Alternative Fuels and refractories

$: Alternative Fuels and refractories$
Dipl. Ing. Stefan Thomas

Use of alternative fuels in the cement industry

How can you make Profit?

Total Profit = Tons x sales prices –

(Cost/t production + costs for distribution and sales) x Tons

The Elements of Profit

Total Profit = Tons x sales prices

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Cost/t production

Fix costs independent from plant output

Variable costs depending on plant output

What to do to increase the profit


–


What to do to increase the profit


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Variable costs

Fuel Coal, Lignite, Petcoke, heavy oil, gas

Electric Power

Raw Materials Limestone, SiO2, Clay, iron ore, gypsum

Materials consumed explosives, Diesel oil, bags, additives,…

How can you reduce the costs ?

Fuel

Reduce fuel consumption by

Optimized kiln output

Increased cooler efficiency

Controled kiln feed chemistry

Increased heat exchange efficiency

Reduced of kiln stops

How can you reduce the costs ?

Fuel

Reduce fuel costs

Reduce number of kiln stops

Minimize the use of noble fuels

Increase the use of alternative fuels

The use of alternative fuels (and raw materials) is mainly driven by

• Economical aspects

Return on invest

Influence on system

Influence on clinker quality

• Environmental aspects

Permission

Public acceptance

Customer acceptance

Why is it possible to burn alternative fuels in Cement Kilns

• Extreme high process/flame temperatures ～ 2000°C

Waste Combustion: min 850°C

• λ > 1, air excess

• Long retention time in Kiln and Calciner > 6 sec

Waste Combustion min. 2 sec

• Free lime as a good absorbance for hazardous Elements

• No solid waste, all ash is product

Tires; 265

waste oil; 69

SRF commercial waste; 1361

meat & bone meal; 317

SRF from MSW; 212

solvents; 93

sewage sludge; 238others ; 45

Tireswaste oilSRF commercial wastemeat & bone mealSRF from MSWsolventssewage sludgeothers

Usage of SRF in German cement kilns in 2006 Sum: 2.6 Mill tons/a

SRF solid recovered fuel

Substitution Rate in German Cement Kilns 2006 >50%

0,0%

10,0%

20,0%

30,0%

40,0%

50,0%

60,0%

70,0%

2001 2002 2003 2004 2005 2006

Fossil SRF

What are Alternative Fuels

Alternative Fuels

Liquid

• Waste oil

• Solvents

• Animal fat

• Sewage sludge

• Etc.

Solid

• Petcoke

• Tyres chipped or complete

• Animal meal + Bone meal

• Dried Sewage sludge

• RDF – refuse derived fuel from:

Pulp, paper and cardboard; plastics; Packaging;

Textile industry; others

• Scrap wood

• Etc…

Liquid Alternative Fuel

Solvents

Availability is depending on the local market

Calorific value changes from 15 -28 MJ/kg, may content water

Used for main burner

Composition:

• Alcohol (Methanol, Ethanol, Isopropanol)

• Ketone (Aceton)

• Ester (Xylol, Benzol, Toluol)

Liquid Alternative Fuel, Equipment

Solvents

Collecting tray

Unloading device

Health and safety Info

Control equipmentLevel, Temperature, Pressure, gas detector

Stainless Steal Tanks2x100m³

Liquid Alternative Fuel, Equipment

Solvents

Fuel pipes to main burner

Leakproof ConcreteSurface with collectingsump

Pump Station with filters

Mixing equipment out ofquality reasons

Solid Alternative Fuel : some examples

Tires


Calorific value 27 MJ/kg,

Chipped 250mm or complete depending on kiln size or dosing system

Used in Preheater, also without calciner

May content water, depending on the environmental conditions

Composition:

• Carbon

• steel

Solid Alternative Fuel

Tires storage

Plant A, all types of tyres


Tires storage

Plant B


Tires storage

Plant C, all types of tires

Storage area

Walking floor bunker for daily/shift consumption

singularize deviceWheel rim detection

Weighing station

Tire transport to kiln

Necessary Equipment for tire use in Cement Kilns


TiresAir lock beforepreheater

Solid alternative fuel, Equipment

Precombustion Chamber, up to 7000 kg/h tires ～ 1000 pcs/h

Solid alternative fuel

RDF - refuse derived fuel


Calorific value depends on contractingHigh calorific value up to 23 MJ/kgMid calorific value approx. 16 MJ/kgLow calorific value approx. 8 MJ/kg

Water Content up to 15%

Chlorine content depends on contracting 0,3% up to 2%

Size:two dimensional 25 – 35 mm for optimized combustion for main burnerup to 150mm for use in calciner

Used in main burner or calciner

RDF before Preparation

RDF final Product

RDF Preparation

Primary Shredder Secondary ShredderFE Separation Heavy Fractionseparation

RDF final Product

RDF Homogenisation

RDF, constant Quality?

RDF Storing and dosing

RDF Input area in a German cement plant

RDF automatic sampling

You still have Fuel Control?

Primary Air

Coal

RDF

Oil, Waist Oil & Solvents

Alternative Fuels, how main burner looks like

Alternative Fuels, how main burner looks like

Axial air channel

Radial air channel

Petcoke channel: 14.000 kg / h

Solid waste: 9.000 kg / h

Natural gas: 6.240 Nm³/ h

Heavy fuel oil: 11.300 kg / h

Waste oil: 9.170 kg / h

The benefit of Alternative Fuels AF

One easy calculation under the following assumptionVARIABLE COSTS

Kiln capacity 3.000 t/dProduction days 330 d/aspecific heat consumption 3.300 kJ/kgHu (coal) noble fuel 27.000 kJ/kgNoble fuel cost at Burner tip 100 EUR/t

Fuel cost 12.100.000 EUR/a


Fuel Cost with noble fuel 12.100.000 EUR/a

Hu AF 20.000 kJ/kgFuel Costs - 10 EUR/tAF rate 50 %Yearly amount of AF 81.675 t/aAF costs -816.750 EUR/aTotal yearly fuel costs 5.233.250 EUR/a

Your save in variable costs 6.866.750 EUR/a


Total yearly fuel costs 5.233.250 EUR/a

Emission TradingCO2 from AF does not count!

Price for CO2 at the European Stock Exchange (EEX)http://www.eex.com04.09.2008 24,49 EUR/t CO2

CO2 Emissions from Noble Fuels (100%) 443.666 t CO2/aYou could save CO2 costs 5.432.690 EUR/aOr increase Production by approx. (0,8tCO2/tklinker) 277.291 t/a

http://www.eex.com/

Alternative Fuels and refractories

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