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Adrian Thompson CIWM & DoENI Consultation Seminar 15 November 2013. Food for Thought Technology Advances. Contents of Presentation. Technology Advances Anaerobic Digestion In-Vessel Composting Anaerobic Digestion Pro’s and Con’s In-Vessel Composting Pro’s and Con’s
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Adrian Thompson CIWM & DoENI Consultation Seminar 15 November 2013 Food for ThoughtTechnology Advances
Contents of Presentation • Technology Advances • Anaerobic Digestion • In-Vessel Composting • Anaerobic Digestion Pro’s and Con’s • In-Vessel Composting Pro’s and Con’s • Current Level of Development
Anaerobic Digestion What is Anaerobic Digestion • Anaerobic – in the absence of air • Digestion – material digested by bacteria to break down the product to a sludge / compost like material and produce a gas (biogas) • Biogas combusted to produce electricity and heat
Public Types of AD and Feedstock • Types of AD • Wet: Pumped and stirred • Dry: Stacked or pushed through as a plug • Typical Farm Feedstock • Animal manure • Silage • Waste crops (Potatoes, cabbage etc) • Energy crops (e.g. Miscanthus) • Dairy wastes • More Complex Feedstock • Household waste (Separately collected organic) • Food processing waste
AD Outputs / Pro’s Digestate • Potential artificial fertiliser replacement • Whole Digestate • Dry Fraction • Wet Fraction Biogas • Can be combusted in an engine to generate electricity and heat
AD Considerations / Con’s Electricity Grid Connection • Is grid connection possible? Feedstock • Are sufficient tonnages of feedstock guaranteed for continuous operation? • Are these homogenous in nature? Sufficient Land to Spread Digestate • Is there sufficient land to spread the digestate (PAS 110 compliance and closed spreading season)? Monitoring • Need for continuous monitoring of the system Finance • Significant capex and opex costs
In-Vessel Composting What is In-Vessel Composting • In-Vessel – in an enclosed system (building or container) • Composting – a biological process in which micro-organisms convert organic matter into a stabilised residue
Types of In-Vessel Composting & Feedstock's Types of In-Vessel Composting • Containers • Silos • Agitated Bays • Tunnels • Enclosed Halls Feedstock • Green Waste • Food Wastes
In-Vessel Composting Outputs / Pro’s Outputs • Compost (PAS100 / Animal By-Product Compliance) • Residual fraction Benefits • Green waste and food waste can be the input waste • Less sensitive to changes in feedstock input • Reduces waste volume • Reduces biodegradability of the waste
In-Vessel Composting Con’s • Large energy usage in aeration and odour control • Large capital costs • Large area required for compost maturation • Product quality and market for final compost • Continuous monitoring
Current Level of Development Existing Capacity *Source NIEA Public Register
Future Development Future Capacity *Source rx3
Organic Resource Management Facilities *Source rx3
Summary Both Anaerobic Digestion and In-Vessel Composting have their place in the market Anaerobic Digestion • Energy recovery • Digestate – potential fertiliser In-Vessel Composting • Potential for a quality compost • Can accept food wastes and green waste co-mingled • Less sensitive to changes in feedstock quantity and quality
For Further Information Contact: Adrian Thompson 028 9066 7914 adrian.thompson@rpsgroup.com