ENVO BIO GAS PLANT

POST NUMBER :08   Date : 02/05/2004
BIO GAS PLANT PROCESS DESCRIPTION:

FLOW CHART: CRUSHER(less than 7mm particle size)----thermophilic Aerobic digester(Temp 55 degree C  )---Mesophilic Anaerobic Digester(37 Degree C )---Manure Pit

Biotechnology process

stage one : hydrolysis by hydrolytic bactaria, conversion of extracellular molecules

stage two : thermophilic fermentation based on carbohydrates

stage three : synthesis of volatile fatty acids by acetogenic bacteria

stage four : synthesis of methane by methanogenic organisms

The Principle:

Add bio degradable Solid waste  into predigestor tank. 

Use of thermophilic microbes for faster degradation of the waste. The growth of thermophiles in the predigestor tank is assured by mixing the waste with hot water and maintaining the temperature in the range of 55-60oC. The hot water supply is from a solar heater. Even one-hour sunlight is sufficient per day to meet the needs of hot water.

After the predigestor tank the slurry enters the main anaerobic tank where it undergoes mainly anaerobic degra-dation by a consortium of archae-bacteria belonging to Methanococcus group.  They produce mainly methane from the cellulosic materials in the slurry.

The undigested lignocellulosic and hemicellulosic materials then are passed on in the settling tank. After about a month high quality manure can be dug out from the settling tanks. Earth worm can be introduced to settling tank to speedup the process.There is no odour to the manure at all. The organic contents are high and this can improve the quality of humus in soil, which in turn is responsible for the fertility.The manure generated is high quality and can be used in fields.This manure can be supplied to farmers at the rate of 4-5 Rs. per Kg. Alternatively municipal gardens and local gardens can be assured of regular manure from this biogas plant.

As the gas is generated in the main tank, the dome is slowly lifted up. This gas is a mixture of methane (70-75%), carbondioxide (10-15%) and water vapours (5-10%). It is taken through GI pipeline to the gas purification unit. Drains for condensed water vapour are provided on line. This gas burns with a blue flame and can be used for cooking as well.

The gas generated in this plant is used for gas lights fitted around the plant. The potential use of this gas would be for a canteen. The purified gas can be fed to bio fuel electric generator to produce electricity. Gas can be bottled and used to run vehicles.

Tanks of Biogas Plant

1.     Mixer with stirrer to mix hot water (1:2) to form a slurry,

2.     Aerobic Digester,

3.     Anaerobic digeter

Mechanical Items :

1.Gas Holding MS Steel Dome

2.Steel Fabricated Covers on Manure Pits,

3.Mixer Stirrer ,

4.Air Compressor

5.Gas Holder and gas purification system

6.Water Pump and Slurry Pump

7.Water and Gas Pipelines on Plant area

8. Electric Fittings & Miscellaneous

Cost details, saving and payback period from a biogas plant:

The cost details and the savings envisaged from the plant are given in the following table. The life of the plant could be 20-30 years and payback period is 4-5 years.

Capacity (Tons / Day)	Installation Cost (Rs In Lacks)	Monthly Operation and Maintenance Charges (Rs)	Methane Generation M3	Manure production (tons /day)	Area Required M2	Power	Manpower	Fresh Water (KL /day)	Hot water (Ltr / day of 50-60 C0)	Cooking Fuel (Equivalent to LPG Cyl / day)
1	30-35	8,000/-	100-120	0.1	300	5hp(2hr)	2	2	200	2-3
2	36-39	12,000/-	200-240	0.2	500	5hp(3hr)	3	3	400	4-5
4	60-65	22,000/-	400-480	0.3	700	5hp(3hr)	4	5	400	8-10
5	85-87	30,000/-	500-600	0.5	800	10hp (4hr)	5	7	600	12-14 (25Kw)
10	1 cr -1.2 cr	50,000/-	1000-1200	2.5	1200	15hp (4hr)	10	15	1000	22-25 (50Kw)

* This is an approximate cost for biogas generation plant and may increase by 10%–20%, depending on location, site-specific parameters, cost of materials, labour cost, etc., in different states/cities. Cost of additional infrastructure like office space, toilets, security, Godown, Shades and power generation will be extra, if required.

Rs – rupees; m3 – cubic meters; m2 – square meters; h – hour; kL – kilolitre; LPG – liquefied petroleum gas; kW – kilowatt; cyl –

Decentralised treatment options introduced in new rules.

The earlier rules relied on costly centralised facilities for treating and disposing municipal wastes while approximately 50 per cent of it can be easily turned into compost at the local level. Thus, the draft rules have made the much-needed provision for providing incentives to decentralised waste treatment facilities. 

http://www.downtoearth.org.in/blog/a-clean-country-in-the-offing-with-new-solid-waste-rules-49484

Considering an average garbage generation per capita per day as 0.450 Kg, we can assume a total garbage generation for a population of 100,000 as 45,000 Kg per day

Proven on wide range of wastes and feedstocks including

• Livestock and agricultural wastes
• Biomass
• Sewage and industrial sludges
• MSW and catering wastes
• Food industry wastes
• Vegetable market waste
• Restaurant Waste
• Farm House/Cattle manure waste
• Slaughter House/Tannery waste
• Presumed waste

Suitable locations for installation of plant

Hotel premises, army/big establishment canteens (private/ government), residential schools/colleges, housing colonies, religious places / temple trusts, hospitals, hotels, sewage treatment plants, villages, etc.

SOLID WASTE MANAGEMENT IN VARIOUS INDIAN CITIES

 SOLID WASTE MANAGEMENT IN VARIOUS INDIAN CITIES  .TAKEN  FROM  DOWN TO EARTH  MAGAZINE  (CSE)

 You can visit  the original source the read the  full article.

Decentralised treatment options introduced in new rules.

The earlier rules relied on costly centralised facilities for treating and disposing municipal wastes while approximately 50 per cent of it can be easily turned into compost at the local level. Thus, the draft rules have made the much-needed provision for providing incentives to decentralised waste treatment facilities. 

http://www.downtoearth.org.in/blog/a-clean-country-in-the-offing-with-new-solid-waste-rules-49484

Dear All,

First of all, I would like to ofeer Thanks for incorporating few new aspects like involvement of Informal Sectors (especially the Scrap Dealers) and also emphasising the Decentralised Composting and the Collection of Users' Charge. 
However, I would like to know the scopes for the following too .... 
(a) Adequate provisions with added importance on the Health Concern fo the Waste Pickers / Handlers, be it in case of House to House Collection of Segregated Solid Wastes or the Decentralised Composting or waste trasformation in the Informal Sectors like Scrap Dealers.
(b) Decentralisaion of all others aspects like Source Management, Collection, Segragation, Waste Transformation, M&E etc. apart from that in Composting.
(c) Emphasising the Labour intensive Approach for the decentralised activities, alongwith demotivating the highly mechanised process.
(d) Full stop for the unsustained Waste to Energy Approaches.
(c) Strict efforts for Monitoring and Evaluation

Proper redress for the abovesiad issues may eventually make the whole Solid Waste Management Approach more meaningful and result oriented.
Hoping for the Best and all success for "Near Zero" to "Zero Waste Plan" under each Municipalities.
Thanks and Regards.
Nripendra Kumar Sarma
Guwahati, Assam, India

Decentralised integrated solid waste, waste water and solar energy project at New Motibagh, New Delhi

please read http://www.downtoearth.org.in/blog/the-waste-conundrum-44092

Waste Water Management: About 70% of the 8 lakh litres of water supplied to the residents, that is, 5.6 lakh litres of waste water generated is treated in a decentralized waste water treatment plant within the campus using the Moving Bed Bio-reactor (MBBR) technology. There is a net savings of Rs.5 lakhs per annum due to direct and indirect savings from a decentralized Waste Water Treatment plant (WWTP) in the campus whose running cost is Rs.55.55 lakhs as opposed to the centralized sewerage system costing Rs.60.62 lakhs.  

The energy savings from 300 solar street lights at the GPRA complex, covering internal roads, common areas, parking lots and bunglows, help in saving Rs.32.28 lakhs per annum. Along with solar water heaters, the savings on electricity is close to Rs.35 lakhs a year.    

Therefore, a decentralised integrated solid waste, waste water and energy project for about 1000 households can achieve clean and green surroundings and financial savings to the tune of Rs.40-50 lakhs per annum

http://www.downtoearth.org.in/news/garbage-to-gold--29414

Garbage to gold  at mumbai

Though Gowariker and his colleagues are confident of the technology, they caution that refuse pelletisation is not the only or best way to deal with the growing urban garbage problem. Gowariker points out, "A product mix of compost and fuel pellets may be more appropriate, depending on the financial situation and the demand."

http://www.downtoearth.org.in/blog/delhi-s-solid-waste-a-systemic-failure-56776

Delhi’s solid waste: a systemic failure

What can Delhi do?

We need hybrid solutions. We need a landfill, but only for rejects and inerts. We need waste to energy, but then such plants should ensure that they run on segregated waste only. With over 50 per cent biodegradable waste, there is high potential to compost or generate biogas out of the segregated wet waste. And all this cannot work, unless we segregate at source. With over thousands of crores being spent on collection and transportation, time has come to think out of the box. We can learn from our neighbours and cities across India that are doing commendable work on waste management.

Look at the Alleypey model, where residents have taken it upon themselves to segregate and treat waste at source. It is the best model in the country on decentralised waste management. We can even look at Panjim; the municipal corporation not only ensures segregation at source, but also segregates dry waste into 30 different categories. And then there is Mysuru, Suryapet, Bobbili and a lot of other cities that are doing commendable work. They have adopted local solutions, not global to become zero-waste cities. The CSE has documented cities that are doing commendable work on waste management.

Government notifies new solid waste management rules

http://www.downtoearth.org.in/news/solid-waste-management-rules-2016-53443

http://www.downtoearth.org.in/blog/a-clean-country-in-the-offing-with-new-solid-waste-rules-49484

Segregation at source should therefore be at the heart of municipalities’ solid waste management system. The only city that has truly adopted segregation is Panaji. Municipal officials have ensured a citywide system that is designed to collect household waste on different days for different waste streams. This ensures separation. It is combined with penalties for non-segregated waste and has promoted colony-level processing as well. Most importantly, for the bulk of commercial establishments such as hotels it has a bag-marking system so that any non-compliance can be caught and fined.

In Kerala’s Alappuzha segregation happens differently. Here the municipality does not collect waste because it has no place to take it to for disposal. The city’s only landfill has been sealed by villagers who live in its vicinity. This withdrawal of the municipality from waste management has meant that the people have to manage their waste, or be drowned in it. They segregate and compost what they can. The compost is used for growing vegetables and plants in their homesteads. The problem is how to handle all the non-biodegradable waste—paper, plastic, aluminum tins, etc. This is where the government has stepped in. It promotes collection through the already well-organised informal waste-recycling sector. The municipality has ended up saving a huge capital cost it would have otherwise incurred for collection and transportation.

http://www.downtoearth.org.in/blog/solving-india-s-garbage-problem-53956

Waste smart cities  http://www.downtoearth.org.in/coverage/waste-smart-cities-54119

Bio Gas plant from Kitchen Waste and other bio degradable solid waste

Bio Gas plant from Kitchen Waste and other bio degradable solid waste

Proven on wide range of wastes and feedstocks including

• Livestock and agricultural wastes
• Biomass
• Sewage and industrial sludges
• MSW and catering wastes
• Food industry wastes
• Vegetable market waste
• Restaurant Waste
• Farm House/Cattle manure waste
• Slaughter House/Tannery waste
• Presumed waste

Suitable locations for installation of plant
Hotel premises, army/big establishment canteens (private/ government), residential schools/colleges, housing colonies, religious places / temple trusts, hospitals, hotels, sewage treatment plants, villages, etc.






The Principle:

Add bio degradable Solid waste to a  mixer to process the waste before putting it into predigestor tank. The waste is converted in slurry by mixing with water  in this mixture.

Use of thermophilic microbes for faster degradation of the waste. The growth of thermophiles in the predigestor tank is assured by mixing the waste with hot water and maintaining the temperature in the range of 55-60oC. The hot water supply is from a solar heater. Even one-hour sunlight is sufficient per day to meet the needs of hot water.

After the predigestor tank the slurry enters the main tank where it undergoes mainly anaerobic degra-dation by a consortium of archae-bacteria belonging to Methanococcus group. These bacteria are naturally present in the alimentary canal of ruminant animals (cattle). They produce mainly methane from the cellulosic materials in the slurry.

The undigested lignocellulosic and hemicellulosic materials then are passed on in the settling tank. After about a month high quality manure can be dug out from the settling tanks. There is no odour to the manure at all. The organic contents are high and this can improve the quality of humus in soil, which in turn is responsible for the fertility.

As the gas is generated in the main tank, the dome is slowly lifted up. This gas is a mixture of methane (70-75%), carbondioxide (10-15%) and water vapours (5-10%). It is taken through GI pipeline to the lamp posts. Drains for condensed water vapour are provided on line. This gas burns with a blue flame and can be used for cooking as well.

The gas generated in this plant is used for gas lights fitted around the plant. The potential use of this gas would be for a canteen. The manure generated is high quality and can be used in fields.

This manure can be supplied to farmers at the rate of 4-5 Rs. per Kg. Alternatively municipal gardens and local gardens can be assured of regular manure from this biogas plant.

Bio Remediation--Microbes Cleaning Up the Environment

Bioremediation is a waste management technique that involves the use of organisms to remove or neutralize pollutants from a contaminated site. According to the EPA,bioremediation is a “treatment that uses naturally occurring organisms to break down hazardous substances into less toxic or non toxic substances”.

Microbes are often used to remedy environmental problems found in soil, water, and sediments. 

We have done the following Technologies in bioremediation

1. Composting for MSW 

2. Aerated Lagoon for waste water

3.Rotating biological contactor for waste water
Watch videos:
https://vimeo.com/tag:bioremediation

waste to energy plants consultancy providing design and supply of Biogas plants, Anaerobic Digestion (Bio Methanation)

http://www.wasteworks.ie/   Wasteworks international consultancy providing design and supply of
Biogas, Anaerobic Digestion and Reedbeds and Wetlands systems

ANAEROBIC DIGESTER SYSTEMS

Proven on wide range of wastes and feedstocks including

• Livestock and agricultural wastes
• Biomass
• Sewage and industrial sludges
• MSW and catering wastes
• Food industry wastes
• Vegetable market waste
• Restaurant Waste
• Farm House/Cattle manure waste
• Slaughter House/Tannery waste
• Presumed waste

Biogas

www.biogasproducts.co.uk
Wasteworks is process consultant to UK Biogas Supplier Biogas Products Ltd,

www.epswater.com
Wasteworks is a long-term AD consultant to EPSwater

www.enviroserv.co.za
Wasteworks is biogas design consultant to Enviroserv of South Africa developing and supplying AD plants in Africa

MSW CONSULTANT

Plastic waste recycling industry in DELHI : The quantity of plastic wastes generated in Delhi is estimated to be 300 mt per day.Plastic waste collection and segregation, recycling and reprocessing systems and promoting end-product applications with desired recyclable component based on Guidelines for Recycling of Plastics to be issued by the Bureau of Indian Standards.

we do consultancy for that.

Landfill Leachate Treatment

Landfill Leachate Treatment

Landfill leachate is generated from liquids existing in the waste as it enters a landfill or from rainwater that passes through the waste within the facility. The leachate consists of different organic and inorganic compounds that may be either dissolved or suspended. An important part of maintaining a landfill is managing the leachate through proper treatment methods designed to prevent pollution into surrounding ground and surface waters

The physical appearance of leachate when it emerges from a typical landfill site is a strongly odoured black, yellow or orange coloured cloudy liquid. The smell is acidic and offensive and may be very pervasive because of hydrogen, nitrogen and sulfur rich organic species such asmercaptans.

If leachates have a distinguishing characteristic, it is that they are variable.  Flows change based on the weather  – increasing during rainy periods, decreasing during dry and waste concentrations can change dramatically over the life of the landfill.   As a result, no landfill leachate is constant over time, and no two leachates are the same.

When the landfill is a few years old the dominated fermentation phase is acidogenic and the leachate generated is generally referred as “young”.In that case, COD and BOD reaches very high concentrations. The ratio of BOD/COD is higherthan 0.7 and pH is low due to the high concentrations VFAs. Landfill grater than 10 years old aregenerally in the methanogenic phase and theleachate generated is referred to as “old”. Duringthe methanogenic phase, bacterias are degradingthe VF-acids and reduce the organic strength ofleachate, leading to the pH value higher than 7.In “old” leachate BOD decreases faster than CODand the radio BOD/COD is stabilized on the levelless than 0.2 [2,4].Anaerobic treatmentprocess is used mainly for young landfill leachate,which BOD5 and BOD5/COD ratio is very high[2]. However, Kettunen, et al. [10] performedthe treatment with UASB reactor were municipal landfill leachate was having COD higher than800 mg × dm−3 and the BOD/COD radio washigher than 0.3.Anaerobic processes of landfill leachate inUASB reactor allow complete removal of CODfrom 65 to 76% and BOD5 removal beyond90% [11].

 

Table 1

Characteristics of landfill leachate 

Parameter Value

COD, mg O2 × dm−3 3500–4200

BOD5, mg O2 × dm−3 380–420

pH 8.2–8.4

Alkalinity mg CaCO3 × dm−3 4900–5200

Chloride mg Cl−× dm−3 1800–2500

Ammonia nitrogen, mg NH4+× dm−3890–994

VFA, mg CH3COOH × dm−3 500–900

landfill leachate  quantity , 5%

UNITS OF TREATMENT OF LANDFILL LEACHATE:

1.      Collection Sump: Areas in which rainfall is higher than average typically have larger sumps. A further criterion for sump planning is accounting for the pump capacity. The relationship of pump capacity and sump size is inversed. If the pump capacity is low, the volume of the sump should be larger than average. It is critical for the volume of the sump to be able to store the expected leachate between pumping cycles. This relationship helps maintain a healthy operation. Sump pumps can function with preset phase times. If the flow is not predictable, a predetermined leachate height level can automatically switch the system on. Other conditions for sump planning are maintenance and pump drawdown. Collection pipes typically convey the leachate by gravity to one or more sumps, depending upon the size of the area drained. Leachate collected in the sump is removed by pumping.

2.    UASB Reactor:

3.     Clarifier Tank :

4.    Clear Water Tank:

5.     Activated Carbon Filter:

LITERATURE STUDY: WASTE TO ENERGY CONCEPTS

Energy recovery as electric power is a feature of all waste-to-energy systems.

Evaluation of the applicability of the technologies of biomethanation, gasification/pyrolysis,incineration and landfilling as Waste-to-Energy options, and their comparison against composting as a competing technology for waste disposal, has shown the following:

• Biomethanation has emerged as a favoured technology for various urban and industrial waste.

• Gasification/pyrolysis have a distinct promise, and although there are limitations to its uptake, these can be overcome as the technology matures.

• Incineration is a mature technology for energy recovery from urban and industrial wastes and has been sucessfully commercialized in the developed countries. The recent focus has been on environmental compliance due to which it will become an expensive option.

• The present trend is in favour of material recovery facilities and a shift away from landfills for MSW disposal in developed countries.

• Compositing is not a WTE option and does not come out as worthwhile waste treatment process.

• Technologies like landfill with gas recovery and composting can become viable options for certain locations in India, as a short to medium term option.

 

Landfill Leachate Treatment Technologies

Landfill leachate may be characterized as a water-based solution of four groups of contaminants ; dissolved organic matter (alcohols, acids, aldehydes, short chain sugars etc.), inorganic macro components (common cations and anions including sulfate, chloride, Iron, aluminium, zinc and ammonia), heavy metals (Pb, Ni, Cu, Hg) , and xenobiotic organic compounds such as halogenatedorganics, (PCBs, dioxins, etc.).^[4]

Leachate treatment technologies fall into two basic types, biological and physical/chemical. In larger systems and depending on the treatment goals, integrated systems which combine the two are often used.
The typical processes used for pretreatment include equalization, aeration, pH adjustment and metals removal.

The most common biological treatment is activated sludge - a suspended-growth process that uses aerobic microorganisms to biodegrade organic contaminants in leachate. With conventional activated-sludge treatment, the leachate is aerated in an open tank with diffusers or mechanical aerators. After the aeration phase, the mixed liquor of microorganisms and leachate is pumped to a gravity clarifier.

The rotating biological contactor (RBC) is an attached-growth, aerobic, biological treatment process in which a series of discs are partially submerged in a tank of leachate. The disks eventually develop a slime layer, then rotational shear forces strip off the excess solids and carry them with the effluent to a clarifier, where they are settled and separated from the treated waste.

The carbon technique removes dissolved organics from the leachate. Although carbon systems may be useful with some older leachates, the cost of the carbon in the regeneration stage can make the process one of the most expensive treatment options.

Advanced Treatment The new landfill regulations have made some treatment systems obsolete. Many landfill operators are now choosing new systems that produce a cleaner effluent and can reduce capital and operating expenses. Such systems include:

* Recirculation and Injection. Direct recirculation distributes the leachate onto the landfill in a semi-closed loop process. While promising, this system has limitations of recirculating 100 percent of the leachate without literally soaking the landfill.

* Membrane Solution. Membrane technology can be adapted to many steps of purification and keep clean-up standards at a high level. Membranes can remove contaminants without extensive biological infrastructure or toxic chemicals.

* Reverse Osmosis (RO). Prior to 1988, reverse osmosis wasn't able to treat leachate successfully due to the core membrane design of spiral-wound modules, which were state-of-the-art at that time. While this method produced efficient results, it also promoted bio-fouling and premature clogging.

Disc Tube technology, developed by the Rochem Group, has been installed in more than 35 European landfills to treat feed waters that would foul conventional RO configurations. After the contaminated water is fed into the tubular chamber, its flow is controlled as it passes through a system of discs and over flat membrane cushions, removing clean water and concentrating the waste material. The turbulent flow reduces the membranes' tendency to scale or foul and requires cleaning less frequently.

The system removes heavy metals, suspended solids, ammonia and hazardous non-degradable organics including pesticides and herbicides without extensive pre-treatment systems. The pure water is clean enough for direct discharge into the environment and accounts for 75 to 92 percent of the leachate. The remaining concentrate can then be recycled to the landfill or further processed.

Siemens Water Technologies' PACT® systems combine biological treatment (activated sludge) with adsorption (powdered activated carbon) so that physical and biological treatment occur simultaneously. The system removes biodegradable and non-biodegradable pollutants in a single process

The most cost effective form of treatment for high levels of BOD, COD and ammonia is intense biological oxidation, and in the UK the sequential batch reactor is the most common technology used. The sequence batch reactor (SBR) is a form of activated sludge treatment.

Granular activated carbon, in combination with biological pretreatment, is a proven and economical technology which is effective in reducing Chemical Oxygen Demand (COD), Adsorbable Organic Halogens (AOX), pesticides, solvents, organic compounds and other toxic substances to the strictest legal National and EC norms. The chemical composition and content of landfill leachate can vary greatly between landfill sites. The age of the landfill, type of waste and treatment processes already in operation are the parameters to be considered.

COD levels can range from 200mg/l to 2000mg/l. Carbon consumption is normally dependent upon the COD adsorption rather than the AOX. Therefore COD will be the determining factor in estimating carbon consumption.

However, an aerobic system must be used after the UASB reactor for the effluent to meet the standards defined for the proposed disposal method.

 

Combined treatment of leachate from sanitary landfill and municipal wastewater by UASB reactors

This study showed the potential of anaerobic treatment in an UASB reactor treating a combination of domestic wastewater and leachate in a 5% volumetric ratio of leachate. Under these conditions the reactor assimilated properly the leachate fraction incorporated. With a HRT of 8 h and a mean volumetric organic load of 2.84 kg m(-3) d(-1) COD removal efficiencies around 70% were obtained,

When installing a leachate treatment system, choose a plan that will provide the maximum amount of long-term flexibility to assure compliance with future regulations and discharge standards.

LEACHATE RECYCLE  CONCEPT :The major objective of gas studies is directed towards maximizing production rates of gas by biodegradation of the waste while simultaneously reducing the period of time that gas is evolved by recycling leachate. It describes potential means of managing both leachate quality and quantity by leachate recirculation to aid in decomposition of the waste while also treating the organic material in the leachate and reducing the quantity of leachate that must be treated and hauled away from the site.