Step by Step Towards Alternative Fuels

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Matthias Mersmann, aixergee GmbH

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Watch Out – You Might Be Getting What You Are After…

• AF can reduce your fuel costs down to zero – or even below!

• At ~30-40% fuel cost contribution to OPEX this can really raise PROFIT!

• …and you can do something good for the environment and society too!

• … so where is the catch??

Effort must be spent on: • Equipment • Process adaptation Mistakes can be made… … but can be avoided by expert advice !

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1. Step: 0-25% TSR in Kiln Riser Duct

Preheater kiln:

Fluff

• no TAD

• short riser duct

Possible limitations: • Insufficient burn-out • Cyclical loading & fall out of suspended

meal and fuel • Fall through into inlet chamber

Necessary modifications: Fluff storage & handling

Injection System

Sluice, flaps, chutes, pneumatic pipes etc.

Adaptation of process conditions

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Kiln bypass system:

2. Step: Bypass for Removal of Cl & S

Limitations/Considerations: • optimal tapping position • efficient quenching to reduce gas volume • Bypass dust handling and utilization

Necessary modifications: • Bypass extraction pipe • Qenching chamber • Dedusting & fans

Necessity: Cl and S-components need to be removed from the kiln gas to allow smooth and efficient operation

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3. Step: 25-60% Total TSR (additionally 25-85% of Calciner Fuel)

Calciner extension

duct length extension

tertiary air duct

Possible limitations: • Fall through into inlet chamber • Unstable calcination • Unstable kiln process • Ring & ball formation


Calciner modification

Optimization of injection ports

Optimization of process conditions

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Rocket mill instead of Calciner extension:

LQ-Fluff


meal and fuel • Fall through into inlet chamber • Ring & ball formation

Necessary modifications: RDF storage & handling

Rocket Mill



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Combustion Chamber:


Combustion chamber



meal and fuel • Fall through into inlet chamber • Ring & ball formation

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Mixing Chamber:


Mixing Chamber



Possible limitations: • High temperatures in lowest stage

cyclone • Temperature peaks in mixing chamber

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4. Step: 45 – 90% Total TSR (Increase 20-80% TSR at Main Burner)

Main Burner & Rocket Mill:

L

Q-F

luff

Advantages of AF-burner or satellite burner: • High oxygen availability • High temperature field • Long retention of AF-particles „in flight“

Advantages of Rocket Mill: • Smaller particle size • Less humid particles • Ignition facilitating particle surface structure

Necessary modifications: Rocket Mill: Storage, Handling, Dosing, Silos…. High AF-Burner or Satellite Burner

Step by Step Towards Alternative Fuels

Engineering