ANAEROBIC DIGESTION OF WASTE BUSINESS ROUND TABLE ON RENEWABLE ENERGY Aniche Phil-Ebosie MIDORI ENVIRONMENTAL SOLUTIONS 8 TH March 2013.
0. Cast study: Lagos state Piggery (Future) 1. Case study: Ibeju lekki biogas plant (Present) 1.1 Energy Kiosk 2. Case study: Ketu fruit market biogas plant (Past) 2.1 A waste management system 2.2 A form of renewable energy 2.3 An organic manure producer 2.4 A GHG saving tool 3. Conclusion
0. Case study: Oke Aro Pig Farm (Future) The OKE ARO pig farm is located in Alimosho Local Government, Agege, Lagos State. It is located on 25 Hectares of land and harbors over 2000 pig farmers with a minimum of 200,000 pigs The OKE ARO pig farm has the highest concentration of pigs in the West African Sub Region. The farm is a Lagos State initiative set up in the 1980s to provide employment opportunities within the state.
0. Large scale biogas plant A pig produces on average 1kg of waste everyday. 200,000 pigs will produce 200,000 kilograms of manure daily. This has the capacity to produce biogas which can be converted into about 2MW (megawatt) of electricity or used as an alternative to natural gas. We have sourced and are currently starting a partnership with a prospective off taker for the biogas. Midori requires renewable energy financing to be able to carry out this project. Midori visited the OKE ARO pig farm in November 2012 with our technical partners from Europe to make an initial assessment of the scale of work to be done. Our plan is to build a large scale biogas plant at OKE ARO.
1. Case study: Ibeju Lekki biogas plant (Present) Ibeju Lekki is a local government area of Lagos state and has over 30 rural communities. The locals are predominantly fishermen These communities are not connected to the national grid. Community Conservation Development Initiative (CCDI) decided to provide one of the communities with a waste management and energy generation system using biogas.
1.1 Energy Kiosk The idea is to use fish gut and water hyacinth in the production of biogas. The biogas will be used as a source of fuel for a 10KVA generator This generator will in turn provide power for an Energy kiosk. Regular car batteries can be combined with 300-500 watts inverters to generate electricity for fans,light bulbs and small tv sets The locals bring their batteries to the energy kiosk and pay a small fee to have them charged.
2. Case study: Ketu biogas plant (Past) Lagos state generates 9000 tons of waste daily. Over 50% of this waste is organic. How can this be converted into a source of value? The Lagos Waste Management Authority (LAWMA) and Midori Environmental Solutions embarked on a pilot project to convert fruit waste at the Ketu market Lagos to biogas, organic manure and electricity for the market. Midori obtained a technology transfer / license from Africom Technology of German to fabricate their small scale anaerobic digesters in Nigeria. This low tech biogas system can be fabricated 100% locally in Nigeria or anywhere else in the world.
The Ketu fruit market generates over 5 tons of fruit waste daily. These come as squashed and rotten fruit during transportation and storage. It includes: pawpaw water melon pineapples oranges plantain and banana peels 2.1 A waste management system LAWMA trucks collect this waste daily 45% goes to landfill 50% taken off-site and composted 5% is used for our biogas process on-site
2.2 A form of Renewable Energy The small scale biogas digester technical Characteristics: Digester tank volume Complete fermentation Daily organic waste Daily biogas production Electricity capacity 26 m3 21 days 200 kg 20-30 m3 7.5 KVA Running cost 7.5 KVA petrol generator: N4000 - N5000 petrol for 12 hours. Running cost 7.5KVA biogas generator: Negative cost The electricity generated will be used within the market, especially for security lights at night.
2.3 A source of organic manure Another product of anaerobic digestion is organic manure or digestate. Digestate has improved fertiliser efficiency due to its: homogeneity higher nutrient availability nitrogen content phosphorus content Potassium content micronutrients The digestate collected at the Ketu market biogas plant will be bottled and sold for a token fee to the same farmers that bring in fresh organic fruits into the market to be used on their farms.
2.4 A GHG saving tool In contrast to fossil fuels, burning biogas only releases the amount of atmospheric CO2 that was stored in plants during its growth. Thus, the carbon cycle of biogas is closed. GHG savings include three main parts: Potential emission saved due to CH4 utilization from organic waste. Emission saved due to electricity produced from biogas instead of burning petrol or diesel. Emission saved due to replacement of mineral fertilizers. The Ketu biogas plant adequately combats the hazards of two green house gases, CO2 and CH4.
3. Conclusion Small scale biogas plant organic waste capacity: 200 kg / 0.2 tons per day 1400 kg / 1.4 tons per week 5600 kg / 5.6 tons per month 67200 kg/67.2 tons per year Imagine we had just a hundred of these plants spread in markets, poultry farms, abattoirs and rural communities all over Nigeria. 67200 kg X 100 = 6,720,000 kg of organic waste could be dealt with yearly, making a fair contribution to the reduction of greenhouse gas emissions in Nigeria.
Thank you