ANIMP Milano - 11 Luglio 2013

Fuel flexibility and high efficiency

biomass power plants

Antonio Zingales Omar Merlin Kim Kokholm

Background• Security of fuel supply to ensure operational

hours of the power plant.• Reduced fuel price sensitivity in the power plant

business plan.• Improved negotiation basis with fuel suppliers.• Ability to consider higher level of local fuels

from agro-industry (wheat straw, poultry litter, olive husk, rice husk, rice straw etc.)

• Ability to mix “opportunity” fuels into the normal fuel supply to the boiler. Positive impact on OPEX.

KEM solution• Based on more than 20 years proven

operational background.• Wide range of fuel types based on similar

design concept.• Same basic grate technology used for all

plants.• Modifications mainly required at fuel in-feed and

fuel handling in order to expand fuel range. Limited CAPEX impact.

• Boiler design with steam parameters up to 110 bar, 520°C.

Boiler designFinal SH. Platen SH in TP 347

(austenite). High pitch. Designed to foul (no cleaning).

Intermediate convection SH with rectractable soot blowers.

ECO with in-line bare tubes with fixed type soot blower.

APH for sec. Air. Airtube design with high pitch and fixed type

soot blowers.

Firing technologyFiring technology:• Continuous feeding of high and low density fuel.• Equal distribution on grate by controlled mechanical

feeding in full width of grate sections.

Firing technology• Safety gate for isolating the feeding system from the hot

zone (boiler trip).• Frequency control + total mass flow adjustment.• Silo with downwards expanding dimensions/area.

Firing technology

Straw bale shredding

Grate TechnologyGrate technology:• Air cooled mechanical step grate used in many high

and low LHV biomass power plants (wheat straw, olive husk, rice husk, poultry litter, wood chips A+B type, peat…)

• Controlled combustion with constant fuel movement. • Individually controlled combustion zones (drying,

combustion, burn-out).

Grate technologyGrate technology:• Advanced air flow control (distribution to 4 zones,

distribution PA + SA + FGT).• Low C-content in bottom ashes due to long residence

time of embers.• Fuel flexible.

Capacity diagram

• Controllable thermal output with high variation in LHV and boiler load • Automatically adjustable combustion parameters based on steam load

and fuel conditions.• Mass flow feeding system avoiding variations in fuel density.

• Combustion monitoring with feed back to fuel feeding, combustion air system and grate parameters (speed and air zone division).

FGT

SNCR concept:• Up to 3 injection levels according to the Emission

Limits in the Erection Site;• Good effect in Ammonia Slip (Guarantee ≤10mg/Nm3, expected 3÷8mg/Nm3)

• Dedicated PLC for flow rate regulation of each Lance

FGT

FGT concept:• Circular bag filter design with improved security

towards ember collision with the bags.• Dry adsorption for reduction of SO2 and

HCl/TOC.• BAT for straw FGT. In general for high KCl fuel

types (1 year growing).

FGT

• Flat bottom ash extraction. No angled hoppers with reducing area.

• No direct bag impact of ashes due to cyclonic design compared to rectangular designs.

• Well referenced with various biomass types.• Equal temperatures inside the filter casing

reducing cold zones (corrosion).

Limiti emissione COMedia Mensile

≤100 mg/Nm3

Limiti emissione SOxMedia mensile

≤100 mg/Nm3

@ 11% O2

Limiti emissione NOxMedia mensile

≤150 mg/Nm3

@ 11% O2

Ammonia slip ≤10 mg/Nm3

Material HandlingLong Term Storage

Material HandlingMedium Term Storage

Material HandlingShort Term Storage

Ref. 1 - Slagelse, DKSteam production: 40 Steam production: 40 Steam production: 40 Steam production: 40 t/ht/ht/ht/h, , , , 450450450450°°°°C, 64 barC, 64 barC, 64 barC, 64 bar.

Grate fired water tube steam boiler fired with wheat straw.

Complete supply with :

• Fuel feeding system • Air cooled mechanical grate• Furnace design ( w/ AB) • Combustion air system• Wet ash transport system

Ref 2. - Fibro Power, UKSteam production: 58 Steam production: 58 Steam production: 58 Steam production: 58 t/ht/ht/ht/h, , , , 450450450450°°°°C, 64 barC, 64 barC, 64 barC, 64 bar.

The grate fired water tube steam boiler is designed to be fired with poultry litter based on straw/wood fines.

Complete supply with :

- Fuel feeding system- Air cooled mechanical grate- Furnace design (W/ AB)- Combustion air system- Wet and dry ash transport sys

Steam production: 42 Steam production: 42 Steam production: 42 Steam production: 42 t/ht/ht/ht/h, , , , 400400400400°°°°C, 42 bar.C, 42 bar.C, 42 bar.C, 42 bar.The grate fired water tube steam boiler is designed to be fired with residues from olive oil production (orujillo) and cuttings from olive trees (residuos de poda). High LHV fuel types.

- Automatic crane system- Fuel feeding system- Air cooled mechanical grate- Steam boiler w/ economiser- Deaerator and feedwater sys- Combustion air system- Fluegas cleaning system- Chimney and ducts- Gangways and stairs

Ref. 3 - Extragol, ES

Ref. 4 - Valorbois, BESteam prod. 20 Steam prod. 20 Steam prod. 20 Steam prod. 20 t/ht/ht/ht/h, 455, 455, 455, 455°°°°C, 46,5 barC, 46,5 barC, 46,5 barC, 46,5 bar.

The grate fired water tube steam boiler is designed to be fired with wood biomass class A and B. Complete supply with :- Fuel handling by automatic crane- Fuel feeding (weighting system)- Air cooled mechanical grate- Steam boiler- Combustion air system- Ash transport- Flue gas treatment (bag filter)- Electrical installations,- instrumentation etc.Project carried out in consortium with Areva Bioenergies (Bremen).

Ref. 5 - Taufkirchen, DESteam prod. 12 Steam prod. 12 Steam prod. 12 Steam prod. 12 t/ht/ht/ht/h, 455, 455, 455, 455°°°°C, 35 barC, 35 barC, 35 barC, 35 bar.

The grate fired water tube steam boiler is designed to be fired with wood biomass class A and B. The plant was commissioned in 1999

Complete supply with :- Fuel handling by automatic crane- Fuel feeding (weighting system)- Air cooled mechanical grate- Steam boiler- Combustion air system- Ash transport- Flue gas treatment

(ESP + wet scrubber 17 BmSch)- Electrical installations,- instrumentation etc.

Steam prod.: 43 Steam prod.: 43 Steam prod.: 43 Steam prod.: 43 t/ht/ht/ht/h, 450, 450, 450, 450°°°°C, 64 bar.C, 64 bar.C, 64 bar.C, 64 bar.The grate fired water tube steam boiler is designed to be fired with forest wood chips and cork powder.Complete supply with :- Automatic crane system -2 cranes- Fuel feeding system- Pneumatic fuel feeding system- Air cooled mechanical grate- Air preheater- Steam boiler w/ economiser- Combustion air system- Fluegas clean. w/multicyclone ESP- Chimney and ducts- Gangways and stairs

Ref. 6 Santa Maria,PT