Egaa energy producing WWTP reaching 150% through partnerships and cooperation

Transcription

1 Egaa energy producing WWT reaching 150% through partnerships and cooperation

2 Overall Goal Through development of innovative processes the project partners wish to demonstrate that Egaa WWT can generate 50% more electricity than it uses for daily operation and at the same time recover 50% of the phosphate load as a fertilizer with easy availability of nutrients. The project is supported by EUD

3 Treated sludge liquor and excess ANAMMOX bacteria roces Layout Egaa WWT before changes Egaa WWT was built in 1993 and is operated with an inlet flow on about 8 mill. m 3 /year and an organic load on about E (person equivalent). Annual surplus sludge production is about 9,000 tons of dewatered sludge with a TS content on 22%. The total organic sludge production is about 1,400 tons TSG/year and electricity consumption is about 2.9 mill. kwh. Inlet N/DN Outlet Screening Sand/Grit Grease Excess sludge Return sludge FA N/DN rocesline rocess rocesline line 1 1 N/DN N/DN N/DN N/DN rocesline rocess line 2 2 RI SF R SV FF BL AN HYD ET E IT FA RT GB GM RB BT SA : Inlet screen : Grit Chamber & Grease trap : Screening ress : Sand washer : Salsnes Filters : Mixing tank : Anoxic tank : Tank for sludge hydrolysis : Settling tanks : Sand filters : Outlet aeration : re-dewatering : Digester : Gas storage : Gas motor : DEMON tank : Buffer tank : Dewatering : Cold Anammox Electricity and heating ORC Electricity

4 Treated sludge liquor and excess ANAMMOX bacteria Anammox bacteria roces Layout Egaa WWT after implementation Implementation of Carbon harvest with Salsnes Filters Implementation of the cold Anammox process, Inlet Outlet Screening Implementation of a DEMON -plant for sludge liquor treatment and feeding the Cold Anammox Sand/Grit -Recovery Grease Implementation a complete system for digestion and gas storage Return sludge Excess sludge FA rocess line 1 Available Available rocess line 2 ORC Electricity and heating Electricity RI SF R SV FF BL AN HYD ET E IT FA RT GB GM RB BT SA : Inlet screen : Grit Chamber & Grease trap : Screening ress : Sand washer : Salsnes Filters : Mixing tank : Anoxic tank : Tank for sludge hydrolysis : Settling tanks : Sand filters : Outlet aeration : re-dewatering : Digester : Gas storage : Gas motor : DEMON tank : Buffer tank : Dewatering : Cold Anammox : -Recovery Implementation an Organic Ranking Cycle (ORC) for maximizing electricity production

5 Carbon Harvest with Salsnes Filters

6 Installation of 8 Salsnes Filters 8 filters with a hydraulic capacity of 250 m 3 /h each ossible to harvest approx. 60% of the incoming Carbon over the Salsnes Filters The primary sludge from the Salsnes Filters will have a dry solid content of 6-7 %, and can be pumped to the digester with out pre-watering By maximizing the COD harvest over the Salsnes filters the COD / N ratio is too low for conventional nitrogen removal by Nitrification / Denitrification in the process tanks.

7 Biological treatment with a low Carbon Requirement Cold Anammox ( provided by Sweco) Consumption Unit Conventional N- removal Cold Anammox process Reduction Oxygen Kg O2/kg N 4,57 1,95 ~ 57 % Carbon (BOD) Kg BOD/kg N 2,86 << 1,72 ~ 40 % Expected requirement for oxygen and carbon for concentional nitrogem removal and Cold Anammox, (Sweco )

8 Implementation of at Egaa WWT To implement the process the following points will be addressed: There shall be implemented cyclones in the excess sludge line. Implementation of sludge age control (to promote the growth of AOB s (ammonia-oxidizing bacteria) and inhibit the growth of NOB (nitrite-oxidizing bacteria) DEMON -plant for sludge liquor treatment and seeding of.

9 Sludge liquor Treatment with DEMON - Seeding with Anammox bacteria and AOB s to the main stream

10 rinciples behind the DEMON installation Volume is approx. 435 m 3 Continuously feed with sludge liquor Based on activated sludge

11 Digester and gas storage The digester and gas system has been Mesophilic Gas extended storage temperature during for approx. the project, range 12 thus (39 hours we - 40 can production ºC) receive all excess sludge from a neighboring water utility Syddjurs Spildevand.

12 Optimizing the value of the energy output A fully automatic Organic Ranking Cycle plant (ORC) where thermal energy (exhaust from gas motor) is converted to electrical energy

13 Treated sludge liquor and excess ANAMMOX bacteria Anammox bacteria roces Layout Egaa WWT after implementation Inlet Outlet Screening Sand/Grit Design of the - Recovery system awaits process results after implementation of Grease Return sludge Excess sludge FA rocess line 1 Available Available rocess line 2 Electricity and heating RI SF R SV FF BL AN HYD ET E IT FA RT GB GM RB BT SA : Inlet screen : Grit Chamber & Grease trap : Screening ress : Sand washer : Salsnes Filters : Mixing tank : Anoxic tank : Tank for sludge hydrolysis : Settling tanks : Sand filters : Outlet aeration : re-dewatering : Digester : Gas storage : Gas motor : DEMON tank : Buffer tank : Dewatering : Cold Anammox : -Recovery ORC Electricity

14 Incorporation at existing plant Cold Anammox hospor recovery in existing building Digester Anammox Reject water treatment Filter- and engine building Construction site

15 What do we achieve? Our contractor has calculated the energy saving and energy generation potentially can move a 120,000 E WWT from an electricity consumption of approximately 31 kwh/year/e to a net electricity generation of 14 kwh/year/e, representing net electricity balance of more than 150 %.