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NEWAPP Wet biomass waste in Europe - Present initiatives and future targets Christoph Knauer ttz Bremerhaven 4th NEWAPP Workshop June 4th, 2015 Vienna, Austria. Index. Screening of wet biomass waste Sources , amounts , properties , current treatment , etc.
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NEWAPP Wet biomass waste in Europe - Present initiatives and future targets Christoph Knauer ttz Bremerhaven 4th NEWAPP Workshop June 4th, 2015 Vienna, Austria
Index • Screening ofwetbiomasswaste • Sources, amounts, properties, currenttreatment, etc. • Investigation ofsuitabilityfor HTC • Political frameworkconditions • Conclusionsandoutlook
Wet biomass waste • Biomass = matter producedbylivingorganisms • Life requireswater -> biomassusuallywet • Problems: • Waste-> low-valueproduct (energeticuse) • High moisture content -> cannot be burned or transported (drying economically inefficient) -> Efficient valorization processes need to be found
Wet biomass waste • Photos
The Waste Framework Directive • Directive 2008/98/EC • Sets the framework for waste legislation in the EU member states • Demands material uses for organic waste • Target: 50 % re-use and recycling of certain waste streams by 2020
Methodology • Identification and first evaluation of organic waste categories (EUROSTAT) • Cross-linking of the data with data on waste generating sectors (NACE-2) to obtain further infos • Chemical analyses, literature studies and questionnaires • Final selection of waste streams most suitable for HTC
Organic waste categories (EUROSTAT) • Industrial Effluent Sludges (3.2) • Sludges and Liquid Wastes from Waste Treatment (3.3) • Health Care and Biological Wastes (5) • Paper and Cardboard Wastes (7.2) • Wood Wastes (7.5) • Textile Wastes (7.6) • Animal and mixed food wastes (9.1) • Vegetal Wastes (9.2) • Animal, Urine and Manure (9.3) • Household and Similar Wastes (10.1) • Mixed and undifferentiated Material (10.2) • Sorting Residues (10.3) • Common Sludges (11)
Current ways of waste treatment All wastecategories
Current ways of waste treatment Vegetalwaste
Chemical analyses & literature study • Chemical analysis: Determination of • Humidity • Lignocellulose content (incl. Cellulose + Lignin content) • Ash content • Volatiles content • Extractives content • Elemental analysis • ICP-OES analysis for ash composition • Cl- and F- content • HHV • Extensive literature research and questionnaires to confirm and complete lab results
Most suitable waste streams After the chemical analyses, literature studies and questionnaires 5 biomass waste streams with the highest potential for HTC were finally selected: • Sewage sludge • Digestate • Green waste • Food waste • Organic fraction of municipal solid waste (OFMSW)
Final evaluation Sewage Sludge • For the HTC process the water content should be increased slightly to 80–85%. • The pH value is neutral to slightly basic (from 7.1 to 8.1), while moderately acidic is required. Therefore, it has to be evaluated if the process can be run without any additives. • The carbon content is only 20 to 30%, mainly due to a high inorganic (= ash) content of 25 to 50%. • As for HHV, literature values (16.7 MJ/kg) reflect very well the composition of a mixture of organics with a high ash content. An interesting issue is the considerable content of nitrogen as ammonium nitrogen. It has to be monitored if it is released as gas or dissolved in the process water. Sewage sludge was selected for the HTC testing. • Low value waste that has to be disposed under the responsibility of the municipal and regional public administrations. • Due to its composition the waste stream should be suitable for the HTC process but process parameter might have to be adjusted.
Final evaluation Digestate • Very heterogeneous waste stream. Properties strongly depend on feedstock. • Water content is more than 90%, slight reduction required. • The pH is ranging between slightly acidic and slightly alkaline (6.5 – 8.4), might need to be adapted. • Carbon content is around 40% (comparable to garden waste). • The HHV ranges from 18.2 to 19.1 MJ/kg DM (comparable to wood). • The high ash content will likely require a reduction after the HTC process. This will yield cleaner char, with a broader range of purposes. • The high content of phosphorous (15.9%) as P2O5 could make the produced char suitable as a fertilizer. Potassium content (as K2O) of 5.2% is rather low. Digestate was recommended for further testing with HTC. • It is a waste stream that appears almost directly suitable for HTC, although cleaning of the char to remove ash may be needed. • Current treatment is primarily a responsibility of the municipalities, and the current treatment is limited and mainly restricted to disposal or combustion.
Final evaluation green waste, vegetable waste, OFMSW • In 2010, around 48 M tons of organic household waste were generated in the EU-27, suitable for HTC treatment. • If HTC-treated, assuming an average carbon content of 40% and 90% efficiency in the carbonization process, over 26 M tons of carbon could be produced in the EU per year. • Moisture content: the values in the survey (60-79%) are consistent with literature studies (54-85%) and lab analyses (77.3%), suitable for the HTC. • Carbon content around 40%. • Literature reports relatively low ash contents: 5.8% for the food waste fraction, 6-25% for total OFMSW, but up to 48% for garden prunings (lab analysis only 7.9%). Values compatible with potential HTC products. Green & vegetable waste, OFMSW were recommended for further testing with HTC. • Properties andproducedamounts fit well(biggest potential) • Dissatisfaction of stakeholders with current treatment options reported in the questionnaires (lack of real market for compost, high costs compared to quality).
Conclusions and outlook • Large amounts of unused wet biomass waste available • Sources, composition and current way of treatment strongly depend on country • Several waste streams suitable for HTC identified: • Sewage sludge • Digestate • Green waste • Food waste • Organic fraction of municipal solid waste (OFMSW) • Further research required
Thank you for your attention! Christoph Knauer ttz Bremerhaven Fischkai1 27572 Bremerhaven (Germany) E-Mail: cknauer@ttz-bremerhaven.de Tel. : +49 471 80934-159