National Cement Company. P.S.C Dubai

LOESCHE SYMPOSIUM:

Cost saving as result of conversion from HFO to pulverized coal

Presented by: Eng. Radwan MouakatDüsseldorf, 25.09.2014

National Cement Company P.S.CDubai

Dubai City in year 1976

Dubai City Today

National Cement Co. P.S.C Dubai Works

Today in the heart of Dubai City

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

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

Challenges

For cost saving as result of conversion from HFO to pulverized coal

Selection of the Coal grinding CompanyA Strategic Decision

?

Selection

Coal Grinding Plant Concepts and

Considerations

Concepts and Considerations

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

Design latest regulations regarding constructions

Processing

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 grinding plant

Filters and coal mills silos

Conditions

Coal stacking and storing

Other Safety precautions, the following tips should be considered:

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.

Conditions

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

Benefits

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

Challenges

A Strategic Decision

Selection of the Coal grinding Company

LOESCHE GmbH

For cost saving as result of conversion from HFO to pulverized coal

Result of selection and evaluation

Beginning in 2012

One Compact System, comprising grinding, drying and classification

Stable running conditions, hence easy to operate

Easy to maintain and reduced specific wear rates

Highly energy efficient

Very flexible grinding system

Why LOESCHE Vertical Roller Mill

Mill Type: LM 28.2 D

Feed Material: Hard Coal

Throughput (design): 40 tph

Product Fineness: 12%R90μm

Drive Capacity: 600 kW

Commissioned:2012

LOESCHE Coal Mill in the City of Dubai

National Cement Co. Coal Mill Building

Numbers represent the year 2007/08

Share Vertical Mills for Coal Grinding

LOESCHE Mill Flow-sheet

Dosing Unit DRW 4.12/2 DRW 4.12/2

Type Rotor weigh feeder Rotor weigh feeder

Material Coal Dust Coal Dust

Capacity 16,2 t/h 17,8 t/h

Application Calciner Main Burner

Commissioning 02.05.2012 02.05.2012

Bulk Density 0,35 – 0,6 t/m3 0,35 – 0,6 t/m3

Distance of Feed Line

70m 123m

Pulverized Coal Dosing

S.NO SPECIFICATIONS UNIT SPECIFICATION YEAR2013

YEAR2014

01 TOTAL MOISTURE % MAX - 8.50 7.58 8.93

02 INHERENT MOISTURE % MAX - 3.50 1.60 1.86

03 GROSS CALORIFIC VALUE Kcal/kg

MIN - 6400 6438.11 6549.72

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

Raw coal specifications

Coal price for the year 2012

Market prices for coal 2013 & 2014

COAL CONSUMPTION PER TON OF CLINKER FROM JUNE - DEC. 2012

0.115

0.12

0.125

0.13

M. TON

M. TON 0.1241 0.1249 0.1248 0.1211 0.1244 0.1243 0.1277

JAN. FEB. MARC APRIL MAY JUNE JULY AUG. SEPT. OCT. NOV. DEC.

CONSUMPTION OF COAL PER TON OF CLINKER FOR THE YEAR 2013

0.115

0.12

0.125

0.13

0.135

M.TON

M.TON 0.1263 0.1296 0.1281 0.1290 0.1312 0.1326 0.1265 0.1266 0.1225 0.1237 0.1225 0.1229

JAN. FEB. MARC APRIL MAY JUNE JULY AUG. SEPT. OCT. NOV. DEC.

CONSUMPTION OF COAL PER TON OF CLINKER FROM JAN. - JULY 2014

0.12

0.125

0.13

0.135

M.TON

M.TON 0.1255 0.1244 0.1324 0.1283 0.1250 0.1252 0.1252

JAN. FEB. MARC APRIL MAY JUNE JULY AUG. SEPT. OCT. NOV. DEC.

Coal consumption

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.

Alternative fuels

S.NO SPECIFICATION UNIT YEAR-2013 YEAR-2014

CARBONDUST GRADE-I

CARBONDUST GRADE-II

CARBONDUST GRADE-I

CARBONDUST GRADE-II

01 GROSS CALORIFIC VALUE

Kcal / Kg 7562.26 3586.11 7534.07 4095.51

02 SULPHUR % 1.69 1.07 1.48 1.30

03 ASH CONTENT % 3.01 45.68 2.85 38.23

Carbon Dust Specifications

Alternative fuels

%

Alternative fuels

PERCENTAGE OF COAL AND ALTERNATE FUEL FROM JUNE 2012 TO JULY 2014

94.90 91.45 92.40

5.10 8.55 7.60-5.0010.0015.0020.0025.0030.0035.0040.0045.0050.0055.0060.0065.0070.0075.0080.0085.0090.0095.00100.00

2012 2013 2014

COALALTERNATE FUEL

ENERGY COST IN USD/TON OF CLINKER

-

10.00

20.00

30.00

40.00

50.00

60.00

Series1

Series1 51.70 13.67 13.30 13.16 12.79

FUEL OIL COA L COA L + CA RB ON DUST COA L + TYRESCOA L + CA RB ON DUST +

TYRE

Energy cost

ENERGY COST IN USD/TON OF CLINKER

10.00

11.00

12.00

13.00

14.00

15.00

Series1

Series1 13.67 13.30 13.16 12.79

COAL COAL + CARBON DUST

COAL + TYRES COAL + CARBON DUST + TYRE

Energy cost

Thank you very muchfor your

kind attention!