HOW TO DESIGN A BIO GAS PLANT--- SOLVED EXAMPLE

 FLOW CHART

ALL ABOUT DESIGN OF BIO GAS PLANT

The two commonly used types of bio-gas plants are:

a) Floating drum type, and

b) Fixed dome type.

The commonly used model of bio-gas plants are: 

a) Floating drum design:

i) KVIC model, 

ii) Pre-fabricated ferro-cement digester model, and 

iii) Pragati model. 

b) Fixed dome type: 

i) Janta model, and 

ii) Deenbandhu model.

Source: https://archive.org/stream/gov.in.is.9478.1989/is.9478.1989_djvu.txt

Design Parameters taken for  Bio Methanation

·         Feed Substrate Total Solid Concentration(TSC):  8-9 % (For Cow dung)

·         Ratio of Dung to Water: 1:1

·         Bio Gas produced : 0.06 cu mtr / kg dung (Summer 47 degree)

·         0.03 cu mtr / kg dung (winter 8 degree)

·         Temperature : 35 degree centigrade

·         PH – 7-8

·         Retention Time : 30 days (For temp 25-35 Degree Cent)

·         Depth of the plant is between 4 to 6 m according to the size

·         Depth to diameter ratio between 1.0 to 1.3

·         When the digester diameter exceeds 1.6 m, a partition wall is provided in the digester

·         Average gas production from dung may be taken as 40 lit/kg. of fresh dung

·         One Cu. m gas is equivalent to 1000 litres

DESIGN EXAMPLE OF BIO GAS PLANT
http://archive.unu.edu/unupress/unupbooks/80362e/80362E0j.htm
FIG. 3. Chinese Biogas Plant Design
The digester is of standard KIVC design, consisting of a cylindrical underground chamber using 23-cm (9 in.) brick walls and a concrete floor. It has two standard 10-cm (4 in.) cement household pipes for the inlet and outlet. A feed trough, slurry pit, and soaking pit for the digested slurry are provided. Figure 1 shows the details. The only departure from the standard design is provision of a water trough to hold the gas holder (as explained below).
The gas holder consists of a geodesic dome made of wood, to which a vinyl balloon is secured. The balloon is made of heat-sealed vinyl fabric available on the market. The whole assembly sits inside a water trough that serves two purposes: it prevents gas leakage through the water seal if filled with 20 to 30 cm of water, and it helps to anchor the balloon. Hooks around the gas dome also help to secure the structure so that it does not blow off under pressure. The dome struts and hubs were made as shown in figure 2A and B.

Design of Biogas Plant
Number of cows	4
Assuming 1 cow produces	10 kg of dung/day
Amount of dung produced by 4 cows	40 kg
Amount of gas produced by 1 kg of dung	0.05 m�
Amount of gas produced by 40 kg of dung	2 m�
Daily requirement of gas for cooking and lighting
for 1 person	0.5 to 0.6 m�
2 m� of gas per day will provide cooking and lighting for	2/ 0.6 to 2/0.5= 3 or 4 persons

The volume of the fermentation well should be at least 30 times as large as the daily input. Since manure is usually retained in the fermentation well for about six weeks, it is desirable for the well to be about 45 times the volume of the daily input.

Using a 1:1 ratio of cow dung and water:
Daily input of cow dung	40 kg
Daily input of water	40 kg
Total input	80 kg
Volume of the well required
(45 times the daily input)	80 x 45 = 3,600 kg
100 kg of dung and water occupy	1 m�
3,600 kg of dung and water occupy	3.6 m�
Digester tank capacity required	3.6 m�

The gas holder volume should be enough for 60 to 70 per cent of one day's production.

70 % of 2 m� gas	[70 x 2] /100 = 1.4 m�
Digester tank capacity	3.6 m�
Gas holder capacity required	1.4 m�

Size of the Digestion Tank
Assume 1.75 m as the internal diameter of the digestion tank.

The depth required will be	1.5 m
Using a 20 cm thick wall, the external diameter will be	1.75+0.2+0.2m = 2.15 m

Size of the Gas Holder
A hemispherical PVC balloon is used as the gas collecter.

Assuming diameter of the dome to be	1.9 m
Volume of the dome (half sphere)	1.795 m�

Design of Dome to Support the Gas Holder
Type	2 frequency dome,Class I,
	Method I
Diameter of dome	1.95 m
Radius of dome	0.975 m = 38.38 in.
Length of struts (including hubs)
Long struts	radius of dome x 0.618= 23.75 in.
Short struts	radius of dome x 0.5465= 21 in.
Distance from centre of hub to centre of hole at end of strut	2.75 in.
Length from centres of holes at each end of strut to ends of strut	1.5 in.
Actual length of long struts	23.75 in. - (2 x 2.75 in.)
	+ (2 x 1.5 in.) = 21.25 in.
Hole-to-hole distance	18.25 in.
Actual length of short struts	21 in. - (2 x 2.75 in.)+ (2 x 1.5 in.) = 18.5 in.
Hole-to-hole distance	15.5 in.
Number of long struts required	35
Number of short struts required	30
Number of five-element hubs required	6
Number of six-element hubs required	20

How much Biogas can I produce?

The following is a calculator for estimating the amount of biogas your operation can produce. The calculator is a guideline only and should not be used for design purposes.

Choose the biogas production number that applies to your operation...
Example: 600 sow farrow to finish operation, choose Farrow to Finish 

Hogs

Cubic metres biogas per hog per year

Farrow to Finish

720

Farrow to Wean

222

Farrowing

174

Weaner

24

Feeder

78

Dairy

Cubic metres biogas per cow per year

Freestall

860

Multiply the number of animals by biogas production number...
Example: 600 hogs x 720 m³ biogas / hog / yr = 432000 m³ biogas / year

Multiply the result by the numbers below for cogeneration of electricity and heat...

____________ x 1.7 kWh/ m³ biogas = _________ kWh of electricity per year
____________ x 7.7 MJ/ m³ biogas = _________ MJ of heat per year

Multiply the result by the numbers below for heat production using boiler....
____________ x 15 MJ/ m³ biogas = _________ MJ of heat per year

Different methods of filtering and purifying drinking water

Source Of The Article ::http://www.aviva.ca/article.asp?articleid=131

Water Purification and Treatment Technologies

A comprehensive look at the different methods of filtering and purifying drinking water.

The drinking water treatment technologies used in the majority of systems include one or more of the following methods or media types:

• Sediment Filters - Ranging from 1 to 20 microns are normally used as a prefilter to protect and extend the life of other filters.
• Activated Carbon, including Granulated Activated (GAC), Carbon Block, and Catalytic Carbon – Standalone, or combined with other technologies to remove chlorine, chloramines, VOCs, MTBE, and a wide range of contaminants including lead and mercury.
• Water Softeners – Used to soften "hard" water using ion exchange technology that exchanges magnesium and calcium with sodium or potassium.  Water softeners are not designed to purify water that is microbioligically unsafe.
• BASF ATS Media  – Home systems, usually combined with activated carbon.
• Steam Distillation – Systems for home, business and commercial use.
• Reverse Osmosis (RO) - Systems for home, business and commercial use.
• Deionization – Not recommended for drinking water.
• Ozonation – Nature’s natural sterilizer.
• KDF Media – Advanced zinc-copper alloy with the widest range of contaminant removal.  Usually combined with Granulated Activated Carbon.
• Ceramic – Alternative to germicidal UV-C for filtration of bacteria, etc. 
• Activated Alumina – Specifically designed to remove fluoride and arsenic by adsorption.
• Bone Char – The best material for removing fluoride. Bone Char also removes chlorine, heavy metals and radioactive isotopes. For this reason, it is placed after a chlorine adsorption filter in all OPUS systems, to ensure maximum efficiency for adsorbing fluoride.
• Ultraviolet Germicidal Irradiation (UV-C) - To disinfect microbioligically unsafe water.
• Ultra-Filtration (UF) - Ultra Filtration uses membrane technology to reject contaminants from 0.01 to 0.2 microns. UF is effective in the removal of bacteria, pyrogens, high molecular weight dissolved solids and other water contaminants without removing healthful minerals.
• Bioceramic Water Amplification (BCWA) –Technically not a filter, BCWA improves the health promoting qualities of water by increasing alkalinity, oxygen, active hydrogen ions and healthful minerals, while lowering the ORP (Oxidation Reduction Potential), giving water antioxidant properties. BCWA is available as an inline filter that can be added to an existing water treatment system, integrated into a drinking glass (Alkalark) to treat individual glasses of water, and as Balance Water Sticks designed to be inserted into your drinking bottle.

Treatment of Oily waste water Ceramic Membrane Application

Source of Article: http://www.videurtechnologies.in/ceramic-membrane

Ceramic Membrane Application

Separation of liquids and solids; separation of oil and water; separation of liquids and liquids; (especially for filtration food and beverage industries, chemical and petrochemical industries, pharmaceutical and mining industries.)

High Turbidity Water (HTW)

This type of water is common in rivers, lakes and dams and industrial wastewater the prevalence of grease, dyes, ink, metal cutting liquids, alkaline and acid processing stream, diary fruit juice clarification and food processing water containing residues from example, soy sauce and vinegars to fermentation of beer in breweries increases turbidity.

Formerly, when treating HTW a Flocculation-Sedimentation Method was used. This process can treat HTW to a degree, but its short comings are many. Firstly this process needs a large tank to be successful. Area in today’s world is often hard to come by and expensive, not to mention when clean is needed in an emergency in natural disasters, the above technology would also take to long to construct. Hence this is not a viable process.

Sand Filter data over an extended period indicated that whilst the treatment time was short，the treated water quality is not good. The turbidity of the product water was still high which meant it could not safely be used. The tests concluded that if the raw water had very high turbidity, it can block the filters in several minutes.

Ceramic Membrane filtration system transforms high turbidity water into clean water in 2 – 3 seconds.

As this kind of system is equipped with a back wash component, the unit cannot be clogged easily. After the initial investment, users can use this application for years without need of spending more money. It can specially meet the needs of building small tap water plant for factories, towns and farms.

Municipal Wastewater Recycling

India is a country where water is scarce. Municipal Sewage from Wastewater Treatment Plant can be converted into clean water with our ceramic membrane technology for recycling use. This is an excellent method in preserving the water sources of some cities where water is not readily available.  Output wastewater after Multi-media filter and organic membrane quality is very poor, turbidity reached to 300 – 500 NTU, oil volume is 5 – 10 ppm hence not good for recycling. CMs filtering system can effectively remove oil, dirt, mud and sand from sewage. Combine this with our RO system, recycling target can be reached. 

M/s. Kemtech International Ltd.

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