Cofiring of biomass with municipal solid waste and sludge in Brescia waste incineration plant

ASM Brescia S.p.a.

Utility services : Data 1999 ELECTRIC POWER 1.175 GWh NATURAL GAS 332 Mm3

DRINKING WATER 46 Mm3

DISTRICT HEATING 1.030 GWh SEWAGE WATER 34,0 Mm3

STREET LIGHTING 31.101 point

PUBLIC TRANSPORT 30,2 M passengers

WASTE COLLECTION AND DISPOSAL (t) landfill waste to energy separate collect. total

387.027 371.703 53.544 758.730

DISTRICT HEATING NETWORK

414 km of double pipe 120.000 inhabit.supplied 31,5 Mm3 heated vol.

9800 clients 650 MWth 200 MWe

1 km

SUSTAINABLE DEVELOPMENT

To keep

a

positive rate of development

without compromising the availability of resources and the quality of environment for future generations 1

WASTE MANAGEMENT BRESCIA INTEGRATED SYSTEM · Waste prevention · Separate collection (for material recycling) · Composting of organic waste · Energy from remaining waste · Safe landfilling of residues 4

SEPARATE WASTE COLLECTION IN BRESCIA (percentage on waste produced ) 40

37,3

35

29,6

30 24

25

26,4

19,3

20

15,7

15 10

31,3

11 6,3

5 0 1991 1992 1993 1994 1995 1996 1997 1998 1999

PROJECT EVOLUTION CENTRALIZED SELECTION PLANT (1988)

SEPARATION IN ORIGIN WITH PEOPLE INVOLVEMENT (1991) 6

BRESCIA WTE PLANT DESIGN GOALS:

1.

ENVIRONMENT PROTECTION

2.

HIGH EFFICIENCY OF ENERGY RECOVERY

3.

RELIABILITY, SAFETY, AVAILABILITY

THE EFFICIENCY OF ENERGY PRODUCTION IS AN IMPORTANT ENVIRONMENTAL PROTECTION FACTOR, AS IT ALLOWS BOTH THE SAVING OF NON-RENEWABLE ENERGY RESOURCES AND THE AVOIDANCE OF EMISSIONS FROM POWER PLANTS FIRED WITH TRADITIONAL FOSSIL FUELS.

COMPARISON BETWEEN THE EMISSIONS FROM WTE PLANTS AND TRADITIONAL FUEL PLANTS

10

TERMOUTILIZZATORE AVOIDED EMISSION PER TON OF TREATED WASTE

(compared with landfill disposal of waste, electricity production with heavy oil ,heat production with natural gas)

%

kg/twaste

t/100.000 t waste

Dust

- 94

0,11

11

SO2

- 93

3,64

364

NOx

- 47

0,64

63

CO2

- 43

760

76.000

STACK EMISSION COMPARISON ITALY EXISITING REGION. PLANTS

EUROPEAN AUTOR.

COMPONENTS

UNION

DIR 89/369 40001/93

ITALY NEW

ACTUAL ASM VALUES DESIGN

PLANTS

DM 503/97 DM 503/97

DUST

30

10

SO2 NOx HCl HF

300 -

150 300 100 100 <30 600 200 <100 <100 200

50 2 100

30 1 100

CO Pb+Cr+Cu+Mn

5

Ni+As Cd) Hg PAC

1

Dioxine (ng/Nm3)

30

2

0,1 0,2 0,1 0,05 0,1 -

10

50 2 100

20 1 50

5

0,5

1 0,2 -

5

20 1 50

<1

5-20 <0,1 <20

0,5 <0,01 0,05 0,05 0,05 0,05 0,01 0,01 0,1 0,1

<0,002 <0,002 <0,001

<0,01

ENVIRONMENT PROTECTION 1. CLOSED BUILDINGS, AT NEGATIVE PRESSURE 2. ADVANCED COMBUSTION . Fully automatic waste feeding, grate movement and combustion control . “expert system” with infrared camera control . 30 compartments under grate, with automatic indipendent primary air flow control . Flue gas recirculation 3. DRY GAS CLEANING SYSTEM (LIME+ACTIVE CARBON) 4. FABRIC FILTER WITH 6 INDEPENDENT SECTIONS 5. REAGENT SILOS AND DOSING EQUIPMENT FULLY REDUNDANT 6. MINIMUM WATER CONSUMPTION. NO LIQUID EFFLUENTS 7. LOW NOISE COMPONENTS AND DESIGN 13

NET ENERGY EFFICIENCY 1. LOW COMBUSTION ECCESS AIR 2. HIGH HEAT RECOVERY FROM COMBUSTION GASES (FROM 1100 TO 130째C TO HIGH PRESSURE STEAM) 3. COMBUSTION AIR PRE-HEATING (WITH LOW PRESSURE STEAM) 4. LOW POWER SELF CONSUMPTION 5. HIGH STEAM DATA 60 BAR-450째C 6. HIGH EFFICIENCY TURBINE AND THERMAL CYCLE 7. POWER AND HEAT COGENERATION

OPERATION RELIABILITY AND SAFETY 1 PROVEN AND RELIABLE TECHNOLOGIES 2. WIDE TOLERANCE TO WASTE COMPOSITION (6,3 - 13,8 Mj/kg) 3. REDUNDANCY FOR CRITICAL SYSTEM 4. HIGH LEVEL OF AUTOMATION (15.000 PROCESS PARAMETERS REPORTED TO CONTROL ROOM) 4. DISTRIBUTED CONTROL SYSTEM 5. REDUNDANCY IN MEASURES AND PROCESS DATA

16

WASTE IS A RENEWABLE ENERGY SOURCE, AS IT IS MAINLY MADE BY VEGETABLE-CELLULOSIC SUBSTANCES; THE NON RENEWABLE COMPONENTS WHICH ARE PRESENT, FOR INSTANCE PLASTIC, WOULD OTHERWISE BE DISPOSED OF BY LANDFILL, WHICH PERMITS ONLY VERY LITTLE ENERGY RECOVERY

WTE BRESCIA WASTE CAPACITY ENERGY RECOVERED (NET) ELECTRICITY HEAT TO DISTRICT HEATING ENERGY NET EFFICIENCY ELECTRICITY HEAT TO DISTRICT HEATING

2 X 23 t/h 2 x 88,3 MWwaste 200 Gwhe/a 350 GWhth/a

TOTAL

25% 57% -----82%>

PRIMARY ENERGY SAVING

80,000 Tons oil eq./a

AVOIDED CO2 EMISSIONS

200,000 T/a

CO-COMBUSTION OF SEWAGE SLUDGE • Closed system: no odours emissions; employees have no contact with the sludge.

• 20 - 50 % dry substance.

• Solid pumps feed the sludge from 2 x 255 m3 silos to the spreaders in closed pipelines over a distance of 150 m.

• Two spreaders with bilateral feed into each furnace.

• Uniform distribution of the sewage sludge is effected by varing the rotor speed and the discharge angle.

• Sewage sludge particles do not clump together: good burnout.

Sewage sludge - MSW co-combustion Operating Results Unit 1

Unit 2

Boiler load

%

70

80

Sludge flow

m3/h

0

3

Steam production t/h

70

83

Furnace temp.

C

951

971

CO

mg/Nm3 7.5

11.9

NOx

mg/Nm3 78.5

70.5

O2

mg/Nm3 8.3

7.0

BIOMASS CO-COMBUSTION IN BRESCIA WTE PLANT WASTE DATA 1999:

• 370.000 t of municipal solid waste • 16.000 t of biomass WASTE DATA 2000 (FIRST SIX MONTH):

• 218.000 t of municipal solid waste • 40.000 t of biomass

BRESCIA WTE PLANT BIOMASS RECOVERED:

• • • •

Pulper from paper recycling processes Wood chips Sewage sludge Marc (residues from wine production)

SCHEMA CICLO TERMICO 212 t/h

60 bar

450 째C 5 MW

45 MW

55 째C 115 째C

102 MW 70 째C

SCHEMA IMPIANTO TRATTAMENTO FUMI

Waste-to-Energy unit cost & revenues (without incentives) ECU/ton waste COSTS Investment pay off (k=0,1) Personnel (80 pers. - 42.500 ECU/p x a) Maintenance (4% of plant investm.)

Bottom ash (50 ECU/t - 25% of waste) Gas cleaning residue (200 ECU/t - 5%) Chemicals Others

REVENUES (from energy) electricity (0,045 ECU/kWh) heat (0,012 ECU/kWh)

WASTE DISPOSAL COST

Total (MECU/a)

50,00 9,50 17,00 12,50 10,00 3,00 2,50

17,50 3,30 6,00 4,40 3,50 1,00 0,90

104,50

36,60

25,50 12,00

8,90 4,20

37,50

13,10

67,00