The document discusses MIROM's installation of an organic rankine cycle (ORC) system to their municipal waste incinerator to increase energy efficiency and generate electricity. It describes the incinerator's existing heat recovery process and need to find additional ways to recover energy. The ORC was chosen for its ability to generate electricity from the incinerator's low temperature heat. Data provided shows the ORC generating over 16,000 MWh of electricity annually while maintaining high availability. The system has proven profitable and increased the total energy recovered from the incinerator.

1. EXPERIENCES WITH AN ORC TO
INCREASE THE ENERGY EFFICIENCY
IN
A MUNICIPAL WASTE INCINERATOR
Jeroen Vanwalleghem
1 2-4-2012

2. Summary
 The waste incinerator of MIROM.
 Extension of the heat recovery with electricity.
 The organic rankine cycle.
 Application in MIROM Roeselare.
 Some data, graphs and results.
 Calculation of expenses.
 Conclusion and future.
2 2-4-2012

3. MIROM Roeselare
 Is a union of 15 municipalities established for
collecting and treating municipal waste. The
region counts 270.000 inhabitants.
 The waste is collected separately: residual
waste, paper, PMD (plastic and metal
cans, bricks).
 20 recycling parks.
 Own waste incinerator – only residual waste.
3 2-4-2012

4. The waste incinerator of MIROM
 Two lines, each with a furnace, boiler, ESP,
dry gascleaning with injection of bicar and
active coal. Baghouse with Remedia catalytic
filters and a shell denox system.
 2 * 4 ton/h or 62.000 ton/year.
 Boilers with superheated water of 180 C.
2 * 7 MW or 115.000 MWh/y.
 Since 2010 extra Economizers: 2 * 0,75 MW
4 2-4-2012

5. 110 C
1986 2004
18MW-180 C
1976
2008
180 C
Gas : 7MW
3,1MWe
5
5 2-4-2012

6. Heat recovery
 Primary circuit of 180 C, pression 15 bar and heat
exchanger.
 Town heating system of 110 C, 5 bar.
 21 customers with a heat demand around 25.000
MWh.
 5.000 MWh for preheating of combustion air.
 Expansion of the distance heating is not possible.
Forced to look for other systems to increase energy
recovery.
6 2-4-2012

7. 7 2-4-2012

8. District heating
• Circuit to city centre: 4,5
km(x2)
MIROM
• Circuit to greenhouses:
2,5 km(x2)
• 21 customers
8

9. Choice for electricity
 MIROM did not find other customers who
needed lots of energy.
 Production of electricity was the only option.
 Primary temperature of 180 C is far too low
to make electricity with steam.
9 2-4-2012

10. Why did MIROM choose an ORC
 Boilers are still in perfect condition.
 The town heating system stays primary, so
energy to ORC will fluctuate.
 ORC is easily adjustable.
 Organic fluid evaporates at low temperature.
10 2-4-2012

11. Property of solkatherm
 Looks like water, smells like solvent.
 Heavier than water: 1,36 kg/l.
 Boils at 35,6 C.
 Not toxic.
 Not explosive or flammable.
 Self-ignition temp.: 580 C.
11 2-4-2012

12. 12 2-4-2012

13. 13 2-4-2012

14. 14 2-4-2012

15. Some data
 Installed: input = 17 MWth, output = 3,1MWe.
 Design conditions: input 15 MW, T amb. 15 C
gives output 2,4 MWe.
 Average efficiency: 15,6%.
 Range: 2.900 kW – 100 kW.
15 2-4-2012

16. Investment in EUR
 ORC: 5.300.000
 Heat connection: 725.000
 Building: 900.000
 Total: 6.925.000
16 2-4-2012

17. Heat recovery in 2011 in MWh
Produc- Town Preheat Energy Produ- Total
tion heating Prim. to ORC ced Recov.
boilers Air electr.
MWhth MWhth MWhth MWhth Mwhe MWh
142.525 24.100 5.200 107.000 16.930 46.230
17 2-4-2012

18. Production of electricity
 See next slide.
 ORC runs since july 2008.
 Even in winter there is still production.
18 2-4-2012

19. Electricity - BOUGHT [MWh]
Energy balance '08 - '09
Electricity - SOLD [MWh]
MWh/month Total Electricity Production [MWh]
Own consumption [MWh]
1800
1600
1400
1200
1000
800
600
400
200
0
19 jan feb mar apr may jun jul aug sep oct nov
2-4-2012 dec jan feb mar apr may jun jul aug sep oct nov dec

20. Aankoop - Totaal 195 MWh
Balans elektriciteit 2011 Verkoop - Totaal 8814 MWh
MWh/maand Productie - Totaal 16930 MWh
Eigen verbruik - Totaal 8325 MWh
1800
1600
1400
1200
1000
800
600
400
200
0
Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec
20 2-4-2012

21. Electricity - BOUGHT [kW]
kW Power '08 - '09
Electricity - SOLD [kW]
Total Electricity Production [MWh]
2500
2400
2300
2200
2100
2000
1900
1800
1700
1600
1500
1400
1300
1200
1100
1000
900
800
700
600
500
400
300
200
100
0
21 2-4-2012

22. Gemiddelde Injectie actief vermogen
kW Vermogens Gemiddelde Afname actief vermogen
2011 Gemiddeld opgewekt vermogen ORC
Eigen verbruik
2500
2400
2300
2200
2100
2000
1900
1800
1700
1600
1500
1400
1300
1200
1100
1000
900
800
700
600
500
400
300
200
100
0
22 2-4-2012

23. Efficiency
 ORC follows thermal load between full range
 Guaranteed average gross efficiency =
15,6%
 Gross efficiency varies between 15% and
17% depending on outside temperature
conditions and thermal load
23 2-4-2012

24. 24 2-4-2012

25. Reliability - Availability
 Total amount of running hours during 2011
8364 hours (total availibility = 95,5%)
 Total amount of running hours incinerators :
8396 hours
25 2-4-2012

26. Conclusion.
 An ORC is a real added value for our heat
recovery.
 Even in winter we still have production of
electricity.
 Thanks to the GEC, the system is profitable.
 After the typical start-up problems, the ORC
runs smoothly with high availibility
 Little supervision necessary
26 2-4-2012

27. Future
 There is a plan to build greenhouses of about
200.000 m² next to our ORC. We’ll use the
cooling system to warm up the greenhouses.
 There are plans to enlarge the town heating
system: Up to 30 more industrial clients and
50 residential clients.
In this case, efficiency will decrease by a
certain percentage, but the total recovery of
energy will be very important.
27 4/2/2012