FUTURE PROOFING WASTEWATER TREATMENT INFRASTRUCTURE

Transcription

1 FUTURE PROOFING WASTEWATER TREATMENT INFRASTRUCTURE EMANZ Conference, Auckland, May 2016 EMANZ CONFERENCE, MAY 2016

2 CALIBRE CONSULTING OFFICES Urban Development & Civil Infrastructure Water & Environment Buildings & Structures Transportation 2

3 CO-DIGESTION OF TRADE WASTE 1. Reduces costs of wastewater treatment services 2. Improves digester utilisation and efficiencies (2 fold) 3. Minimises energy costs (generates 100 % of site power) 4. Provides new sources of revenue (gate fee) 5. Maximises whole of life cost effectiveness 3 RESIDUES TO REVENUES 2016

4 The end user energy potential from industrial, agricultural, commercial and municipal biosolids Co-digestion in New Zealand energy potential, 2016 about 110 % of MSW Scenario 1 (PJ/annum) R + ICI Sewerage Biosolids (PJ/annum) Paunch Processing (PJ/annum) Meat Processing (PJ/annum) 1 PJ methane/annum = 13 MW el generation Dairy Processing (PJ/annum) Dairy Farming (PJ/annum) Estimate of Nett National methane bioenergy potential from each sector (given in PJ methane biofuel/year) Note: The processing energy requirement (heat, power) is assumed to be covered from the produced methane and is already subtracted 4

5 SUITABLE LIQUID TRADE WASTE Feedstock Material Dissolved Air (DAF) float (dairy factory, meat processing) % Dry Solids (DS) Range % (very high fat content) Cheese whey 5 % (high sugar content) Grease trap waste (municipal, commercial collection) Municipal biosolids (primary sludge) 5 10 % (high fat content) 3-4 % (medium fat content) 5

6 REGIONAL CO-DIGESTION OPPORTUNITIES : Existing WWTP digesters with available capacity Total: 16 MWel potential GHG savings: 80,000 t CO 2 -equ/annum Sector specific COP 21 (30 % of 2005 emissions) 6 #

7 POWER PRODUCTION POTENTIAL Grease trap waste resource: Municipal sludge resource: Dairy factory WWTP DAF sludge resource: 0.15 MW el per 100,000 EP 0.15 MW el per 100,000 EP MW el per dairy factory Urban New Zealand (incl. dairy processing): about 18 MW el 7 RESIDUES TO REVENUES 2016

8 THE GAME CHANGER (CALIBRE, 2008) ( BOOSTER PROCESS WITH RECUPERATIVE THICKENER) 1. Low power consumption ( < 15 KW) 2. Fully automated 3. Low maintenance (weekly clean) 4. Low polymer consumption (4-5 kg polymer/t DS) Digester Feed Anaerobic Digester Sludge dewatering Polymer Dosing System Thickener Thickened Sludge Thickener Filtrate Water NZ Innovation Award: 2010 ACENZ Innovation Silver Award: 2015

9 The Energy Opportunity with Booster Parameter Influent Treatment Primary Sludge Digestion (4 % solids) Waste Activated Sludge Digestion (4 % solids) Flow (m 3 /day). 40, BOD content (kg/day). 13,500 4,650 1,400 Power consumption (kwh/day). 19,500 1,400 N/A Power production potential (kwh/day) N/A 12,000 N/A Power shortfall (kwh/day). - 8,900 0 N/A Co-digestion power production + GTW + dairy factory waste N/A 36,000 N/A (kwh/day). Power surplus (kwh/day). 15,100 9 #

10 Client Brief: Design and install Residues to Revenues program to maximise biogas production at lowest possible costs Client Benefits: 100 % treatment capacity increase 65 % reduced construction costs 240 % increased biogas production 100 % energy self-sufficient plant Electricity export to grid $2.5 million cost savings. Less than 4 years payback Palmerston North Digester Upgrade (operating since 2011) Location: Palmerston North WWTP, North Island, New Zealand Client: Palmerston North City Council Project Value: $2.5 million

11 REVENUES FROM RESIDUES (100,000 EP PLANT, 2 DIGESTER TANKS) Construction costs (incl. waste reception) Operating cost Revenue from trade waste gate fees Revenue from biogas sales as genset fuel Simple Payback Period Gate fee: 30 $/m 3 $ 1.1 million $ 0.2 million/ annum $ 0.38 million/ annum $ 0.15 million/ annum 3.3 years (30 % ROI) Gate fee: 50 $/m 3 $ 1.1 million $ 0.2 million/ annum $ 0.63 million/ annum $ 0.15 million/ annum 1.9 years (53 % ROI) ROI: Return On Investment Electricity: 0.15 $/kwh. Polymer: 10 $/kg and 6 kg polymer/t DS. Value of biogas: $/kwh biogas. Annual trade waste processing capacity: 13,000 wet t/annum

12 Urban Area NZ WIDE APPLICATION Nominal WWTP use (kwh/day) Co-generation potential, WWTP sludge + grease trap waste (kwh/day) Max. Co-generation potential with Booster (kwh/day) Auckland 110, Christchurch 29, Hamilton 17, Tauranga 9, Dunedin Palmerston N Whangarei 4, Invercargill 3, Total (MW el ) Waste resource (municipal sludge, GTW, dairy factories): 18 MW el 12

13 COUNCIL BUSINESS OBJECTIVES 1. Reduced costs of wastewater treatment services 2. Improved asset utilisation and efficiencies 3. Reduced energy costs 4. Reduced environmental footprint 5. New sources of revenue 6. Maximised whole of life cost effectiveness 7. Unconstrained development 13 RESIDUES TO REVENUES 2016

14 SIMILAR INITIATIVES 1. Queensland Urban Utilities (planning) 2. Sydney Water (planning) 3. South Australia Water (Glenelg and Bolivar plants) 4. Other Australian Water Companies (planning) 5. Watercare, Auckland (planning) 6. Palmerston North City Council (since 2011) 7. Hamilton City Council (since 2014) 14 RESIDUES TO REVENUES 2016

15 PROJECT SUMMARY 1. Efficiency upgrade of existing infrastructure 2. Robust digester operation at high fat loading rates 3. Over 4 years of successful operation 4. No materials handling or blockage issues % improved trade waste throughput and gate fee income % improved gas and electricity production 7. CAPEX costs recovered in less than 3.5 years 8. Profitable investment (30 50 % IRR) 9. Energy self sufficient and efficient Contact: jurgen.thiele@calibreconsulting.co RESIDUES TO REVENUES 2016