Efforts to improve the production of Methane are made applying Mesophilic reaction which
is again an AD technique. A process is made through which the Carbon dioxide (C02)
produced in the digester is converted into Methane (CH4). A prototype biogas plant for
methane production with purity up to 90-95% is developed and the results are analyzed. A
model is made in the Faculty of Engineering & Technology, Jamia Millia Islamia campus
for converting the organic waste available in the canteen into Biogas. The practical model is
made functional and the produced Biogas is refined to Biomethane by passing it through
Lime water. Hydrogen is produced through a unique process using zinc of used battery and
HCL. The mixture of Biomethane and Hydrogen produced a burning gas of High Calorific
value with clear blue flame at high intensity which is much better then methanc alone. The
gas is colorless. It is found that the efficiency and quality of Methane gas of this mixture is
superior than pure methane.
DESCRIPITION:
4.1 A Small model for a family of where 4-6 people is developed using their kitchen waste which is
just 1 to 2 Kg on daily basis. The plant can be installed in a back yard or roof top of a house and can
Tullill the requirement of cooking gas used every day. 'l'he plant can also be developed at community
level where the quantity of waste is in large quantity. A bigger plant can be installed in a community
hall or RWA offices where the organic wastekitchen waste of large quantity is available. The size of
the plant will depend on the daily quantity of waste and the requirement of the community hall. The
gas production depends on the temperature. The optimum temperature is 35 "C. This will replace
conventional LPG usage in cities such as Delhi, Faridabad, NOIDA, Gurgaon etc. where the daily
organic waste of a house is more than 1 Kg. Finally Biogas collected is stored in a gas chamber
having 92 to 95 % Methane component. The C02 has become negligible.
4.2 Methane gas production and efficiency of the Plant
The anaerobic digestion process is applied for producing the Biogas out of kitchen waste. The
composition of Methane gas (CH,) generally is 50-55% maximum for all practical models available
today. Some techniques have been developed to improve the efficiency of the digester and there by
the production of the biogas. But here a model has been developed where the quantity of Methane is
improved to 90-95%. This became possible by passing the biogas through lime water. CO2 reacts
with lime water to give calcium carbonate thereby thk quantity of CH4 was enhanced to 90-95% in
the final gas which we call Biomethane.
This is practically done and found that the Biogas is of high calorific value, the flame is colorless and
it bums in fraction of seconds. The purified Biomethane gas obtained mixed with Hydrogen gives
better intensity with high calorific value. This is extremely clear gas. To get the Biomethane gas
mixed with Hydrogen, an additional chamber is added, which produces the hydrogen gas. The
chemical reaction to produce the hydrogen gas is as below:
' HPO DELHI IE-El4-2LO15 17 PBl
The uniqueness of mixing hydrogen gas is the work done under the research. Though the knowledge
was available and hydrogen gas too but could not be exploited for such pllrposes. One basic reason
might be due to high cost of the hydrogen gas. The process and chemical reaction proposed in the
model is cheap and easy. Zinc is available at a. very low cost in the market. However for the practical
purpose used battery (Pencil cell) were used and HCI is also readily available at low cost. Both the
items can be mixed out of which hydrogen gas will be produced.
The design and implementation of physical plant is shown in figures 1.1 to 1.5. The benefit of such
plants are:
1. Carbon dioxide (COz) is almost zero
2. Environment friendly
3. Carbon credits in the international market
4. Organic waste management
5. Best conversion of waste energy into useable form
6. Compact in size to process more waste - saves space
7. Negligible H2S formation in process - no foul smell during gas use & no corrosion of
metal parts
8. Desired gas pressure like LPG - can be used as commercial kitchen burners
9. Better manure
10. Gas Storage also possible
1 1. Efficient Methane Gas production
12. Color less, high calorific value Biogas will reduce the time of burning.
13. Consumption of LPG reduces
14. Use of manure for growing the plants at home
15. Low maintenance .
.I 6. Money saving. .
4.3 Gas Requirement
On average 26 liters of gas is required to boil 1 liter of water so approximately 200 liters of gas per
day is required to cook three meals. If this gas is 60 % methane (this is reasonable to achieve and
biogas must be at least 50% methane to bum) we need about 120 liters of methane per day. Methane
has an energy content of about 39 MJ per cubic meter.
4.4 Waste Requirement
One kg of "Volatile Solids" produces 0.5 cubic meters of methane but only about half the VS added
to a digester will be broken down which may vary. This means approximately 0.5 kg of VS must be
added to the digester per day to produce 120 liters of methane. Waste must be held in the digester for
a period of time for digestion to occur, just how long depends on temperature. It is also worth
considering that a longer retention time will release more of the potential gas, is likely to be more
stable and does allow for future increases in demand (one can increase the loading rate a bit without
fear of failure) but one do need a larger digester to hold the effluent long enough.
Temperature (OC) Retention Time (days) minimum recommended
10 5 5
20 20
For 20 OC operating temperature and a retention time of 20 days, 20 liters per day input gives a
design capacity of 400 1iters.A~th e digester needs to be 5 to 10 times longer than its diameter it is
possible to come up with a range of suitable dimensions for this capacity, allowing at least 10% extra
volume for the gas head space.
For 1 :5 proportions Diameter = cube root (4 x Volume / 5 / pi) and for 1: 10 proportions Diameter =
cube root (4 x Volume 1 10 / pi) and pi = 3.14 or 2217
eg. For a volume of 440 liters (or 0.44 cubic meters) Diameter = 0.48 m, with a length of 2.4 m, to
0.37 m, with a length of 3.7 m. A larger digester will extract more gas, be more robust and allow
some room for extra manure if necessary.
For any diameter of digester the required length can be found by Length = 4 x Volume / pi / Diameter
squared. Knowing the Flat Width of a poly "tube" (which is half the circumference) Diameter = 2 x
Flat Width 1 pi. The above are the parameters available for the development of the Biogas in an
anaerobic process in a digester. All kinds of model produce only 50 to 55% methane gas and
remaining is the Carbon di oxide. This work proposes to refine Methan in Biogass to 90 to 95 %
which when mixed with Hydrogen gives a very efficient, color less gas which burns with clear blue
flame. This gives both the advantages that of high calorific value as well as intensity.
HPO DELHI L O - 8 4 - 2 0 1 5 13:11
.
4.5 Design 'and description of the working Plant
In Figure 1.1 the process for gas formation is given. The lSt chamber is used to feed
the organic kitchen waste. Initially to set up the process and establish the mesophilic reaction, the
chamber I was fed with 10% of cow dung with equal quantity of water. 30 kg of waste is added with
equal amount of water after three days of initial setup. Later on one kg was added on daily basis for
the next thirty days. Equal amount of slurry was taken out everyday. The feed stock is grinded, mixed
with water and poured into the 1" chamber. Slowly it is automatically transferred to the chamber I1
which is a digester.
The digester is air tight and anaerobic process takes place. HRT is 5 days and from fifth day
biogas start producing. The gas collected in 3rd chamber is as shown in figure 1.1. This biogas
consists of CH4, COz,H2S, Nitrogen etc. Till this stage, all the conventional biogas plants produce 50-
55% of methane (CH,) gas. The same amount of gas is also produced in the above plant.
To increase the efficiency of the final produced gas an additional chamber is added, which produces
the hydrogen gas. The chemical reaction to produce the hydrogen gas is as below:
2HC1+ Zn 3 ZnCI2 + H2
There are two uniqueness of this work. The first one is the production of Hydrogen using Zinc which
is obtained at a low cost. The fact is that the production of Hydrogen is very costly and we applied a
simple and easy method for the same. The other one is mixing hydrogen gas and getting high
calorific gas with better intensity. Though the knowledge was available and hydrogen gas too but
could not be exploited for such purposes. One basic reason might be due to high cost of the hydrogen
gas. The process and chemical reaction proposed in the model is cheap and easy. Zinc is available at
a very low cost in the market and HCI is also readily available at low cost. Both the items can be
mixed in IV Chamber, out of which hydrogen gas will be produced.

CLAIMS:
1 . We claim that the gas produced is purified Methane upto 90-95% through this design.
2. We claim that the digester design formula is generalized.
3. We claim that the Biomethane with Hydrogen gives high calorific and high intensity flame
which was observed in practical model.
4. We claim that the flame is colorless and it bums in fraction of seconds.
5. We claim that the design and implementation of physical plant is shown in figures 1.1 to 1.5
are unique.
6. We claim that the production of Hydrogen using Zinc obtain from "used pencil cells" is
unique idea.
2HCl+ Zn → ZnCl2 + H2