Design of an advanced integrated energy system based on micro gas turbines for waste water treatment plants

  • 191 views
Uploaded on

This is my pre-Ph.D thesis presentation. DEA in Spanish academic system. …

This is my pre-Ph.D thesis presentation. DEA in Spanish academic system.
Thought it's been long since I finished, I'd love of assisting you!

More in: Technology
  • Full Name Full Name Comment goes here.
    Are you sure you want to
    Your message goes here
    Be the first to comment
    Be the first to like this
No Downloads

Views

Total Views
191
On Slideshare
0
From Embeds
0
Number of Embeds
0

Actions

Shares
Downloads
0
Comments
0
Likes
0

Embeds 0

No embeds

Report content

Flagged as inappropriate Flag as inappropriate
Flag as inappropriate

Select your reason for flagging this presentation as inappropriate.

Cancel
    No notes for slide
  • Hay que explicar el porqué de avanzado e integrado

Transcript

  • 1. Design of an advanced integrated energysystem based on micro gas turbines forwaste water treatment plants DEA Work. Ph-D. in Chemical and Process Engineering Academic years 2003-2005. Universitat Rovira i Virgili Víctor Ortega-López Tutor: Joan Carles Bruno 1
  • 2. Summary 1. Biogas 2. Applied technology 3. WWTP Reus 4. Base case 5. Biogas Pretreatment 6. MGT configurations only with biogas 7. MGT NG + Biogas 8. Chillers configurations 9. Economical analysys 10. Performance analysis 11. Conclusions 12. Back-upDEA Work – Víctor Ortega-LópezPh-D. in process engineering 2003-2005 2
  • 3. Project motivation Development of using Biogas must cover the 13% of all renewable energy sources renewable energy sources by 2010* Improvement of Waste water Cost reduction of treated water and treatment plants reliable use of by-products (biogas) Application of new technologies Most common technology that simultaneously produced (Reciprocating engines) seems to have not further development electricity and thermal energy “BIOPROM – Overcoming the Non-technical Barriers of Project- implementation for Bioenergy in Condensed Urban Environments” Intelligent Energy - Europe Programme, EIE/04/100/S07.38585.DEA Work – Víctor Ortega-LópezPh-D. in process engineering 2003-2005 3
  • 4. Objective “The objective of this DEA work is to design advanced integrated energy system (AIES) to cover the heating demand of a waste water treatment plant and to co-produce simultaneously power and cooling. The AIES is based on MGTs technology for heat and electricity production, and on absorption chillers for cooling production. The generated electricity will contribute to reduce the electrical bill, and the cooling will be used to cool the biogas to reduce its moisture content and the air inlet to MGTs.”DEA Work – Víctor Ortega-LópezPh-D. in process engineering 2003-2005 3
  • 5. Characteristics of biogas Primary energy source Produced by anaerobic digestion of the organic matter suspended in waste water by mesophilic and thermophilic microorganism Low Methane content (50-70%) Low heating power Natural Gas: 49600 kJ/kg Hard to be used by Biogas (65%CH4): 20800 kJ/kg commercial engines Its main use in Europe is to be burned in flares The EU energy potential of converting waste water’s sludge’s is given as 20,000 GWh/year High content of impurities: siloxanes, sulphides, etc.DEA Work – Víctor Ortega-LópezPh-D. in process engineering 2003-2005 4
  • 6. Micro Gas Turbine Technology Main technical characteristics of MGTs Operates as a Brayton cycle Low compression ratio ( 3 < r < 5 ) One stage centrifugal compressor of axial flux coupled to a turbine High speed alternator (75000-100000 rpm) directly coupled to the turbine rotor Combustion chamber Regenerator Commercial debut in 1998DEA Work – Víctor Ortega-LópezPh-D. in process engineering 2003-2005 5
  • 7. Micro Gas Turbine Technology Advantages and disadvantages Power range: 20 – 200 kW Low maintenance cost Very compact High reliability Low emissions High exhaust gas temperatures Flexible to use different fuels Lower efficiency in its basic configuration than an equal power output reciprocating engine. Efficiency decreases significantly at part load High qualified maintenance workforce Need of fuel conditioning systems High investmentsDEA Work – Víctor Ortega-LópezPh-D. in process engineering 2003-2005 5
  • 8. MGT Performance 32,00 30,00 29,00 30,00 28,00 Net elect. efficiency (%) 27,00 28,00 Wnet (kW) 26,00 26,00 25,00 24,00 24,00 23,00 22,00 22,00 W net Net eff. 21,00 20,00 20,00 0,00 5,00 10,00 15,00 20,00 25,00 30,00 35,00 Ambient TemperatureDEA Work – Víctor Ortega-LópezPh-D. in process engineering 2003-2005 6
  • 9. Reus Waste Water Treatment Plant BIOGAS 105 Nm3/h, at 35ºC and 1,2 bar Annual capacity 6 millions of m3 Average. Component water (110.000 equivalent-inhabitants) value CH4 % 64 Nominal capacity 25000 m3/day CO2 % 31,4 Treated water flow 17000 m3/day H2O % 3 Treated sludge flow 220 Tm/day H2 % 0,2 Sludge dryness 25 % Sludge Temp inlet to H2S ppm 100 35 ºC Siloxanes ppm 50 2nd digesterDEA Work – Víctor Ortega-LópezPh-D. in process engineering 2003-2005
  • 10. Case Study Reus Waste Water Treatment Plant 600,0 600,0 500,0 500,0 400,0 400,0 kWth kWe 300,0 300,0 200,0 200,0 Heating demand 100,0 Electric demand 100,0 0,0 0,0 r ry ne ry ly r ch ril r er st ay be be be Ju Ap ua a gu ob Ju ar M m nu m em M br Au ct ve ce Ja Fe O pt No De SeDEA Work – Víctor Ortega-López * Heating demand calculated accordingPh-D. in process engineering 2003-2005 to ambient temperature
  • 11. Design model of the AIES MGT Capstone C30 for Biogas and Natural Gas Electricity Reduction of electrical bill Exhaust Heat Exchanger Hot Water Heating of 1st and 2nd digesters Absorption chiller - Single effect water driven LiBr/water Absorption chiller - Exhaust direct fired ammonia/water Absorption chiller - Double effect exhaust direct fired LiBr/water Abs. chiller Cooling of air to MGTs Cooling Moisture condensation in biogasDEA Work – Víctor Ortega-LópezPh-D. in process engineering 2003-2005
  • 12. AIES configurationDEA Work – Víctor Ortega-LópezPh-D. in process engineering 2003-2005
  • 13. Design model of the AIES Performance Q total + W net,system + Q cooling Fuel Utilization Factor FUF = H NG + H biogas = η Heating + η electric + η cooling H biogas Biogas utilization fraction BioUF = H NG + H biogas W net, system - W bio,comp Electric coverage (%) EC = ·100 W grid Economics (Differential inversion cost respect to the base case) Payback coefficient PBP= (differential benefit respect to the base case)DEA Work – Víctor Ortega-LópezPh-D. in process engineering 2003-2005
  • 14. Raw biogas input Biogas pre-treatment Sediment trap Removal of Siloxanes (max. 5ppb) Adsorption on Removal of Sulphides activated carbon Liquid/gas separator Drying Dryer Compressor Moisture condenser High O&M cost (35000€/year) Siloxanes/H2S MGT O&M Co&m,mgt 0,005 €/kWh removal Rest of installation M&O Co&m,rest 0,005 €/kWh Biogas pretreatment Co&m,rest 0,01 €/kWh MGTDEA Work – Víctor Ortega-LópezPh-D. in process engineering 2003-2005
  • 15. Base case configuration Current situation 600,0 50,00 45,00 500,0 40,00 Kg/h Additional Natural gas 35,00 400,0 Flare 30,00 kW (th) 300,0 25,00 Natural Gas Additional NG Heating 20,00 200,0 Overall Heat demand 15,00 Heat produced by biogas Biogas 10,00 Boiler 100,0 5,00 0,0 0,00 Digesters ry ry st e r ch r r ly ril er ay be be be n ua gu ua Ju Ap ob ar Ju M em em em Au br n M ct Heating Ja Month Fe pt O ov ec Se N D % Biogas = 86,4DEA Work – Víctor Ortega-López Electric coverage = 0%Ph-D. in process engineering 2003-2005 FUF = 80 %
  • 16. AIES configuration Case 1(a): MGT with biogas + Boiler with NG Cooling Cooling is provided by standard electric Exhaust refrigeration recuperator Biogas %Electric coverage = 37,2 % Biogas %Biogas = 63,52% pretreatment MGTs Elec. FUF = 72,75% MGTs MGTs Air Air cooling NG Boiler Digesters HeatingDEA Work – Víctor Ortega-LópezPh-D. in process engineering 2003-2005
  • 17. AIES configuration Case 1(b): MGT with biogas + Boiler with NG + Water driven Absorp. chiller Absorp. Chiller All biogas is consumed in MGT Cooling Exhaust Cooling is provided by an recuperator Biogas absorp. Chiller Biogas pretreatment MGTs Elec. %Electric coverage = 38,4 % MGTs MGTs %Biogas = 62,06% Air Air cooling FUF = 72,8% NG Boiler Digesters HeatingDEA Work – Víctor Ortega-LópezPh-D. in process engineering 2003-2005
  • 18. AIES configuration Case 1(c-d): MGT with biogas + Boiler with NG + direct fired Absorp. chiller Absorp. Chiller All biogas is consumed in MGT Cooling Exhaust Cooling is provided by a recuperator Biogas direct fired absorp. Chiller Biogas pretreatment MGTs Elec. %Electric coverage = 38,4 % MGTs MGTs %Biogas* = 62% Air Air cooling FUF = 72,7% NG Boiler Digesters HeatingDEA Work – Víctor Ortega-LópezPh-D. in process engineering 2003-2005
  • 19. AIES configuration Case 2 (b): MGT with biogas + MGT with NG + water driven Absorp. chiller Absorp. All biogas is consumed in Chiller MGT Cooling Exhaust Some MGTs with NG shall be recuperator powered off during summer Biogas Biogas season pretreatment Higher number of MGT, MGTs MGTs MGTs Elec. higher cooling demand for Air Air cooling air conditioning MGTs MGTs MGTs Elec. %Electric coverage = 86,5 % NG Digesters %Biogas = 47% FUF = 69,3% HeatingDEA Work – Víctor Ortega-LópezPh-D. in process engineering 2003-2005
  • 20. AIES configuration Case 2 (c-d): MGT with biogas + MGT with NG + direct fired Absorp. chiller All biogas is consumed in Absorp. Absorp. MGT Chiller Chiller Some MGTs with NG shall be Cooling Exhaust powered off during summer recuperator season Biogas Biogas Higher number of MGT, pretreatment higher cooling demand for MGTs MGTs MGTs Elec. air conditioning Air Air cooling One chiller cannot afford the cooling requirements, MGTs MGTs MGTs Elec. therefore efficiency losses NG Digesters are admitted Heating %Electric coverage = 87,8 % %Biogas = 47%DEA Work – Víctor Ortega-López FUF = 69,4%Ph-D. in process engineering 2003-2005
  • 21. Chillers configuration 450,00 Vent Vent Auxiliary 400,00 Abs. MGT Abs. MGT Waste Heat Chiller Chiller Boiler 350,00 MGT Waste MGT Waste Heat MGT Heat MGT Boiler Boiler 300,00 MGT MGT kW NG (b) Absorption chiller connected exclusively to one MGT, (a)250,00 Absorption chiller connected exclusively to one MGT recovering the exhaust gas heat (160ºC) in an auxiliary venting the exhaust gases boiler 200,00 Vent Abs. Vent Abs. Chiller Chiller 150,00 Chiller to one MGT venting exhaust gas (a) Waste MGT Waste MGT Chiller to one MGT with 100,00 MGT Heat MGT Heat auxiliary boiler (b) Boiler MGT Boiler MGT MGT MGT Chiller in exhaust gas net 50,00 (c) (c) Absorption chiller connected in bypass with the exhaust (d) Absorption chiller connected to the exhaust gas collector, gas collector venting the exhaust fraction used. 0,00 1 2 3 4 5 6 7 8 9 10 11 12DEA Work – Víctor Ortega-LópezPh-D. in process engineering 2003-2005
  • 22. Economical analysis Best Economical Case Absorp. Capital O&M Chiller Fix Cost Variable cost Total cost PBP amortization €/year €/year €/year €/year €/year % Cooling Exhaust Case 0 19091 1632 recuperator 10111 268535 278646 Case 1-A 58511 41310 49789 237973 287762 130 Biogas1-B Case 58511 42347 50826 236910 287736 129 Biogas Case 1-C (a) 58511 pretreatment 42500 50979 243163 294142 161 Case 1-C (b) 58511 42636 MGTs 51115 Elec. 239439 290554 141 Case 1-D (a) 58511 MGTs MGTs 43197 51676 242451 294127 159 Case 1-D (b) Air 58511 Air cooling 43197 51676 237663 289339 135 Case 1-D (c) 58511 44268 52747 237155 289902 136 Case 2-A 65315 63937 72416 170008 242424 63 MGTs MGTs Elec. Case 2-B 65315 NG 65297 MGTs 73776 158243 232020 58 Digesters Case 2-C (b) 65315 65042 73521 160609 234131 59 Case 2-D (b) 65315 66997 75476 158510 233986 59 HeatingDEA Work – Víctor Ortega-LópezPh-D. in process engineering 2003-2005
  • 23. Economical analysis 25000 20000 15000 €/month Electricity O&M NG 10000 Fix cost 5000 0 il ly r st ay ch ry r r r y ne e be be be pr ar Ju u ob ua M ar Ju A nu ug m m m M ct br e e e A Ja O ec pt ov Fe Se D NDEA Work – Víctor Ortega-LópezPh-D. in process engineering 2003-2005
  • 24. Economical analysis Influence of tariff conditions 350000 300000 250000 €/year 200000 0,022 €/kWh 150000 Case 0 Case 1-B Case 2-B 100000 0,01 0,015 0,02 0,025 0,03 NG Tariff [€/kWh]DEA Work – Víctor Ortega-LópezPh-D. in process engineering 2003-2005
  • 25. Economical analysis % electrical coverage Case 1A 120,00 Case 1B Case 1C Case 1D 100,00 Case 2A Case 2B Case 2C 80,00 Case 2D % coverage 60,00 40,00 20,00 0,00 er r y r r st il ch ly y ay ne be be be pr r ar Ju u ob ua ar M Ju m nu ug em A em M ct br te A Ja ec O ov Fe ep D N SDEA Work – Víctor Ortega-LópezPh-D. in process engineering 2003-2005
  • 26. ConclusionsCurrent production rates of biogas are not enough to cover the heatingdemand. Additional NG have to be burned.AIES using MGT exclusively biogas are not economically optimal dueto the high cost of biogas pre-treatments.Tariff situation encourages the use of MGT with NG to produce asmuch electricity as possibleAIES (MGTs) at part load (during warm season) has worse performancethan full load.Direct fired water/ammonia chiller has the worst performance due tothe high heat lost. Double effect chillers with higher COP valueimprove this performance.Parallel connection of absorption chillers are better than direct ventedor coupled to one MGT.MGT’s has a promising future as far as the technology improveefficiencies.
  • 27. Design of an advanced integrated energysystem based on micro gas turbines forwaste water treatment plants DEA Work. Ph-D. in Chemical and Process Engineering Academic years 2003-2005. Universitat Rovira i Virgili Víctor Ortega-López Tutor: Joan Carles Bruno
  • 28. Back-upDEA Work – Víctor Ortega-LópezPh-D. in process engineering 2003-2005
  • 29. References The European Renewable Energy Study: Prospects for Renewable Energy in the European Community and Eastern Europe up to 2010, DG XVII, 1994DEA Work – Víctor Ortega-LópezPh-D. in process engineering 2003-2005 4