AFR and Petcoke - Preparation and Utilization.ppt

AFR

1. AFR/fuel preparation & utilization
Contents:
1. Performance Indicators
2. Impact AFR/petcoke
3. Example Héming (by Henri Maurel)
4. Useful tools & practices
5. Conclusion/messages
6. AFR Case Study
A.Obrist/CTS/TPT

2. 2
15.07.2024/TPT/Ot
Tech PMF AFR.ppt
Holcim Group Support 3
rd
Technical Forum for Plant Managers, 2003
Performance Indicators (AFR) 1.1
Specific fuel cost (LC/t cli)
decrease specific fuel consumption
reduce spec. fuel energy cost (LC/GJ), incl. preparation
introduce cost effective AFR
Thermal substitution rate (TSR)
Holcim : average 13.8% (range 0 -79%)
increase proportion of AF (if AF GJ price << conventional
GJ price !)
= spec. fuel cons (GJ/t cli) x average fuel energy cost (LC/GJ)
TSR = alternative fuel energy / total fuel energy (%)

3. 3
15.07.2024/TPT/Ot
Tech PMF AFR.ppt
Holcim Group Support 3
rd
Technical Forum for Plant Managers, 2003
Performance Indicators (AFR) 1.2
Thermo Economic Efficiency
theoretical fuel costs : defined at 100% conventional fuels
fuel savings= theoretical fuel costs -actual fuel costs
TEE shows economical benefit of fuel substitution by AF.
Example : If AF costs = 0 then TEE =TSR.
But : TEE alone does NOT give a final answer whether the
AF activity as a whole is profitable.
Holcim : average 19.9% (range 0 -95%)
TEE = fuel savings / theoretical fuel costs (%)

4. 4
15.07.2024/TPT/Ot
Tech PMF AFR.ppt
Holcim Group Support 3
rd
Technical Forum for Plant Managers, 2003
Performance Indicators (AFR) 1.3
% alternative raw materials (AR)
%AR refers to what would be possible as a theoretical
maximum material replacement (analog to TSR).
Naturally low due to chemical compatibility with raw mix
Holcim average 3.1 % AR (usually in the range 0 -10%).
= AR used based on raw mix (%)

5. 5
15.07.2024/TPT/Ot
Tech PMF AFR.ppt
Holcim Group Support 3
rd
Technical Forum for Plant Managers, 2003
Performance Indicators (kiln/AFR related)1.4
% O2/CO at kiln inlet
Shows combustion performance
O2 = 2 -4% for AFR (any kilns, excluding “AT” firings)
Hot meal analysis (K2O, SO3, Cl) (on SP kilns only)
SO3 indicates circulation & combustionperformance
(>2.5% -5% SO3 is critical)
Cl indicates how saturated the kiln is with chlorine (>0.8 -
2% Cl is critical)

6. 6
15.07.2024/TPT/Ot
Tech PMF AFR.ppt
Holcim Group Support 3
rd
Technical Forum for Plant Managers, 2003
Impact of AFR/petcoke on kiln operation2.1
Petcoke
Low Grade Fuel (LGF)

7. 7
15.07.2024/TPT/Ot
Tech PMF AFR.ppt
Holcim Group Support 3
rd
Technical Forum for Plant Managers, 2003
Impact of petcoke on process 2.2
Petcoke is not“AFR”, but also challenging the kiln
Adequate petcoke fineness
R 90<= 5%
R 200<= 1%
lower grindability than coal (watch HGI )
In mixtures with coal : use average fineness
Sulfur issues
Petcoke causes sulphur cycles, therefore limits required
Total SO3 input (all sources) < 1.5% SO3 on clinker
Molar A/S > 0.8
Hot meal < 5% SO3
Do Sulfur/alkali balance

8. 8
15.07.2024/TPT/Ot
Tech PMF AFR.ppt
Holcim Group Support 3
rd
Technical Forum for Plant Managers, 2003
Impact of petcoke on process 2.3
Combustion issues
Ignition/combustionproblems (low
reactive fuel). Requirements :
-Burner : Short&compact flame -> high
momentum, retract burner
-Precalciner: Ignition (hot spot)
Sufficient O2required, because of
-A) Combustion/ignition
-B) To keep sulfur volatility down
Lump solid AFRincreases S-volatility due
to local reducing conditions
Oxygen
Min 2%
Max 4%
CO
COCO
CO
CO

9. 9
15.07.2024/TPT/Ot
Tech PMF AFR.ppt
Holcim Group Support 3
rd
Technical Forum for Plant Managers, 2003
Impact of petcoke on process 2.4
All pervious hints (and many others) are included in our
“Petcoke Rules”
Available on Holspace “CoP Petcoke”

10. 10
15.07.2024/TPT/Ot
Tech PMF AFR.ppt
Holcim Group Support 3
rd
Technical Forum for Plant Managers, 2003
Low Grade Fuel 2.5
Definition Low Grade Fuel (LGF) :
At least one of the following factors is critical:
-Low CV
-High water
-High ash
-High in circulating elements
-Coarse granulometry
WATCH YOUR KILN

11. 11
15.07.2024/TPT/Ot
Tech PMF AFR.ppt
Holcim Group Support 3
rd
Technical Forum for Plant Managers, 2003
Low Grade Fuel : Impact on kiln 2.6
Impacts of LGF on clinker burning process
heat consumption
flame temperature
kiln capacity
availability
clinker quality

12. 12
15.07.2024/TPT/Ot
Tech PMF AFR.ppt
Holcim Group Support 3
rd
Technical Forum for Plant Managers, 2003
Low Grade Fuel : Impact causes 2.7
1
2
3
Poor
comb.
Ash
Water
4
5
6
Fluct.
AF feed
Cold air
introduct.
Circul.
Phenom.
6 factors for increased heat consumption due to AF
Consequence : More exhaust gas, less kiln capacity

13. 13
15.07.2024/TPT/Ot
Tech PMF AFR.ppt
Holcim Group Support 3
rd
Technical Forum for Plant Managers, 2003
Low Grade Fuel : Impact of water on kiln cap.2.8Influence of water injection on kiln capacity
2.0
1.6
0.8
0.0
0.5
1.0
1.5
2.0
2.5
Dry Grate PH Wet
Kiln type
Prod. loss in t cli/t water

14. 14
15.07.2024/TPT/Ot
Tech PMF AFR.ppt
Holcim Group Support 3
rd
Technical Forum for Plant Managers, 2003
Low Grade Fuel : Impact of water on kiln cap.2.9Influence of water injection on heat
consumption
4.6 4.6 4.6
2.15 2.15 2.15
0.0
1.0
2.0
3.0
4.0
5.0
Dry Grate PH Wet
Kiln Type
GJ/t water
Water injection
If water incl. in fuel

15. 15
15.07.2024/TPT/Ot
Tech PMF AFR.ppt
Holcim Group Support 3
rd
Technical Forum for Plant Managers, 2003
Low Grade Fuel : Imp. water on flame temp.2.10
Water influence on theoretical flame temp
2100
2150
2200
2250
2300
2350
2400
2450
2500
0 0.02 0.04 0.06 0.08 0.1 0.12
Water into flame [kg/kg cli]
Flame Temp. [C]
Dry SP 100% MF
Dry PC 40% MF
Wet
Min = 2100 C
For 2 %O2, oil/coal flame, 15% PA, standard grate cooler

16. 16
15.07.2024/TPT/Ot
Tech PMF AFR.ppt
Holcim Group Support 3
rd
Technical Forum for Plant Managers, 2003
Low Grade Fuel : Imp. of water on heat cons.2.11
What can the LGF study tell us ?
Example : 1% water injection (0.01 kg water/kg clinker)
into the main flame of a precalciner kiln
Impact on kiln capacity = …………………………...
Impact on heat cons. = …………………………...
Impact on flame temp. = …………………………...
1
2
3
4
-2 %
+ 0.046 GJ/ tcli (or + 1.5%)
-100 C (or 25% of max. potential)

17. 17
15.07.2024/TPT/Ot
Tech PMF AFR.ppt
Holcim Group Support 3
rd
Technical Forum for Plant Managers, 2003
LGF : Impact on circulation/kiln availability2.12
Kiln system
MaterialsFuels
Clinker
Chlorine Limit (SP kiln)
< 200 -300 g Cl per t cli
300
Chlorine

18. 18
15.07.2024/TPT/Ot
Tech PMF AFR.ppt
Holcim Group Support 3
rd
Technical Forum for Plant Managers, 2003
Sulfur cyclesdepend on : S input
Lump fuel
Local reducing
conditions !
Chlorine Chlorine cycle
If too much
Sulfur Sulfur cycle
S from RM
and fuels
LGF : Impact on circulation/availability2.13
Chlorine cyclesdepend on : Cl input
and local reducing conditions/insufficient O2

19. 19
15.07.2024/TPT/Ot
Tech PMF AFR.ppt
Holcim Group Support 3
rd
Technical Forum for Plant Managers, 2003
LGF : All types of impacts on kiln 2.14
AFR Properties
Heat
Cons.
Combust
ion 
Plugging 
Ballast
(water,
ash)
Coarse Circ.El.
(Cl,S)
Availa
bility 
T/d Prod 
OEE 
Inhom
Prod costs() Clinker
Qual
Impact root causes
water (see example)
ash
inhomgeneity
coarse granulometry
circulating elements
Final impact :

20. 20
15.07.2024/TPT/Ot
Tech PMF AFR.ppt
Holcim Group Support 3
rd
Technical Forum for Plant Managers, 2003
LGF : compensation of impacts 2.15
1 Assessment by process indicators
2 Enhanced process control
3 Enhanced control of circulat. elem.
4 Enhanced preheater cleaning
5 Quality control (LGF ash)
6 Improve LGF homogeneity and
dosing
7 Dust extraction
8 Bypass technology
9 Increase gas handling capacity
10 Increase critical cross sections
11 Burner adaptations
12 Cooler modifications
13 Precalciner modification
14 Mixing air on long kilns
15 Oxygen enrichment
16 Gasifier
17 Drying of LGF
Measures to compensate or alleviate negative impacts by LGF
(17 items as treated in the LGF study)

21. 21
15.07.2024/TPT/Ot
Tech PMF AFR.ppt
Holcim Group Support 3
rd
Technical Forum for Plant Managers, 2003
Practical example: Héming 3.1
Experience of Héming with petcoke and AFR
By Henri Maurel

22. 22
15.07.2024/TPT/Ot
Tech PMF AFR.ppt
Holcim Group Support 3
rd
Technical Forum for Plant Managers, 2003
Useful tools & practices 4.1
Recommended AFR installations
Combustion check
Alk/S/Cl Balance
Burner criteria
Precalciner criteria
Note : The “Technical AFR assessment”by HGRS/TPT
includes most of above single tools/elements

23. 23
15.07.2024/TPT/Ot
Tech PMF AFR.ppt
Holcim Group Support 3
rd
Technical Forum for Plant Managers, 2003
Recommended AFR installation (liquids)4.2Burner
Pressurized Air
Feed Pumps
Flow Meter
for Atomization
Discharge
Pump
Discharge
Filters
Vertical Tanks
with Mechanical Mixing

24. 24
15.07.2024/TPT/Ot
Tech PMF AFR.ppt
Holcim Group Support 3
rd
Technical Forum for Plant Managers, 2003
Recommended AFR installation (solids) 4.3Bridge Crane
Belt Scale
Belt Conveyors
Double or
Triple Flap
Gate
Rotary Feeder
Storage Hall
Feed Hopper
with Activated
Flat Bottom
Belt Conveyors Burner
Rotary Separator
Precalciner or Secondary Firing
Main Firing
Vertical walls

25. 25
15.07.2024/TPT/Ot
Tech PMF AFR.ppt
Holcim Group Support 3
rd
Technical Forum for Plant Managers, 2003
Recommended AFR installation 4.4
Equipment must be flexible(supply, market changes)
Go for proven, standardsolutions
Source of information :
CoP “AFR utilization on kiln”
contains all technical information (including detailed Euremi files)

26. 26
15.07.2024/TPT/Ot
Tech PMF AFR.ppt
Holcim Group Support 3
rd
Technical Forum for Plant Managers, 2003
Combustion check 4.5
=procedure to asses combustion situation, comprising :
Kiln burner
(PA, velocities, momentum, swirl,
burner position and orientation,
fuel injection)
Fuel preparation
(fineness, viscosity, homogeneity)
Fuel dosing
(accuracy, fluctuations)
Solid fuel pneumatic transport
(design, length, velocity, pressure
fluct. at burner)

27. 27
15.07.2024/TPT/Ot
Tech PMF AFR.ppt
Holcim Group Support 3
rd
Technical Forum for Plant Managers, 2003
Combustion check (contd.) 4.6
Kiln feed
(chemistry, variations, dosing
accuracy,fineness)
Rotary kiln
(refractory cons., temp. profile,
fixed coating)
Cooler
(hood pressure, smooth
operation, SA temp., TA temp)
Kiln inlet
(O2, CO, NO, temp.)
Calciner
(O2/CO, temp.versus
calcination, retention time, hot
spot)
Circulating elements
(hot meal, SO3, volatility, A/S,
Cl input, encrustations)
Clinker quality
(free lime)

28. 28
15.07.2024/TPT/Ot
Tech PMF AFR.ppt
Holcim Group Support 3
rd
Technical Forum for Plant Managers, 2003
Combustion check (contd.) 4.7
Benefits :
Max. AFR
Max. kiln availability
Max. production
AFR

29. 29
15.07.2024/TPT/Ot
Tech PMF AFR.ppt
Holcim Group Support 3
rd
Technical Forum for Plant Managers, 2003
Alkali/sulfur/chlorine balance 4.8
=procedure to assess Alk/SO3/Cl situation on kiln :
Materials & hot meal sampling
Calculations (Balances for
Alkalis, SO3 and Chlorine)

30. 30
15.07.2024/TPT/Ot
Tech PMF AFR.ppt
Holcim Group Support 3
rd
Technical Forum for Plant Managers, 2003
Alkali/sulfur/chlorine balance 4.9
A standard
calculation tool
is available from
TPT

31. 31
15.07.2024/TPT/Ot
Tech PMF AFR.ppt
Holcim Group Support 3
rd
Technical Forum for Plant Managers, 20030 1.0 2.0 3.0 4.0 5.0
1.0
2.0
0.8
1.4
2.5 3.75
% Cl
% SO3
Zone of increasing encrustation problems
No encrustations
Frequent blockages
Concl.: increased encrustation problems
Main Results
1. "Relevant" Alk / SO31.09 HGRS crit.: 0.8 -1.2 Concl.: Alk/SO3 ratio balanced
2. Sulfur Input: 1.22%SO3HGRS crit.: < 1.5 % SO3 Concl.: Sulfur input o.k.
3. "Relevant" Cl-Input :216g/t cliHGRS crit.: < 200-300 g/t cliConcl.: Cl input elevated
4. Sulfur Volatility:0.35 HGRS crit.: < 0.7 Concl.: Volatility o.k.
5. Hot Meal: HGRS crit.: see graph
Alkali/sulfur/chlorine balance 4.10
Typical output as given in spreadsheet

32. 32
15.07.2024/TPT/Ot
Tech PMF AFR.ppt
Holcim Group Support 3
rd
Technical Forum for Plant Managers, 2003
Alkali/sulfur/chlorine balance 4.11
Benefits :
Identify potential for AFR containing chlorine
Know sulfur/alkali situation (e.g. to evaluate
potential for petcoke use)
Show combustion problems (via SO3 volatility)
Reveal possible inconsistencies (inaccurate
data, balance errors)

33. 33
15.07.2024/TPT/Ot
Tech PMF AFR.ppt
Holcim Group Support 3
rd
Technical Forum for Plant Managers, 2003
Burner criteria 4.12
Key figures for burner design and operation:
Primary air rate: PA = 10 -12%

% based on Amin, excl. transport air
Specific axial momentum: Gax = 7-10 N/MW

including fuel and transport air
Requires min.200 mbarprimary air fan (at 12%PA)
Injection velocity coal: v = 25 -30 m/s
AFR center channel
10 for
petcoke

34. 34
15.07.2024/TPT/Ot
Tech PMF AFR.ppt
Holcim Group Support 3
rd
Technical Forum for Plant Managers, 2003
Burner criteria 4.13
A standard assessment (spreadsheet sheet) for
running burners is available from TPT
Requires data collection, in particular airflow
measurements

35. 35
15.07.2024/TPT/Ot
Tech PMF AFR.ppt
Holcim Group Support 3
rd
Technical Forum for Plant Managers, 2003
Precalciner criteria 4.14
Design
4.5 sec, turbulence, etc (see precalciner presentation)
Suitability for lump fuel (E.g. ILC not usable)
Max. potential for lump AFR <50% of PC fuel
 

36. 36
15.07.2024/TPT/Ot
Tech PMF AFR.ppt
Holcim Group Support 3
rd
Technical Forum for Plant Managers, 2003
Precalciner criteria 4.15
Operation :see “combustion check”, PC part
Hot meal
O2/CO/ temp
ignition
(petcoke)

37. 37
15.07.2024/TPT/Ot
Tech PMF AFR.ppt
Holcim Group Support 3
rd
Technical Forum for Plant Managers, 2003
Conclusions/messages 5.1
Successful AFR and petcoke application are strongly
connected to kiln process.
Use standard procedures and tools to assess and
enhance the kiln process. Example : Combustion check.
Broad view when selecting AFR feeding equipment (info
sources and future flexibility).