advanced digestion technology Integration of New Biowaste Facilities on Waste Water Treatment Infrastructure Dorian Harrison, Technical Director (Monsal)

advanced digestion technology Project Brief Develop AD Assets / Strategy in Scotland for Biowaste Plant ,000 tpa (Cumbernauld) Plant ,000 tpa (Prestwick) Plant ,000 tpa (Johnstone) Merchant Site Category 3 Material Separate Packaged Feed Materials Produce High Quality (PAS110) Product Maximise Revenue from Energy Generation Integrate into Existing Facility

advanced digestion technology Project Procurement & Team Initial OJEC Notice (short list 6 bidders) Phase 1 – Permit Design Development Phase 2 – Detail Design Development Phase 3 – Construction Phase

advanced digestion technology Project Overview Existing Open Windrow and IVC Composting Facility Mixed green waste Catering waste Slurries (Odour) Current Capacity 40,000 tpa New Biowaste AD – Additional 30,000 tpa Kerbside collection (source segregated) Packaged food waste Category 3 Commercial and industrial (C&I) Slurries 1MWe Generation

advanced digestion technology Cumbernauld - Site History Site History Operated as Deerdykes STW Converted to open windrow composting facility (2003) In vessel composting completed (2008) Merchant AD facility (2010)

advanced digestion technology Integration Issues – WwTW Upgrade to Biowaste Difficulties Traffic management Electrical Connection Discharge Consent Permit Modification Planning Permission Product (PAS110 / Waste Exemption License) Benefits Dilution Effluent Existing Discharge to Sewer / Liquor Treatment? Existing Logistics Trained Operations Staff Grid Connection / Generating Capacity

advanced digestion technology Permitting Issues Odour at boundary 1.5OUe NOx, SOx emissions Noise Effluent (liquor treatment) Normal operation Abnormal operation Best Available Technology Environmental risk assessment integral with design risk assessment Modelling of emissions (noise, NOx, SOx, odour) Design to minimise emissions Environmental HAZOP to look at risks Visit working sites to familiarise Define BAT

advanced digestion technology Commercial Viability Revenue Streams (Maximise!) Gate fee Power Product Opex Costs (Minimise!) Parasitic power Fuel costs Manpower Product? Infrastructure Cost Minimise development costs (phased contract) Biowaste AD asset specification Development support

advanced digestion technology 30,000 Biowaste plant– Short Mass Balance Pre-Processing AD plant Biogas CHP Waste 30,000 tpa Power 1 MWe Compost 16,600 tpa Makeup Water m3/d Biogas production 439 m3/h Waste Water 36 m3/d

advanced digestion technology Monsal Biowaste Flowsheet

advanced digestion technology Feed Preparation for Digestion Up to 20% Contamination Solids 20% to 40% This is what we get What we Want Solids ~ 10% by weight Contamination < 0.25% in feed

advanced digestion technology Cleaning up Biowaste – how it works

advanced digestion technology Ideal Feed to Digester Liquified Slurry Feed (Wet Digestion) 10% DS 12mm screened Low Contaminants PAS110 req <0.5% by Weight Digestion Concentrates Contamination 0.25% Feed = 0.5% Cake

advanced digestion technology Required Product Contamination < 0.5% PAS110 compliant Product 25 – 35% dry solids

advanced digestion technology Conclusions Co-development of Biowaste AD with WW assets minimises development costs & programme Planning Permitting Synergises – liquors, power, infrastructure, staff. Water industry pedigree of client and technology provider ensures robust quality and professional project delivery Biowaste asset standard optimised to deliver good commercial IRR Model can be expanded rapidly across Scotland (Plants 2 & 3) delivering: 110,000 tpa capacity 4 MWe + renewable energy Valuable compost for recycling

advanced digestion technology Acknowledgments Scottish Water Horizons Donald MacBrayne Helen Gillard Kristine Leitch Enviros Jonty Olufsen Joe Short HBS Andrew Russell Bill Taylor SEPA WRAP (demonstrator program)

advanced digestion technology Thank You Dorian Harrison Technical Director (Monsal)

advanced digestion technology Magnetic Separation (for source segregated?)

advanced digestion technology Waste Dissolvers Liquify Organic Material Separate out Heavy Contaminants Float Light Contaminants

advanced digestion technology Animal By-Products Category 1 Incineration Category 2 Rendering 133 o C for 20 minutes as a batch 3 bar pressure No Disposal to Agricultural Land Category 3 70 o C for 1 hour as a batch <12mm in one plane Catering Waste (UK) Meat Excluded Biogas - 57C for 5 hour as a batch <50mm in one plane 18 days storage