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Constructing a Medium Sized Biogas Plant Using Kitchen Wasteby antoniraj on September 19, 2014

Table of Contents

Constructing a Medium Sized Biogas Plant Using Kitchen Waste . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1

Intro:   Constructing a Medium Sized Biogas Plant Using Kitchen Waste . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2

Step 1:   What is Biogas, What is Biogas Plant and How it Functions...? . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2

Step 2:   Selection of Tanks . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3

Step 3:   Other Materials Required . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4

Step 4:   Adhesives Used . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6

Step 5:   Tools Required . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7

Step 6:   Preparation of Gas Holder Tank . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8

Step 7:   Preparation of Digester Tank . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10

Step 8:   Fixing the Feed Pipe to the Digester Tank . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12

Step 9:   Fixing Slurry Outlet Pipe With The Digester Tank . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 14

Step 10:   Fixing The Guides Over Digester for the Movement of Gas Holder Tank . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 16

Step 11:   Providing Guide Support on the Gas Holder Tank . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 18

Step 12:   Preparation of Gas Pipes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 19

Step 13:   Fixing Gas Outlet from the Gas Holder Tank . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 21

Step 14:   Placing Tank and Fixing Slurry Outlet Pipe . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 23

Step 15:   Fixing the Waste Feed Pipe . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 24

Step 16:   Place the Gas Holder Tank and Finish . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 25

Step 17:   Feeding the Biogas Plant for the First Time . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 26

Step 18:   Gas Formation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 27

Step 19:   Type of Material whicn can be used for Feeding the Biogas Plant . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 28

Step 20:   Materials unfit for Biogas Digester . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 31

Step 21:   How Much to Feed...? . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 31

Step 22:   A Word of Caution : Never Try This . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 32

Step 23:   My Presentation on Biogas and Panchagavya . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 33

Related Instructables . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 35

Advertisements . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 35

Comments . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 35

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Author:antonirajI like to make things more simple with easily available resources. My favorite quote: A human being should be able to change a diaper, plan an invasion,butcher a hog, conn a ship, design a building, write a sonnet, balance accounts, build a wall, set a bone, comfort the dying, take orders, give orders,cooperate, act alone, solve equations, analyze a new problem, pitch manure, program a computer,cook a tasty meal, fight efficiently, and die gallantly.Specialization is for insects.! - Robert A. Heinlein

Intro:  Constructing a Medium Sized Biogas Plant Using Kitchen WasteLong back I have posted an instructable on how to construct prototype of a Biogas plant, using 50 liter capacity tank as digester, which you can see here :http://www.instructables.com/id/Bio-gas-plant-usin...

That was my first instructable and people are still commenting and asking me for guidance on Biogas plants for home use and for demonstration at schools & colleges. Ihave replied and mailed guidelines to almost all of the queries and I hope that helped them in their quest for building their Biogas plant.

As you can see in the last step of this instructable, I was invited by Hajee Karutha Rowther Howdia College, Uthamapalayam, Theni District in Tamil Nadu, India, topresent a keynote address on Biogas and Panchagavya (an organic product made from produce from cow). This event was supported by the Tamil Nadu State Councilfor Science and Technology, Chennai, attended by local farmers, self-help group members and students. Many of the attendees expressed their interest in Biogas plantusing kitchen waste and wanted to see a working plant.

This is my attempt at constructing a medium sized Biogas plant for home use as well for demonstration to students and others using a 750 liter capacity tank as digesterand a 500 liter capacity tank as a gas holder, a floating type gas holder method. I have provided easy to understand step-by-step instructions on how to build the plant.Please go through this instructable and feel free to post your comments and queries with respect to biogas.

Step 1: What is Biogas, What is Biogas Plant and How it Functions...?What is Biogas...?

For those who are not familiar with the term Biogas :

Microorganisms who thrive in the absence of air digests the organic material and releases a mixture of gases. The gases thus produced contains mostly methane alongwith other gases like Carbon dioxide, Nitrogen and Hydrogen Sulphide in small quantities. This process is known as anaerobic digestion.

Methane is a colorless and odorless gas and is highly flammable. (It is Hydrogen Sulphide that smells bad) Methane is not poisonous.

Methane along with other gases occurs naturally in swamps, waste dumps and even in home toilets in the septic tank. Due to its highly flammable quality, it can be usedas fuel. But capturing the methane from the atmosphere is very difficult as it is lighter than air. The Biogas Digester or Biogas Plant we see here is a device which helpsus in collecting this gas and use it as fuel.

Biogas Plant

You can see the opened-up prototype of a Biogas plant in above photograph.

The Biogas plant consists of a digester tank, where the organic material is stored and the microorganisms work on them and release gas.

The gas thus produced is collected in a tank known as gas collector. In a floating type model, this tank is floating in the slurry and moves up-and-down based on theamount of gas stored in it

A guide pipe helps the gas collector tank to move up-and-down inside the digester tank.

Waste is fed through feed pipe inside the digester tank.

The fully digested slurry drains out through the outlet pipe. This can be collected, diluted and used as fertilizer for plants.

A gas pipe line from the Gas collector tank helps in utilizing the gas for cooking and lighting

Now let's get down to business and construct a medium sized Biogas plant for home use

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Step 2: Selection of TanksBefore selection of tanks, I need to consider how much of digestible kitchen and garden waste I could collect everyday for feeding the tank. In my case I can easily collectbetween 3.5 to 4 kilogram of waste from kitchen and home garden. This quantity will be sufficient for a biogas plant with 700 to 800 liter capacity digester tank. Since only750 liter capacity tanks are available in the market, I have selected a 750 liter tank to be used as the digester. A simple thump rule for biogas plant for home use is 5kilograms of waste needs a 1000 liter capacity digester.

Now for the selection of gas holder tank, I need to consider the following before buying the tank:

The model I am building is with a floating type gas holder tank. That means the gas holder will move up and down based on the amount of gas inside. So, the gas holdertank should fit inside the digester and also should have minimum difference between their width as this will reduce in loss of gas through the sides.

During market search, I found that the 500 liters capacity tank will meet the requirement, having a width difference of about 100 mm, that means 50 mm on each side. So,I have decided to use the 500 liter tank as gas holder, which will have an up-and- down movement inside the digester using guides.

Some designs cater for a water seal between the digester and gas holder, but in my case that will considerably reduce the capacity of the digester. However, the gas lossthrough the sides will be very marginal with respect to providing a water seal and reducing the capacity of the digester.

In the above photographs, you can see the selection of my tanks. They are of very good quality three layered tanks that can withstand exposure to sunlight and acidiccondition of the slurry inside.

Image Notes1. 750 liter capacity tank to be used as Digester

Image Notes1. 500 liter capacity tank to be used as Gas Holder

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Image Notes1. These tanks are high quality 3 layered tanks

Step 3: Other Materials RequiredIn addition to the tanks, I have utilized the following PVC parts

PVC Door elbow 120 mm dia one number to be used for feeding wastePVC pipe 50 mm dia 300 mm long to be fitted with digester for slurry outletPVC pipes 32 mm dia 250 mm long 4 pieces to be fitted with digester for guide systemPVC pipes 32 mm dia 1000 mm long 4 pieces for guide systemPVC pipes 12 mm dia 1000 mm long 4 pieces for guide system and stabilizing gas tankPVC pipe 120 mm dia one piece to be used for waste feedingPVC cap 120 mm dia for the waste feed pipePVC pipe 50 mm dia about 5 meters for the slurry outlet systemPVC bend 50 mm dia one piece for the slurry outlet systemPVC 32 mm dia threaded couplers 4 pieces to be fitted with gas tank for guide systemPVC 32 mm dia plain couplers 4 pieces to be fitted with digester for guide systemPVC Elbow reducer 32 mm to 12 mm 4 pieces for the guide system

Items required for the Gas pipe line is given separately in Step 10 below

Image Notes1. 120 mm dia Elbow with provision for opening: to be used for feeding waste

Image Notes1. 50 mm dia pipe to be used for slurry outlet

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Image Notes1. four pieces of 32 mm dia pipes to be used as guides: will be fitted on digestertank

Image Notes1. 4 pieces of 32 mm dia, 1 meter long pipes to be used for guide2. 4 pieces of 12 mm dia, 1 meter long pipes

Image Notes1. 120 mm dia pipe one meter long for feeding waste2. Cap for the 120 mm dia pipe

Image Notes1. 50 mm dia bend2. 50 mm dia pipes about 5 meters to be used for slurry outlet

Image Notes1. 32 mm dia coupler 4 numbers to be fitted with gas tank for guide

Image Notes1. 32 mm dia coupler 4 pieces to be fitted with digester for guide

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Image Notes1. reducer elbows 32 mm to 12 mm to be fitted on guide pipes

Step 4: Adhesives UsedFor joining the parts of the gas plant, I have used the following adhesives

Araldite Epoxy AdhesiveM-Seal Epoxy CompoundPvC Solvent Cement

Image Notes1. Araldite Epoxy Adhesive

Image Notes1. M-seal, a two parts based epoxy compound

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Image Notes1. PVC Solvent cement

Step 5: Tools RequiredYou can see here that construction of this plant does not require many tools. These are list of tools I have used:

A hacksaw with frameA single sided hacksaw bladeA sharp knifeA medium sized hammerSet of spanners to tighten the gas pipe connectors

For crimping the connectors with the ends of gas pipes, I got assistance from the shop from where I bought the gas pipes. They helped me with their Hand crimpingequipment as per my requirement. (please see Step 10)

Image Notes1. Hacksaw

Image Notes1. Single-edge Hacksaw Blade

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Image Notes1. Sharp Knife

Image Notes1. Hammer

Image Notes1. Spanner sets

Step 6: Preparation of Gas Holder TankThe 500 liter capacity tank is required to be cut at the top. The visible top ridge will be used as guide line to cut the tank

Using a sharp knife make a slot along the lineNow you can insert a hacksaw blade in the slot and cut along the ridgeThe hacksaw blade gets very hot. Wrap the end with a piece of clothCut through the ridge and remove the top cut portion from the tank

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Image Notes1. The gas holder tank will be cut here

Image Notes1. Make an insertion with a sharp knife

Image Notes1. insert a hacksaw blade and cut along the line

Image Notes1. cut along the line using a hacksaw blade

Image Notes1. wrap the hacksaw blade in a piece of cloth as it gets very hot

Image Notes1. Top portion of the 500 liter tank removed

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Image Notes1. To be used as Gas holder tank

Step 7: Preparation of Digester TankThe top portion of the digester tank also needs to be cut and removed. However, the width of cutting should be just enough for the free movement of gas tank

Place the removed top portion of gas holder on top of digester tankLeave about 20 mm on all sides and mark the guide line for cuttingUsing a hacksaw, cut slots on top of projected portion of digester tankNow use a hacksaw blade to cut along the guide line and remove the topFinish the cut edges with sand paper

Image Notes1. place the cut top portion of 500 liter tank over the 750 liter tank

Image Notes1. Approximately mark the line for cutting the 750 liter tank

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Image Notes1. cut on top of projected portions of 750 liter tank

Image Notes1. use a hacksaw blade to cut all around the 750 liter tank

Image Notes1. wrap a piece of cloth over the hacksaw blade as it gets very hot

Image Notes1. Top portion of 750 liter tank removed. This will be used as Digester tank

Image Notes1. clean the cut edges using a piece of sand paper

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Step 8: Fixing the Feed Pipe to the Digester TankThe 120 mm dia door elbow need to be fixed at the bottom of the digester tank

Place the elbow and mark the cutting linemake a slot along the line with a sharp knifeInsert the hacksaw blade in the slot and cut along the guide lineInsert the Elbow in placeSeal with M-seal epoxy compound on both outer and inner sides of the tank

Image Notes1. 100 mm dia elbow to be used for feeding the digester

Image Notes1. mark the outline to be cut

Image Notes1. make an insertion using a sharp knife

Image Notes1. cut along the line with a hacksaw blade

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Image Notes1. Hole ready for fixing elbow

Image Notes1. insert the elbow in the cut hole

Image Notes1. mix equal parts of epoxy compound

Image Notes1. epoxy compound

Image Notes1. seal the elbow with epoxy compound

Image Notes1. elbow fixed with the digester

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Image Notes1. the feed pipe will connect with the elbow like this

Image Notes1. seal from the inside also with epoxy compound

Image Notes1. view of the feed pipe inside the digester tank

Step 9: Fixing Slurry Outlet Pipe With The Digester TankThe 50 mm dia 300 mm long pipe is to be fitted at the top of digester for the slurry outlet

Place the pipe on top portion of digester tank opposite to the feed pipeMark the cutting lineUsing a sharp knife cut along the guide line and remove the cut pieceInsert the slurry outlet pipe and seal with M-seal epoxy compound from both sides of the tankYou can cut and remove the extra projection inside tank if required. Otherwise leave as it is

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Image Notes1. place the 40 mm dia pipe on top portion of digester

Image Notes1. mark the outline for cutting

Image Notes1. make an insertion with a sharp knife

Image Notes1. cut along the line with the sharp knife

Image Notes1. finished cutting the opening

Image Notes1. hole for fixing slurry outlet pipe

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Image Notes1. insert the 40 mm dia pipe through the hole

Image Notes1. fix the slurry outlet pipe using epoxy compound

Image Notes1. cut and remove any unwanted length of slurry outlet pipe from inside

Step 10: Fixing The Guides Over Digester for the Movement of Gas Holder TankSome sort of guides are to be provided for the easy up-and-down movement of gas holder tank. We will use the 250 mm long 32 mm dia pipes for this.There are sixprojected portions on top of the digester. The slurry outlet pipe and waste input pipe are in alignment with two them opposite to each other. Leaving these two we will fix32 mm pipes on other four projections. These pipes will be extended after placing the gas holder tank.

Place the 32 mm dia pipe on top of projections and make a markUsing a hacksaw cut and removea square portion of the marked area.Insert 32 mm dia pipes on all these cut portions and fix with M-seal epoxy compoundAfter the compound is cured cut and remove excess leaving about 25 mm projection

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Image Notes1. mark the outline of 32 mm dia pipe on top of extended portion

Image Notes1. A slot to be made here

Image Notes1. cut with a hacksaw

Image Notes1. place the 32 mm dia pipe

Image Notes1. this will be used as guides for movement of gas holder tank

Image Notes1. fix with epoxy compound

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Image Notes1. These pipes will be used to as guiding system for the gas tank

Image Notes1. trim excess leaving about 25 mm projection

Step 11: Providing Guide Support on the Gas Holder TankAs we have seen in the previous step, 4 numbers of 32 mm dia guide pipes have been provided on top of the digester. In order to keep the gas holder tank in alignment,we will provide a sort of guide system on the sides of the gas tanks. Here we can use the 40 mm dia threaded couplers for this. Fix only two numbers opposite to eachother. We can fix the other two once we place gas tank inside the digester and observing the movement of gas holder.

Image Notes1. apply epoxy compound on the side

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Image Notes1. use a flat object to position the guide

Image Notes1. guides fitted with gas holder tank

Step 12: Preparation of Gas PipesI spent one full afternoon in shopping and preparing the Gas pipes. There will be three sets of gas pipes as below

From Gas Holder tank to the Link Pipe mounted on wallLink pipe between gas holder tank pipe and kitchenFrom the link pipe to Biogas stove

Parts required

Three pieces of gas pipes, all about 2.5 meters longBall valve 2 numbers one with gas outlet on gas tank and another with the end of link pipeBend 1 number over the gas tankNipple 1 number over gas tankAdapter 1 number inside gas tank connecting nipple with the bendThree numbers of barbs with male threaded ends crimped with clips at one end of pipesTwo numbers of barbs with female ends crimped with clips at other end of pipes (One end of the pipe is left free as this will connect with the stove)Inner and outer washersOne roll of teflon tapeFew 12 mm size U-clamps for fixing the link pipe on the wall

At the shop itself I have measured all the pipes and used their hand-crimping tool to crimp all the ends of pipes. The pipes are tested for leakage by fixing the closed ballvalve at each end separately, immersed in water and blowing air from the other end.

Image Notes1. Gas pipe with accessories to be connected with Gas tank and Link pipe

Image Notes1. Accessories to be connected with Gas Holder Tank

Image Notes1. Link pipe, both ends crimped with a ball valve

Image Notes1. Gas pipe to be used from link pipe to Stove

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Image Notes1. All three sets of gas pipes with accessories

Image Notes1. inner and outer washers for the gas pipe connection

Image Notes1. A roll of teflon tape

Image Notes1. Clamps for fixing gas pipe on the wall

Image Notes1. Measuring and cutting the gas pipes at the shop

Image Notes1. Hand crimping the gas pipes at the shop

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Image Notes1. Hand crimping tool

Image Notes1. close one end with ball valve, keep the joint inside water, blow air and check forleakage

Step 13: Fixing Gas Outlet from the Gas Holder TankAssemble all parts required for the gas outlet.Using a sharp knife, make a small hole at the center of the Gas holder tank. You can make a neat round hole by just twisting the knife all around. This hole shouldnot be larger than the threaded portion of the accessoriesUse suitable inner and outer washers at all joints. All threads must be covered with teflon tape.Connect the gas pipe with the bendConnect the bend with the nippleConnect the nipple with the adapter inside the tank. Make sure all joints are tightened properlyProvide a leak proof joint by applying epoxy resin over the joint from outside and inside the tank

Image Notes1. make a small hole on top of gas holder with a sharp knife

Image Notes1. hole visible fro inside tank

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Image Notes1. add washer to inside of fittings2. use teflon tape over threads

Image Notes1. use outer washer

Image Notes1. Gas outlet assembly

Image Notes1. Gas outlet fitted with gas holder tank

Image Notes1. seal with epoxy emulsion to prevent leakage

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Step 14: Placing Tank and Fixing Slurry Outlet PipeNow we can move our digester tank to the desired location. Select a site where,

The unit gets more sunlightEasier access for feeding wasteEasy to remove the slurry and use it properlyMinimum distance from the Biogas unit to the place of utilization

Here, I have place the unit on the terrace which gets maximum sunlight throughout the day. I have also provided a pipeline from the biogas plant for easy collection ofslurry down. The kitchen is very adjacent to the plant and the gas line can be taken through the ventilator opening on the wall.

The couplers required for fixing guide pipes for the gas holders also added at this point. Place the couplers over the already fixed 32 mm dia pipes and lightly tap themdown in place using a hammer

Image Notes1. The Biogas plant will be placed here2. Gas pipeline will be taken to kitchen through this opening

Image Notes1. Place the couplers over the fixed guides and lightly tap them down

Image Notes1. Digester tank ready for the Gas holder tank2. 32 mm couplers added on all four guide points

Image Notes1. Place the tank in position2. Attach the slurry outlet pipe line

http://www.instructables.com/id/Constructing-a-Medium-Sized-Biogas-Plant-Using-Kit/

Image Notes1. The slurry can be collected down and used in the home garden

Step 15: Fixing the Waste Feed PipeClean the inner surface of door elbow and bottom outer surface 120 mm dia waste feed pipeApply PVC solvent cement over both the cleaned surfacesJoin them together immediately before the solvent cement dries outPlace the cap on top of the feed pipe

http://www.instructables.com/id/Constructing-a-Medium-Sized-Biogas-Plant-Using-Kit/

Step 16: Place the Gas Holder Tank and FinishGently lift the gas holder tank and place it over the digester tank so that the 40 mm dia guide couplers fixed on the sides of the gas tank sits over the 32 mm dia couplerson the digester

Place one set of guide pipes through the 40 mm dia coupler as seen in the photograph

Now our Biogas plant is ready...

Image Notes1. Place the gas holder tank inside digester tank

Image Notes1. Another view of Gas tank inside digester tank

http://www.instructables.com/id/Constructing-a-Medium-Sized-Biogas-Plant-Using-Kit/

Image Notes1. Provide guide pipes for vertical movement of gas holder and finish

Step 17: Feeding the Biogas Plant for the First TimeInitially you need to feed fresh cow dung to start the process. On the same day this plant was made ready, I collected about 10 kilograms of cow dung from nearby farmand another 20 kilogram the next day. Visited a cattle farm again and collected 50 kilograms of more cow dung. Now I have a total of 80 kilograms of cow dung for initialfeed.

I have diluted these 80 kilograms of cow dung with about 300 liters of water. I have also added about 250 grams of country-made jaggery (it is a concentrated solidproduct made from sugarcane, palm sap and coconut sap). The addition of jaggery will help the multiplication of microorganisms at a faster rate.

This mixture was fed into the digester through the feed pipe.

After feeding, wash the feed pipe and replace cap.

We use bore well water. Most of the water supplied through municipalities, corporations are treated with chlorine. Do not use chlorinated water as this will kill allmicroorganisms. If you have access to only chlorinated water, then keep the required amount of water open to atmosphere overnight and stir well, so that the chlorineevaporates.

Image Notes1. Fresh cow dung

Image Notes1. Dilute with chlorine-free water

Image Notes1. Add about 250 grams of country-made jaggery

Image Notes1. Mix well using a laddle

http://www.instructables.com/id/Constructing-a-Medium-Sized-Biogas-Plant-Using-Kit/

Image Notes1. Feed the cow dung mix through the feed pipe

Image Notes1. Wash the pipe and replace cap

Image Notes1. visit to a cattle farm for collecting cow dung

Image Notes1. Another 50 kilograms of fresh cow dung in 2 buckets

Step 18: Gas FormationGas formation will start after about two days of feeding the digester with cow dung slurry. You can see here in these photographs that the gas holder tank started raisingalong the guide pipes.

But, this gas contains lot of impurities and will not burn. Moreover, there was air present in the gas tank when we placed it over the digester.

Once the gas tank is full, this gas will be released to the atmosphere.

http://www.instructables.com/id/Constructing-a-Medium-Sized-Biogas-Plant-Using-Kit/

Image Notes1. The gas holder tank started raising due to gas formation

Image Notes1. The gas holder tank started raising due to gas formation- top view

Step 19: Type of Material whicn can be used for Feeding the Biogas PlantOnce the gas formation starts, you can feed waste material to the digester. The following are some of the wastes commonly available in a household

Rotten vegetablesVegetable peelsFruit skinsLeft-over spoiled food which are unfit for consumptionVery sour curd unfit for consumptionOver-fermented Dosa batterLeft-over vegetable oil used for fryingGrass and weed clippingsDried flowersTender banana stemsCattle waste like cow dung, goat's dung and poultry wasteLeftovers coffee grounds and leftover tea leavesWater used for rinsing rice and pulses. You can use this water for diluting the feed material

This list is endless... there are so many organic waste material you can use in the anaerobic digester. Make sure you chop them into pieces as small as possible.However, avoid certain items given in the next step which are unfit for feeding the biogas plant.

Remember, food is precious. Do not waste food. Use only spoiled food which is unfit for consumption

Image Notes1. Rotten tomatoes2. Rotten okra

Image Notes1. Rotten chilies

http://www.instructables.com/id/Constructing-a-Medium-Sized-Biogas-Plant-Using-Kit/

Image Notes1. Potato peel

Image Notes1. Fruit skins

Image Notes1. Spoiled cooked vegetable

Image Notes1. Spoiled rice

Image Notes1. Very sour curd

Image Notes1. over-fermented Dosa batter

http://www.instructables.com/id/Constructing-a-Medium-Sized-Biogas-Plant-Using-Kit/

Image Notes1. Leftover oil used for frying

Image Notes1. Grass and weed clippings

Image Notes1. Dried flowers

Image Notes1. Tender Banana stem

Image Notes1. Goat's dung

Image Notes1. water collected after rinsing rice and pulses

http://www.instructables.com/id/Constructing-a-Medium-Sized-Biogas-Plant-Using-Kit/

Step 20: Materials unfit for Biogas DigesterAvoid following type of materials in a Biogas plant

Dry skins of Onion and GarlicEgg shellsFibrous materials like coconut huskBones, raw or cooked

Step 21: How Much to Feed...?Once gas formation starts, you can start feeding the digester regularly with wastes from kitchen and home garden. But the big question is How much waste we can feed ?

Here, the capacity of my digester is 750 liters. So I will feed about 3500 to 4000 grams of waste in this plant daily.

Why this much quantity only ?

All solid wastes we feed into the digester will take between 30 to 50 days to get fully digested based on the type of waste. For example, cow dung will take about 30 daysfor full digestion and solid vegetable wastes may take 50 days. This is known as Retention Time.

By adding the wastes in small quantities everyday, I will have a regular supply of about 750 grams of gas after about 30 days. This will assist the wastes to get fullydigested and release optimum gas and get discharged through the slurry outlet pipe. Overfeeding the digester will drain out the partially digested wastes, which willincrease acidity of the slurry in the digester as well decrease the colony of microorganisms working on the wastes.

As a thump rule, for 1000 liter capacity digester, feed approximately about 5000 grams of waste.

Also, the solid wastes should be made into chunks as small as possible. Here, you can see in the photographs above that I have used an old mixer grinder to pulverizethe larger chunks of vegetable waste.

http://www.instructables.com/id/Constructing-a-Medium-Sized-Biogas-Plant-Using-Kit/

Step 22: A Word of Caution : Never Try ThisReal Story... One student who got guidance from me over telephone, constructed a mini biogas plant for school exhibition and was overenthusiastic... She opened thegas valve from the gas holder and tested whether the gas burns or not by holding a burning match stick in front of the gas pipe. The entire gas tank exploded.Fortunately, nobody was injured but they had to spent lot of time to clean up the mess.

Never do this... only use a Biogas stove or a Bunsen burner or a suitable nozzle arrangement to test the gas.

http://www.instructables.com/id/Constructing-a-Medium-Sized-Biogas-Plant-Using-Kit/

Step 23: My Presentation on Biogas and PanchagavyaA Science awareness Program was organised at Hajee Karutha Rowther Howdia College, Uthamapalayam, Theni District in Tamil Nadu, India, during 15th and 16th July2014. The event was supported by the Tamil Nadu State Council for Science and Technology, Chennai. I was invited to present a Key Note Address on Biogas andPanchagavya. Many local farmers, ladies from Self-Help groups and Staff & Students of Biology Department attended the presentation.

My presentation covered all aspects of Biogas plant including construction, feeding and functioning. As you can see in the photographs above, the local farmers werevery much interested in the simple technology which can convert organic waste from the kitchen in to useful biogas and the composted slurry as fertilizer for the plants.They were also very much eager to visit a working unit of a plant which uses only wastes to make fuel. My attempt in constructing this model is for home use as well fordemonstration to students, farmers, Self-help groups and all those who are interested in this technology

Image Notes1. The Invitation

Image Notes1. Welcome note from the College

Image Notes1. It is me addressing the audience about Biogas and Panchagavya

Image Notes1. some of the local farmers who attended the meet

http://www.instructables.com/id/Constructing-a-Medium-Sized-Biogas-Plant-Using-Kit/

Image Notes1. Students from the College at the meet

Image Notes1. Ladies from Self-Help groups

Image Notes1. Interaction with farmers

Image Notes1. Interaction with farmers

Image Notes1. The audience and me

http://www.instructables.com/id/Constructing-a-Medium-Sized-Biogas-Plant-Using-Kit/

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Mini Bio-gasplant using foodwaste,decomposableorganic materialand kitchenwaste byantoniraj

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The CompleteVegan Compostby Attila-RT

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Comments

50 comments Add Comment view all 87 comments

 GiulioI says:  Oct 1, 2014. 7:42 AM  REPLYDear all, my lab is an excellence in Italy for biogas production and my comment is in this scientific paper:

Small-scale household biogas digesters:An option for global warmingmitigation or apotential climate bomb?

Renewable and Sustainable Energy Reviews 33(2014) 736–741

GI

 antoniraj says:  Oct 2, 2014. 6:48 AM  REPLYcould not locate the scientific paper you mentioned above. Even google is not of much help. please provide a link

 richardl2 says:  Sep 28, 2014. 10:54 PM  REPLYa great chance for a neighborhood project.

 antoniraj says:  Oct 1, 2014. 6:53 AM  REPLYThank you...

 comitrago says:  Sep 29, 2014. 5:59 AM  REPLYLos artefactos que consumen biogas, son distintos a los usados normalmente en casa. Gracias

 antoniraj says:  Oct 1, 2014. 6:52 AM  REPLYThank you...

 richardl2 says:  Sep 28, 2014. 10:44 PM  REPLYgreat chance to help, start 300 of these at our south border crossings.

 timvier says:  Sep 27, 2014. 7:05 AM  REPLYI like this, every house should have this and also include the waste from our toilet.

But in stead of using a water closed WC we have to use vacuum operated toilets.

Result: no waste water. no sewage treatment no water usage, but from the digester we get gas and compost and liquid fertilizer.

WIN/WIN if we want to safe our planet this is one element we can use to help.

visist www.envierho.ie

http://www.instructables.com/id/Constructing-a-Medium-Sized-Biogas-Plant-Using-Kit/

 antoniraj says:  Sep 27, 2014. 7:27 AM  REPLYthanks for the information...

 rippa700 says:  Sep 26, 2014. 2:03 PM  REPLYI see you put the digester in a sunny place. DOes that mean in the UK it would be too cold to work?

Thanks - great instructions,

 antoniraj says:  Sep 27, 2014. 6:22 AM  REPLYBiogas digester needs warm and sunny place. However, there are biogas digester installed and working in cold climate also by keeping the slurry warm.Some people use the same biogas produced from the plant for maintaining the required temperature

 licon says:  Sep 26, 2014. 10:55 PM  REPLYVery informative and useful instructions. Can you pls advise how much gas is produced in small prototype bio gas plant. Can it make sufficient gas to burnone demostic gas burner for 1 hrs continuously.Thanks

 antoniraj says:  Sep 27, 2014. 6:18 AM  REPLYyou will not get enough gas from a small prototype biogas plant. for example, in a 100 liter capacity digester tank, you can feed only 500 grams of wasteper day, which will produce about 100 grams of biogas. That will hardly burn for about 10 to 15 minutes

 Rimwulf says:  Sep 25, 2014. 10:20 PM  REPLYI don't have access to cow dung can I use a yeastin its place also can I use molasses in place of jaggery?

 antoniraj says:  Sep 26, 2014. 7:17 AM  REPLYI came across this information recently... instead of cow dung, you can use activation sludge from a waste-water treatment plant to start the process.

 ianheavy says:  Sep 25, 2014. 11:23 PM  REPLYRimwulf, yeast does not produce methane, it will produce carbon dioxide. The other wast product it will produce is alcohol, which will remain in thedigester tank, and eventually kill the yeast.

 antoniraj says:  Sep 25, 2014. 10:53 PM  REPLYdo you mean yeast...? I don't think you can use yeast. You need a starter culture to produce the microorganisms for anaerobic digestion and cow dung isthe best choice for that. I have not tried with any material other than cow dung.

Regarding jaggery, you need to add only once during start up. If you do not add jaggery also does not matter.

 lordfloppy says:  Sep 26, 2014. 6:52 AM  REPLYI have a large dog, would I be able to use his feces for the gas plant instead of cow dung?

 antoniraj says:  Sep 26, 2014. 7:12 AM  REPLYyes, you can do that... but for starters you need cow dung slurry or activation sludge from a waste-water treatment plant.

 kalyan.sen says:  Sep 25, 2014. 11:56 PM  REPLYDoes it smell bad during burning or from the effluent discharged? Keep it up.

 antoniraj says:  Sep 26, 2014. 12:26 AM  REPLYNo, it won't smell during burning. Methane is an odorless gas. Hydrogen Sulphide, a by-product, smells bad. If you mix enough water, HydrogenSulphide will dissolve in it and drained out with the effluent, which also does not have much odor as it is fully digested

 ianheavy says:  Sep 25, 2014. 9:13 PM  REPLYThank-you for your excellent Instructable, which I found most interesting. I can see that the materials you show to feed the process would be readilyavailable in any urban area, however I cannot understand why the feed pipe would not get blocked unless this waste was macerateed before being added?

There also must be the need for the collection tank to be quite light, otherwise gas will just vent through the slurry seal rather than be collected. Is there aformula for how heavy the tank should be for a given volume or diameter?

Does the system need to be regularly disassembled for removing solids that collect in the bottom of the digester tank?

I can understand why this has produced interest in your community, and applaud your use of readily available items in your project.

http://www.instructables.com/id/Constructing-a-Medium-Sized-Biogas-Plant-Using-Kit/

 antoniraj says:  Sep 25, 2014. 10:06 PM  REPLY

thank you ianheavy... you are right about larger chunks blocking the feed pipe.. you need to make waste into small pieces before feeding or you canmacerate using an old blender (I am doing this only). However, a day or two after adding the waste, they become heavier and sink down to the bottom.Digested material is very light, which raises up and drained out.

Secondly, I found the collection tank is rather very light and needs some more weight on top to provide the necessary gas pressure required. Methane islighter than air and if you do not add some weight on top, it may create negative pressure. I will also do some pressure measurements and add weightaccordingly.

You need not to disassemble the system frequently for cleaning. The digested material is drained out along with the slurry. If you feed material which arenot suitable for biogas, then you may have some undigested deposits inside

thank you once again

 ianheavy says:  Sep 25, 2014. 11:21 PM  REPLYI thought the collector tank weight would be critical, too light a tank is an easier problem to solve than too heavy a tank, I am glad that this is the casefor you, as adding ballast to optimise the solution is an easy thing to do.

I look forward to hearing more from you on this project. It is too me an excellent use of waste and simple materials to make something useful.

 antoniraj says:  Sep 25, 2014. 11:07 PM  REPLY

ianheavy, now I made this to unblock feed pipe. this will be used after every feed. I think this will push larger chunks down into the digester allowingwater to seep through

 ianheavy says:  Sep 25, 2014. 11:16 PM  REPLYThank-you for your reply, I had assumed there would need to be some way of dealing with it, and your vented ram looks perfect and simple.

 BeeKeeper2012 says:  Sep 25, 2014. 10:31 PM  REPLYGreat work, really inspiring.

Just a thought: for fixing the elbow (waste feeding) cut a smaller diameter hole, heat the rim and press the elbow tube to fit tight, this adds additional strengthto the joint.

 antoniraj says:  Sep 25, 2014. 10:41 PM  REPLYthank you BeeKeeper2012...

may be the elbow for feed pipe can be fixed by heating the rim with a smaller dia hole. However, I have used epoxy compound for sealing and there is noleakage

 sumitec says:  Sep 25, 2014. 9:00 PM  REPLYBig Al 1048.

It is a coarse dark brown sugar made in India by evaporation of the sap of palm trees or sugar cane.

 antoniraj says:  Sep 25, 2014. 9:46 PM  REPLYthanks for the reply...

http://www.instructables.com/id/Constructing-a-Medium-Sized-Biogas-Plant-Using-Kit/

 iamuke says:  Sep 25, 2014. 8:40 PM  REPLYOutstanding. Thanks for sharing!

 antoniraj says:  Sep 25, 2014. 9:45 PM  REPLY

thank you iamuke...

 rogerhyam says:  Sep 25, 2014. 8:21 PM  REPLYThanks for sharing this. A really fascinating detailed instruction. I feel I understand a lot more about building a bio gas digester. Unfortunately/fortunately thewaste food in our city is now collected for large scale fermentation so I have no excuse to build one!

 antoniraj says:  Sep 25, 2014. 9:45 PM  REPLY

Thank you rogerhyam...

 AlphaRomeo says:  Sep 25, 2014. 9:30 PM  REPLYFrom the goole search

Jaggery (also transliterated as jaggeree) is a traditionalNon-centrifugal cane sugar consumed in Asia and Africa. It is aconcentrated product of date, cane juice, or palm sap (see palm sugar)without separation of the molasses and crystals, and can vary fromgolden brown to dark brown in color.

And do check out this wiki link too

en.wikipedia.org/wiki/Jaggery

 antoniraj says:  Sep 25, 2014. 9:41 PM  REPLYthanks again...

 AlphaRomeo says:  Sep 25, 2014. 9:32 PM  REPLYGR8 work antoniraj

 antoniraj says:  Sep 25, 2014. 9:41 PM  REPLY

thank you AlphaRomeo...

 big al 1048 says:  Sep 25, 2014. 7:28 PM  REPLYSorry, I need an explanation for the word jaggery !

 antoniraj says:  Sep 25, 2014. 7:42 PM  REPLYIt is a concentrated product of sugar cane juice, or palm sap and can vary from golden brown to dark brown in color

See Wikipedia article here...

http://en.wikipedia.org/wiki/Jaggery

 big al 1048 says:  Sep 25, 2014. 8:11 PM  REPLYThank you, this will help other people to i am sure !

 big al 1048 says:  Sep 25, 2014. 7:25 PM  REPLYSorry I am going to need a breakdown of the term Jaggery !

 geraldpaxton says:  Sep 25, 2014. 6:28 PM  REPLYLooks like an ideal way to process pet poop (like all that 'free' stuff they drop on your lawn), and how 'bout that stuff you drain from the RV? A small herd ofthese tied together would heat a small house.

http://www.instructables.com/id/Constructing-a-Medium-Sized-Biogas-Plant-Using-Kit/

 antoniraj says:  Sep 25, 2014. 6:46 PM  REPLYyes, you can do that...

 giampyypmaig says:  Sep 25, 2014. 4:12 PM  REPLYGreat project compliments

 antoniraj says:  Sep 25, 2014. 5:47 PM  REPLYthank you...

 dpiccine says:  Sep 25, 2014. 12:43 PM  REPLYOutstanding! Can you make a video showing it burning? Thanks!!!

 antoniraj says:  Sep 25, 2014. 3:37 PM  REPLYthank you... definitely I will post a video of the gas burning soon

 dpiccine says:  Sep 25, 2014. 4:26 PM  REPLYawesome!

 designine says:  Sep 25, 2014. 11:06 AM  REPLYVery nice project! You probably made a fantastic contribution to help the everyday of poor people in the developing countries. Thank you for sharing yourknowledge!

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