Biological Treatments

Transcription

1 Biological Treatments Key issues in choosing appropriate technologies Boris Efremenko VEOLIA Environmental Services Athens - March 2007

2 Which waste can be treated with Biological Treatments?

3 Types of wastes Household Waste Biowaste or kitchen waste(separative collection) Green waste or garden waste Sewage sludge BioDIV Agriculture waste Others organic waste

4 Different solutions to treat the Organic Matter

5 Different solutions for different aims: Agronomical valorization of the Organic Matter Production of organic soil improvement Stabilization of the Organic Matter Thermical valorization of the Organic Matter Production of biogas for energy production Stabilization of the Organic Matter Stabilization of the Organic Matter Reduction of the volume Stabilization of the Organic Matter

6 What are the process for a biological treatment?

7 Biological Treatment Composting Aerobic degradation Natural or forced Aeration Methanisation or Anaerobic Digestion Anaerobic Fermentation MBT Pre-treatment which recovers maximum value from waste with the residue being used either as a fuel, a compost or going to landfill

8 Composting Production of compost: Organic soil conditioner High product quality with strict regulation

9 Composting phases 1. Reception, Possible Manual Sorting - Visual quality control of input waste 2. Preparation - Mixing if needed (ligneous and non ligneous waste) 3. Active phase - Optimising the moisture (50-60 %) and the air flow. - Windrow watering and turning are necessary. 4. Maturation or curing phase - Turning the pile if necessary 5. Screening - Refining the compost if presence of physical contaminants 6. Storage - Storage before selling.

10 Composting 6 main composting process families family 1 : Trapezoidal windrows, (regular compost line) family 2 : Silos (table windrows /corridors), family 3 : Boxes or racks family 4 : Containers family 5 : In-vessel family 6 : Rotary drums with or without forced ventilation for the composting pre-treatments or preparation process for MSW

11 Residual MSW Composting Depending on the country, regulation imposes compost quality thresholds or treatment requirements. Possible but not evident everytime and everywhere Separative Collection of Toxic Wastes in Spreaded Quantity (batteries), Separate Collection for household hazardous waste (Paint, White Spirit ) No shredding (refining of inerts impossible) Good management of different composting phases Thresholds for high compost quality are needed

12 In France: different processes 2 main types of composting process : Bioreactor or BRS (MSW) - Mechanical pre-treatment Siloda

13 In Egypt : Alexandria Organic Matter : Sorting, Windrow watering and turning every 4 to 6 days with a turner, Active (fermentation) and maturation phases Sieving depending the compost client (14, 20 or 40mm) Recyclables

14 In Brasil:Vila Leopoldina (Sao Paulo) t/y t/d Recycling Plastics (2600 t/y), Metals (2300t/y), Glass (675 t/y), Paper (4200 t/y) and Aluminium(105 t/y) Organic Matter : Sorting & overband Bio-digestion Windrow Turning Active and maturation phases Production of compost

15 Anaerobic Digestion Production of biogas for: electricity generation or heat production or cogeneration. Production of Soil amendment - compost

16 Anaerobic Organic waste Digestion 3 by-products: Sorting + Pretreatment Residus Methan Possible ways for biogas recovery : vehicle fuel injection into town network electricity generation Methanization reactor Raw digester s sludge Dehydration heat Biogas Purifying Biogas Recycling Treatment of contaminated air heat production Liquid effluent Water from process Dehydrated digester s sludge Energy Compost Composting Residus Effluent to be disposed Compost

17 Anaerobic Digestion Methanisation : Available technologies Dry process 15-40% DM Wet process 3-8% DM Low water consumption, High DM content of digestate, Easier dehydration, Low solid sedimentation, Smaller digester volume. Easier pre-treatment, Less wear, Easy process control (watertightness), Better flexibility. More difficult pre-treatment treatment, High water consumption, Difficult mixing, Bigger digester volume, High DCO content in water from Necessary moistening of solid waste. dehydration unit.

18 Anaerobic digestion : Main manufacturers KOMPOGAS VALORGA LINDE OWS DRANCO Kompogas process : dry digestion (30-45 % DM) at thermophilic temperature (55 C). Valorga process : dry digestion (25-35 % DM) mesophilic (35 C) or thermophilic (55 C) process. Linde process 2 technologies : wet mesophilic process, in vertical reactor dry process in cross section horizontal reactor OWS process thermophilic process high concentration of DM: % digestate progresses in plugflow from the top to the bottom

19 .B.T.: Mechanical Biological Treatment MECHANICAL SECTION aims reducing waste size (shredding) separating recyclables separating dry/wet fractions (sieving) BIOLOGICAL SECTION aims stabilising of the waste organic matter (bio-stabilisation) drying of the waste (bio-drying)

20 M.B.T. 2 Streams Scheme Residual Waste Shredding-Sieving High Caloric Fraction Low Calorific Fraction Refinement Landfill Biological Treatment Fuel Stabilised fraction Metals Inerts Inerts Refinement Material Recovery Combustion Restoration Compost

21 M.B.T. 1 Stream Scheme Residual Waste Shredding-Sieving Biological Treatment Landfill Bio-Stabilised Fraction or Bio-Dried Fraction Metals Material Recovery Refinement Fuel Combustion Undersieve fraction Landfill

22 MBT NeuwiedBio-Mechanical Waste-Treatment

23 BIOCUBI PROCESS Simplified Cycle MANAGEMENT OF BIOLOGICAL PROCESS One stream (biological treatment on the whole waste) some dozens of plants in Europe

24 Lorient Plant by LINDE KCA Cap l Orient B.T. Unit t/y Residual MSW t/y Encombrants t/y Biowaste t/y Stabilisation Shredding Composting Stabilised MSW t/y Encombrants t/y Compost t/y Biological Treatment Plant Council : Cap l Orient Constructor : LINDE KCA City : Caudan Investment : 23 M Operator : VEOLIA Environmental Services

25 Whatever you want to do, don t forget to think: about the context, the different waste, the biological processes, the composting techniques... about the material and their maintenance... about the management of gas and liquid effluents, the environmental risk, the occupational safety about the agronomic assets, marketing...

26 Thanks for your Attention