Lecture__04_AG.Engg._232_2012.pdf

Different Models of Biogas Plants  Different Models of Biogas Plants Kaccha-Pacca Plant Developed at: PAU, Ludhiana Salient Features: This plant consists of a pit, steel gas holder, guide frame, feed inlet and slurry outlet. A brick lining is provided around the gas holder. T...

Different Models of Biogas Plants  Different Models of Biogas Plants Kaccha-Pacca Plant Developed at: PAU, Ludhiana Salient Features: This plant consists of a pit, steel gas holder, guide frame, feed inlet and slurry outlet. A brick lining is provided around the gas holder. The gas holder rests on a steel frame which itself is fixed on the top of the kaccha pit. This type of biogas plant is suitable where the topsoil is sandy The plant is cheaper by about 50-60%. Kaccha-Pacca Plant  Capsule Biogas Plant Developed at : CSK HPKV, Palampur Salient Features: The biogas plant resembles the shape of a horizontal capsule. consists of fixed dome type RCC gas holder, digestion chamber, feed inlet and slurry outlet. The arch segment has only 1.4m section diameter in comparison to 2.72 m-in case of Janata biogas plant which makes it easier to construct it with stones. A higher gas production is reported in case of this digester as compared to Janata, KVIC, etc. It maintains high temperature in the digestion chamber as compared to other plants. Capsule Biogas Plant  Janata Biogas Plant Developed at : PRAD, SPI, Lucknow Salient Features: The gas holder of the plant is built with bricks and cement as dome cover of the well like digester. It does not use any steel components. Besides gas holder and dome, other parts of the plant are outlet chamber, inlet chamber and gas pipes. When the gas is produced, it ascends towards the top of the dome and pushes the slurry down. This provides necessary pressure for release of gas upto the burner. Plant upto 6 0 m3 capacity are available. Janata Biogas Plant  IARI Biogas Plant Developed at : IARI, New Delhi Salient Features : The plant consists of a fermentation well, a gasholder, a feeder basin, a moisture trap weight hanger and necessary pipe connections. This small size gas plant produces about 3 m3 of fuel gas and requires about 50 kg of fresh dung per day. When fresh slurry is added through the feeding basin, the digested slurry from the fermentation well automatically overflows into the collection pit. A medium size gas plant producing about 9 0 m3 gas/ day has also been made by 1ARI, New Delhi IARI Biogas Plant  Deenbandhu Biogas Plant Developed at: AFPRO, Lucknow Salient features: The plant is the fixed underground digester chamber, constructed with a layer of bricks and an additional layer of cement mortar forming the roof above. Connected to the underground chamber is an inlet tank (labelled on diagram as “Mixing Tank”), through which dung is fed into the plant. The dung then ferments separating the slurry from the methane gas which rises and collects at the top of the digester tank, and is released through the gas outlet pipe. The slurry passes into the outlet tank where it is ejected from the plant.  Deenbandhu Biogas Plant Developed at: AFPRO, Lucknow  KVIC Biogas Plant Developed at: Khadi and Village Ind Comm. Bombay Salient Features: The plant has a digester, a gas holder, inlet and outlet pipes, slurry preparation tank and slurry pits. Fresh dung is mixed with water in ratio 1 : 1 and fed to the digester where it undergoes anaerobic fermentation to produce biogas. Spent slurry is a rich source of plant nutrient and is used as a manure. Plant up to 140 m3 capacity are available. KVIC Biogas Plant  PLANNING & DESIGN CONSIDERATIONS SELECTION OF SITE As nearer as possible to the source of animal waste. As nearer as possible to the points of utilization. kitchen. (minimizing cost on pipe line) A place with enough open space to build the biogas plant , manure pits and to store the digested slurry. A place fully exposed to sun light. Away from a drinking water well or a similar source of water. Safe distance is 15 metres.  SELECTION OF SITE There should not be big trees near the site selected (Shady area) and the roots may cause damage to the digester. At a higher elevation than the surroundings. The edge of the biogas plant should be about 2 m away from the foundation of the house or any other building.  FAMILY SIZE BIOGAS PLANTS Basic inputs for family size biogas plants are Animal dung and Water. It should therefore be ascertained as to whether there is an adequate supply of these inputs.  Technical feasibility To decide about the feasibility of a proposal, it is necessary to have a broad idea about requirement of biogas for various uses, quantity of biogas that could be obtained from various animal wastes.  Requirement of biogas Cooking : 8 to 10 cft.(0.23 m3 to 0.29 m3)/person/day Lighting : 4.5 to 5 cft (0.13 m3/h to 0.14 m3/h), for single mantle lamp of 100 cp. Motive power : 15 cft.(0.45 m3)/h /hp