Nat i o n al Cement Nat Cemen t Com Comp p any. P.S .S.C .C Dubai
LOESCHE SYMPOSIUM: Cost savin saving g as as result of o f conversion co nversion from fro m HF HFO to pulv pu lve eriz ri zed coal c oal
Presented by: Eng. Radwan Mouakat Düsseldorf, 25.09.2014
Nati atio o n al Cem en t Comp Com p an y P.S P.S.C Dubai
Nati atio o n al Cem en t Comp Com p an y P.S P.S.C Dubai
Dubai City in year 1976
Dubai City Today Today
Today in the heart of Dubai City National Cement Co. P.S.C Dubai Works
National Cement Co. Works in brief
Commissioned wet process in 1978 Converted to dry process in 1987
National Cement Co. Works in brief
Current capacity 4000 tpd Original heat source was HFO Conversion to coal firing since 2012
Fuel price from 2004 to 2012 (USD/TON)
Consumption of fuel per ton of clinker
Challenges
Rising price of heavy oil and gas Difficult market conditions Strong impact on production costs Cost reduction challenge Decision – cost saving conversion from HFO to pulverized coal
Selection A Strategic Decision Selection of the Coal grinding Company
? For cost saving as result of conversion from HFO to pulverized coal
Concepts and Considerations
Coal Grinding Plant Concepts and Considerations
Processing Design latest regulations regarding constructions Lay-out and operation of coal handling facilities Safety regulations Modern fuel efficient kiln types Drying of coal Grindability of coal meal fineness Mill for grinding of coal
Conditions Arrangement of coal grinding plant: There are various factors have to be taken into considerations when arranging a coal grinding plant:
Quality of coal
Supply of hot air for drying
Type and numbers of Kiln
Investment cost
Maintenance cost
Reliability
Conditions Based on evaluation of these matters, decision can be made regarding the following:
Direct, semi-direct or indirect firing
Inert or non-inert operation
Ball mill or Vertical Roller Mill
Bag Filter or EP for possible dedusting
Instrumentation & automation of the coal grindi ng plant Filters and coal mills silos
Conditions Coal stacking and storing Other Safety precautions, the following tips be considered:
should
Feeding arrangement, to ensure steady feed of raw coal to the mill.
Horizontal surfaces, where coal may settle. Ducts should have proper inclinations (min. 60° upwards and 45°downwards.)
Gas velocity in ducts (min. 20m/sec.)
Conditions
Mill separator, duct between separator and filter, filter and coal meal silos should be fitted with pressure relief valve, which must open to the outside air, not inside the buildings.
The installations mechanical and electrical equipment to be well maintained for future maintenance.
Buildings and equipment should be kept clean
Common sense: To consider the operation, designed plant which is in accordance with current industrial standards, to reduce risks.
Benefits
Lower energy consumption Higher drying capacity Output capacity can easily be varied within a wide range corresponding to the fuel consumption of the Kilns Fast feed output response Accept larger feed sizes up to 80mm Lower noise level Requires less building volume
Challenges
Larger quantity of air to be dedusted Less suitable for abrasive coal. Wear parts are expensive and replacement causes downtime. Sensitive to variations in feed rate and feed quantity
Result of selection and evaluation
A Strategic Decision Selection of the Coal grinding Company
LOESCHE GmbH For cost saving as result of conversion from HFO to pulverized coal
Beginning in 2012
Why LOESCHE Vertical Roller Mill One Compact System, comprising grinding, drying and classification Stable running conditions, hence easy to operate Easy to m aintain and reduced specific w ear rates
Highly energy efficient
Very flexible grinding system
LOESCHE Coal Mill in the City of Dubai Mill Type: LM 28.2 D
Feed Material: Hard Coal
Throughput (design): 40 tph
Product Fineness: 12%R90μm
Drive Capacity: 600 kW
Commissioned:2012
National Cement Co. Coal Mill Building
Share Vertical Mills for Coal Grinding
Numbers represent the year 2007/08
LOESCHE Mill Flow-sheet
Pulverized Coal Dosing Dosing Unit Type Material Capacity Application Commissioning Bulk Density Distance of Feed Line
DRW 4.12/2 Rotor weigh feeder
DRW 4.12/2 Rotor weigh feeder
Coal Dust
Coal Dust
16,2 t/h
17,8 t/h
Calciner
Main Burner
02.05.2012
02.05.2012
0,35 – 0,6 t/m3
0,35 – 0,6 t/m3
70m
123m
Raw coal specifications S.NO
SPECIFICATIONS
UNIT
SPECIFICATION
YEAR 2013
YEAR 2014
01
TOTAL MOISTURE
%
MAX - 8.50
7.58
8.93
02
INHERENT MOISTURE
%
MAX - 3.50
1.60
1.86
K cal /k g
MIN - 6400
6438.11
6549.72
03
GROSS CA LORIFIC VA LUE
04
SULPHUR
%
MAX - 1.00
0.60
0.61
05
ASH CONTENT
%
MAX - 16.00
15.91
15.01
06
VOLATILE MATTER
%
MAX - 26.00
28.02
29.00
Coal price for the year 2012
Market prices for coal 2013 & 2014
Coal consumption COAL CONSUMPTI ON PER TON OF CLI NKER FROM J UNE - DEC. 2012
0.13
0.125 M. TON 0.12
0.115 JA N.
FEB.
MA RC
A PRIL
MA Y
JUNE 0.1241
M. TON
JULY 0.1249
A UG.
SEPT.
OCT.
NOV .
DEC.
0.1248
0.1211
0.1244
0.1243
0.1277
CONSUM PTION OF COAL PER TON OF CLINKER FOR THE YEAR 2013
0.135
0.13
0.125
M.TON
0.12
0.115 JA N. M.TON 0.1263
FEB.
MA RC
A PRIL
0.1296
0.1281
0.1290
MA Y
JUNE
JULY
A UG.
SEPT.
OCT.
NOV .
DEC.
0.1312
0.1326
0.1265
0.1266
0.1225
0.1237
0.1225
0.1229
CONSUMPTION OF COAL P ER TON OF CLINKER FROM J AN. - J ULY 20 14
0.135
0.13 M.TON 0.125
0.12 JA N. M.TON 0.1255
FEB.
MA RC
A PRIL
MA Y
JUNE
JULY
0.1244
0.1324
0.1283
0.1250
0.1252
0.1252
A UG.
SEPT.
OCT.
NOV .
DEC.
Alternative fuels
Alternative fuels Such fuels as wood chips , sludge, used car tyres or even house hold garbage ….. etc. The application of these fuels are becoming more and more interesting. There is no doubt that in the future the cement kiln will be used more and more as incineration plant for disposal of hazardous waste. In this regard, we are nowadays using carbon dust which is available in Aluminium industry with reasonable Price , also full unit of used car tyres.
Carbon Dust Specifications S.NO
SPECIFICATION
UNIT
YEAR-2013 CARBON DUST GRADE-I
YEAR-2014
CARBON DUST GRADEII
CARBON DUST GRADE-I
CARBON DUST GRADEII
Kcal / Kg
7562.26
3586.11
7534.07
4095.51
SULPHUR
%
1.69
1.07
1.48
1.30
ASH CONTENT
%
3.01
45.68
2.85
38.23
01
GROSS CALORIFIC VALUE
02
03
Alternative fuels
Alternative fuels PERCENTA GE OF COAL AND ALTERNATE FUEL FROM JUNE 2012 TO JUL Y 2014 100.00 95.00 90.00 85.00 80.00 75.00 70.00 65.00 60.00 55.00 50.00 45.00 40.00 35.00 30.00 25.00 20.00 15.00 10.00 5.00 -
94.90
91.45
92.40
COAL
%
5.10 2012
ALTERNATE FUEL
8.55 2013
7.60 2014
Energy cost ENERGY COST IN USD/TON OF CLINKER 60.00 50.00 40.00 30.00
Series1
20.00 10.00 Series1
FUEL OIL
C OA L
COA L + CA R B ON D UST
COA L + TYR ES
COAL + CARB ON DUST + TYRE
51.70
13.67
13.3 0
13.16
12.79
Energy cost ENERGY COST IN USD/TON OF CLINKER 15.00 14.00 13.00 Series1 12.00 11.00 10.00 COAL
Series1
13.67
COAL + CARBON DUST 13.30
COAL + TYRES
13.16
COAL + CARBON DUST + TYRE 12.79
