Carbon footprint and biosolids treatment. Dr Bill Barber

Carbon footprint and biosolids treatment Dr Bill Barber

Carbon footprint Embodied + Operating Indirect + Direct Owned + Influenced manufacture construction vs. operating fossil fuel use vs. process emissions process generated vs. supply chain

Indirect Carbon Footprint Depends on power source Wind 0.05 Solar 0.02 0.04 Nuclear 0.05 Biomass 0.02 0.08 Gas 0.20 Coal 0.80 1.20 CO 2 e / kwhr N 2 O, CH 4 Emissions Processing Power (kwhr) Fuel

UK Power GHG emission factor [kgco2e/kwhr] Power Emission Factors depend on energy mix 1.2 1 0.8 0.6 0.4 0.2 0 1960 1970 1980 1990 2000 2010 2020 2030 4

Carbon footprint [kg CO2/kWhr] Power Emission Factors depend on energy mix 1.4 1.2 1 Coal 0.8 0.6 0.4 0.2 Gas 0 NSW + ACT VIC QLD SA WA TAS NT UK

Embodied Carbon Footprint CO 2 e CO 2 e CO 2 e N 2 O, CH 4 Design Power Emissions Fuel Quantity Manufacture Transport

Aggregate Sand Soil Asphalt Stone Plaster Concrete Road Soil-cement High strength Pre-cast Bricks Clay Mortar Plasterboard Clay pipe Clay tile Timber Bitumen Cement Glass Hardboard Portland Paper Carbon Steel Insulation Plastics Copper Paint Stainless Steel Aluminium Embodied Carbon Footprint Embodied Carbon Footprint Natural materials Processed Natural Materials Metals complex materials fertilizers

Sustainability Carbon Footprint Process Emissions, 17% Transport, 5% Other, 1% Electricity, 77% Biosolids influences all of these parameters UK Water industry > 5 million tonnes CO 2 e Only the power industry emits more carbon footprint Pumping + Aeration

Carbon Impacts in Biosolids Carbon Footprint of Biosolids CO 2 e CO 2 e CO 2 e -CO 2 e CO 2 e N 2 O, CH 4 Power Chemicals Emissions Biogas Fuel WwTW Transport

CO 2 e -CO 2 e -CO 2 e N 2 O, CH 4 Emissions Fertilizer Disp (Sequestration) Land Application

CO 2 e -CO 2 e CH 4 Emissions Biogas Landfill

391 kg -532 kg CO 2 e +380 kg CO 2 e +168 kg CO 2 e +16 CO 2 e CHP 138.9 kg CH 4 157 kg CH 4 18.1 kg CH 4 Direct atmospheric emission Direct atmospheric emission 649 kwhr 20 kg 8 kg CH 4 8 kg CH 4 1000 kg 609 kg 589 kg Primary Digestion Open secondary Digestion

504 kg -893 kg CO 2 e +189 kg CO 2 e 9 kg CH4 Direct atmospheric emission -704 CO 2 e 1089 kwhr CHP Parasitic Demand 193 kg CH 4 202 kg CH 4 1000 kg 496 kg Pre-treatment Primary Digestion Secondary Digestion

Lime + supp heat Class A liming Raw Drying Raw Incineration Thermal hydrolysis + MAD Series acid phase + MAD TAD-MAD Pre-MAD pasteurisation Digested Drying Advanced Digested Inc Digested Incineration ATAD Carbon Footprint Carbon Footprint of Class A Biosolids treatment No digestion With digestion

Carbon footprint breakdown Liming Composting TH + MAD BH + MAD TAD + MAD ATAD Key: ( Biosolids Transport); ( Land Emissions); ( Chemicals); ( Dewatering); ( Transport Other); ( Power); ( Gas); ( Process Emissions); ( Down Time)

Carbon footprint breakdown Liq Past + MAD Raw Drying MAD + Drying Lime + S H Raw Incineration MAD + Incineration Key: ( Biosolids Transport); ( Land Emissions); ( Chemicals); ( Dewatering); ( Transport Other); ( Power); ( Gas); ( Process Emissions); ( Down Time)

Australia - Australian government reduction target of 5% of 2000 levels by 2020 357 million t/co 2 e year - Currently being measured and reported - Carbon tax will come in force 1 July 2012 Will cover 500 worst polluters (approx 60% of the emissions) This will include all large water companies $ 23 AUD/t carbon dioxide Rising 2.5% per year - Will become trade scheme 1 July 2015

Carbon footprint [t CO2/yr] Carbon Footprint of Australian Water Industry 700,000 600,000 SCOPE 2 SCOPE 1 500,000 400,000 300,000 200,000 100,000 0 Hunter Water Melbourne Water SA Water SunWater Sydney Water Water Corp. Data plot using Australian Government NGER 2009/10 data

Carbon Footprint of Australian Water Industry

Normalised (to UK) Carbon Footprint of Australian Water Industry

Tightening Legislation

Case Study New advanced digestion facility

Option 1 New raw sludge incineration plant Main Inputs/Outputs impacting Carbon Dewatering Conveying Contributing Sites Power Chemicals Sludge Transport Pre-drying Air provision Waste Heat Recovery Dust Removal Acid gas clean-up Scrubber Effluent Treatment Incinerator Plant Waste Sludge Flue gas Ash Transport Power Chemicals Start-up Gas Combustion Air Power Generation

Option 2 Advanced Digestion with existing incineration Dewatering Conveying Re-liquification Thickening Thermal Hydrolysis Anaerobic Digestion Liquor Treatment Dewatering Conveying CHP Plant Pre-drying Air provision Waste Heat Recovery Dust Removal Acid gas clean-up Scrubber Effluent Treatment Contributing Sites Sludge Transport Digestion Centre Liquid Sludge Pumping Existing Incinerator Plant Waste Sludge Flue gas Ash Transport Power Chemicals Power Chemicals Natural Gas Renewable Energy Generation Sludge cake Export Power Chemicals Start-up Gas Combustion Air Power Generation

Weight of Construction material Weight of Construction Materials Steel Concrete Raw Incinerator Advanced Digestion

Embodied Carbon (CO 2 e) Embodied Carbon Total Concrete (CO 2 e) Total Steel (CO 2 e) Raw Incinerator Advanced Digestion

Breakdown of carbon footprint Factors Contributing to Increasing Operating Carbon Dewatering at DH Land Application Additional pumping to SG Incinerator chemicals Incinerator power demand Ash transport Downtime Incinerator emissions Sludge transport Dewatering (inc liquor treatment) Raw Incinerator Advanced Digestion

Operating Carbon footprint Impacts and benefits on operating carbon Total Total Benefits Biogas production Energy generation at incinerator Fertilizer displacement Carbon sequestration Raw Incinerator Advanced Digestion

Cumulative Carbon Footprint Whole Life Carbon Impact Liming Raw Incineration AD AD delay 5 AD Delay 10 0 10 20 30 40 50 Years in operation

Summary - Everything we do has a carbon impact and that also includes biosolids production and processing - Carbon footprint is made up of: embodied and operating Indirect and Direct Owned and influenced emissions - Choice of technology has large impact on carbon footprint of biosolids options - Anaerobic digestion is very influential Renewable energy generation Reduces biosolids for further processing Can improve dewatering so reducing transport

Thank You bill.barber@aecom.com

52,230 Power 8,640 37,370 Polymer Power Gas Manufacture 6,220 7,360 CO 2 e CO 2 e CO 2 e CO 2 e 44,870 (Raw Incineration) Dewatering Fuel Transport Chemicals Manufacture Emissions N 2 O Downtime CH 4 + N 2 O Incineration Ash Transport Avoided Power Power Generation

29,300 29,300 (Option 1 (Option Existing) 1 Existing) Polymer Power Manufacture Power N 2 O 40,200 6,500 5,600 11,300 16,800 10,850 CO 2 e Dewatering CO 2 e CO 2 Lime Manufacture Lime Addition CO 2 e Fuel Transport CH 4 CO 2 e GHG Emissions Field Application CO 2 e Avoided Power Fertiliser Manufacture

Advanced Digestion Carbon Footprint 1. Impact on existing digestion plant 2. Impact at existing incineration facility processing additional sludge 3. Recycling of additional Class A biosolids 4. Additional transport (double-handling)

SBAP Impact at Davyhulme Impact on existing digestion plant 652 (Existing Digestion) 26,282 (New Digestion) = 26,934 (Reduction at Existing Digestion)

Additional land application emissions 10,778 (Contributory land application) 1,969 (Beneficial land application) = 8,809 (Additional land application)

Impact on existing incineration plant 10,778 (Contributory incineration) 1,969 (Beneficial incineration) = 8,809 (Additional Incineration)

Total for Advanced Digestion Option + + + = -26,934 (Reduction at existing digestion) 3,829 (Additional land application) 8,809 (Additional Incineration) 11,408 (Additional Transport) 2,888 (Advanced Digestion Total)