Anaerobic Digestion of Solid Waste 1 Dorothee Spuhler, seecon gmbh

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<ul><li> Slide 1 </li> <li> Anaerobic Digestion of Solid Waste 1 Dorothee Spuhler, seecon gmbh </li> <li> Slide 2 </li> <li> Anaerobic Digestion of Solid Waste Find this presentation and more on: www.sswm.info.www.sswm.info Copy it, adapt it, use it but acknowledge the source! Copyright Included in the SSWM Toolbox are materials from various organisations and sources. Those materials are open source. Following the open- source concept for capacity building and non-profit use, copying and adapting is allowed provided proper acknowledgement of the source is made (see below). The publication of these materials in the SSWM Toolbox does not alter any existing copyrights. Material published in the SSWM Toolbox for the first time follows the same open-source concept, with all rights remaining with the original authors or producing organisations. To view an official copy of the the Creative Commons Attribution Works 3.0 Unported License we build upon, visit http://creativecommons.org/licenses/by/3.0. This agreement officially states that: http://creativecommons.org/licenses/by/3.0 You are free to: Share - to copy, distribute and transmit this document Remix - to adapt this document. We would appreciate receiving a copy of any changes that you have made to improve this document. Under the following conditions: Attribution: You must always give the original authors or publishing agencies credit for the document or picture you are using. Disclaimer The contents of the SSWM Toolbox reflect the opinions of the respective authors and not necessarily the official opinion of the funding or supporting partner organisations. Depending on the initial situations and respective local circumstances, there is no guarantee that single measures described in the toolbox will make the local water and sanitation system more sustainable. The main aim of the SSWM Toolbox is to be a reference tool to provide ideas for improving the local water and sanitation situation in a sustainable manner. Results depend largely on the respective situation and the implementation and combination of the measures described. An in-depth analysis of respective advantages and disadvantages and the suitability of the measure is necessary in every single case. We do not assume any responsibility for and make no warranty with respect to the results that may be obtained from the use of the information provided. Copyright &amp; Disclaimer </li> <li> Slide 3 </li> <li> Anaerobic Digestion of Solid Waste Find this presentation and more on: www.sswm.info.www.sswm.info 3 Contents 1.Concept 2.How can Digestion of Green Waste optimise SSWM 3.Design Principals 4.Examples of Applications 5.Applicability 6.Pros and Cons 7.References </li> <li> Slide 4 </li> <li> Anaerobic Digestion of Solid Waste Find this presentation and more on: www.sswm.info.www.sswm.info 4 Background Anaerobic digestion is a natural process which occurs when organic material is kept in the absence of air. Thereby, the organic material is transformed into biogas, a renewable and green energy. In developed countries, this process has been evolved over the past twenty years, resulting in more and more complex large-scale biogas plants including heating and multiple stage processes. So far, several million conventional biogas plants, using predominantly animal manure as feedstock, have been successfully installed in rural areas of developing countries. (VOEGELI &amp; ZURBRUEGG 2008) Anaerobic digestion, as a controlled and voluntary process for the reduction and reuse of green wastes has a large potential to give answer to the soaring crisis of increasing municipal solid wastes for instance in urban and peri-urban areas of the developing world. (VOEGELI &amp; ZURBRUEGG 2008) 1. Concept </li> <li> Slide 5 </li> <li> Anaerobic Digestion of Solid Waste Find this presentation and more on: www.sswm.info.www.sswm.info Anaerobic Digestion takes place in airtight reactors. The organic fraction of the wastes is transformed into a mixture of CH 4, CO 2 and some trace gases (biogas). The produced biogas can be used either directly for cooking, heating or lightening. It can also be transformed into combined heat and power (CHP) in cogeneration plants. Biogas can also be compressed and sold as fuel (e.g. for vehicles), much like natural gas. With time the reactors fill up and digested sludge (sludge which organic fraction was already converted to biogas) accumulates in the bottom. Nutrients remain in the sludge is a well-balanced fertiliser and can be used in agriculture as a rich soil amendment. 5 Anaerobic Digestion of Green Waste (1/2) 1. Concept </li> <li> Slide 6 </li> <li> Anaerobic Digestion of Solid Waste Find this presentation and more on: www.sswm.info.www.sswm.info Anaerobic Digestion of Green Waste 6 1. Concept D. SPUHLER (2010), Pictures from: www.kristianstad.se/; http://www.newseedadvisors.com/2009/09/10/invest/; http://www.hydroharrys.com/hydroharrys_about_fertilizer.php; http://www.mytinyplot.co.uk/advice/the-art-of-composting/ www.clker.com [Accessed: 02.06.2010]www.kristianstad.se/http://www.newseedadvisors.com/2009/09/10/invest/ http://www.hydroharrys.com/hydroharrys_about_fertilizer.phphttp://www.mytinyplot.co.uk/advice/the-art-of-composting/ www.clker.com Green Waste Coocking Lightning Electricity Fuel Biogas Heating Fertiliser Agriculture </li> <li> Slide 7 </li> <li> Anaerobic Digestion of Solid Waste Find this presentation and more on: www.sswm.info.www.sswm.info Anaerobic Digestion of Green Waste: Small-scale 7 1. Concept Biogas Soil amendement Food Energy D. SPUHLER (2010). Pictures from: //gardening.ygoy.com/wp-content/uploads/2009/10/how-to-plant-a-decorative-vegetable- garden0.jpg; http://www.gardenplansireland.com/forum/about436.html; http://www.clker.com/ [Accessed: 06.06.2010] </li> <li> Slide 8 </li> <li> Anaerobic Digestion of Solid Waste Find this presentation and more on: www.sswm.info.www.sswm.info Anaerobic Digestion of Green Waste: Large-scale 8 1. Concept Source: HOLLIGER (2008) </li> <li> Slide 9 </li> <li> Anaerobic Digestion of Solid Waste Find this presentation and more on: www.sswm.info.www.sswm.info 9 1. Concept Co-digestion of waste and manure Food production at farms Re-use of nutrients Re-use of energy The example of Kristianstad (Sweden) Green waste from households and industries </li> <li> Slide 10 </li> <li> Anaerobic Digestion of Solid Waste Find this presentation and more on: www.sswm.info.www.sswm.info 10 What is Green Waste? 1. Concept Kitchen refuses http://www.mytinyplot.co.uk/advice/the-art-of- composting/http://www.mytinyplot.co.uk/advice/the-art-of- composting/ [Accessed: 04.06.2010] http://www.ceroi.net/reports/dushanbe/eng/waste.htm http://www.ceroi.net/reports/dushanbe/eng/waste.htm [Accessed: 04.06.2010] Organic fraction of municipal waste http://www.agro- resources.com/uploads/images /chocolate%20waste.jpg http://www.agro- resources.com/uploads/images /chocolate%20waste.jpg [Accessed: 04.06.2010] Refuses from the food industry http://www.titech.com/assets/x/50186 ?width=82http://www.titech.com/assets/x/50186 ?width=82 [Accessed: 04.06.2010] Some industrial wastes http://www.bawbawshire.vic.gov.au/Page/i mages/green-waste-grass.jpghttp://www.bawbawshire.vic.gov.au/Page/i mages/green-waste-grass.jpg [Accessed: 04.06.2010] Garden refuses Waste from agriculture http://planetgreen.discovery.com/hom e-garden/images/2009-04/organic- waste.jpghttp://planetgreen.discovery.com/hom e-garden/images/2009-04/organic- waste.jpg [Accessed: 04.06.2010] Market waste http://www.ducorwaste.org/images/Rally_Time_ Stockpike.jpghttp://www.ducorwaste.org/images/Rally_Time_ Stockpike.jpg [Accessed: 04.06.2010] Green waste is any kind refused material which is biodegradable and has a high fraction of organic matter, which can be transformed into biogas. Some examples </li> <li> Slide 11 </li> <li> Anaerobic Digestion of Solid Waste Find this presentation and more on: www.sswm.info.www.sswm.info 11 What is Biogas ? Biogas is a mixture of methane and carbon dioxide. The properties of biogas are similar to the ones of natural gas. Biogas is the common name for the mixture of gases released from anaerobic digestion. Typically biogas is composed of: Methane is the valuable part of the biogas. Biogas that contains about 60 to 70 % of CH 4 has a calorific value of about 6 kWh/m3 what corresponds to about half an L of diesel oil. (ISAT/GTZ 1999, Vol. I) 1. Concept Sources: YADAV &amp; HESSE (1981); FAO (1996); PIPOLI (2005); GTZ (2009 Methane (CH 4 )50 to 75 % Carbon Dioxide (CO 2 )25 to 50 % Hydrogen (H)5 to 10 % Nitrogen (N 2 )1 to 2 % Hydrogen sulphide (H 2 S)Traces Source: MUENCH (2008) </li> <li> Slide 12 </li> <li> Anaerobic Digestion of Solid Waste Find this presentation and more on: www.sswm.info.www.sswm.info 12 What is Anaerobic Digeastion ? (1/2) Degradation of organic material by bacteria. In the absence of air (anaerobic). Four stages: Hydrolisis Cleavage of a chemical compound through the reaction with water. Insoluble complex molecules are bracken down to short sugars, fatty acids and amino acids. Fermentation (Acidogenesis) Products from hydrolysis are transformed into organic acids, alcohols, carbon dioxide (CO 2 ), hydrogen (H) and ammonia (NH 3 ). Acetogenesis Organic acids and alcohols are converted into hydrogen (H 2 ), carbon dioxide (CO 2 ) and acetic acid (CH 3 COOH). Therefore, oxygen is consumed and anaerobic conditions are created Methanogenesis Methanogenic bacteria (methanogenesis), transform the acetic acid, carbon dioxide and hydrogen into biogas. 1. Concept </li> <li> Slide 13 </li> <li> Anaerobic Digestion of Solid Waste Find this presentation and more on: www.sswm.info.www.sswm.info 13 What is Anaerobic Digestion ? (2/2) 1. Concept D. SPUHLER (2010) </li> <li> Slide 14 </li> <li> Anaerobic Digestion of Solid Waste Find this presentation and more on: www.sswm.info.www.sswm.info 14 What is a anaerobic digester ? 1. Airtight chamber, filled with green waste 2. Anaerobic digestion takes place 3. Sludge settles on the bottom 4. Gas bubbles to the top where it is collected Reaction temperature is &gt; 35 to 55 C: mesophilic or thermophilic range Either continuous or in batch mode: Batch: filled and left for digestion; After the hydraulic retention time (HRT) emptied and filled again for a new cycle Continuously-stirred tank reactor (CSTR): continuous in/out flow and mixing Plug-flow reactor: the sludge moves through the reactor much like a train to a tunnel, with a velocity corresponding to the minimal HRT The liquid phase can be re-circulated to maintain optimal moisture conditions 1. Concept Source: HOLLIGER (2008) </li> <li> Slide 15 </li> <li> Anaerobic Digestion of Solid Waste Find this presentation and more on: www.sswm.info.www.sswm.info 15 Examples: Small-scale digesters 1. Concept http://colli239.fts.educ.msu.edu/wp- content/uploads/2009/05/biotech2007cc.jpghttp://colli239.fts.educ.msu.edu/wp- content/uploads/2009/05/biotech2007cc.jpg [Accessed: 04.06.2010] Source: F. HEEB http://images01.olx.in/ui/4/96/20 /67509620_1-Install-biotech- portable-biogas-plants-and- convert-food-waste-to-biogas- Vazhuthacaud.jpghttp://images01.olx.in/ui/4/96/20 /67509620_1-Install-biotech- portable-biogas-plants-and- convert-food-waste-to-biogas- Vazhuthacaud.jpg [Accessed: 04.06.2010] http://www.open2.net/blo gs/media/blogs/Biogas_pla nt_Kerala.jpg Household floating-drum digesters Portable reactors form the Indian NGO BIOTECH </li> <li> Slide 16 </li> <li> Anaerobic Digestion of Solid Waste Find this presentation and more on: www.sswm.info.www.sswm.info 16 Examples: Large-scale digesters 1. Concept http://www.klima-sucht-schutz.de/mitmachen/klima- quiz/lexikon.htmlhttp://www.klima-sucht-schutz.de/mitmachen/klima- quiz/lexikon.html []Accessed: 04.06.2010 Source: BRUYN (2006) </li> <li> Slide 17 </li> <li> Anaerobic Digestion of Solid Waste Find this presentation and more on: www.sswm.info.www.sswm.info 17 Examples: Biogas Appliances 1. Concept Chang Mai M. WAFLER Mini biogas generator Large combined heat and power (CHP) Cogeneratio n plant Biogas boiler Biogas lamp Biogas cooking stove http://www.power.alstom.com/home/new_plants/steam/products/steam_turbines/refe rences/_files/file_40796_97389.jpg </li> <li> Slide 18 </li> <li> Anaerobic Digestion of Solid Waste Find this presentation and more on: www.sswm.info.www.sswm.info 18 2. How the Digestion of Green Waste optimises SSWM Digested sludge can substitute chemical fertiliser and enhance food production Green Waste Coocking Lightning Electricity Fuel Biogas Heating Fertiliser Agriculture Sustainable development: Improved health Improved economy Anaerobic digestion is a promising answer to the soaring crises of municipal waste explosion and thus prevent the pollution of water sources and the evnvironment Biogas is an renewable energy and has the potential to replace other fuel sources. Biogas contributes to prevent and lower greenhouse gas emission. </li> <li> Slide 19 </li> <li> Anaerobic Digestion of Solid Waste Find this presentation and more on: www.sswm.info.www.sswm.info 19 Basics: Process Parameters The biogas yield depends on the process and the substrate. Substrate: High COD (Chemical Oxygen Demand) = High potential of biogas generation Process: Anaerobic digestion = Biological system of bacteria Optimal conditions required that bacteria feel wealthy Temperature Performance Retention time pH Wide range, but methanogenesis requires neutrality (6.5-7.5) Multistage process for better pH and temperature control Total solid (TS) and moisture Wet digestion (TS &lt; 20 %): easier to maintain, good fluidity Dry digestion (TS &gt; 20 %): sophisticated but safes space 3. Design Principals </li> <li> Slide 20 </li> <li> Anaerobic Digestion of Solid Waste Find this presentation and more on: www.sswm.info.www.sswm.info 20 The ARTI compact biogas plant Developed in 2003 ARTI = Appropriate Rural Technology Institute 2000 plants currently used in Maharashtra, India (WRAPAI 2009) Some have been constructed in Tanzania (VOEGELI &amp; LOHRI 2009) Floating-drum design: 2 conventional polyethylene tanks (0.75 and 1 m 3 ). (MUELLER 2007) Standard plumber piping. The smaller tank is the gasholder and the larger holds the mixture of decomposing feedstock and water Inlet and an overflow Overflow liquid is mixed with the feedstock and back recycled into the plant to maintain optimal moisture condition. (MUELLER 2007) A pipe takes the biogas to a collection balloon or directly to the kitchen. 4. Examples of Applications Source: HEEB (2009) Source: VOEGELI &amp; LOHRI (2009) </li> <li> Slide 21 </li> <li> Anaerobic Digestion of Solid Waste Find this presentation and more on: www.sswm.info.www.sswm.info 21 The BIOTECH Plant (1/2) BIOTECH is a nodal agency of the Ministry of Non-Conventional Energy Sources in Kerala, South India. (MUELLER 2007) Domestic plants: 1 m 3 for a 3 to 5 member-family meets about 50 % of cooking needs. (MUELLER 2007) Decentralised treatment of market waste,...</li></ul>