Kitchen waste can be utilized for production of Biogas (daily waste of 4 member family – aprox 500gm). In existing designs of biogas (developed by different NGO/agencies) their are few problem and one of major problem is that most of them are bulky units. To check feasibility of making tiny domestic Kitchen waste biogas unit project is started at Vigyan ashram, Pabal. Mr. Sandesh Mhadalekar ( Agril Btech Student , Dapoli Agri Btech college) worked on this project in last 3 months and concluded following results as-
Objectives of the project:-

  • To develop low cost biogas until suitable for small family (4 members) kitchen waste.
  • To utilize kitchen waste for its maximum biogas production capacity.
  • To recycle kitchen waste by treating it in biogas unit so as reduce pollution.

Considerations:-

  • Small family of 4 members on an average produces 500 gm kitchen waste per day.
  • Biogas unit should be very handle (small in size) which probably fit into kitchen.
  • It should produce any of odours.
  • It should be low maintenance biogas unit.

Considering above objectives and considerations we found that developing fixed dome type biogas unit will be more suitable for our study.
Biogas unit construction details – 
PVC pipe of 20 cm diameter & 127 cm length was taken and 2 holes of 2.5 cm diameter are made on at 30 cm from top of this pipe as shown in fig. 3.1.1 The holes are apposite to each other. One of them was used as inlet and other used as outlet. The inlet pipe was 90 cm long inside the PVC pipe (dia. 20 cm) and reducer was fitted to the inlet pipe from the outside. Connected the PVC pipe (dia. 5 cm) has length 15 cm. After that the ‘T’ joint was connected to pipe for the placement of mirchi cutter and 10 cm of PVC pipe connected to the ‘T’ joint also connected the end cap to the PVC pipe as shown in fig. 3.1.2.
On the end cap the hole was made for the handle of the screw conveyor. The 1.2 cm diameter of MS rod was taken for screw conveyor. The metal sheet was taken for made the disk of screw conveyor. The metal sheet was cutted in circular shape has dia. 2.4 cm. Make the hole at the centre of disk and cut it as shown in fig.3.2.1. The circular disk was bended as shown in fig.3.2.2. All circular disks are welded on the MS rod as shown in fig. 3.2.2. Screw conveyor was fitted in the PVC pipe (dia. 5 cm) and fitted the end cap.
PVC pipe was fitted in the hole has diameter 2.5 cm. Holes was made to the both end-caps (dia.20 cm) has diameter 2.5 cm, one for gas outlet and other for flush value for flush the total biogas system.
DIAGRAM ATTACHED BELOW SEPARATELY.
Results of project so far- 
Gas produced agents feed input and burner run time is recorded.
The gas burn with blue flame for 6 to 8 min. in the 24 hrs after adding the feed in the biogas.
Following table shows relation input Vs gas produced –

Sr. No.

Date

Feed for biogas

(gm)

Weight of material for drying (gm)

Weight of dried material (gm)

Volume of gas produced (cm3)

pH

21/02/2012

400

100

22

10303.41

7.0

22/02/2012

700

300

51

8765.31

7.0

23/02/2012

610

200

38

22815.24

7.0

24/02/2012

480

200

42

18427.13

7.0

25/02/2012

500

100

19

20163.57

7.0

26/02/2012

700

200

33

22407.39

7.0

Gas produced Vs Burner run time shown below –

Sr. No.

Date

Burning time (min.)

Quality of flame

1

29/03/2012

2

Blue

2

31/03/2012

8

Blue

3

04/04/2012

3

Blue

4

05/04/2012

5

Blue

5

06/04/2012

7

Blue

6

07/04/2012

6

Blue

7

08/04/2012

9

Blue

Diagram of Biogas Unit –