Floating Drum Biogas Plants - Revision history

Ranisha: /* Floating Drum Biogas Plants */

2015-12-04T13:43:44Z

‎Floating Drum Biogas Plants

Ranisha: /* Further Information */

2015-12-03T12:50:53Z

‎Further Information

Ranisha: /* Overview */

2015-12-03T12:49:00Z

‎Overview

Ranisha: /* Overview */

2015-12-03T12:47:54Z

‎Overview

Ranisha at 12:46, 3 December 2015

2015-12-03T12:46:25Z

Ranisha at 16:16, 2 December 2015

2015-12-02T16:16:34Z

Ranisha: Created page with "here are different types of small scale biogas digesters. Some of the biogas digesters are summarized below: *[[Fixed-dome Biogas Plants#Fixed-dome Plants|Fixed-dome P..."

2015-12-02T16:09:15Z

Created page with "here are different types of small scale biogas digesters. Some of the biogas digesters are summarized below: *[[Fixed-dome Biogas Plants#Fixed-dome Plants|Fixed-dome P..."

New page

here are different types of small scale biogas digesters. Some of the biogas digesters are summarized below:

*[[Fixed-dome Biogas Plants#Fixed-dome Plants|Fixed-dome Plants]]
*[[Fixed-dome Biogas Plants#Floating-drum Plants|Floating-drum Plants]]
*[[Fixed-dome Biogas Plants#Low-Cost Polyethylen Tube Digester|Low-Cost Polyethylen Tube Digester]]
*[[Fixed-dome Biogas Plants#Balloon Plants|Balloon Plants]]

 The table below gives a first comparision of the different types. 

{| cellspacing="0" cellpadding="0" border="0" style="width:100%;"
|-
! style="width: 126px;" scope="col" |  Factors
! style="width: 126px;" scope="col" | Fixed dome
! style="width: 126px;" scope="col" | Floating drum
! style="width: 126px;" scope="col" | Tubular design
! style="width: 126px;" scope="col" | Plastic containers
|-
| style="width:126px" | Gas storage
| style="width:126px" | Internal Gas storage up to 20 m³ (large)
| style="width:126px" | Internal Gas storage drum size (small)
| style="width:126px" | Internal eventually external plastic bags
| style="width:126px" | Internal Gas storage drum sizes (small)
|-
| style="width:126px" | Gas pressure
| style="width:126px" | Between 60 and 120 mbar
| style="width:126px" | Upto 20 mbar
| style="width:126px" | Low, around 2 mbar
| style="width:126px" | Low around 2mbar
|-
| style="width:126px" | Skills of contractor
| style="width:126px" | High; masonry, plumbing
| style="width:126px" | High; masonry, plumbing, welding
| style="width:126px" | Medium; plumbing
| style="width:126px" | Low; plumbing
|-
| style="width:126px" | Availability of Material
| style="width:126px" | yes
| style="width:126px" | yes
| style="width:126px" | yes
| style="width:126px" | yes
|-
| style="width:126px" | Durability
| style="width:126px" | Very high >20 years
| style="width:126px" | High; drum is weakness
| style="width:126px" | Medium; Depending on chosen liner
| style="width:126px" | Medium 
|-
| style="width:126px" | Agitation
| style="width:126px" | Self agitated by Biogas pressure
| style="width:126px" | Manual steering
| style="width:126px" | Not possible; plug flow type
| style="width:126px" | Evtl Manual steering
|-
| style="width:126px" | Sizing
| style="width:126px" | 6 to 124 m³ digester vol
| style="width:126px" | Up to 20 m³
| style="width:126px" | Combination possible
| style="width:126px" | Up to 6 m³ digester vol 
|-
| style="width:126px" | Methane emission
| style="width:126px" | High
| style="width:126px" | Medium
| style="width:126px" | Low
| style="width:126px" | Medium 
|}

= Floating Drum Biogas Plants =
[[File:Floating drum mauretania.jpg|thumb|right|250px|Floating drum plant in Mauretania]] Floating-drum plants consist of an underground digester and a moving gas-holder. The gas-holder floats either directly on the fermentation slurry or in a water jacket of its own. The gas is collected in the gas drum, which rises or moves down, according to the amount of gas stored. The gas drum is prevented from tilting by a guiding frame. If the drum floats in a water jacket, it cannot get stuck, even in substrate with high solid content.
<div style="both:clear"></div>
 [[Fixed-dome Biogas Plants#toc|►Go to Top]]

== The Drum ==

In the past, floating-drum plants were mainly built in India. A floating-drum plant consists of a cylindrical or dome-shaped digester and a moving, floating gas-holder, or drum. The gas-holder floats either directly in the fermenting slurry or in a separate water jacket. The drum in which the biogas collects has an internal and/or external guide frame that provides stability and keeps the drum upright. If biogas is produced, the drum moves up, if gas is consumed, the gas-holder sinks back.

 [[Fixed-dome Biogas Plants#toc|►Go to Top]] 

== Size ==

[[File:Floatdrumschemewaterjack s.gif|thumb|right|250pxpx|Water-jacket plant with external guide frame: 1 Mixing pit, 11 Fill pipe, 2 Digester, 3 Gasholder, 31 Guide frame, 4 Slurry store, 5 Gas pipe]] Floating-drum plants are used chiefly for digesting animal and human feces on a continuous-feed mode of operation, i.e. with daily input. They are used most frequently by small- to middle-sized farms (digester size: 5-15m3) or in institutions and larger agro-industrial estates (digester size: 20-100m3)'''''.''''' '''Disadvantages''': The steel drum is relatively expensive and maintenance-intensive. Removing rust and painting has to be carried out regularly. The life-time of the drum is short (up to 15 years; in tropical coastal regions about five years). If fibrous substrates are used, the gas-holder shows a tendency to get "stuck" in the resultant floating scum. 
<div style="both:clear"></div>
 [[Fixed-dome Biogas Plants#toc|►Go to Top]] 

== Water-jacket Floating-drum Plants ==

Water-jacket plants are universally applicable and easy to maintain. The drum cannot get stuck in a scum layer, even if the substrate has a high solids content. Water-jacket plants are characterized by a long useful life and a more aesthetic appearance (no dirty gas-holder). Due to their superior sealing of the substrate (hygiene!), they are recommended for use in the fermentation of night soil. The extra cost of the masonry water jacket is relatively modest.

 

[[Fixed-dome Biogas Plants#toc|►Go to Top]] 

== Material of Digester and Drum ==

The digester is usually made of brick, concrete or quarry-stone masonry with plaster. The gas drum normally consists of 2.5 mm steel sheets for the sides and 2 mm sheets for the top. It has welded-in braces which break up surface scum when the drum rotates. The drum must be protected against corrosion. Suitable coating products are oil paints, synthetic paints and bitumen paints. Correct priming is important. There must be at least two preliminary coats and one topcoat. Coatings of used oil are cheap. They must be renewed monthly. Plastic sheeting stuck to bitumen sealant has not given good results. In coastal regions, repainting is necessary at least once a year, and in dry uplands at least every other year. Gas production will be higher if the drum is painted black or red rather than blue or white, because the digester temperature is increased by solar radiation. Gas drums made of 2 cm wire-mesh-reinforced concrete or fiber-cement must receive a gas-tight internal coating. The gas drum should have a slightly sloping roof, otherwise rainwater will be trapped on it, leading to rust damage. An excessively steep-pitched roof is unnecessarily expensive and the gas in the tip cannot be used because when the drum is resting on the bottom, the gas is no longer under pressure. Floating-drums made of glass-fiber reinforced plastic and high-density polyethylene have been used successfully, but the construction costs are higher compared to using steel. Floating-drums made of wire-mesh-reinforced concrete are liable to hairline cracking and are intrinsically porous. They require a gas-tight, elastic internal coating. PVC drums are unsuitable because they are not resistant to UV.

 

[[Fixed-dome Biogas Plants#toc|►Go to Top]] 

== Guide Frame ==

The side wall of the gas drum should be just as high as the wall above the support ledge. The floating-drum must not touch the outer walls. It must not tilt, otherwise the coating will be damaged or it will get stuck. For this reason, a floating-drum always requires a guide. This guide frame must be designed in a way that allows the gas drum to be removed for repair. The drum can only be removed if air can flow into it, either by opening the gas outlet or by emptying the water jacket. The floating gas drum can be replaced by a balloon above the digester. This reduces construction costs but in practice problems always arise with the attachment of the balloon to the digester and with the high susceptibility to physical damage.

 

[[Fixed-dome Biogas Plants#toc|►Go to Top]] 

== Types of Floating-drum Plants ==

There are different types of floating-drum plants:

*'''KVIC model''' with a cylindrical digester, the oldest and most widespread floating drum biogas plant from India.
*'''Pragati model''' with a hemisphere digester
*'''Ganesh model''' made of angular steel and plastic foil
*floating-drum plant made of pre-fabricated reinforced concrete compound units
*floating-drum plant made of fibre-glass reinforced polyester
*low cost floating-drum plants made of plastic water containers or fiberglass drums: [[Biogas Plant by ARTI|ARTI Biogas plants]]
*'''BORDA model: '''The BORDA-plant combines the static advantages of hemispherical digester with the process-stability of the floating-drum and the longer life span of a water jacket plant.

 

[[Fixed-dome Biogas Plants#toc|►Go to Top]] 

== Summary ==

'''Advantages: ''' '''Disadvantages: '''Disadvantages are high material costs of the steel drum, the susceptibility of steel parts to corrosion. Because of this, floating drum plants have a shorter life span than fixed-dome plants and regular maintenance costs for the painting of the drum. 

[[Fixed-dome Biogas Plants#toc|►Go to Top]] 

=

@@ Line 69: / Line 69: @@
 <br/>
 = Floating Drum Biogas Plants =
-[[File:Floating drum mauretania.jpg|thumb|right|250px|Floating drum plant in Mauretania]] Floating-drum plants consist of an underground digester (<span style="font-size: 13.6px; line-height: 20.4px; background-color: rgb(255, 255, 255);">cylindrical or dome-shaped&nbsp;</span>) and a moving [[Types_of_Gasholders_for_Biogas_Plants#Floating-drum_Gasholders|gas-holder]]. The gas-holder floats either directly on the fermentation slurry or in a water jacket of its own. The gas is collected in the gas drum, which rises or moves down, according to the amount of gas stored. The gas drum is prevented from tilting by a guiding frame. When biogas is produced, the drum moves up adn when it is consumed, the drum goes down.<br/>
+[[File:Floating drum mauretania.jpg|thumb|right|250px|Floating drum plant in Mauretania]] Om 1956, Jashu Bhai J Patel from India designed the first floating drum biogas plant, popularly called Gobar gas plant. Floating-drum plants consist of an underground digester (cylindrical or dome-shaped) and a moving [[Types of Gasholders for Biogas Plants#Floating-drum Gasholders|gas-holder]]. The gas-holder floats either directly on the fermentation slurry or in a water jacket of its own. The gas is collected in the gas drum, which rises or moves down, according to the amount of gas stored. The gas drum is prevented from tilting by a guiding frame. When biogas is produced, the drum moves up adn when it is consumed, the drum goes down.<br/>
-If the drum floats in a water jacket, it cannot get stuck, even in substrate with high solid content.
+If the drum floats in a water jacket, it cannot get stuck, even in substrate with high solid content. After the introduction of cheap Fixed-dome Chinese model, the floating drum plants became obsolete as they have high investment and maintenance cost along with other design weakness
 <br/>[[#toc|►Go to Top]]<br/>
@@ Line 81: / Line 82: @@
 == Size ==
-[[File:Floatdrumschemewaterjack s.gif|thumb|right|250px|Water-jacket plant with external guide frame: 1 Mixing pit, 11 Fill pipe, 2 Digester, 3 Gasholder, 31 Guide frame, 4 Slurry store, 5 Gas pipe]] <span style="font-size: 13.6px; line-height: 20.4px; background-color: rgb(255, 255, 255);">In the past, floating-drum plants were mainly built in India.&nbsp;</span>They are chiefly used for digesting animal and human feces on a continuous-feed mode of operation, i.e. with daily input. They are used most frequently by small to middle-sized farms (digester size: <span data-scayt_word="5-15m3" data-scaytid="132">5-15m<sup>3</sup></span>) or in institutions and larger agro-industrial estates (digester size: <span data-scayt_word="20-100m3" data-scaytid="252">20-100m<sup>3</sup></span>)'''''.'''''<br/>
+[[File:Floatdrumschemewaterjack s.gif|thumb|right|250px|Water-jacket plant with external guide frame: 1 Mixing pit, 11 Fill pipe, 2 Digester, 3 Gasholder, 31 Guide frame, 4 Slurry store, 5 Gas pipe]] In the past, floating-drum plants were mainly built in India.&nbsp;They are chiefly used for digesting animal and human feces on a continuous-feed mode of operation, i.e. with daily input. They are used most frequently by small to middle-sized farms (digester size: 5-15m<sup>3</sup>) or in institutions and larger agro-industrial estates (digester size: 20-100m<sup>3</sup>)'''''.'''''<br/>
 '''Disadvantages''': The steel drum is relatively expensive and maintenance-intensive. Removing rust and painting has to be carried out regularly. The life-time of the drum is short (up to 15 years; in tropical coastal regions about five years). If fibrous substrates are used, the gas-holder shows a tendency to get "stuck" in the resultant floating scum.<br/>
@@ Line 128: / Line 129: @@
 <br/>
 = Further Information =

@@ Line 133: / Line 133: @@
 *[[Portal:Biogas|Biogas portal on energypedia]]<br/>
 *[[Types_of_Gasholders_for_Biogas_Plants#Floating-drum_Gasholders|Floating drum gas holders]]<br/>
 = References =

@@ Line 5: / Line 5: @@
 *[[Fixed-dome Biogas Plants|Fixed-dome Plants]]
-*[[Floating-drum Plants|Floating-drum Plants]]
+*[[Floating Drum Biogas Plants|Floating-drum Plants]]
 *[[Low-Cost Polyethylene Tube Digester|Low-Cost Polyethylen Tube Digester]]
 *[[Balloon Digester for Biogas Plants|Balloon Plants]]

@@ Line 4: / Line 4: @@
 There are different types of small scale biogas digesters. <u>Some of the biogas digesters are summarized below:</u>
-*[[Fixed-dome Biogas Plants#Fixed-dome Plants|Fixed-dome Plants]]
+*[[Fixed-dome Biogas Plants|Fixed-dome Plants]]
-*[[Fixed-dome Biogas Plants#Floating-drum Plants|Floating-drum Plants]]
+*[[Floating-drum Plants|Floating-drum Plants]]
-*[[Fixed-dome Biogas Plants#Low-Cost Polyethylen Tube Digester|Low-Cost Polyethylen Tube Digester]]
+*[[Low-Cost Polyethylene Tube Digester|Low-Cost Polyethylen Tube Digester]]
-*[[Fixed-dome Biogas Plants#Balloon Plants|Balloon Plants]]
+*[[Balloon Digester for Biogas Plants|Balloon Plants]]
 <br/>The table below gives a first comparision of the different types.<br/>
@@ Line 69: / Line 69: @@
 <br/>
 = Floating Drum Biogas Plants =

@@ Line 72: / Line 72: @@
 = Floating Drum Biogas Plants =
-[[File:Floating drum mauretania.jpg|thumb|right|250px|Floating drum plant in Mauretania]] Floating-drum plants consist of an underground digester (<span style="font-size: 13.6px; line-height: 20.4px; background-color: rgb(255, 255, 255);">cylindrical or dome-shaped&nbsp;</span>) and a moving gas-holder. The gas-holder floats either directly on the fermentation slurry or in a water jacket of its own. The gas is collected in the gas drum, which rises or moves down, according to the amount of gas stored. The gas drum is prevented from tilting by a guiding frame. When biogas is produced, the drum moves up adn when it is consumed, the drum goes down. <br/>
+[[File:Floating drum mauretania.jpg|thumb|right|250px|Floating drum plant in Mauretania]] Floating-drum plants consist of an underground digester (<span style="font-size: 13.6px; line-height: 20.4px; background-color: rgb(255, 255, 255);">cylindrical or dome-shaped&nbsp;</span>) and a moving [[Types_of_Gasholders_for_Biogas_Plants#Floating-drum_Gasholders|gas-holder]]. The gas-holder floats either directly on the fermentation slurry or in a water jacket of its own. The gas is collected in the gas drum, which rises or moves down, according to the amount of gas stored. The gas drum is prevented from tilting by a guiding frame. When biogas is produced, the drum moves up adn when it is consumed, the drum goes down.<br/>
 If the drum floats in a water jacket, it cannot get stuck, even in substrate with high solid content.
-<br/>[[Fixed-dome Biogas Plants#toc|►Go to Top]]<br/>
+<br/>[[#toc|►Go to Top]]<br/>
 == Size ==
-[[File:Floatdrumschemewaterjack s.gif|thumb|right|250px|Water-jacket plant with external guide frame: 1 Mixing pit, 11 Fill pipe, 2 Digester, 3 Gasholder, 31 Guide frame, 4 Slurry store, 5 Gas pipe]] <span style="font-size: 13.6px; line-height: 20.4px; background-color: rgb(255, 255, 255);">In the past, floating-drum plants were mainly built in India.&nbsp;</span>They are chiefly used for digesting animal and human feces on a continuous-feed mode of operation, i.e. with daily input. They are used most frequently by small to middle-sized farms (digester size: <span data-scayt_word="5-15m3" data-scaytid="132">5-15m<sup>3</sup></span>) or in institutions and larger agro-industrial estates (digester size: <span data-scayt_word="20-100m3" data-scaytid="252">20-100m<sup>3</sup></span>)'''''.''''' <br/>
+[[File:Floatdrumschemewaterjack s.gif|thumb|right|250px|Water-jacket plant with external guide frame: 1 Mixing pit, 11 Fill pipe, 2 Digester, 3 Gasholder, 31 Guide frame, 4 Slurry store, 5 Gas pipe]] <span style="font-size: 13.6px; line-height: 20.4px; background-color: rgb(255, 255, 255);">In the past, floating-drum plants were mainly built in India.&nbsp;</span>They are chiefly used for digesting animal and human feces on a continuous-feed mode of operation, i.e. with daily input. They are used most frequently by small to middle-sized farms (digester size: <span data-scayt_word="5-15m3" data-scaytid="132">5-15m<sup>3</sup></span>) or in institutions and larger agro-industrial estates (digester size: <span data-scayt_word="20-100m3" data-scaytid="252">20-100m<sup>3</sup></span>)'''''.'''''<br/>
 '''Disadvantages''': The steel drum is relatively expensive and maintenance-intensive. Removing rust and painting has to be carried out regularly. The life-time of the drum is short (up to 15 years; in tropical coastal regions about five years). If fibrous substrates are used, the gas-holder shows a tendency to get "stuck" in the resultant floating scum.<br/>
 <div style="both:clear"></div>
-<br/>[[Fixed-dome Biogas Plants#toc|►Go to Top]]<br/>
+<br/>[[#toc|►Go to Top]]<br/>
 == Water-jacket Floating-drum Plants<br/> ==
@@ Line 92: / Line 92: @@
 <br/>
-[[Fixed-dome Biogas Plants#toc|►Go to Top]]<br/>
+[[#toc|►Go to Top]]<br/>
 == Material of Digester and Drum<br/> ==
@@ Line 100: / Line 100: @@
 <br/>
-[[Fixed-dome Biogas Plants#toc|►Go to Top]]<br/>
+[[#toc|►Go to Top]]<br/>
 == Guide Frame<br/> ==
@@ Line 108: / Line 108: @@
 <br/>
-[[Fixed-dome Biogas Plants#toc|►Go to Top]]<br/>
+[[#toc|►Go to Top]]<br/>
 == Types of Floating-drum Plants<br/> ==
@@ Line 124: / Line 124: @@
 <br/>
-[[Fixed-dome Biogas Plants#toc|►Go to Top]]
+[[#toc|►Go to Top]]
 [[Category:Biogas]]