % 95 97
Exit O2 % 4.2 3.9
Calciner Exit Temperature (C) 865 866
 So the burners have been modified and part of the Venturi has been
installed, with the change below from the Plant info, which shows
already 85% TSR , more output, less CO and better kcals/kg, with a
potential savings of > €1mpa and a pay back on the MI-CFD of @
2weeks
Year Before part Mod After part Mod Percentage
 Clinker tpd 2788 2838 2%
EF firing rate tph 6.8 8.2 21%
PH Exit Temperature 431 416 4%
ID fan O2 ppm 7.5 6.6 14%
ID Fan CO ppm 1110 930 19%
Fuel Comsumption kcals/kg 936 896 5%

29. Case IV
A Plant is 100% petcoke, but cannot
get above 2.5% S, without running into
build up issues, even though it has a
clinker MR of 0.6 and wishes to go for
100% high S petcoke plus AFR and
meet 600 mg/Nm3
Current issues apart from build up is a
hot spot
Calciner RT @ 2.5 sec

30. Meal and Fuel Particles Tracking – current operation
Meal Particles
Av. Burnout: 83% Av. Calc: 75% Fuel Particles & & Temperature
O2
T [oC]
Burnout /
Calcination O2 [kg/kg]
Poor burnout/ calcination plus a hot spot
Engine need TUNING

31. Splitting Meal, Modifying Petcoke Burner and Injecting Alternative Fuels
T [oC]
Pink: SRF
O2 [kg/kg]
Black:
Petcoke
Purple:
BF 1
Hotspots at
cone and 60% Meal
cylinder mass
injected Yellow:
body
below TA BF 2
reduced by
better meal
calcination. AF´s falling to kiln hearth
should be avoided by
Av. Calcination: 88% insert installation in order
High temperatures to prevent build up
Petcoke Av. Burnout: 98%
caused by AF´s , formation .
dropping through SRF Av. Burnout: 95%
need a customised Bio Fuel 1 Av. Burnout: 86%
venturi Biofuel 2 Av. Burnout:90%

32. Case V
A newly built coal fired calciner running
at 800 to 1000 mg/Nm3 needs to hit < 500
mg/Nm3 without SNCR
Needed CINAR Hot Reburn Technology

33. Essentials of Hot Reburn Retrofit
 1300C for 0.15 sec followed by at least 0.5 secs at @ 1000C – meal
quench – at the SR for volatiles < 0.9 to allow for HCN and NHi to
go to N2 and not convert to NO
 Care has to be taken to ensure that the TA does not mix in before
this via MI-CFD
 For the hot section SIC and Cardox and blasters should be planned
to minimise the impact of build up
 The burners need to be optimised with the O2 and NOx profile from
the kiln.
 Best Configuration developed via MI – CFD – up to 4 plus variable
PA/Velocity probably optimum for the lowest NOx
 However 2 at 30 deg down and @ 60 m/s is giving @ 500 mg/Nm3 at
10% O2
 This can be applied to all ILC and also MINOX and RSP’s however
up to 50% of the fuel for the latter 2 has to be taken out and put in
the riser to reburn the kiln NOx and stage the calciner fuel NOx
 SLC’s are much trickier , thermal NOx needs to be stopped and the
fuel N staged OR the TA split

34. NOx to 500 mg/Nm3
 The simulation below shows a prediction for normal
operation that show the calciner NO generation to give a
calciner exit NOx of 850 ppm , with a reburn temperature max
< 1200oC;
NOx T [oC]
[ppm]
Coal injection
/Meal injection
@ 12 m (@ 0.5
secs) to TA
mixing
 The reason it is not meeting 500 mg/Nm3 is that the reburn
temperature is too low for the 0.5 secs RT between the coal
injection and the TA mixing into the reburn zone
 Dropping the burners by 3.5 m and optimizing them gets
1300C for 0.15 sec before meal and plus 0.5 before TA mixing

35. Coal Volatiles and NOx predictions
45 m/s 105 m/s 45 m/s
30 deg 30 deg 60 deg
Plenty of
volatiles
for reburn
at 1300oC
Vel Pred. Stack NOx Actual NOx
m/s mg/Nm3 mg/Nm3 NOx
45 450 No Test Predictions
& Tests
105 518 350
45 540 550

36. Normal operation, Hot Reburn plus a 1200C > 1 sec RT calciner
1000.0
S 900.0
t
a
800.0
y = 0.3172x + 569.05
c
k
700.0
m
g Burners Down rebutn
/ 600.0
N
73%, staging - 50%
m
30 deg at But not fuly optimised
500.0
3 105 m/s
a 400.0
t y = 0.1143x + 294.16
1 300.0
0
%
200.0 > 1 sec
O
reburn
2 100.0 y = 0.0365x + 192.32 reburn 92%
staging 70%
0.0
0.0 200.0 400.0 600.0 800.0 1000.0 1200.0 1400.0 1600.0 1800.0 2000.0
KBE NO ppm

37. NOx Summary
 Hot reburn can and is being applied to ILC, RSP’s and AT calciners,
via MI-CFD to reach < 500 mg/Nm3 without SNCR
 Petcoke can be trickier due to its low volatiles
 Which results in a higher NOx for the same fuel N
 This is due to the char N contributing potentially @ 50% of the NOx
emission, due to the fact that while the NO from the char N is
normally reduced to < 100 ppm by the NOx form the volatiles in the
boundary layer, the low SSA of low volatile petcoke does not allow
this to happen
 However the hot reburn 0.15 sec section drives off more volatiles
than the proximate analysis test gives and is working well for ILC
 SLC’s of the long vertical type are giving an problem, the key need
is a not reburn after most of the volatile and char NOx has been
formed
 This is under development and Plant tests currently being carried out
12000 kms East of here

38. Generic Calciner for < 500 mg/Nm3 and
90% TSR
AFR and Coal
burners design
and location
customised as a 2.5 secs RT above TA, for
function of calcination and burnout
specification Enhanced mixing
and combustion
region – hot spot –
Opposed TA controlled by rest
inlets or of meal
horseshoe to
enhance mixing Further reburn and stating
and avoid section to allow HCN ->
stratifications N2with up to 50% meal
quench, at least 0.5 secs
Cinar customised HOT
Non coating refractory(SiC)
REBURN – 0.15 secs at 1300C
plus blasters
SR volatile < 0.9
Customised Venturi for AFR

39. 100% AFR and high S petcoke with 500
mg/Nm3 NOx without SNCR
 Difficult but can be done, SO REMEMBER
 Do not throw CAPEX or SNCR at a problem
 All that is needed to succeed is to do:
 VF < 2
 HM Carbon < 0.1%
 HM Cl < 1%
 Eliminate Kiln and Calciner Stratification via MOT
 M – Micro mixing
 O – Oxygen
 T – Temperature
 Additionally for 500 mg/Nm3
 MOT ++
 i.e. Volatiles and sub stoichiometric RT
 Workout HOW to do it for Low/Zero Capex from
fundamental process knowledge and experience
aided by MI-CFD simulation and interpretation and
IMPLIMENT IT

40. Cinar’s Clients- Producers and Manufacturers
CINAR delivers solutions to AFR, Process and Emission
Issues in 3 months from Kick Off.
Over 130 projects for cement and lime.
Have Corporate Contracts for all aspects of Process, AFR,
Output and Emissions
CHERAT
CEMENT

41. Cinar Tech - Associates
Alterros and Collaborative
Cementis Suppliers
• Customised AFR
design/installation •BMH AFR Pre and Co
•AFR Projects processing
•Strategy •Pillard Kiln and
• Business planning Cinar Ltd Calciner Burner
• AFR Market analysis • Plant performance optimisation
• Permitting/lobby analysis via Mi-CFD
• Burner/Combustion
system design
•Higher TSR
•Increased Output TML - CPEC
•NOx /CO reduction Plant/Process/Burner &
PM-Tech •Low –CapEx Solutions Cyclone Assessment
•MLRA data analysis
•More O2 for AFR •Workshops/training
•Cyclone technologies •AFR specification
•Preheater/calciner We aim to help the •Impact on Output
upgrade Customer with the •SO3 cycle drivers
•By passes •Quality improvement
complete Project
as needed via
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