Biowaste to power plants at highportions ”Biosafe” TEKES 40181/06

Martti Aho, VTT,  Liekki IV Day 23.1.2008

T 1Fu el selection,

D etailed analysisÅ A U , V TT  (J)

T 2P ilo t­ scaleexperim en ts

with a B FB  reactor:pro tective reactions

VT T

T3F urnacesam pling(N a , K  Cl,

U K U

T 4D eposition  m od el

(Å AU )

T5M ixing of additive

in  a  fu rnaceU  T sin ghu an

E ffective utilisation of b iow asteIn energy produ ction

H arm ful andprotec tive

com pounds

K loorinK errostum inen,likaantum inen

T o validation

F uels

L iuotetutSuojaaineet

R eliable sam plingof risky com p ounds

T est op tim i­sation

Henkilö Asema Puh.TEKES/TE­keskus  Mauri Marjaniemi

Jatta Jussila*teknologia­asiantuntija

010 521 5224

VTT prosessit Martti Aho** Var. Pasi Vainikka

johtava tutkijatiimin vetäjä

040 558 6945014 672 514

Åbo Akademi Mikko HupaVar. Patrik Yrjas

professoriTkT

02 215 3102 215 31

Kuopion yliopisto Jorma Jokiniemi:Var. Olli Sippula

professoriDI

040 5050 668

Kvaerner Power Jaani Silvennoinen  Tutkija 020 14 121Kemira OYJ Jari Kukkonen Tutkija Oulun yks.  010 862 5611Lassila & Tikanoja  Lassi Hietanen Tuotepäälllikkö 010 636 5412Helsingin vesi Yrjö Lundstöm Ympäristöpäällikkö  09 4734 3425*Climbus­ohjelman  koordinaattori, jakelulistalla ** Projektiyhteenliittymän kokoonkutsuja

Biosafe/ members of the leading group

Background

Heat transfersurface

Lack ofprotecting

compounds

Low ashcontent

RI

SKY COMPOUNDSALKALICHLORIDES

Cl releases corrosionä

BARK/FOREST RESIDUE

CASE 1. BARK/FOREST RESIDUE

Risk description:Cl depositionwhichcan leadto hightemperaturesuperheatercorrosion

Fouling of superheater tubes

Superheater tubes damaged by hightemperature chlorine corrosion

Optional ways to problem solution

CASE 2. PROTECTING POWER OF COAL

FOREST RESIDUE COAL

Co­combustion

PR

OTECTING REACTIONSALKALISILICATES,SULPHATES

ALKALICHLORIDES

RISKY COMPOUNS

SULPHUR DIOXIDE,Al­SILICATES

PROTECTIVES

Problem solution byco­firing means:

Coal contains sulphurand aluminium silicates:Alkali chloride destructionPossible bya) Sulphation SO3 + 2 KCl+H2O ­> K2SO4 + 2 HCl Note:

sulphur in SO3 form!b) Alkali aluminium silicateformation:Al2O3*2SiO2 + 2KCl +H2O ­>M2*Al2SiO3*2SiO2 + 2 HCl

Note: Sulphation may need high Smass flow to be effective increasingSO2 emissions

New and patented: Effective alkali chloride destructionby additives forming SO3 at critical furnace zones

2MCl + SO3  + H2O  ­> M2SO4  + 2 HCl

NaCl, KCl

Na2SO4K2SO4HCl

SO3 attach

Very effective S => small dosages,no increase of SO2 emissions

This project

•Utilisation of effective sulphur presentin different sludges to alkali chloridesdestruction in the boiler furnace

•Destruction of alkali chlorides withminimum sludge portions and SO2 slip

•No bed agglomeration allowed•Toxic emissions must controlled•Note: Emissions limits are determined

by the co­incineration directive

Plant idea• Dried and pelletised sludge is transported from

selected sources to a particular power plantequipped with a bag filter and chemicals to cleanthe flue gases

• The plant has high efficiency (with high steamvalues , > 500 C steam)

• The main fuel can be for example forest­basedbiomass and also include biomass componentsclassified to waste (demolition wood,impregnated wood)

Workprogramme briefly

Goals

• Main goal: Basis to utilise demanding biowaste inenergy production in effective power plants willstrengthen

• Sub goals (serving power plant availability):(a) Improved furnace probing tools for risky compounds(b) Improved control of formation and destruction of risky

furnace compounds(c) Utilisation of the protective compounds in sludges

Tasks and time schedule

T1Fuel selection,

Detailed analysisÅAU, VTT (J)

T2Pilot­ scaleexperiments

with a BFB reactor:protective reactions

VTT

T3Furnacesampling(Na, K Cl,

UKU

T4Deposition model

(ÅAU)

T5Mixing of additive

in a furnaceU Tsinghuan

Effective utilisation of biowasteIn energy production

Harmful andprotective

compounds

KloorinKerrostuminen,likaantuminen

To validation

Fuels

LiuotetutSuojaaineet

Reliable samplingof risky compounds

Test optimi­sation

Tasks

Time schedule 1.8.2006­>

02  04  06  08  10  12  14  16  18  20  22  24  26  28T1 x  x  x  x  xT2 x  x  x  x  x  x  x  x  x  x  x  xT3 x  x  x  x  x  x  x  x  x  x  xT4 x  x  x  x  x  x  x  x  xT5 x  x  x

Task 1 Fuels

•Risky fuels as sources of  KCl and NaClBark, bark/recycled fuel (REF)

Protective sludge with effective sulphur• 2MCl + SO2 + ½ O2  + H2O  ­> M2SO4  + 2 HCl

where M is K or Na

Power of fractionation analysis: instead of elementcontents it gives information of the reactivity of the

elements

REF to be used

Biosafe REF

0.002000.004000.006000.008000.00

10000.0012000.0014000.0016000.0018000.0020000.00

Si Al Fe Ti Mn Ca Mg P Na K S Cl

Rest

HCl

AcetateWater

Untreated

ppmW By Åbo Akademi

Task2: Reactor 20 kWBFB pilot plant

To stack

Samplingport

Samplingport

Samplingport

Gas cooling

Bagfilter

Gas probe

Observationport

Cyclone

Gassample

Temperaturecontrol

Tertiary air optional

Tertiary air optional

Tertiary air (preheated)

Fuel container 2Fuel container 1

Secondary air(preheated)

Nitrogen

Air

Additivecontainer

Primary gas heating

Heating zone 2/Cooling zone 2

Heating zone 3

Heating zone 4

Heating zone 1/Cooling zone 1

BEDmade of quarz

PC control and data logging system

Obervation port

Obervation port

Obervation port

Obervation port/Deposit probe

Depositprobe

ELPIEjektor

DLPI

Cooling system

VTT diluter

Cyclone

Cyclone

MFC

dib. air

Exh

Ejektor

nitrogen Ftir & CO2

T 800­1000°C

Tasks 2, 3 related to probing of Cl, S, Na and K compounds

Task 2 Deposit probing to analysis

Further illustration:

30mm

16mm

To: ÅboAkademi

Results from first tests

Cl concentrations at critical positions of the deposit:base fuel:  spruce bark

0

1

2

3

4

5

6

7

8

Kuori FBtulo

Kuori FBsivu

Kuori FBjättö

KuoriVK tulo

KuoriVK sivu

KuoriVK jättö

2% VKMFB tulo

2% VKMFB sivu

2% VKMFB jättö

2% VKMVK tulo

2% VKMVK sivu

2% VKMVK jättö

p­%

 Cl k

erro

stum

assa

2 % enb sludge 1 mixed to bark

Tmetal 500 CTflue gas. 650 C

Tmetal 500 CTflue gas 850 C

Bark alone

Klooripitoisuudet välikanavanäytteissä eri polttoaineilla

0

1

2

3

4

5

6

Kuori 2%VKM 4%VKM 6% VKM 8%VKM 4%KEMC

mg/

Nm

3

4.02 ­ 10 µm1.61 ­ 4.02 µm0.64 ­ 1.61 µm0.26 ­ 0.64 µm0.1 ­ 0.26 µm0.03 ­ 0.1 µm<0.03 µm

!

!

Cl concentrations in the fine fly ash with different sludges and dosages

Bark alone

Conclusion:

• Even a small portion of sludge mixed to barkdestroyed the alkali chlorides in the furnaceand prevented Cl deposition to thesuperheaters during bark combustion

• Next stage: More demanding startpoint willbe used: 10% enb. REF will be mixed to bark

• Old aspect: Sludges make only harm to theboilers by increasing emissions etc.

• New aspects: Sludges can protect boilerfurnaces!