FORM 2
THE PATENTS ACT, 197 0 (39 of 1970)
COMPLETE SPECIFICATION (See Section 10)
AN IMPROVED APPARATUS AND A PROCESS FOR GENERATION OF BIOGAS USING ANAEROBIC DIGESTION
LARS ENVIRO PVT. LTD. of 218, BAJAJ NAGAR71-'SOUTH AMBAZARI ROAD, NAGPUR - 440 010, MAHARASHTRA, India, INDIAN Company
GRANTED
The following specification particularly describes the nature of the invention and the manner in which it is to be performed : -


28-12-2001

The present invention relates to the AN IMPROVED APPARATUS AND A PROCESS FOR GENERATION OF BIOGAS USING ANAEROBIC DIGESTION. The Anaerobic digestion of Industrial Wastewater or Sewage generated out of housing communities results in generation of Biogas.
Conventionally there are number of devices & processes for
generation of biogas from Wastewater. The anaerobic process is
carried out for wastewater as per its characteristics.

The Wastewater released by various industries differs in characteristics and in volume. The Wastewater from industries such as fermentation generally contains high organic impurities and can be used to generate biogas. The anaerobic treatment also reduces the pollution load of wastewater after generation of Biogas.
To provide economically viable and technically efficient solution to enhance the biogas production inventor has come forward with AN IMPROVED APPARATUS AND A PROCESS FOR GENERATION OF BIOGAS USING-ANAEROBIC DIGESTION.
The object of present invention is to provide' an apparatus and process for the enhanced biogas yield and associated effective removal of organics from Wastewater specially the Wastewater from fermentation industries.
Another object of the invention is to provide an apparatus for GENERATION OF BIOGAS USING ANAEROBIC DIGESTION with large volume
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for development and maintenance of bacterial population in constant suspension in turn to achieve higher Biogas production.
Yet another object of the invention is to provide an apparatus wherein the suspended solids are settled in parallel plate sttler and returned to digester to achieve higher biogas production.
Still other object of invention is to provide constant overflow from anaerobic digester irrespective of pressure inside digester. The necessary "U-trap" is incorporated to prevent accidental release of Biogas to atmosphere.
Another object of invention is to provide an apparatus wherein the Bio-chemical Oxygen Demanding material is reduced to desired limits.
Still another object of invention is to provide apparatus for conversion of Bio-chemical Oxygen Demanding material into fully digested solids that can be removed and recycled to digester as per the process requirement.
The following description will be clear from the illustration in Figure 1 in the accompanying drawing.
Referring to drawing the cooled and settled wastewater is fed to digester central mixing pipe column. The central feed pipe is having central mixer. The central pipe also gathers tank content from the rectangular notches provided at liquid level. The feed get mixed with the digester content at the central pipe and is
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well mixed with the help of central mixer. This ensures optimized mixing of untreated Wastewater and partially treated Wastewater.
This mixture then travels to the digester bottom due to propelling action of central agitator. Also enters at the central pipe the recirculated sludge from the parallel plate settler. The required bacterial population is maintained by controlling the recirculation of
return sludge. Bacteria convert the organics present in Wastewater to Biogas and. other end products. The Bio-gas bubbles through reactor content and get collected in the gas zone of digester, where from it is taken out to Gas Holder.
Subsequently the gas is taken to Flare stack or to biogas utilization facility. The digester contents are kept in suspension and in well mixed state by lateral mixers. The specially developed overflow arrangement collects mixed liquor from digester top. The overflow
arrangement ensures uniform overflow irrespective of pressure inside digester. The overflowed digester content is then taken to Degassifier column before its discharge to parallel plate separator '[PPS] . The degasified digester content then enters parallel plate separator and the settled sludge of PPS is either discharged out or recycled as per the process requirement. The Biogas is conveyed to Gas Holder.
The Gas Holder acts as a buffer for digester gas pressure and generation fluctuations. For subsequent gas utilization the biogas blower are provided. The excess gas is routed to Flare
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Stack for proper burning.
The invention will now be described with reference to accompanying drawing in which:
Figure - 1 is a process flow diagram showing all details of the process units.
Referring to figure -1, the Wastewater from industry is brought by open channel or pipeline to heat Exchanger or cooling sump [1] before it is taken to buffer sump [2] . The desired level of acidification is carried out bv here. The temperature of buffer tank content is kept at. 35-42° C as per the process requirement. Feed Pump [3] then pumps Wastewater to Digester [4] . The feed enters the central feed pipe/ column [5]. The central agitator / mixer [6] mixes feed with the return sludge and digester content.
The requisite number of lateral mixers [7] ensures proper mixing regime in the digester. These lateral mixers also help in sludge scouring of digester bottom. The suitably designed overflow arrangement allows the. uniform outflow from the digester. The overflowed digester content is then taken to Degassifier [8]. At Degassifier the dissolved Biogas from the treated wastewater escapes to atmosphere. The degasified wastewater then enters Parallel Plate Separator [9]. In parallel plate separator the sludge is settled and as per the process requirement the sludge is recycled back to digester or wasted using recycle pump [10]. The biogas generated in Digester is then taken to Gas Holder [11] . The Gas Holder allows the pressure regulation in digester and flow regulation for its onward conveyance. To allow emergency
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WE CLAIM:
1. An improved anaerobic Digester Plant for generation of
biogas comprising of a heat exchanger or cooling sump (1)
for the conversion of waste water from industries
brought by open channel or pipeline into biogas having a
buffer sump (2) connected in tandem by conduit for
maintenance of pH in acidic level while maintaining the temperature of contents of buffer tank from 3 5 to 42*C which is supplied to the digester 4) through the feed pump (3) , the said digester comprising of a tank with top open for the introduction of a central feed pipe/column (5) ; a central agitator mixer (6) is housed in the central feed pipe for the agitating/mixing of waste water, returned sludge and digester content through the port provided at the top of the central feed pipe; plurality of lateral mixer (7) are provided near the bottom to ensure proper mixing, sludges scouring of digester bottom; the said digester is provided a over flow weir for the digester content taken to degassifier (8); the dissolved biogas from the treated waste water escapes to atmosphere; the degasified waste water then conveyed to parallel plate separator (9) where the sludge settles, the settled sludge is recycled in the digester or waste using recycle pump (10); the biogas generated in . the digester is then taken to gasholder (11) which
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allows the pressure regulation in digester and flow regulation for its onward conveyance the excess biogas is pass through emergency release to the flare stack (12) ; the generated biogas is taken to biogas utilisation unit through suitable biogas blower (13).
2. An improved anaerobic Digester Plant for generation of biogas as claimed in claim 1 wherein the drain valves, safety valves, breather valves, flare arrester are provided for proper management.
3. An improved anaerobic Digester Plant for generation of biogas as claimed in claim 1 wherein the required bacterial population is maintained by controlling the recycling of returned sludge.
4. An improved anaerobic Digester Plant for generation of biogas as claimed in claim 1 wherein the central pipe having central mixer which also gathers tank content from the lateral mixer to the bottom of the digester.
5. An improved anaerobic Digester Plant for generation of biogas as claimed in claim 1 wherein a U trap is incorporated to prevent accidental release of biogas to atmosphere.
6. An improved anaerobic Digester Plant for generation of biogas as claimed in claim 1 wherein the generation of biogas using anaerobic digestion with large volume for development and maintenance of bacterial population in
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constant suspension to achieve higher biogas production
associated with effective removal of organic from waste
water. •
7. A process of generation of biogas using anaerobic digestion
through the digester plant as claimed in claim 1 where in the
pH level in the buffer sump is maintained in the required
acidic level and temperature of the buffer tank contained is
preferably maintained at 35 to 45*C.
8. A process as claimed in claim 1 wherein the temperature of
the contained of buffer tank is most preferably at 40 + -
3*C with required pre acidification of feed outside the
biogas digester.
9. An improved anaerobic Digester Plant for generation of
biogas as claimed in claim 1 and substantially herein
described and illustrated in figure 1 in the accompanying
drawing.
10. A process of generation of biogas using anaerobic digestion
by the digester as claimed in claim 1 as substantially
herein described with examples.

HIRAL CHANDRAKANT JOSHI
AGENT FOR
LARS ENVIRO PVT. LTD.
Dated this 6th day of December, 2001.
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