Anaerobic Digestion - Gas Production

A typical gas system comprises the digester cover, pressure and vacuum relief devices, water trap, flame trap, pressure regulator, gas meter, check valve, pressure gauges, waste gas burner and a gas holder. Mixing of digesters by means of gas re-circulation requires a compressor.




The digester is covered to contain odours, maintain temperature, keeps air out and to collect the gas. Fixed covers are more usual than floating covers. During normal operation, there is a space for gas collection between the cover and the liquid surface of the digester contents. The cover of a digester has certain unique features that the operating staff must be aware of, for example, how the variation in pressure and the level inside the digester may affect the cover. The biggest danger associated with the operation of fixed cover digesters occurs when the pressure relief device mounted on top of the digester fails or the sludge overflow line blocks and the liquid level in the digester continues to rise. In such a situation, the excess gas pressure inside the digester can exceed the maximum design pressure and damage the cover or its mountings. Fixed covers can also be damaged by excess negative pressure (vacuum) or if the rate of waste sludge withdrawal exceeds the feed rate or the vacuum relief device fails.

The function of the pressure relief device is to allow pressure that exceeds a safe level to escape from the digester. The manufacturer's specifications should provide the following information to enable the operating staff to control the gas system safely. (a) The system's normal operating pressure (mm water gauge). (b) The pressure at which the pressure relief device should operate. (c) The rated gas flow capacity of the pipes.

A gas system generally comprises three pressure relief devices; one mounted on the cover of the digester, one on the gas holder and one situated at the end of the gas line before the gas burner. This device releases gas to the waste gas burner before the design gas pressure of the digester cover is reached.

The vacuum relief device functions in the opposite manner to the pressure relief device and allows air to enter the digester in the event of the waste sludge being withdrawn too rapidly. Air should not, under normal conditions, be allowed to enter the digester because a mixture of air and methane is potentially highly explosive.

Gas leaving the digester is almost saturated with water vapour. As the gas cools, the water vapour condenses causing problems. The problem is more severe when digesters are heated. To solve the problem it is essential to remove as much of the moisture as possible before the gas comes into contact with the gas system devices. For this reason, water traps should be located as close to the digester as possible. All piping should be sloped a minimum of 1% towards the water trap, which should be situated at a low point in the gas line.

Flame traps are emergency devices installed in gas lines to prevent flames travelling back up the gas line (flashback) and reaching the digester. The flame trap generally consists of a box filled with stone or a metal grid. If a flame develops in the gas line, the temperature of the flame is reduced below the ignition point as it passes through the trap and the flame is extinguished.

Pressure regulators are used when a lower pressure than the system operating pressure, is required for a specific device such as a boiler water heater or incinerator. Regulators maintain a constant gas pressure at the point of use

The rate of gas production is probably the most sensitive process control indicator at the disposal of the operating staff. Gas meters should be regularly serviced so as to give accurate and reliable gas readings. Every effort should be made to have the gas meter calibrated every six months.

Check valves (non-return valves) are installed in the gas line to allow gas flow in one direction only i.e. out of the digester.

Gas pressure gauges indicate the pressure in the gas system and assist in locating any blockages in the line. If a blockage occurs, a pressure reading downstream will register a lower pressure than that of a gauge upstream.

The pressure relief device at the waste gas burner safely flares excess gas to the atmosphere and thus reduces the potential for a dangerous accumulation of gas in the system.

Many anaerobic digestion waste treatment plants have a means of storing excess gas. This can be in the form of either a floating roof on the digester or a separate gasholder.

A mixture of biogas and air can be explosive. Methane gas in concentrations of between 5% and 15% in air by volume is explosive. Operating staff on waste treatment plants should ensure that no air is allowed to enter the digester or gasholder. All piping and equipment must be sealed properly to prevent gas from escaping to the outside. There must be no smoking and all electrical installations, including light switches, torches etc must be of the explosion-proof type, as the smallest spark could ignite escaped gases.

Michael Russell

Your Independent guide to Waste Treatments [http://waste-treatments.com]

Digestion of Sludge - Optimizing Digestion in Wastewater Treatment

Sludge Digestion Tanks

A sludge digestion tank is an R.C.C. tank of cylindrical shape with a hopper bottom and is covered with a fixed or floating type of roof. The latter makes the digestion of sludge much more effective. The weight of the cover is supported by sludge, and the liquid forced between the tank wall and the side of the cover provides a good seal. The raw sludge is pumped into the tank where it is seeded with digested sludge.

On undergoing anaerobic digestion, gases of decomposition (chiefly Ch4 , CO2) are given out by the anaerobic digester. Sludge gas rises out of the digesting sludge. It moves along the ceiling of the cover and collects in the gas dome. The cover can float on the surface of the sludge between the landing brackets and the overflow pipe. Rollers around the circumference of the cover keep it from binding against the tank wall.

The digested sludge, which settles down to the bottom of the tank is removed under hydrostatic pressure periodically, say, once a week. To maintain optimum temperature, the tank is generally provided with heating coils through which hot water is circulated.

The supernatant liquor i.e., the part of the tank content lying between the scum and the sludge is withdrawn at the optimum level through a number of withdrawal points located at different elevations of the tank. As it is high in BOD and suspended matter contents, it is sent back to the incoming raw sewage for undergoing re-treatment. During the digestion of sludge, the scum formed at the surface gets broken up by the recirculating flow or through mechanical rackers called scum-breakers.

The amount of sludge gas produced during digestion of sludge varies from 0.014 to 0.028 m3 per capita with 0.017 m3 being quite common. The gas produced contains 65 per cent of methane with a calorific value 5400 -- 5850 kcal. m3, 30 per cent of carbon dioxide and balance 5 per cent of nitrogen and other inert gases. It resembles natural gas and may be used as a fuel for cooking. Principal uses however, are for driving gas engines, and for heating sludge to promote quick digestion of sludge.

For a free eBook on a great new wastewater treatment technology and for everything else you want to know about wastewater treatment including digestion of sludge, click http://www.all-about-wastewater-treatment.com.

Richard J. Runion is the President of Geostar Publishing & Services LLC. Rich loves net research & blogging. His new blog on Wastewater Treatment is fast becoming popular, as it is comprehensive and well-researched.

Prospect of Jatropha Curcas as Energy Plant (3)

Solid fuel from physic nut waste

Physic nut seed contains the oil around of 25-35% of the total unit weight. This form of waste has a crude oil content of 75-65%. Waste can be processed into solid fuel through a process of densification. The process of carbonization or non-carbonization can also be applied to improve the quality of these solid fuels.




In the carbonization process, waste is inserted into the reactor in order to remove moisture, volatile matter and tar. After this process, they are sent to the densification process. This process forms the material into briquettes using a press machine.

There are two types of press machine used, is hydraulic and screw machine. Densification product is densified material called briquettes. This fuel can be used as solid fuel. Briquettes can be easily burned into the furnace or conventional stove. In commercial production, briquettes used to burn water in the boiler. Steam generated, is sent to a steam turbine. This steam spins the generator wheel to produce electricity.

Gas fuel from physic nut waste

The gas fuels can be produced through an anaerobic digestion process. This process is a chemical process involving microorganisms without the presence of oxygen in a digester. This process produces the methane, carbon dioxide, hydrogen, nitrogen, hydrogen sulfide and a small amount of gas. Methane is the largest composition compared with other gas products. This process can be classified into two types: dry and wet anaerobic digestion. The Differences between these anaerobic processes are the ratio of biomass and water used in the digester.

Nugroho Agung Pambudi has been writing articles including papers for nearly 3 years now. His journal papers can be reached both international journal and conference. Come visit his latest website at methylcobalamin which help people find information about vitamin B12 methylcobalamin

Rural Estates and Farms Set to Benefit From Feed-In-Tariffs

Estate agency firm Knight Frank claims that rural estates and farms in the UK could bring in extra income in the tens of thousands if they take advantage of the renewable energy feed-in tariff. In its latest publication, Rural Report Knight Frank created a hypothetical renewable energy farm utilizing all forms of renewable energy as a means of generating revenue through the feed-in tariff calculating the cash that could be generated from wind, solar, hydro and anaerobic digestion.




The report found that if complete grid-connectivity were achieved, the following incomes could be generated:

2 wind turbines: 300,000 Anaerobic digester: 460,000 Hydroelectric Installation: 190,000 Solar Panels: 26,300

The total income for these renewable projects would be an impressive 916,000 with a potential of 18.5m to be made over the project's lifetime.

The potential for landowners to benefit from feed-in tariff legislation in the UK is enormous with the potential not only to receive tariff payments but also to significantly reduce overheads by using the energy produced on the land.

The Knight Frank report explains the mechanism stating,

"Feed-in tariffs were introduced in the dying days of the Labour government and were designed to encourage people to create their own renewable electricity.

An index-linked payment guaranteed for up to 25 years is made for each unit of electricity produced even if it used by the generator for their own consumption. The tariff varies depending on how the energy is being generated and the scale of the scheme".

Although the hypothetical estate set out in the Rural Report gives the absolute optimal conditions for generating revenue from renewable energy, it nevertheless highlights the potential to make money though renewable energy. With project lifetimes of 25 years and revenues protected by government legislation, landowners are catching on to the fact that there is real money to be made from investing in renewable installations.

Kevin Langley is a leading knowledge in the Solar Investment and Renewable Energy world. Having worked with the subject for many years, he is fast becoming an expert on green energy and investments in green stocks.

He writes for many blogs and runs a range of Solar websites. He has a keen interest in green renewable energy and spends most of this writing time focusing on this subject.

http://solarfeedintariff.co.uk/

The Importance of Biogas Digesters For All Our Futures

Biogas digesters hold a high level of importance for all our futures as the only way to turn the tide on global emissions from a huge range of waste organic materials. Society is blinded by the opportunities of solar energy, wave and wind power, but so far has failed to see that unless the rising quantities of argnic waste we produce are disposed of without decomposing to produce methane a huge problem remains. As a result of that failure a very large and growing greenhouse gas emission load will remain and we can never become truly sustainable, as things are now, and future generations are doomed.




We are now using our natural gas (carbonaceous fuel) resources up at a huge rate. These were formed from the fossilized remains of plants and animals in a process that took millions of years.

Such resources do not "grow back" in a time scale that is meaningful for humans. Natural gas is a fossil fuel that was created eons ago by the anaerobic decomposition of organic materials. It is often found in association with oil and coal. It will deplete without an adequate replacement other than biogas, so we had better get on with it and improve our ability to produce biogas and sngas (from gasification) - its only real replacement other than converting other carbonaceous fuels into gas fuels!

Cooking is best with with clean-burning gas, rather than smoky wood. Introducing gas cooking improves respiratory health and reduces the pressure on local fuelwood. In contrast, cooking on open fires emits gases that endanger people's health and contributes unnecessarily to global warming.

The German government saw the potential for biogas a number of years ago and introduced incentives to encourage biogas and biofuel production. German technology companies has a head start over the US, and the UK. Based on their experience, acquired over a number of years in partnership with their German customers, they have built a formidable record in biogas digestion.

The US should welcome these experts into the US. They do say that they want to share their expertise in other markets.

According to reports available on the internet they already have numerous projects and installations completed in Russia, Thailand, England, France, Spain and Turkey, and this they consider to be just the beginning.

It is stated in a recent report available on the worldwide web, that biogas even offers the possibility of stepping towards energy security for rural and even peri-urban communities in some areas. However, the converse is certainly true, and there is no energy security for any nation now in depending on imports of natural gas, whereas literally home-grown biogas is right on our doorstep, and as secure a supply as can be imagined.

There are two great sites where you can find out more about this developing alternative energy source and those are the electricity from methane digester web page and the biogas digestion web site. Take a look now!

The Many Sources of Methane and Biogas

Methane is a combustible gas, which exists in two ways as part of the natural biological cycle when it is known as biogas, or biomethane, or as a mineral or fossil-fuel gas when it is called "natural gas".

As a mineral fuel it can be extracted from the earth's crust in the form of natural gas, or from waste sludge and biological sources including organic waste as biogas. Methane is widely accepted as the cleanest burning of all fossil fuels, but the extraction process itself requires careful consideration of the natural environment and local community.

Methane has been recently identified as a powerful greenhouse gas (GHG), and it has also been shown that its atmospheric concentration has been steadily increasing over the past 300 years. It is described as sustainable when it is produced by renewable energy (non mineral) sources, when it does not add to the GHG effect. All mineral sources are non-sustainable sources because they contribute to the GHG effect.

Methane is found trapped in air bubbles in ice cores, and measuring the quantity allows us to work out how much was present in the past. Studies of bubbles from the Greenland ice cap show that the concentration of methane in the air remained steady for 10,000 years, up until about 300 years ago.

If really large "burps" were released, quite substantial climatic changes would probably ensue. Methane is currently emitted in enough volume to make any reductions significant in terms of the overall GHG picture. Geochemical evidence for this process has been observed in numerous marine sediments along the continental margins, in methane seeps and vents, around methane hydrate deposits, and in anoxic waters.

There are two major ways in which methane is removed from the environment and these are aerobic oxidation by a specialized group of bacteria, and atmospheric oxidation.

Biogas /biomethane is produced by anaerobic oxidation by a specialized group of archaea, or methanogens.

Methane is emitted during the production and leaks from the distribution of natural gas and petroleum, and is released as a by-product of coal mining and incomplete fossil fuel combustion. Over many centuries as coal deposits are formed, some methane is absorbed by the coal and that is the usual source from which it is found in mines.

Biogas methane is released as vegetation rots under water. This is is happening in millions of square miles of rice fields throughout Asia.

It is combustible, and mixtures of about 5 to 15% in air are explosive. It is the main constituent of natural gas, a fossil fuel . Methane is far more lethal as a greenhouse gas - assuming that one believes in all this - than carbon dioxide. It is between 20 and 23 times more potent than Carbon Dioxide in terms of its GHG climate warming potential, depending upon how you look at its potency, although it does not last forever in the atmosphere.

Cows produce huge volumes of it. Contrary to what might be expected, organic cows produce less milk than conventionally farmed cattle, so their methane output per litre of milk tends to be much higher than the non-organic type.

When we say that methane is a much more potent greenhouse gas than CO2 we refer to the fact that eight for weight, it traps 21 times more heat energy. However, to get this in proportion methane is just one of six gases held responsible for global warming. Carbon dioxide is the second most abundant greenhouse gas behind water vapor.

There are huge quantities of methane in the permafrost. Permafrost in northern Siberia is reported to be 1,600 meters, (5,250 feet) thick and in in northern Alaska it is estimated at 650 meters (2,100 feet) thick Permafrost lies beneath about 80 percent of Alaska, and a higher percentage of Siberia. Permafrost on land, though, is as cold as -12.4 degrees Celsius.

Why do the GHG potencies vary so much between gases? Gases in the atmosphere, such as methane, absorb light energy and different gases absorb different amounts of energy.

Gas pipeline inspection is essential to maintain gas distribution systems, and minimize leakage, but it is a huge task. Just looking at the figures for Germany alone, with a network of more than 40,000 km of long-distance gas transport pipelines. Also, the need for a fast and remote monitoring system is apparent, to identify damage quickly.

Emissions from animal wastes depend on the method of storage or management of those wastes. When manure is stored as slurry, much of the decomposition is anaerobic and methane is produced in significant quantities. These emissions can and should be controlled by specific regulations.

Anaerobic digesters at local organic waste landfill sites or installed as part of large PFI systems capture and destroy the methane or clean it to comply with consumer standards. Large numbers of these plants installed throughout Europe would help to reverse the upward trend in methane discharges to the atmosphere. Nevertheless, even if large numbers of AD Plants were built rapidly, anaerobic methane oxidation will always remain biogeochemically important because methane is such a potent greenhouse gas in the atmosphere.

Steve Evans writes about methane biogas and runs the united kingdom anaerobic digestion web site http://www.anaerobic-digestion.com

Understanding Biogas As an Alternative Fuel Choice

Biogas is a mix mainly of methane and carbon dioxide and is produced naturally when organic matter decomposes in the absence of oxygen. Biogas is produces from Land filling and through anaerobic digestion. Depending on place where it is produced, biogas can also be called swamp gas, marsh gas, and landfill gas or digester gas.




Anaerobic digestion is one of the methods through which biogas is produced. Biogas can be produced utilizing anaerobic digesters. Here, the plants can be fed with energy crops such as maize silage or biodegradable wastes including sewage sludge and food waste; whereas, the landfill gas is produced by organic waste decomposing under anaerobic conditions in a landfill. Gober Gas is the other form of biogas generated out of cow dung. This type of biogas is produced mainly in the households of India and Pakistan.

Biogas has many advantages over other alternative fuels. One of the main advantages of biogas is that the technology is cheaper and much simpler than those for other biofuels. Recovery of the methane is spontaneous as the gas automatically separates from the substrates. Dilute waste materials can be used as substrate. In the process of making biogas, organic pollutants are removed from the environment and used to generate useful biogas and this actually cleans the environment. Aseptic conditions are not needed for operation. Other advantage of biogas is that it will not produce any unpleasant odours. Electricity can be generated with biogas 24 hours a day. There is reduced risk of explosion as compared to pure methane and any biodegradable matter can be used as substrate for producing biogas.

As it has many advantages, biogas too has few disadvantages as well. One among them is that the product (biogas) value is rather low and this makes it an unattractive commercial activity. This process is not very attractive economically (as compared to other biofuels) on a large industrial scale. Biogas contains some gases as impurities, which are corrosive to the metal parts of internal combustion. Other major disadvantage of biogas is that its yields are lower due to the dilute nature of substrates.

Nevertheless, Biogas can become a great substitute for other conventional energy sources.

Clifton is a qualified mechanical engineer committed to finding alternative fuel sources that can be incorporated into everyday life. Alternative energy sources with reduced environmental effects will need to be discovered and used in order to generate the power requirements our lifestyle currently demands.

Why Farmers Choose the Anaerobic Digestion Process

The farming community will invest to improve their farms and ultimately to improve yield and profit, but there has to be a very good reason for doing so, and when it comes to shelling out hard-earned revenue, or going for additional borrowing, agricultural businesses usually look for dead certain investment winners, or nothing at all.




Yet, many farms are now going into Anaerobic Digestion plant installation and operation, investing in a process which is fairly new, at least for farming applications, and which they would expect to be operating on their farms for at least the next twenty years once installed. On the face of it this is a highly risky investment, and a surprise.

Well actually, there is good reason for this and it has very little to do with improving their crops, although the fertilizer it produces will be very useful there, it is to avoid environmental problems caused by the success of industrial farming methods, and particularly for dairy farmers who over-winter large numbers of stock in barns.

Let's not get too "down to earth" and talk about the brass tacks too much here, so shall we say that the problem is one of waste management, and leave as much as possible to your imagination!

Yes, the run-off from these barns and the effect this can have on pollution of rivers, in dairy farming and beef cattle rearing areas, can be and often is, very serious. So much enteric bacteria (stomach organism) type pollution has been occurring in in some estuarial areas of the UK that the quality of the sea on bathing beaches has failed to meet European Union Green Flag standards after heavy rainstorms.

These farms really have to reduce the pollutants in their run-off, and Anaerobic Digestion of their farm waste using a Biogas Digester is proving to be the top solution, once the problem is recognised. They are having to spend to reduce pollution because not cutting back massively on the quantities of organic waste being washed off their farms will increasingly mean that they will be prosecuted for the water pollution caused. Thus, this is a necessary spend for them, just to keep their farms operating on the right side of the law.

However, a biogas digester also can be used to generate renewable energy and provide fuel to run farm vehicles. So, many are finding it a great way to diversify away from solely food crop income dependence. In fact we would suggest that nowadays every farmer should be aware of the benefits of Anaerobic Digestion for its multiple benefits and great sustainability credentials.

Space is limited here so we recommend that you visit the Anaerobic Digestion community web site. It is well worth a visit for EVERYONE involved in a farm business. Much invaluable additional reading about the Biogas Digester's process, is available on that site.

GCC looks into using renewable energy - Stroud News and Journal

RENEWABLE energy could be used in future to power Gloucestershire County Council’s buildings, to save money and cut carbon.

The innovative idea, being looked at by the Environment Scrutiny Task Group, could see the council saving £5m annually, generating income and becoming almost carbon neutral within 10 years.

In our video below we provide an example of a renewable energy biomass boiler in the London Borough of Havering. AD is another method which could be used.




Currently the council produces around 60,000 tonnes of carbon every year and spend more than £8million on energy bills.

The pioneering approach to renewables would make Gloucestershire one of the first councils in the UK to look at generating and selling our own electricity on this scale.

This will involve using green technology like solar panels, wind turbines and anaerobic digestion to become a lean, green council which provides all its own energy, reducing the financial burden on the council taxpayer.

At the moment there are no firm plans in place, but feasibility studies will be carried out over the next six months to determine what could be done.

One of the ideas is to set up a separate company to sell our surplus energy generated back to the grid, which will generate further income for the council.

The scrutiny group charged with looking into the issue was asked to investigate everything that we could achieve.

If GCC takes on all the ideas scrutiny have looked at, an estimated capital investment of £180 million would be needed to put all these ideas into place – but that would bring an annual return of £420 million.

To achieve the £5million savings and become carbon neutral would mean investments of around £25million, however no money has been committed to this project yet.

The council would also be eligible for funding from government if it decided to go down the renewable route and if the renewable plans are feasible they could generate additional incomes of around £14 million a year.

Cllr Mark Hawthorne, leader of the council, said: "This is not a quick fix, it’s about finding a sustainable way of working which dramatically cuts costs, reduces our impact on the environment and increases the security of energy supply.

"There is a cost involved here and before we commit to spending any money, we will ensure whatever we end up doing is worthwhile and will provide the benefits we expect.

"We have to invest now to save for the future and if we can save around £5 million every year and then make money on selling energy on top of that, this money can be ploughed into frontline services and that for me is the most important thing."

Cllr John Cordwell, who is the chair of the scrutiny committee looking into the project, said: "This group is looking into ways of saving money and investing into renewable energy by using council buildings and land.

"We are pleased to see the administration is of the same mind and we shall look forward to scrutinising the plans as they develop."

View the original article here

Co-op Backs Energy Farms - Manchester Evening News

The Co-operative Bank in Manchester has agreed a £2.1m funding package for a north west company with plans to build a new generation of innovative 'energy farms'.

Lancashire-based Farmgen aims to build 50 environmentally-friendly anaerobic digestion power plants, which mimic the processes inside a cow's stomach to generate a methane-rich biogas.




The farm-based plants are fuelled by crops grown on site, and Farmgen has already agreed a deal to supply energy to Marks & Spencer.

The company is lead by Simon Rigby, former chief executive of the Leeds-based utilities infrastructure business Spice, which was sold to private equity outfit Cinven in September for £251m.

Farmgen's first plant at Carr Farm near Warton in Lancashire, which was formerly a dairy farm, is financed by a £2.1m loan from the Co-op, as well as funding from a group of private investors.

When fully operational next year it will generate 800kW of electricity – enough to power more than 1,000 homes.

Mr Rigby said: "It's a real lifeline for farmers and a big help for the UK economy. It gives farmers long term stability.

"It allows them to farm much more intensively, rather than just being subsistence farmers. It's going to breathe life into the countryside."

Farmgen was advised by a team from Manchester-based solicitors Heatons, which worked with the Co-op for nine months to secure the 11 year loan facility.

A team of six lawyers from the firm were involved in the project, advising on banking, corporate, construction, commercial and property matters.

Planning applications are currently being prepared for more plants across Lancashire, Cumbria and Staffordshire, with more sites being lined up across the country.

Partner James Flynn said: “This deal represented a new direction for the Co-operative but Farmgen’s plans for the plant are absolutely ground breaking.

“Farmgen’s overarching plan is to set up AD plants on farms across the UK. This could be a key driver in the country achieving its renewable energy targets, and we look forward to working with Farmgen on the future programme.

“For us, the energy sector is a big growth market for our business and so it is great to be involved in a project that is the first of its kind.”

View the original article here

Anaerobic Digestion Planning Application Underway in Fife, Scotland - Waste Management World

23 November 2010 - UK based environmental consultancy, SLR Consulting is to carry out work for Fife Council on a planning application for a proposed Anaerobic Digestion (AD) facility.

The facility, at Lochhead Landfill Site near Dunfermline, is projected to generate up to 1.4 MW of renewable electricity and a similar quantity of heat from the processing of around 43,000 tonnes of co-mingled food and green waste.




SLR says that following two or three years of feasibility studies, it has been commissioned to undertake site investigation works, planning, permitting and procurement support for development of the facility which is projected to be operational by 2013.

Chris Ewing, environmental sstainability manager for Fife Council Environmental Services said: "The scheme represents a real opportunity for us to realise the true value from our expanding programme for source segregation of food and green wastes.

"The site already produces around 1.5MW of electricity through the combustion of landfill gas. The proposed development would nearly double the output of the site in addition to allowing for the expansion of the existing district heating scheme which utilises the excess heat from the CHP units."

SLR principal and project manager for the development Duncan Thomas, who is based in SLR's Edinburgh Office, said: "It is great to be assisting this long standing client in delivery of this ground-breaking project.

"We have been providing technical consultancy support to Fife Council for over seven years and continue to provide support on landfill engineering and development, permitting, planning, landscape and site investigation works."


View the original article here

Study reveals new solution in battle against emissions - IBTimes

A study published by the National Grid in the UK is suggesting that Bio-SNG (Synthetic Natural Gas) could achieve carbon dioxide (CO2) savings of up to 90 per cent compared with fossil fuel alternatives.




The report, prepared by Progressive Energy and CNG Services, shows that unlike biomethane produced by anaerobic digestion Bio-SNG is formed by the conversion of thermally derived syngas into methane. Feedstocks can also include more durable materials such as woody biomass and wastes that are not broken down in traditional anaerobic digester plants.

It states that biomethane retains all the attributes of natural gas with the advantage that the fuel is renewable, which means there are substantial carbon dioxide savings. However, in order to achieve a step change in production capacity alternative approaches such as thermal routes are necessary.

Among the conclusions of the report are that implementation of Bio-SNG will only occur with the appropriate tax, incentive and legislative environment; and that it is likely the development of Bio-SNG facilities would require the developer to go upstream into the supply chain for both grown and waste derived fuels.

A process and technology review found that the major process operations required to produce Bio-SNG can be identified and assembled from existing technology suppliers; while a full lifecycle analysis of Bio-SNG production found that for many types of feedstock the savings of Bio-SNG compared with fossil fuel alternatives are as high as 90 per cent.

Source: The Green Car Website

View the original article here

Digestion Technology Developments For Cheaper Renewable Fuel

A very popular idea currently gaining publicity is a very old concept: methane digestion. The methane given off during the decomposition of the manure is captured and burned, providing either heat or power, for electrical generation. These promise a minor revolution in small and medium scale energy generation from methane, with a scale smaller than wind turbines, but still significant in terms of national adjustments to high oil prices.

However, the digestion process has been criticized for being inefficient and unstable in operation. But, the technology of anaerobic digestion has been largely ignored until the last run on oil prices about 5 years ago (about 2003), when for the first time for as long as anyone can remember the oil price exceeded the production cost for fuel produced as methane by digestion.

Five years has been scarcely long enough for more than some half a dozen to one dozen AD plants to be designed, constructed and commissioned, in the UK for example. These should be considered to be a first generation of a new breed of reactors using this technology. This is a bit like the people who criticized the motor car for being slow while the law (in the UK certainly) required all automobiles to be preceded by a man holding a flag to warn pedestrians.

Many did criticize the automobile at that time, but do you want to do so for digestion, as I think that you will be looking as silly as those flag wavers were just ten years later, when the motor car became an established mode of transport.

There are many ways in which the efficiency of Anaerobic Digestion bio-reactors are being improved, and the first is by using sophisticated ultrasonic technology to break up the particles and so allow breakdown of a bigger proportion of the organic content.

In some of the other processes being developed the excess liquor from the process is used to re-wet incoming biowaste as it contains useful bacterial populations. This method can produce a faster reaction then the original start-up.

It is important because on-farm Digester (Anaerobic Digestion) projects can provide needed services to farmers; develop local, renewable electrical generation; enhance environmental quality; and generate income for the community.

Other researchers have identified the fact that if you have fluctuating temperatures, then you will not be able to establish an optimum microbial population. The digester stirring system must be efficient and operational at all times to ensure that the cold, newly introduced sludge, is mixed with the warm older solids and the bacteria. This sounds easy but in a large tank with a fairly viscous sludge mass it can be surprisingly onerous on the mixing technology.

Anaerobic digestion consists of a series of reactions which are catalyzed by a mixed group of bacteria and through which organic matter is converted in a step-wise fashion to methane and carbon dioxide. Polymers such as cellulose, hemicellulose, pectin, and starch are hydrolyzed to oligomers or monomers, which are then metabolized by fermentative bacteria with the production of hydrogen (H2), carbon dioxide (CO2), and volatile organic acids such as acetate, propionate, and butyrate. Clearly, this is a complex reaction which e can be greatly improved by better knowledge gained by further academic study which can now take place given the raised awareness and importance of this technique. This will most likely yet result in big advances in how man designs and runs its new digesters.

In the developing world another angle for them is selling carbon credits from the renewable energy created by anaerobic digestion on the worldwide market. Those credits should be a source of income for as well as providing a way to readily obtain seed capital for these projects from the banks.

However, the process also produces a solid and a liquid digestate in the slurry. The use of the process would not be sustainable without an environmentally safe method of disposal, and better still preferably a 'beneficial use' of the output from digestion.

The market for the digestion processing outputs is still undeveloped just about everywhere. However, there are some positive signs reported that the outputs will be genuinely useful, and indeed a source for additional revenue for the operators of these plants.

The adoption of manure digesters at animal operations is much more advanced in Europe than in the U.S. But, there are many successful AD plants in operation throughout the U.S.

Northern Concrete has one such installation and has reported on its digestion process. They have said that the feedstock (animal byproduct) goes into a holding area until it is ready to enter the digester. It sits in the digester for 22 days and is released as useful by-products like methane and a grassy sawdust-like product that can be used as fertilizer, animal bedding or after further processing for floor boards.

There is certainly other evidence of progress in selling AD outputs. Another operator (Pro-Gro Mixes of Tualatin, Ore.) is thought to have contracted to market the solids material or digested fiber to the wholesale nursery and landscape industries, reportedly. It is understood to be selling between 1,000 to 3,000 yards of digested fiber, under the FiberLife brand, per month in the Willamette Valley.

There is also potential for the methane to be burnt in efficient turbines, rather than today's ubiquitous reciprocating engines. Here the heat from turbine exhaust is used to maintain the optimum digester temperature and sustain bio-gas production. The resultant bio-gas is collected from one such system and cleaned, then used to fire the turbines. The results have reportedly been way above expectations, with a significant increase in production, higher yield and fewer rejects being recorded. The digester in question is thought to qualify as a small-power production facility, which means it follows a funding schedule, enabling projects to gain rapid approval.

Digestion can be considered for a wide variety of agricultural and industrial and commercial sites. From agricultural community scale Digesters to supermarkets with waste food, to municipal authorities with organic waste in their collected waste streams. All should now be considering the installation of digestion of one type of another. For more information visit the Digestion web site.

Utilisation And Disposal Of Digested Sludge

After anaerobic digestion, the sludge would contain about 35% organic and about 65% inorganic material. The digested sludge contains about 2,5% nitrogen, about 1% phosphorus and about 0,2% potassium. In addition to these so-called macro-nutrients, the sludge also contains the minor nutrients such as calcium, magnesium, iron, sulphur etc. Depending on the source of the waste-water, the sludge would also contain metals such as copper, chromium, nickel, zinc and cadmium.




Certain components of the sludge may be advantageously utilised when the sludge is incorporated into agricultural land. In fact, as a result of the organic content and the presence of the nutrients and the trace elements essential for plant growth, sludge is generally valued as a soil conditioner. However, due to the presence of certain contaminants such as heavy metals, viable pathogenic and other organisms and complex organic compounds, careful consideration must be given to its potentially dangerous and hazardous properties when disposing of waste treatment sludge.

Waste-water sludge is classified into three types; (a) unstable with high odour and fly nuisance potential, contains a high content of pathogenic organisms - primary or raw sludge falls into this grouping, (b) stable with low odour and fly nuisance potential, has a reduced content of pathogenic organisms - humus, waste activated and anaerobically digested sludges fall into this grouping, (c) stable with insignificant odour and fly nuisance potential, contains insignificant numbers of pathogenic organisms - anaerobically digested sludge when preceded or followed by pasteurisation falls into this grouping, (d) as type c but with contents of specified elements below prescribed limits.

The purpose of describing the waste sludge in terms of the above classification and placing certain restrictions on the disposal of waste sludge is to minimise nuisances and the transmission of pathogenic organisms either directly to man or indirectly through the food chain, as well as protecting water resources and the environment from pollution.

As indicated above, waste-water sludge contains nutrients which can be used beneficially to improve the condition of the soil. Sludge helps to break up heavy clay soils and improves the moisture retaining ability of sandy soils. Although the nitrogen, phosphorus and potassium contents of waste sludges are low compared with the inorganic fertilisers, these nutrients are not leached out as quickly as those from inorganic fertilisers.

Sludges derived from domestic waste-water treatment contains trace elements and minor nutrients in relative concentrations that are of the same order as required by most crops. This means that provided reasonable spreading rates are used, one should not experience metal accumulation problems with domestic sludges. However, when industrial effluents are present in the waste-water, significant concentrations of metals and other undesirable constituents may be present in the sludge and it becomes most important to ensure that the spreading rate is such that undesirable concentrations of metals etc, do not accumulate in the soil.

Where waste sludge cannot be disposed as a soil conditioner, it may be desirable or even necessary to co-dispose the sludge in admixture with refuse on a sanitary landfill site. The co-disposal of refuse and secondary waste-water sludge (in particular digested sludge) in sanitary landfills is being practised in many parts of the world, especially in drier areas which have a perennial water deficit.

Although the utilisation of waste sludge to improve soils used for agricultural process provides an attractive means of disposing of the waste sludge, there are many factors to be considered to avoid creating a secondary waste pollution problem that may be very costly and time-consuming to rectify.

Michael Russell Your Independent guide to Waste Treatments [http://waste-treatments.com].

The Basics Of The Anaerobic Digestion Process

It is, therefore necessary to contain and treat these wastes so that the treated waste sludge is stable; the offensive odour is removed; the quantity of pathogenic bacteria is reduced; the mass and volume of sludge is reduced and the sludge can be readily dewatered and dried.




Anaerobic digestion is the most common method in use today for treating waste water sludges. Its attractiveness comes from it being a relatively stable process if properly controlled, with low operating costs and the production of a useful by-product, a combustible gas, which can be used as a source of energy.

The advantages of this process:

The organic content of the sludges is significantly reduced by conversion into gaseous end-products; the obnoxious odour of the sludge is removed and the final digested sludge has a characteristic 'tarry' odour; fats and greases are broken down by the process; there is a significant reduction in the quality of pathogenic bacteria; there is a marked chemical change after digestion. The liquid fraction (supernatant) contains increased levels of ammonia as a result of the breakdown of organic nitrogen (proteins). This makes the digested sludge liquor potentially suitable for agricultural use; the biogas that is formed is a mixture of carbon dioxide (CO2) and methane (CH4) that can be used for digester heating or to generate power.

The disadvantages of this process:

A relatively high initial capital cost is involved, which tends to limit the process to medium to large size waste water works. The slow rate of bacterial growth requires long periods of time for start-up and limits the flexibility of the process to adjust to changing feed loads, temperatures and other environmental conditions. The process is prone to upsets if not regularly monitored and if corrective action is not taken in time.

Anaerobic digestion is a multi-stage biological waste treatment process whereby bacteria, in the absence of oxygen, decompose organic matter to carbon dioxide, methane and water. In this way, the waste sludge is stabilised and the obnoxious odour is removed. The process can, however be described adequately and simply as occurring in two stages, involving two different types of bacteria. The first stage, the organic material present in the feed sludge is converted into organic acids (also called volatile fatty acids) by acid forming bacteria. In the second stage, these organic acids serve as the substrate (food) for the strictly anaerobic methane-producing bacteria, which converts the acids into methane and carbon dioxide. The end result of the process is a well-established sludge in which 40 to 60% of the volatile solids are destroyed. Finally, a combustible gas consisting of 60 to 75% methane and the remainder largely being carbon dioxide.

The digestion process is continuous. Fresh feed sludge must be added continuously or at frequent intervals. The gas formed during digestion is removed continuously. In high-rate digestion, stabilised sludge is displaced from the digester during feeding. In low-rate digestion, sludge 'supernatant' is normally removed as the feed sludge is added, stabilised sludge is removed at less frequent intervals.

It is essential that the organic acids formed in the first stage of the waste treatment process are converted to methane at the same rate at which they are formed. If not, they accumulate and ultimately lower the pH, leading to inhibition of the second stage of the digestion process and digester failure. Temperature must be maintained within certain ranges - heating increases the activity of the anaerobic bacteria reducing the required digestion time. A pH of 7,0 to 7,5 is recommended to encourage the methane-producing stage. A correctly operating digester will have sufficient buffer capacity (alkalinity) introduced from the breakdown of organic matter.

Michael Russell

Your Independent guide to Waste Treatments [http://waste-treatments.com]

Government to encourage anaerobic digestion projects - Guttridge

The government has pledged to encourage farmers to invest in anaerobic digestion projects, it has been revealed.



Junior DEFRA minister Lord Henley said he was in talks with the Department for Energy and Climate Change (DECC) to help improve Feed-in Tariff rates which are rewarded to those who set up renewable energy programmes.

Speaking at the Northern Farming Conference today (October 15th), he said: "We want to do what we can. That obviously will in due course with DECC mean looking at feed-in tariffs and a whole range of other things.

"We have given a commitment that we will encourage anaerobic digestion."

Lord Henley also claimed the technology can offer farmers a wide range of benefits other than energy production.

In addition to reducing the amount of waste which is sent to the landfill, the bi-product of the anaerobic digestion process can be used as a fertiliser for crops.

Typical Guttridge equipment used in the anaerobic digestion industry includes; elevators – bucket elevators – valves
James Smith 

View the original article here

Distillery secures £3m green loan - BBC News

29 October 2010 Last updated at 17:22  The firm hopes to generate 33% of its energy needs from renewable sources An Edinburgh-based distillery has secured a £3m loan to develop an ambitious green business strategy.




North British Distillery will use the cash to part-fund a three-year £9m investment programme which could generate 33% of its energy needs from renewable sources.

The firm hopes to save between 9,000 and 10,000 tonnes of carbon dioxide emissions annually from the programme.

The £3m loan was provided by Lloyds Banking Group.

The programme includes the installation of a biogas boiler and gas engine that will enable North British to generate its own electricity via anaerobic digestion of its distillate residues.

David Rae, managing director of North British, said: "Our sustainable business strategy will enable North British to make savings in terms of energy costs whilst at the same time significantly reducing the environmental impact of our production process."

The distillery, which has been based in Edinburgh's West End since 1885, already recycles residual low-grade waste heat to heat classrooms at nearby Tynecastle High School.

The firm said the supply enabled the school to make significant energy savings and reduce its own carbon dioxide emissions by 500 tonnes per year.

Most the firm's whisky spirit is sold to other companies for blending purposes, with Famous Grouse, Johnnie Walker Black Label and J&B Rare among its customers.

View the original article here

Anaerobic Digestion in the US "The Time is Right" - Waste Management World

28 October 2010

According to the EPA, the Unites States generate over 30 million tons (27.2 million tonnes) of food waste every year, and recycles less than 3%.

As anaerobic bacteria digest our trash, they release carbon dioxide and methane gas, both of which seep out of the soil and into the air. As a result, landfills are one of the largest producers of methane, which has been proven to be a leading cause of global warming.

It takes an average of 30 years for organic waste to break down into stable compounds in your average landfill, in comparison, a well run composter will complete the job in as little as three weeks.

Brian Dick, CEO of Quest Recycling Services LLC and Matt Hedrick, EVP of Quest Recycling Services LLC were keynote speakers at Biocycle Tenth Annual Renewable Energy From Organics Recycling Conference in Des Moines, IA this month.

Dick and Hedrick encouraged conference participants to jump on the waste to energy revolution and build additional outlets to process organics into high value end products such as energy and compost.

"The time is right" said Dick. "There are less than 200 operating anaerobic digesters in the United States currently and only a select few of those have the ability to process food waste. In contrast, Europe has thousands that have been successful for many years producing green power from food waste. The time to invest in this technology is now."

"We are excited to be in the fore front of this exciting emerging business that can reduce the amount of food waste in our landfills and provide a much need green power source", said Matt Hedrick.

View the original article here

United Ethanol to install anaerobic digester

A $6.75 million project to install an anaerobic digester at a 50 MMgy ethanol plant in Milton, Wis., will begin in a few weeks. United Ethanol LLC will complete the project with the help of $2.25 million in state energy program funds.

It's a way to extract a little more value out of our inputs, the corn, and make the plant greener and more energy efficient, said Alan Jentz, United Cooperative and United Ethanol vice president of grain operations and risk management.




On Oct. 21, Wisconsin Gov. Jim Doyle announced $2.95 million in funding for three southern Wisconsin companies, including United Ethanol. The money comes from Wisconsin?s economic development tax credits and energy program, which is funded through the American Recovery and Reinvestment Act.

The other two projects were $250,000 in tax credits for Standard Process Inc., a whole food supplements company, and $450,000 in energy program funds for Idle Free Systems Inc., which sells battery-powered, idle-elimination systems for over-the-road trucks.

In total, more than $55 million in state energy funds from the recovery act are being used in Wisconsin to help manufacturers with energy efficiency and renewable energy projects. According to the governor's office, Wisconsin is the only state using 100 percent of these funds for these types of projects. In August, Ace Ethanol LLC received $595,000 in funding from the same program for heat exchange equipment.

United Ethanol's anaerobic digester will utilize a portion of the plant's thin stillage to create methane, which will help reduce natural gas use at the plant by up to 25 percent. The project will have an estimated four-year payback, Jentz said.

The project has multiple benefits, including reducing the plant's carbon footprint. The anaerobic digester is also expected to reduce the number of fermentation solids that have to be recycled, reduce fermentation inhibitors, reduce evaporator bottlenecks and eliminate syrup load-out, Jentz said.

Technology provider Eisenmann Corp. will install the digester. The project should take about a year to complete. We hope to get that under way here in the next few weeks, so hopefully it will be online by this time next year,? he said.

Anaerobic digestion isn?t the only technology upgrade project United Ethanol has on its plate. David Cramer, president and CEO, mentioned three projects in the company's August newsletter. The company is working to tie in the CO2 scrubber stack and process vent gas scrubber stack into the regenerative thermal oxidizer for odor control.

In addition, it has a license agreement with GreenShift Corp. to use its corn oil extraction technology. United Ethanol has also contracted with Arisdyne Systems Inc. to install controlled flow cavitation, a patented process to reduce particle size, disrupt cell structures and disperse agglomerates for increased ethanol yield.

View the original article here

Government must prioritise food waste for AD - New Energy Focus

Friday 08 October 2010

ADBA claims food waste should be prioritised for AD over incineration and composting

The government must prioritise food waste for anaerobic digestion due to the benefit of energy generation, a renewables trade body has claimed.

In response to the coalition's Waste Review, which closed yesterday (October 7), the Anaerobic Digestion and Biogas Association (ADBA) has called for food waste to go to AD over composting and incineration.

And, it has stressed the need for a massive increase in household food waste collection and is advocating separate collections, where households have a bin reserved for food waste, so that the "valuable" resource can be more easily used for AD.

ADBA notes that the coalition is committed to a ‘huge increase in energy from waste through anaerobic digestion', but claims that the government will fail to achieve this unless the waste is made available for digestion. This will require changes to waste collection, and priority for treatment through AD, it says.

With cuts imminent in this month's Spending Review, ADBA highlights that many local authorities may be considering shelving schemes to segregate food. However, the association claims that while there are short term savings available now, they will lead to much higher costs to the whole community in the medium term, "especially if we do not build an infrastructure to deal with organic waste away from landfill".

According to ADBA, processing waste through AD offers a sustainable solution for landfill waste, with the added benefit of preserving crucial finite nutrients, such as nitrates and phosphorus.

Commenting on the need to secure food waste for AD, ADBA chairman, Lord Redesdale, said:

"The government knows it must act now to meet the UK's responsibilities on climate change.
Committing to AD technology was a good first step, but it must be followed up by the right decisions about how we deal with waste if the industry is to flourish."

"We need to collect food waste and prioritise it for AD, so that it can make the maximum possible contribution to targets for renewable energy, climate change, landfill mitigation and preserving resources such as phosphorus. This review needs to do more than move towards a "zero-waste" economy, it must also ensure we maximise the use of waste as a valuable resource."

The association added that if supported appropriately, AD could meet up to 40% of the UK's target for renewable heat production by 2020.

View the original article here

Prominent UK business group calls for more energy from waste

Launching a new report, Going to waste: Making the case for energy from waste, the leading business group highlighted the important role that energy from waste could play in a broad-based energy mix, which improves energy security.

Technologies include using anaerobic digestion, where biological processes produce bio-gas from waste, and incineration. These provide consistent and reliable power supplies, unaffected by the weather, and are not imported.

With strong leadership from the Government on planning, financing and procurement, the UK could quadruple the proportion of energy it generates from waste from 1.5% to 6% by 2015.

And the CBI warned that unless urgent steps are taken to cut landfill use, the UK will face fines from the European Union of around £182.5m a year.

Neil Bentley, CBI Director of Business Environment, said:

“We cannot continue dumping rubbish in landfill sites. Waste that can’t be recycled could be used to heat homes and produce electricity, as well as improving our energy security.

“Across Europe, generating energy from waste is common and compatible with high levels of recycling.

“The Government needs to encourage the development of more anaerobic digestion and incineration plants, and tackle delays in the planning system.”

The report focuses on the family of energy from waste technologies, which can be broadly divided into biological and thermal types. Anaerobic digestion can be used on-site to produce heat and electricity, or injected into the National Grid after being purified.

Thermal treatments include technologies, such as gasification and pyrolysis, which involve heating waste to produce gas, as well as incineration. The CBI argues that non-recyclable waste should be incinerated, and emphasises that it is cleaner, more efficient, and environmentally sounder than burning fossil fuels or relying on landfill.

Among the CBI’s recommendations for the Government are:

Recognising the important role that energy from waste could play in reducing the UK’s landfill, securing energy supplies and increasing the proportion of renewable sources;Avoiding picking winners from the various energy from waste technologies and allowing the market to decide the most cost effective option;Reassuring the public that delivering more energy from waste is compatible with high levels of recycling and that new plants are clean and safe.

Echoing her support for the report, Gaynor Hartnell, Chief Executive of the UK Renewable Energy Association (REA) said,

“The Government has already said it wants to encourage Energy from Waste, and it would do well to heed the CBI’s recommendations. Most of the energy content of our household waste is renewable, yet often projects are dogged by overly complex and unnecessary regulation, which prevents them from getting the rewards they are entitled to for generating green energy. A healthy dose of pragmatism would be in everyone’s interests and would enable one of the cheapest forms of green energy to play its part in meeting the UK’s renewables target.”

View the original article here

UK brewery embraces anaerobic digestion - Guttridge

Rapid growth of the anaerobic digestion sector has been highlighted by the adoption of the technology by a Suffolk brewery.

Adnams Brewery has introduced anaerobic digestors to its Southwold plant to turn waste from the site and surrounding companies into biogas for the national grid.

Climate change minister Greg Barker expressed his delight at the move as it follows the announcement that Thames Water and British Gas will turn sewage into biogas.

He said: "This has been an excellent week for progress in renewable energy. As well as the waste from making beer, Adnams Bio Energy is taking in food waste from local businesses large and small."
Adnams claimed that the waste by-products generated from brewing 600 pints of beer could generate enough gas for one home a day.

In addition to producing power for the local community, the gas will also be used to power the Southwold brewery and run its fleet of vehicles.



Typical  uses in the anaerobic digestion industry includes; elevators – bucket elevators – valves
James Smith

View the original article here

Brewery AD plant delivers renewable gas to grid - New Energy Focus

Tuesday 12 October 2010

Adnams Bio Energy has injected the first renewable gas from brewery waste to the National Grid from its AD facility in Suffolk

An anaerobic digestion facility in Suffolk has become the first plant in the UK to produce renewable gas from brewery and local food waste for export to the National Grid, and only the second AD plant in the UK to inject biomethane into the gas network.

Adnams Bio Energy delivered the first biomethane late last week (October 8) from its AD plant in Southwold; just three days after Didcot sewage works in Oxfordshire celebrated being the first project to send renewable gas produced from sewage to the grid (see this NewEnergyFocus.com story).

In partnership with British Gas and National Grid, Adnams Bio Energy says it will generate up to 4.8 million kWh per year, which it claims is enough to heat around 235 family homes for a year.

In the future, the facility will also produce enough renewable gas to power the Adnams brewery and run its fleet of lorries while still leaving up to 60% of the output for injection into the National Grid.

Waitrose is the first business to sign up to supply waste to the facility and has committed to sending food waste from seven of its nearby branches, along with a John Lewis.

Commenting on the project, Mike Walters, recycling and waste operations manager for Waitrose and John Lewis, said: "We are delighted to be the first retailer to become involved with Adnams Bio Energy in this exciting project.

He added: "This project is unique as it produces renewable gas from brewery and food waste for injection into the national gas grid rather than to generate electricity."

The Adnams Bio Energy plant consists of three digesters, which are sealed vessels in which naturally-occurring bacteria act without oxygen to break down up to 12,500 tonnes of organic waste each year. The result is the production of renewable gas as well as a liquid organic fertiliser.

In addition, following an agreement with British Gas, Adnams Bio Energy has deployed solar thermal panels and will shortly install photovoltaic cells to generate renewable electricity for the plant.
The deal will ensure that all of the site, including the Adnams Distribution Centre, will be using renewable energy generated on-site with some surplus energy available for export.

Chief Executive of Adnams, Andy Wood, commented: "We are delighted that Adnams Bio Energy is located on the site of our eco-distribution centre. For a number of years now, Adnams has been investing in ways to reduce our impact on the environment. The reality of being able to convert our own brewing waste and local food waste to power Adnams' brewery and vehicles, as well as the wider community is very exciting.

"The industrial ecology cycle is completed when the fertiliser produced from the anaerobic digestion process can be used on farmland to grow barley for Adnams beer. This facility will have a major impact on the reduction of carbon emissions in the region and the production of renewable energy. The food waste would otherwise be destined for landfill, but processing it through the digester will save an estimated 50,000 tonnes of CO2 equivalents from landfill."

Construction of the AD plant concluded in July (see this NewEnergyFocus.com story).

View the original article here

PROjEN Joins Forces with Doctor Les Gornall in Anaerobic Digestion and Waste ... - Online PR News (press release)

Specialist Engineering Project Management company PROjEN PLC, based in Preston Brook, Cheshire has formed an Alliance with Doctor Les Gornall who is widely regarded as the UK?s leading expert in Anaerobic Digestion and Waste Water Treatment.

Online PR News – 11-October-2010 – Specialist Engineering Project Management company PROjEN PLC, based in Preston Brook, Cheshire has formed an Alliance with Doctor Les Gornall who is widely regarded as the UK?s leading expert in Anaerobic Digestion and Waste Water Treatment. This partnership gives even greater weight to PROjEN?s service offering and demonstrates the company?s commitment in becoming the UK?s leading supplier in all aspects of waste management, including de-packaging, anaerobic digestion, CHP and conversion of waste heat to electricity.

Dr Gornall has over 30 years experience of building, operating, designing and commissioning anaerobic digesters and waste water treatment plants. He has become an internationally recognised environmental consultant who has extensive experience in waste and biogas issues across the world. He has written many papers for technical magazines and is often quoted by his pseudonym ?Dr Sludge?.

PROjEN have expanded their service offering into a number of niche areas such as helping companies to reduce their energy costs and meet legislative compliance issues including DSEAR, IPPC and post Buncefield Requirements. These new services have been driven by clients and in recent times many in the waste industry have been pushing for a combination of both the theoretical and practical aspects of waste management. PROjEN?s Managing Director, Martin Seabrook comments:

?PROjEN?s strength is that when we offer a service we ensure we can add value to the client. We recognise that no one individual or company has all the answers and by working with like minded associates we can each focus on our own strengths. Through Les? extensive knowledge of the waste market and our own award winning history in project and construction management we feel we are able to offer our clients a much stronger package than our competitors?.

In addition to working with Dr Gornall PROjEN have also renewed their distributor agreement with FreePower - this product generates electricity from waste heat and will become a major talking point this year in both waste and industrial applications. PROjEN have also formed an alliance with Axion Consulting ? process experts in the field of waste and recycling.

View the original article here

USDA tours 300kW farm biogas facility in Vermont

The Chaput Family Farm in North Troy has installed a 300-kilowatt anaerobic digestion facility to turn organic materials like manure into biogas for use generating electricity.

Electricity produced by the project will meet all of the farm’s needs, with excess power sold to the local utility. The facility will also provide heat and hot water for the dairy herd.

As well as producing clean energy, the facility will also produce a solid residue that provides an effective alternative to fertilizer.

The Chaput’s digester is the first facility on Vermont’s Standard Offer Program, which provides the farm a fixed price of 16 cents per kilowatt hour for its power output over the next 20 years. The farm will also receive a renewable energy credit of 4 cents per kWh for the next five years through Central Vermont Power Service’s “Cow Power Program.”

The farm will produce all of its on-farm electricity, heat, hot water and bedding for the cows. It will sell the excess power to the local utility. The excess bedding will be sold to local farms.

Anaerobic digestion involves microbes feeding on liquidized organic material within large tanks, and in the process giving off a methane-rich biogas that can be collected and combusted to produce electricity.

The Chaput Family, which owns four farms, built the digester to handle manure from 1,600 mature cows and young stock.

The digester project in North Troy was given financial assistance by the USDA through its Rural Energy for America Program, authorized by the 2008 Farm Bill.

The REAP program offers development assistance, grants for energy audits and funds to help agricultural producers and rural small businesses purchase and install renewable energy systems and make energy efficiency improvements.

USDA Rural Development Vermont State Director Molly Lambert was joined on the tour of the dairy farm by Rural Business-Cooperative Service Administrator Judith Canales and Farm Service Agency State Executive Director Robert Paquin.

“This project highlights the way USDA agencies are working together to help rural farmers and businesses,” Ms Canales said. “Supporting our farmers in projects like this is good for them, good for the environment, and good for businesses and residents throughout the community.”

The federal Natural Resources Conservation Service provides technical and financial assistance to producers for anaerobic digesters through the Environmental Quality Incentives Program (EQIP), and this year funded four new digesters in Vermont.

The NRCS also offers technical and financial help for other aspects of anaerobic digestion projects.

Commenting on the North Troy facility, NRCS State Conservationist Vicky Drew said: “In addition to reducing greenhouse gas emissions through the collection of methane, the digester will also reduce energy needed to produce and haul bedding to the farm by recycling the manure onsite into a dry bedding material for the cows, creating a closed-loop system.”

The USDA’s Farm Service Agency (FSA) has now established a new conservation loan program that can be used to finance anaerobic digestion projects approved by the NRCS. Up to $300,000 in loans and up to $1.12 million in loan guarantees are available, and can be used along with other grants and loans.

View the original article here

Optimise the Efficiency of Anaerobic Digestion - International Environmental Technology

A high-speed, high-temperature HT200S laboratory digester from HACH LANGE has helped one of Europe’s largest recycled packaging companies to cut analysis times by 75%.

This process has also enabled Smurfit Kappa SSK to optimise the efficiency of the anaerobic digestion to generate quality biogas, which helps to recycle the effluent waste produced on site.

By deploying the advanced HT200S, along with a DR2800 VIS Spectrophotometer at its biogas plant, the analysis of nutrient levels ensure that the site’s anaerobic reactor is running effectively, reducing analysis times by 75% as a result.

Prior to analysis in a DR2800, samples are digested in the HT200S, with digestion times for Nitrogen, Phosphate and Chemical Oxygen Demand (COD), which previously took two hours, now taking just 15 minutes.

Ciaran Conroy, from Smurfit Kappa SSK, explained that the HT200S has radically altered nutrient analysis at the plant. He said: “The HT200S allows us to be more reactive to alterations in the process, as a result of the speed with which we are now able to take measurements. The speed of digestion is complimented by the fact that the HT200S cools the samples so that they can be transferred to the spectrophotometer immediately.”

“The easy identification of COD and Volatile Fatty Acids (VFA) in the biogas reactor is just one example of this, enabling us to react in a matter of minutes, resulting in less time spent on maintaining the biogas reactor.”

The HT200S can also digest samples prior to analysis for Chromium, Tin, Silver and Total Organic Carbon (TOC).

The portable HT200S can provide numerous benefits for virtually every industry where COD, nitrogen, phosphate or metals analysis has to take place, saving significant maintenance time and costs in the process.

For a brochure, please contact sarah.blayds@hach-lange.co.uk

View the original article here

Chickens to power Gloucestershire town - Building.co.uk

First homes to receive power generated from chicken litter after biogas plant opens in November

Cirencester in Gloucestershire is to become one of the first towns in the UK to benefit from power generated using chicken litter.




The power plant which is due to open in November is being built on a farm to the south of the market town.

It will take animal waste as well as corn, wheat and grass from local farms and produce methane-rich biogas via a process of anaerobic digestion.

The gas will be used to power a combined heat and power unit generating around 1MW of electricity, enough to supply 350 homes.

The waste heat will be used for keeping the animal sheds warm, drying grain and local housing. After the biogas is extracted the fibrous material left is spread on the land as fertilizer.

The plant is being supplied by Alfagy who is looking to set up similar facilites throughout the UK.

View the original article here

A Round-Up of the New Anaerobic Digestion Plants in the News - Spring to Summer 2010 UK/Europe

Converting organic waste materials into renewable energy is an essential component of the EU countries both to meet national commitments to renewables EU targets, and indirectly to achieve zero food and packaging to landfill. So, how is the construction and commissioning of new AD plants proceeding, which will contribute to this?

Here is a summary of a few projects recently reported.

Cambi has announced that it will be supplying the technology for a new sludge treatment anaerobic-digestion plant in Drammen, Norway using their thermal hydrolysis process to optimize conversion. This will use feed stock sludge and waste and the contract is worth about 12M USD.

Vertal appears to be using Anaerobic Digestion as a component of its process mix, which includes composting and pasteurisation of food waste. This award winning company accomplishes this, we are informed, entirely through self heating, harnessing the energy released during digestion to carry out the pasteurisation.

A WRAP (Waste Resources Action Programme), part UK Government Funded, 3M GBP anaerobic digestion plant has opened on a Staffordshire (UK) Farm. This plant will supply 1.3MW of renewable energy to the national grid, with most of the energy being derived from source segregated food waste. It will process 15,000 tonnes of waste annually. Full operational output is planned for Autumn 2010.

Xergi's AD plant in Ayrshire, Scotland is moving ahead, and is expected to be operating by early 2011.  The purchaser's Chief Executive has plans to extend the pant to include connection to the gas distribution network. The Ayrshire plant will become Xergi's second UK plant, with their first UK plant located near Boston, Lincolnshire, UK.

AD plants succeed or fail on the ability to mix feedstock and then again within the reactor. System Mix is reported to be providing mixing expertise to Welsh Water, and other clients for their digesters. One of the mixing systems in use will be a drop-in lance type system.

Jenbach (Austria) also announced in July that the troducer of Baby Nutrition Products would soon be saving CO2 based on the special “Green Tariff” available to anaerobic digestion plant generated electricity available at the plant's location.

In this project cow manure is being converted to energy at the first biogas co-generation plant in the Ukraine. The facility, which is powered by 4,000 cows and a GE (NYSE: GE) Jenbacher gas engine, has recently completed nine months of successful operation at the Ukrainian Milk Company Ltd., located near Kiev.

The excess power produced at the plant is being sold to the grid. The Ukrainian Milk Company, which produces milk for baby nutrition products, received the license for selling power to the grid based on the “green” tariff, which is being approved by Ukraine authorities. According to the law, the “green” tariff is “a special tariff for electricity generated at the power plants with use of alternative energy sources.”

The new combined heat and power (CHP) plant is powered by a GE JMC 312 containerized co-generation model gas engine and is able to substitute the equivalent of 1.2 million cubic meters of natural gas annually and, therefore, is projected to reduce the equivalent of 18,000 metric tons of CO2. Once converted into biogas, the manure from the cows produces 625 kW of electricity and 686 kW of thermal output.

This is GE’s first order from the biogas plant construction company ZORG. The unit was sold to ZORG through GE’s distributor and service provider in the Ukraine, SINAPSE. We hope that you found this round-up of the new Anaerobic Digestion Plants in the News from spring to summer 2010 interesting.

More about the Ukraine Plant at Ukraine Milk Company Powered by 4,000 Cows and GE Biogas Engine.

Danish Company to Build Anaerobic Digestion Plant in N Ayrshire Scotland

Denmark’s market leading supplier of AD technology is to build a large AD plant in Scotland. The agreement which amounts to approximately 8.0 million Euros has been entered into with one of the largest energy companies in the UK, Scottish and Southern Energy.

The Scottish AD plant will be built at Barkip, North Ayrshire. It is expected to be operational for energy production in early 2011 and will contribute to achieving Scottish targets for CO2 reduction. The plant will be capable of processing 80,000 tons of organic waste annually, producing 2MW of renewable electricity. The plant will be the first for both Xergi and SSE in Scotland.

The entire plant will be delivered by Xergi and will convert the organic waste into renewable energy in the form of methane gas and nitrogenous organic fertiliser.

The plant consists of reception facilities, a fully automatic feeding system capable of handling many different types of organic waste, anaerobic digesters with a unique stirring system for the production of methane, a CHP (combined heat and power) unit producing power and heat, and storage tanks for the fertiliser.

SSE Chief Executive Ian Marchant said:

“Biogas has the potential to be one of the most important new generation renewable and sustainable energy solutions available to us, capturing the energy contained in waste. SSE is excited about entering the biogas market which we believe offers opportunities beyond on-site electricity generation to include connections to the gas distribution network in the future. This new project will enable SSE to gain experience in owning and operating this technology so we are well placed to bring that knowledge to future projects in Scotland.”

For more information visit the Xergi web site.

Large Ener-G AD Plant Biogas Cogeneration System Gets Hungary on Map of AD User's

ENER-G is the company playing a big part in great Hungarian wastewater scheme.

One of Europe's most bold biogas from wastewater projects has been switched on in Budapest by ENER-G.

The UK clean technology company's Hungarian subsidiary ENER-G Energia Technologia Zrt. Has designed and constructed this 2.6 million renewable power centre at the Budapest wastewater treatment plant in Csepel.

It will be part of the Living Danube programme, which is Europe's biggest environmental investment currently in development.

ENER-G has installed a 4.5 MWe biogas cogeneration system, along with 3 2.5MW Loos boilers for further hot water generation using natural gas, or biogas. The company also manages the operations and upkeep services. The eco-friendly energy centre will form part of a biological treatment facility covering 70,000m on a twenty-nine hectare site at Csepel Island.

The plant will increase the quantity of biologically treated wastewater in Budapest to 95% by 2010 treating a standard 350,000 m3 / day waste water from almost all of Buda and part of Pest, serving roughly 1,000,000 folks.

The development of the plant took more than 2 years and cost almost half a billion EU Bucks. Financially the project has been backed by the ECU , the Hungarian state and Budapest municipality.

It'll meet high environmental standards, achieving nought emissions and no odours outside of the site borders.

It'll supply up to 4.5MWe of renewable (replaceable) electricity to the site which means that it gives over 50% of the plant's total electricity consumption. This is comparable in output of eight giant air turbines. ]

The maximum 8.5MW heat generated by the mixed heat and power ( CHP ) unit is exploited in the digester process consuming 563m3 / h biogas per unit. The Budapest wastewater treatment plant is a clear illustration of how effective anaerobic digestion is as a commercial and environmental solution for sizeable projects like this, related Balazs Marialigeti, Director of ENER-G.

It is very fulfilling to be concerned in this revolutionary venture and we are looking forward enthusiastically to full commissioning in Sep 2010. Anaerobic digestion ( AD ) transforms organic waste material into energy and is a definite winning technology that delivers important commercial benefits, while helping to reduce carbon dioxide emissions.

Digestion plants produce a biogas that has high methane content of 50-70 percent. This otherwise environmentally damaging gas is a rich fuel that may drive a CHP unit to generate both heat and electricity.

The heat may be employed in the digestion plant alongside for heating in close by buildings, while the replaceable electricity can be sold at premium rates.

ENER-G has substantial experience of building, operating and financing major biogas projects across Europe and the company is expanding its team of specialist engineers to meet increasing demand for methane-rich biogas projects , for example AD.

For more information visit ENER-G's web site.