Anaerobic Digestion Wastes

Traditionally anaerobic digestion wastes were manure, animal waste and waste water sludge. But recently food processing waste and organic waste from household have drawn significant attention as promising feedstocks that can increase gas production significantly. In addition, agricultural residues, yard waste and even municipal solid waste can also be used as feedstocks for anaerobic digestion after appropriate pre-treatments. Introduction of new pre-treatment technologies and innovative digester types have opened the option of recovering energy from diverse waste streams rather than sending them to land fill.

Some common and emerging feedstocks for anaerobic digestion are discussed below:

Anaerobic Digestion Wastes Types

Manure

Solid or liquid manure produced in animal farms (cow, pig, chicken etc.) is one of the main feedstocks for biogas production.

Domestic Source Separated Organic (SSO) Waste

This waste category include separately collected kitchen waste like fruit and vegetable waste, food waste, coffee and tea filters and other organic leftovers.

Yard and Plant Waste

Yard or plant waste include leaves; garden wastes likes flowers, plants, vegetables; branches and tree trimmings, grass clippings etc.

Energy Crops

Energy crops are plants suitable for producing biogas and other renewable energy. Examples of energy crop include corn, Sudan grass, maize, millet, white sweet clover, sugar cane etc.

Sewage Sludge

Almost all Wastewater treatment plants produced sewage sludge and this sewage sludge can also be used as feedstocks for anaerobic digestion to produce biogas. Although due to its limited potential for biogas production it is not treated as a high quality substrate.

Industrial and Restaurant Food Waste

Industrial food wastes mainly come from food and meat production sites like slaughter house waste, whey, potato mash, brewer grains etc. In addition food waste can be collected from restaurants, grocery stores, and other food handling facilities and used as high potential biogas producing substrates.

Potential Co-digestion Feedstocks

Many high strength and emerging feedstocks have the potential to be co-digestion feedstocks. A good co-digestion feedstock should fulfill certain requirements such as: