11 December 2008

Anaerobic Digestion Biogas and EU REACH Implemetation

Last week immediately after the UK implementation of the REACH Regulations I found that I had to admit admit ignorance when I received a call in which I was asked whether biogas produced from waste would fall under the REACH regulations.

I was soon reassured by colleagues that all was OK for those, like me that had not even thought of this, and that biogas did not require REACH registration and compliance.

As an Engineer in waste processing I don't have responsibility for legal compliance, and hence this was not a major gap in my knowledge, nevertheless, I did not know of the background until I read Philip Charlesworth's article in the Chartered Institution of Waste Management's monthly journal for this month.

I am sure that Philip will not mind me copying a part of his article below, which hopefully makes the background to all this clear:

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In October this year the lead REACH enforcement body, the Health and Safety Executive (HSE), issued a fact sheet to explain the position on "recovered waste substances". This publication stated that "[waste] recovery businesses are considered to be manufacturers under REACH". A list of waste "recovery" operations is included in the imminent revision of the Waste Framework Directive (WFD).

Registration may be required where a new substance is produced in the manufacturing process. Where a substance has been recovered, or a new substance has been produced, and this is then incorporated into the manufacture of an "article", that “article” may not be caught by REACH.

An article is defined as an “... object which during production is given a special shape, surface or design which determinates its function to a greater degree than does its chemical composition".

This could apply to products made from recycled waste. It follows from Article 7 of REACH that substances contained within the "articles" that are not intended to be released from within the "articles" during use, would not need to be registered (unless the substances are carcinogenic, mutagenic or toxic to reproduction).

REACH specifically exempts the following products that have been manufactured from waste substances; compost, biogas, glass and minerals occurring in their natural state.


These exemptions would appear to support the preamble to REACH, which states that incentives for waste recycling and recovery should be maintained. The exemptions also enable the Government to meet the objectives of Article 6 of the revised WFD by continuing to publish quality protocols for "end of waste" materials. Protocols are already available for compost and some aggregate products derived from waste.

The Government must have enforcement of REACH, following the expiry of the 1 December 2008 deadline. This will see the REACH Enforcement Regulations 2008 come into force (in accordance with Article 126 of REACH). The leading enforcement body (the "competent authority") is the HSE and it will have powers to take action against "recycling and recovery" operations that may have been required to register.

In England and Wales the HSE will join forces with the Environment Agency, the Department for Business, Enterprise and Regulatory Reform and local authorities to control the manufacture and placing on the market of articles and substances, protection of the environment and the safety of consumer products from chemical substances.

The European Chemicals Agency intends to publish a list of all the pre-registered substances in January 2009.
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CIWM Members can email the CIWM for more information. Non-members requiring more information can contact Philip Charlesworth. I will have to avoid giving his email as it reads for fear of him receiving a lot of spam from this posting from the plague of spambots which continually scrape web pages for email addresses to send spam. I will therefore describe his ema-il address as containing enads.co.uk after the @ sign preceded with the word info.

IF you are not already a CIWM member, why not consider applying?

26 November 2008

UK Pre-Budget Report and How it Affects Waste and Resource Management

Waste@Westminster News

CHANCELLOR ISSUES PRE-BUDGET REPORT

The Chancellor of the Exchequer, Alistair Darling MP, has issued the pre-budget report for 2009, emphasising the Government’s desire not to let the current economic downturn impact on spending on renewable energy and other environmental projects.

“Action to achieve environmental goals remains a high priority,” he stated in his address to Parliament. Of key importance, the pre-budget report states the Renewables Obligation will be extended until “at least 2037”, in order to encourage increased investment in renewable energy technologies.

In addition the report reaffirms the Government’s aim to implement a feed in tariff for small-scale energy generation (under 5MW) and a renewable heat incentive to encourage more on site generation. Furthermore a new Low Carbon Industrial Strategy will be developed in 2009, outlining a vision of how companies can take advantage of a “low-carbon economy”.

The report also confirms that the scheduled increases in landfill tax, by £8 per tonne up to 2010/11 will go ahead and indeed will continue post-2011.

The increase in the lower rate of landfill tax, applying to inactive waste, from £2 per tonne to £2.50 (to be frozen at £2.50 in 2009/10) will also stay unchanged, as will the planned phase-out of the exemption from landfill tax for waste arising from the clean up of contaminated land by 2012 (in order to extend land remediation relief).

Finally, as previously announced, a new packaging strategy will be produced in 2009 setting out how packaging policy can contribute to a low carbon economy by reducing waste at source and increasing recycling.

To read the Chancellor’s statement to Parliament in full click here, or to read the full chapter, delivering on environmental goals, click here.

02 November 2008

AD Plants Produce Lovely, Rich Organic Matter - Daily Telegraph

Biogas converters - making fuel and fertiliser from biodegradable waste
By Julia Hailes

Good composting doesn't just mean throwing your food waste into a composting bin and forgetting about it, which is pretty well what I do.

It's actually quite important to get a reasonable mix of wet and dry material and even to turn it over on occasions.

Getting it right, not only means that it will produce lovely, rich organic matter to put on your garden but will also reduce your carbon footprint.

It's not just the CO2 being released into the atmosphere but methane too - which is about 24 times worse in terms of its global warming impact.

Most of the food we throw away in this country ends up in landfill sites, where methane emissions are a real problem.

Not so long ago all these gases were allowed to waft up into the atmosphere or were simply burnt off with flares to stop explosions.

Nowadays, most dumps will be scattered with gas collectors that siphon off some of the methane and use it to make electricity.

But this isn't a very efficient process, which is why there's strict European legislation aimed at reducing the amount of biodegradable waste going to landfill - and hence the amount of gas from rotting waste that adds to the blanket of greenhouse gases warming our planet.

A couple of weeks ago I went to visit one of the few emerging biogas plants in the country.

At Biogen (www.biogen.co.uk), near Bedford, they take in 30,000 tonnes of food waste and put it in large anaerobic digestors (ADs). Actually, they have to remove the packaging first, but the principle is pretty simple.

The digestors are really silos designed to speed up the rotting process and collect the methane that's released. The brilliant thing about it is that all the gas can than be used for electricity generation - or even for vehicle fuel.

And what's left behind is a great fertiliser - so almost nothing is actually wasted.

AThe following additional related UK Daily Telepgraph articles are available:

- Recycling in action at Somerset landfill site
- California converting cow dung into biogas
- Recycling dreamland in Dagenham.

21 October 2008

Agri-food Businesses Could Divert More of their Food Waste to Anaerobic Digestion Plants: Greg Hilton

Bidwells Proposes Anaerobic Solution

Agri-food businesses and householders alike could be diverting more of their food waste to anaerobic digestion plants in order to save on volumes going to landfill and creating a renewable energy source.

Greg Hilton, Renewable Energy consultant for Bidwells Agribusiness said: “We throw away over 6 million tonnes of food waste each year, with the vast majority going to landfill. If we used just 10 per cent of this food waste in AD plants we would be able to supply 50,000 houses with clean, green energy. We would also have a significant impact on our carbon emissions as the food sector is responsible for around 20 per cent of the entire UK carbon emissions.

Diverting food waste from landfill, where it produces the damaging greenhouse gas methane, would make a big difference." The outputs of AD are electricity for use on site or export to the national grid, as well as heat for use in the business or nearby properties, and a rich bio-fertiliser, which could have added benefits for horticultural and agricultural land.

Increases in landfill tax and increased returns from renewable electricity are likely to make AD increasingly attractive in the future. Hilton said: "Anaerobic Digestion offers a win-win situation. It diverts waste from going to landfill, reduces greenhouse gas emissions, and provides high value, sustainable energy.

As energy prices increase, technology develops and pressure mounts to reduce carbon emissions, measures that are green and sustainable become increasingly popular and more viable.

At Bidwells we have…experience in evaluating the technical and economic viability of anaerobic digestion and biomass combined heat and power systems, and we predict that more and more projects will become economically viable over the coming years as margins improve and set up costs fall."

Meanwhile, Leicestershire County Council has recognised the potential value and benefits of anaerobic digestion and is offering support to businesses that would like to evaluate its potential. The council is offering grants of up to £5,000 for a maximum of half the value of an AD feasibility study and is keen to encourage businesses to take up the opportunity. More.

15 October 2008

The Role of Hydrolysis for Advanced Digestion

Many of the the companies which have been involved in sewage sludge digestion and are the most experienced in the field are using thermal hydrolysis within their chosen processes. These companies tend to develop their own slant on optimising the hydrolysis stage and to use their own trade name, neverthelsss there is a common reason for doing this and it is to increase the rate of conversion of organic matter, to reduce retention periods within the digester and improve gas yields.

We have uploaded a new page with the title "Hydrolysis, Sewage Sludge and Anaerobic Digestion", to the Anaerobic Digestion Community web site, based upon Veolia's experience with using hydrolysis a part of the digester systems, which provides more information on this.

Sewage sludge digestion has been carried out by anaerobic digestion at some UK sewage works since in the UK sewage sludge first began to accumulate in the new activated sludge type sewage works built from the 1950's in inland areas. However, most of it was simply discharged to the sea untreated until the 1970s including huge tonnages from our large cities. Fortunately, those days are long past with the practice outlawed by the European Union, and ever since then, the huge volumes produced have been treated and disposed of by a variety of methods. All are expensive, and the lowest cost option of discharge untreated to land, brings with it health and soil-metals build up problems, such that its use has to be limited.

As a result, safe and cost-effective disposal of sewage sludge is, without doubt, one of the biggest challenges now facing the wastewater industry. The high cost of energy means that some disposal routes such as incineration which were once favoured are less viable, and others have ceased to be economic.

However, as one technology fades another shines. That process is thermal hydrolysis, and when combined with anaerobic digestion they are a great combination.

Companies such as CAMBI, Monsal, and Veolia Water Solutions & Technologies have recognised this and produced their own proprietary systems. More about advanced AD with hydrolysis.

02 October 2008

WU Green Paper on Biowastes Before End of Year

The management of biodegradable wastes will be an important item in the EU waste policy agenda during in 2009.

The European Commission has started work on a green paper on biowastes, which it aims to publish before the end of the current year.

"In this green paper, we want to present the current situation in biowaste management and ask the stakeholders where we need to go from here" - Karolina Fras, an official of the EU Commission's DG Environment, told delegates at the recent annual conference of the European Federation of Waste Management and Environmental Services (FEAD) in Paris.

According to Ms Fras, work on this topic will continue in the year 2009 - for instance through workshops. It might then be possible to table a legislative proposal from the European Commission or other initiatives during the Spanish EU presidency in the first half of 2010.

European Biogas Electricity Production Hits 17272GWh a Year

Date: 29/09/2008
In the biogas field, Germany has built itself a world-leading position. The country built 820 systems in 2006, increasing the total installed production units to 3700 and is now the No 1 world biogas-based energy producer, and also the technological leader.

CIAT plays a major role in this country, with approximately a 35percent share of the market, and has acquired significant know how in gas treatment, enabling it to propose systems adapted to ever widening scopes of application. This concept has brought about specific developments in this field. Two installations produced with the German partners of CIAT, SEVA AG and SILOXA AG, perfectly illustrate this progress.

European Biogas electricity production in 2006 was 17272GWh per year, of which 7338GWh was by Germany alone. Biogas now represents 1.2percent of the annual production of electricity and nearly 10percent of renewable energy, with an installed power close to 1500MW.

In particular, this success is due to efficient regulations, intended to promote renewable energies.

In fact, the German law stipulates the purchase price per kWh by energy distributing companies for 20 years. This price takes into account the ‘green’ nature of the energy and recompenses the operators, based on efficiency, technological innovation and agricultural re-conversion criteria.

During the first year, in certain cases it may reach 0.18E/kWh. This incentive, combined with the power of German industry, makes Germany the most advanced country worldwide in biogas based energy production systems.

There are several different types of biogas production systems. Biogas production always means production of electricity using a gas engine and an alternator.
Process heat can also be recovered. This is called cogeneration. Biogas is a gas produced by the fermentation of animal or vegetable organic matter without oxygen.
Fermentation is also called methanisation and occurs naturally (in swamps) or spontaneously in waste dumps containing organic waste.

Also, it can be artificially produced in digesters (when treating purification sludge, industrial organic waste or selected agricultural crops, etc).

Biogas can also be recovered by sucking mine gas. In all cases, the biogas must be dehumidified and purified before combustion; otherwise it can damage the gas engine.

Biogas is a mixture essentially comprising methane (30 to 70percent) and carbon dioxide, with varying quantities of water and hydrogen sulphide (H2S).

Other compounds can also be found from contamination, especially in waste dump biogas: ammonia, hydrogen, nitrogen and carbon monoxide.

Biogas energy is only produced from methane and is in fact a renewable form of fossil energy, which is natural gas. Furthermore, biogas systems are highly respectful of the environment. In fact, the contribution of a methane molecule (CH4) to the greenhouse effect is 21 times greater than that of a carbon dioxide molecule. Therefore burning methane, even though producing CO2, reduces its impact on the environment.
SEVA has developed forefront know-how for small-sized systems. Out of the 820 installed in Germany in 2006, this company, with a payroll of 150, produced 170 biogas combustion units, with a total cumulative 54 MW power.

The philosophy at SEVA ENERGIE is to make biogas profitable by offering high production rate systems, operating continuously with limited human intervention and very high reliability.

CIAT has become a recognised standard for the up-line treatment part of gas. As previously mentioned, the humidity is removed from the gas. Steam is condensed by cooling the gas to temperatures between 15 and 5°C. The advantage of this process is to eliminate part of the impurities in gas by trapping them in the condensates,which are evacuated.

Proposed Irish Biofuels Obligation Scheme Out for Public Consultation

New target for biofuels in Ireland

Energy Minister Eamon Ryan has published the Government’s proposed Biofuels Obligation Scheme for public consultation.

This scheme will set a percentage target of transport fuels used in the State which must consist of biofuels and sets certain conditions regarding the type of biofuels which can be counted towards that target. The obligation will apply to fuel companies, placing no burden on the taxpayer. It will be a key component in achieving the EU target of 10% penetration of renewable energy in transport by 2020. The Government remains committed to this target.

The consultation document proposes a target of 4% by volume of transport fuel by 2010, equating to 3% by energy. It attaches an important condition - the biofuels must come from sustainable sources.

Biofuels in Ireland must be entirely compliant with EU Sustainability Criteria, which are currently being finalised. These will set out stringent conditions which fuels must meet before they can be considered as contributing to the EU targets, including:-

- a minimum level of greenhouse gas savings
- biodiversity requirements to prevent certain lands such as natural forests and protected areas being used in the production of biofuels - and
- social reporting obligations on the Commission.

The essential aim of these criteria is to ensure that biofuels used within the EU do not result in adverse consequences for societies and the environment globally. They will also encourage the next generation of biofuels and support investment in cleaner and more sustainable types of transport fuels.

The Government’s targets up to 2020 will be continually reviewed as more evidence comes to light on the effects of biofuels in the world food markets and new technologies come on-stream.

Publishing the Scheme, Minister Ryan said - “This new target reflects growing concerns that increases in the amounts of biofuels being produced were having some adverse environmental and developmental effects around the world. We will move towards 2020 with gradual, careful progress.

"However, biofuels remain a fundamentally good idea, given that we need alternative sources of fuel. The era of cheap oil is over and Ireland requires new methods of fuelling our transport fleet.

"Biofuels also remain necessary for Ireland in terms of energy security. We need access to a certain percentage of non-fossil fuel to run essential services, in the event of a global oil shortage. This is prudent planning in an uncertain energy world.

11 September 2008

Bioresources to Land: Managing Nutrients to Complete the Cycle

We thought that readers of this blog, especially those that are farmers and several of whom have approached us already at the anaerobic digestion uk web site with concerns to know how adopting Anaerobic Digestion might change plant nutrients in the receiving soils, would be likely to be interested in this conference. I am also informed that Defra also has research in progress on this subject.

To others who might wonder why this subject is of such interest to those operating or planning to operate bio-digesters, the concern to be addressed is that by using AD the farm might be losing soil nutrient quality somehow. It is clearly of great importance that the soils scientists can confirm that there are no unanticipated negative effects of interceding any new biological process into farming which if found later might jeopardise the continued use of the AD, or any other composting process.

Date and Venue: 15th October 2008, The Royal Academy of Engineering, London


This intensive one-day conference, organised on behalf of the Sustainable Organic Resources Partnership, has been designed to provide a forum and opportunity to consider and discuss the significant technical and regulatory developments that have occurred recently concerning the management and recycling of nutrients applied to agricultural land in bioresources. Expert speakers have been invited to talk on the key areas and developments affecting the recycling of nutrients to land in bioresources. These cover policy and strategic issues, the agronomic properties of bioresources and their management as effective fertiliser replacements.

Please find attached the full programme and booking form for the above conference. You can also register online at http://www.aqua-enviro.net/calendar_detail.asp?id=120


Speakers Include:


· Jiggy Lloyd, Associate, Green Alliance

· Peter Dampney, ADAS

· Michael Payne, adviser to the NFU

· Prof Brian Chambers, Senior Principal Scientist, ADAS & Dr David Chadwick, Principal Researcher, IGER

· Dr Stephen R Smith, Department of Civil & Environmental Engineering, Imperial College London

· Bryan Lewens, Andigestion Ltd

· Dr Neil McIntyre, Department of Civil & Environmental Engineering, Imperial College London

· Dr Paul Withers, ADAS

· Diane Mitchell, Chief Environment Adviser, NFU

· Professor Keith Goulding, Head of Department of Soil Science, Rothamsted Research

· Dr Fiona Nicholson, ADAS

Chairmen:

· Chris Ryder, Head of Water Quality Division, Defra

· Andrew Clark, Head Policy Services, NFU


Sponsorship Opportunities:

If you are interested in sponsoring this event and/or if you would like to book an exhibition space please contact Rachel on Tel. 01924 257891 or email rachelwilliamson[at]aquaenviro.co.uk.

Note: While we have suggested that this conference may provide information on a subject it is the responsibility of our readers to verify such, and only to book after having satisfied themselves of the content by reference to the organisers information. All information is provided without accepting any liability whatsoever.

Bioresources to Land: Managing Nutrients to Complete the Cycle

We thought that readers of this blog, especially those that are farmers and several of whom have approached me already at the anaerobic digestion uk web site with concerns to know how adopting Anaerobic Digestion might change plant nutrients in the receiving soils, would be likely to be interested in this conference. I am also informed that Defra also has research in progress on this subject.

To others who might wonder why this subject is of such interest to those operating or planning to operate bio-digesters, the concern to be addressed is that by using AD the farm might be losing soil nutrient quality somehow. It is clearly of great importance that the soils scientists can confirm that there are no unanticipated negative effects of interceding any new biological process into farming which if found later might jeopardise the continued use of the AD, or any other composting process.

Date and Venue: 15th October 2008, The Royal Academy of Engineering, London


Please find attached the full programme and booking form for the above conference. You can also register online at http://www.aqua-enviro.net/calendar_detail.asp?id=120


Speakers Include:


· Jiggy Lloyd, Associate, Green Alliance

· Peter Dampney, ADAS

· Michael Payne, adviser to the NFU

· Prof Brian Chambers, Senior Principal Scientist, ADAS & Dr David Chadwick, Principal Researcher, IGER

· Dr Stephen R Smith, Department of Civil & Environmental Engineering, Imperial College London

· Bryan Lewens, Andigestion Ltd

· Dr Neil McIntyre, Department of Civil & Environmental Engineering, Imperial College London

· Dr Paul Withers, ADAS

· Diane Mitchell, Chief Environment Adviser, NFU

· Professor Keith Goulding, Head of Department of Soil Science, Rothamsted Research

· Dr Fiona Nicholson, ADAS

Chairmen:

· Chris Ryder, Head of Water Quality Division, Defra

· Andrew Clark, Head Policy Services, NFU


Sponsorship Opportunities:

If you are interested in sponsoring this event and/or if you would like to book an exhibition space please contact Rachel on Tel. 01924 257891 or email rachelwilliamson[at]aquaenviro.co.uk.

Note: While we have suggested that this conference may provide information on a subject it is the responsibility of our readers to verify such, and only to book after having satisfied themselves of the content by reference to the organisers information. All information is provided without accepting any liability whatsoever.

09 September 2008

Wales Implementing More Separate Food Waste Collection

The whole of Wales has succeeeded in achieving all the waste targets which have been set for this year, however the targets are raised every year so it is always necessary for additional recycling to be achieved year on year.

Separate food waste collection will enable greater use of anaerobic digestion. Therefore, it is good news to hear of separate food waste collection schemes being started.

On 1st September, the Minister for Environment, Sustainability and Housing Jane Davidson said:

As a nation we need to reduce the amount of waste that we send to landfill as this is the least sustainable method of managing our waste.

We need concerted effort by everyone, both householders and businesses to achieve more recycling and less landfill.

She said Local Authorities in Wales now need to look at ways of recycling food waste.

Food waste is an area of great potential and exploiting this will be essential if we are to continue increasing the amount of waste we recycle and divert from landfill.

Earlier this year, Local Authorities were given an extra £15 million in recycling grants which they were strongly advised to use to prepare for the separate collection and treatment of food waste.

Monmouthshire, Torfaen, Merthyr, Carmarthenshire, RCT, Bridgend and Swansea have already started to introduce food waste collection service.

Cardiff, Gwynedd, Isle of Anglesey, Conwy, Wrexham, and Blaenau Gwent are planning to start collections later this year or early next year.

More here...

04 September 2008

Landfill Gas is Used to Make biomethane Vehicle Fuel

In a first for Europe, waste company Sita is using landfill gas at one of its sites in Surrey to make a transport fuel - liquid biomethane.

Landfill gas is being used to make liquid biomethane for use as a vehicle fuel - the first time it has been used like this in Europe.

Waste firm Sita and technology provider Gasrec are in the final stages of commissioning plant at Sita's Albury landfill site in Surrey. The landfill produces some 2,500m3 of landfill gas per hour, and this will be used to make 5,000 tonnes of biomethane - enough to power 150 heavy goods vehicles.

The plant works by dewatering the landfill gas, then removing hydrogen sulphide, carbon dioxide and nitrogen. The remaining methane, about 95% pure, is liquefied. According to Richard Lilleystone, Gasrec's chief executive, the resulting liquid biomethane cuts CO2 emissions by 70% compared to diesel, particulates by 90% and SO2 by 50%. The fuel is also around 30% cheaper.

The fuel is being used by Sita, haulage firm Hardstaff Group, as well as Sainsbury's in one of its delivery trucks. It is also being trialled by waste company Veolia in a street cleaning vehicle in Camden, north London, to assess its performance in urban areas. All users have their own refuelling infrastructure at depots.

According to Stuart Hayward-Higham, Sita's head of business development, the firm decided to develop the plant as the economic future for electricity from landfill gas is uncertain. "There are many ways of making electricity, many of which are better than waste," he said. From next April, electricity from landfill gas will only receive 0.25 renewable obligation certificates (ROCs) per megawatt hour of electricity generated. This compares to the current 1 ROC.

Using landfill gas to make transport fuel rather than electricity also offers a significantly larger reduction in CO2 emissions, says the Renewable Energy Association.

ENDS Report
403, August 2008, p 25 © 2008 Haymarket Business Media

21 August 2008

Waitrose and Joan Ruddock Very Positive About Anaerobic Digester Success

Waitrose Recycling Waste Manager Arthur Sayer told FoodBev: "Anaerobic digestion has been operating in other European countries, such as Germany, for decades, so we thought it was worth trying out on a commercial scale for our supermarkets. So far, the signs are really positive, and this looks to be a sustainable way of eliminating the need to send waste food to landfill."

Environment minister Joan Ruddock told the Times that an anaerobic digestion plant could fit into any industrial estate in the country.

23 July 2008

Updated List of British Isles Anaerobic Digestion Plants Now Available

We are constatly being asked for lists of AD Plants in operation and planned, so we have compiled an updated list of British Isles Anaerobic Digestion Plants which can be accessed through the following link:

British Anaerobic Digestion Plant List

For readers to assess the rate of uptake of AD technology we have retained a copy of a similar list for 2006 on the bottom of the page.

This shows that while there appears to be a gradually rising number of AD Plants on the list from operational plants to those under consideration with feasibility studies etc underway, the uptake of the technology is not rapid. (For example the 3 plants listed for England and Wales has now risen to 26.)

The total generated capacity remains tiny compared with other sources and even when compared with wind power.

We have no doubt that recent fuel price rises and the ensuing intensified interest in biogas digestion will result in many more plants being planned, and that we will see real starts on construction being achieved in a high percentage of new projects over the next few years.

As the PFI Waste Procurement process continues, more local authorities will reveal plans to produce biogas within their mix of facilities, and a number MBT plus Anaerobic Digestion facilities will also be seen.

Also, the effect of the anticipated improved rate of ROCS for electrical power from these plants has yet to work through in increased AD popularity.

11 July 2008

Peterborough UK Consults on Food Waste Recycling

Peterborough City Council has started investigating the best method for recycling food waste in a bid to raise its 46% recycling rate to over 65%.

And, the council has become one of the few local authorities in the country to launch on-the-go recycling bins in its city centre.

This week, Peterborough council launched a consultation to find out if using anaerobic digestion (AD) or in-vessel composting (IVC) is best way to treat food waste for the city with the aim of reducing the amount of waste that goes to landfill.

Councillor Wayne Fitzgerald, cabinet member for the environment said: "Under the city council's waste strategy we have promised to introduce a system for collecting and treating food waste to prevent it being dumped.

"There are two main options for achieving that objective and we want to choose a system that is both effective and easy for householders to operate. They both involve natural processes but require different methods of collection and processing," he added. More at LetsRecycle.com.

01 July 2008

Methane-Rich Biogas from Agricultural Livestock

Original title: Sizing-Up Anaerobic Digestion

By Bryan Sims / Photos By Jim Manganella

Environmental Power Corp. aims to become a premier player in the biomass industry by developing large-scale anaerobic digestion systems. Biomass Magazine talks with company officials about their thriving business model and how it could become the standard for others who want to convert waste into energy.

When Richard Kessel became the chief executive officer for the Tarrytown, N.Y.-based Environmental Power Corp. in July 2006, he was armed with more than 30 years experience in the energy field and the wherewithal to mold companies into formidable players in the renewable energy industry.

EPC, and its single subsidiary Microgy Inc., is rapidly expanding its renewable energy portfolio by developing, owning and operating large-scale anaerobic digestion facilities that produce methane-rich biogas from agricultural livestock and organic wastes. EPC’s ability to design anaerobic digestion systems and to provide ongoing operational maintenance on a large scale sets it apart from the small-scale, farmer-owned anaerobic digestion model, according to Kessel. “What really makes us unique is the size of our projects,” he says. “We’re really looking to sell—in the wholesale market—a natural gas product and that’s what really differentiates us.”

16 June 2008

UK Carbon Reduction Commitment Lacks Ambition to Meet the Challenge

The United Kingdom as part of the European Union has agreed to the Carbon Reduction Commitment.

This is a huge reduction on current damaging CO2 emissions, and even worse when you consider that without action CO2 emissions are actually set to rise by over 10% by 2030, above 2010 levels.

If the goal is to be achieved there is a need for anaerobic digestion and biogas to be developed as part of the solution and for strong government leadership now, especially to ensure that the soon to be released UK Climate Change Bill includes the policies needed.

Are the necessary incentives going to be there?

Will the commitment be strong enough to meet the challenge?

Read more about this, click on the title now to find out more, and you can also join the UK Friends of Biogas.

11 June 2008

Sludge Power for Riverside Treatment Works in Rainham, Essex, UK

WET News - THAMES WATER is planning to upgrade its sludge treatment facilities at Riverside Sewage Treatment Works in Rainham, Essex to run on renewable energy.

The plant will treat the solid waste left behind after the sewage treatment process and use it to power the entire site.

Nick Fawcett, project manager for Thames Water, said: "All the sludge which is currently produced at Riverside is pumped through an 8km underground pipe to Beckton Sewage Treatment Works where it is incinerated and used to generate renewable energy to power that site.

"However, because of population growth in the area and proposals to extend the treatment works at Beckton - which will inevitably produce more solid waste - we now need to have better facilities to fully treat waste at Riverside. We are planning to digest sludge on site, using anaerobic digestion."

Subject to approval, construction will begin in early 2009, and end by 2010.

19 May 2008

FEY Announces Grants Available for Anaerobic Digestion

For this post we are indebted to FEY's postings on our Forum at http://www.forum.anaerobic-digestion.com . We recommend tha you bookmark our forum and watch out for further valuable information on grants and other AD subjects.

Future Energy Yorkshire offers loans (up to £200k) and revenue share investments (up to £500K) for grid connected Anaerobic Digestion plants in the Yorkshire and Humber region.

More information is available here:
http://www.fey.org.uk/site/home/tabid/36/default.aspx

In addition, in their "decision tree" FEY have endeavoured to pull together all possible sources of funding that someone wanting to undertake a renewable energy project could need.

The Funding Decision Tree allows users to search this information and identify the right source/s of funding for your new and renewable energy project, whether it be technology research, development, demonstration or deployment.

If you think that your AD project entitels you to funding then don't delay as you don't have long to get your application in, because Round 2 of their Grid Connected Renewables funding is now OPEN to applications.

An application for funding is made by submitting an Expression of Interest form followed by a full application form.

The Expression of Interest form must be received by the 30th June 2008 at 5pm.

The full application form must be received by the 31st July 2008 at 5 pm.

If you are not planning a project in Yorkshire there is also the WRAP web site which provides information at:

http://www.wrap.org.uk/wrap_corporate/funding/capital_grants/index.html

Again funding is available with applications needed to an end of June deadline for:

The Waste & Resources Action Programme (WRAP) Organics Capital Grant Programme VI which is now open and can provide financial assistance of up to 30% towards the capital costs of plant, equipment and infrastructure for food waste processing capacity compliant with the Animal By-Products Regulations in England, Northern Ireland and Scotland.

21 April 2008

Consultation on a New AD Protocol Intended to Reduce Organic Waste Sent to Landfill - UK Environment Agency

The following was extracted from the full UK Environment Agency Press release. (Click on the title to see the full press release.)

Encouraging technology that reduces the amount of organic waste sent to landfill is the driving force behind a consultation launched last Monday by the Waste Protocols Project, a joint WRAP (Waste & Resources Action Programme) and Environment Agency initiative.

The Quality Protocol for the production and use of quality outputs from Anaerobic Digestion, could make it easier to turn biodegradable waste into valuable products such as fertilisers and soil conditioners.

Anaerobic Digestion (AD) is a natural process of microbiological conversion of organic matter, such as food waste from households and businesses.

Dr Richard Swannell, Director of Retail and Organics at WRAP, said: "Anaerobic Digestion and the market for products from the AD process are still in their infancy in England and Wales. However, the development of a Quality Protocol will help remove a major barrier to deploying this important technology and open up the market for digestate by giving users confidence in the end product.

"Quality compliant products from the Anaerobic Digestion process will provide users with confidence that these new products derived from waste material conform to agreed quality standards.

"In the long-term, greater use of products derived from the AD process could reduce the amount of organic waste being sent to landfill and save producers the associated disposal costs."

Martin Brocklehurst, Head of Environment Protection External Programmes at the Environment Agency, said: "By clearly defining the standards required to collect, transport, store, recycle and reuse source-segregated biodegradable waste, a Quality Protocol for AD could save businesses the time and costs associated with meeting waste regulations, without harming human health and the environment.

We have now opened this up to consultation and are keen to hear the views of industry and other stakeholders.

"With the recent Defra announcement of a £10 million fund to develop commercial-scale demonstration AD plants, this initiative will add to the growing presence of the technology as a means to treat organic waste."

To participate in the public consultation, please visit qp.dialoguebydesign.net.

Steve's comment: This would seem to be something that the Anaerobic Digestion community should be getting involved with wholeheartedly.

08 April 2008

New EC Directive on Renewable Energy Considered by MEPs

Steve Your Webmaster says: Anaerobic digestion doesn't get a specific mention in this release about the new Directive.

Source: European Parliament
Published Apr. 1, 2008

Spring brings renewal and this spring in parliament MEPs will be considering a new Commission directive on renewable energy. In March last year EU leaders set a target of 20% of energy from renewable sources like the wind and sea by 2020. Alongside greater energy efficiency and a reduction in greenhouse gas emissions it is hoped these steps will mitigate climate change. In the first of our series on the climate change package, we look at the proposed legislation and its likely impact.

One man who will be much occupied with these issues is parliament's newly appointed rapporteur for the proposed directive - Luxembourg Green MEP Claude Turmes. Appointed by the industry, research and energy committee his job will be to report back to MEPs on that committee as they try to finalise their position by the end of June.

The proposals cover electricity, heating, cooling and biofuels. Launched in January this year it proposes national action plans for countries enabling people to see how much progress a country is making. Also envisaged are rules relating to so called 'guarantees of origin'. In layman's terms this is meant to ensure that renewable energy is in fact from a renewable source. The Commission has also set out safeguards on the sustainability of biofuels.

Current 8.5% renewable energy use must rise

Claude Turmes has doubts about the workability of the 'guarantees of origin' as proposed by the Commission. He feels they are based on 'weak legal grounds' and 'may put at peril current systems of national support schemes for renewable energy'. He is more positive however about the national targets the Commission saying that 'we looked into the figures and find they are very good'.

The sea, wind and thermal energy trapped in the earth are likely to be the main facets of Europe's renewable future. The use of biofuel and biomass could also play a part. At present 8.5% of the European Union's energy is produced from renewable means. However, this figure disguises large national disparities in usage. For example in Sweden they get 39% of their energy from renewable sources whereas Malta has no renewable energy.

Less CO2 = more jobs?

Clearly there is a lot of work still to be done if the 20% target is to be achieved. It has been estimated that reaching the target could save from 600-900 million tonnes of CO2 a year and cut fossil fuel consumption by 200-3000 million tonnes per annum.

There are strong economic as well as ecological reasons to strive for that target. The Commission estimates that if the figure is reached up to 1 million people across Europe could be employed in the renewable energy sector. That would represent a substantial increase over the 350,000 currently working in the sector.

Mixed response to biofuels and biomass

Claude Turmes is not a fan of the inclusion of biofuels. EU leaders meeting in March last year pledged to have 10% of the Union's transport running on biofuels by 2020. Speaking in Strasbourg in the January plenary Mr Turmes said the Commission 'did not have the courage to drop' the biofuels target. He hoped that MEPs would find the courage to remove it. Turmes also cites scientific evidence to show that 'annual crops like sugar beet and wheat have a very bad CO2 balance'.

Turning to biomass, Mr Turmes is more positive. 'The biomass we have in Europe would be put to much better use in combined heat and power systems' (for example in power stations that burn biomass instead of coal). On the energy savings of biomass he is clear: 'I can save three to four times as much CO2 when using biomass (as compared to biofuels) instead of coal for electricity and heat generation'.

Claude Turmes is a leading figure in Luxembourg's environmental movement. He was elected to the European Parliament in 1999 for the Green party 'Déi Gréng” in order to participate in discussions 'where European environment and energy policy is formulated'. He is the current vice President of the Green/EFA group of MEPs and is their coordinator for energy policy.

13 March 2008

Surprise UK Biofuel Subsidy Change is Great Bonus for Biodiesel from Biogas

There is an item about this in the Daily Telegraph:-

http://www.telegraph.co.uk

Which describes this biofuel subsidy removal as a negative, which it will be for the big petroleum companies, but for biogas producers it provides an additional incentive to further invest in the equipment to take their biogas and process it into biofuel (eg biodiesel).

All UK biogas producers should now consider biogas to biofuel investment. The reasons for this are explained in the following paragraphs which are provided using information provided by John Baldwin, MD of CNG Services Ltd at http://www.cngservices.co.uk .

In essence, in Tuesday's Budget the Government has increased the RTFO buy-out price to 35 p/litre (from 15 p/litre) so customers pay for the shift to biofuels and not the Govt (in form of duty reduction). Yes, it is a stealth tax, but one that helps biomethane as biomethane still will have the same low fuel duty as it had previously.

If you run a vehicle on biomethane you will pay 13.7 p/kg duty, but you will now (as a result of this budget change) get back 35 p/kg. Before this budget you would have got back 15 p/kg. This means that you will now get paid 20 p/kg by the UK petroleum industry + Government.

How do you make biofuel from biogas? For a small 400,000 kg clean up facility the cost will be about 80,000 pounds, but will result in additional income (and no diesel to be paid for!).

Those with biogas should consider starting to clean some of it up fom now on, and running vehicles on it.

That way the biogas producer will get paid to save the planet.

Now that can’t be bad!

The vehicles are also already available to run on it, made by VW and MB. These are not conversions and still run on petrol.

We can’t see any downsides, and also some biogas operations will be able to run these vehicles on gas that would otherwise be flared!

As ever, your views and comments are very welcome and can be made on the blog, or at www.forum.anaerobic-digestion.com .

10 March 2008

Sintex's Biogas Digester Ingests Crap, Emits Energy


Plastics maker Sintex seeks to solve India's energy and sanitation problems in one stroke - with an at-home biogas digester. By Jeremy Kahn

The Sintex digester can turn manure into fuel for cooking and electricity.

(Fortune Magazine) -- Sintex Industries, a plastics and textiles manufacturer in Gujarat, India, is betting it can find profit in human waste. Its new biogas digester turns human excrement, cow dung, or kitchen garbage into fuel that can be used for cooking or generating electricity, simultaneously addressing two of India's major needs: energy and sanitation.

Sintex bio digester
Copyright Sintex

Sintex's digester uses bacteria to break down waste into sludge, much like a septic tank. In the process, the bacteria emit gases, mostly methane. But instead of being vented into the air, they are piped into a storage canister.

A one-cubic-meter digester, primed with cow dung to provide bacteria, can convert the waste generated by a four-person family into enough gas to cook all its meals and provide sludge for fertilizer. A model this size costs about $425 but will pay for itself in energy savings in less than two years.

That's still a high price for most Indians, even though the government recently agreed to subsidize about a third of the cost for these family-sized units. "We want to create a new industry for portable sanitation in India that's not available now," says S.B. Dangayach, Sintex's managing director.

Sintex Industries' aptly-dubbed biogas digester is most certainly not the first of its kind, but it is somewhat commendable that its maker is making no bones about this thing's purpose.

Destined to "solve India's energy and sanitation problems in one stroke," this concoction can convert "human [waste], cow dung, or kitchen garbage into fuel that can be used for cooking or generating electricity."

Reportedly, a one-cubic-meter digester would sell for around $425, but could pay for itself in energy savings in under 24 months. Excrement to energy -- now there's a concept.

More...

Goodtech MRAB Completes Biogas Projects in Finland and Sweden

In recent press releases Goodtech MRAB has reported the following recent biogas projects since the Autumn of last year, showing the sophistication currently being applied to Anaerobic digestion in Finland:-

Rebuilding of digestion chamber in Västervik

In November 2007 Goodtech MRAB obtained a turn-key contract for rebuilding of the digestion chamber at Lucerna waste water treatment plant in Västervik, Sweden.

The project will provide for more effective biogas production with Goodtechs heat exchange technology. The customer is the city of Västervik. The contract value is 7 MSEK and the plant will be completed in 2008.

Pre-treatment Plant Inauguration

A new pre-treatment plant for organic waste in Torsvik, Jönköping, Sweden was inaugurated the 25 sept 2007.

The plant has a high capacity and is reliable in operation and can receive both firm and floating organic waste.

The special feature of this plant is that the organic waste is fine grinded down to particle size 0,1-0,3 mm. It gives a larger contact surface and therefore a higher gas exchange at the digestion process.

Goodtech MRAB has delivered, installed and started up the mechanical equipment for receiving, disjointing, out-sorting unwanted material, hygienization and intermediate storing of the organic waste.

The plant gives a biomass that is transported to Simsholmens waste water treatment plant for digestion and biogas production.

The Customer is the City of Jönköping, and the plant is licenced for 30,000 tonne/year.

Example of possible raw material:

- foodstuffs from household, large kitchen and restaurants
- organic waste from provision merchant´s
- slaughterhouse waste
- packed waste from provision industry
- fat separator sludge
- milk, whey and cheese
- fish screenings
- potato leftover

More at www.goodtech.fi

24 February 2008

Zimbabwe: Zinwa to Revive Biogas Digesters

The Herald, Harare 11 February 2008

THE Zimbabwe National Water Authority will soon revive the biogas digesters that have been lying idle at Firle and Crowborough waterworks in Harare to cut down on energy costs.

Some of the biogas digesters that have been lying idle for years need to be de-sludged of sand accumulated over the years.

The digesters have the potential of producing enough biogas to run four of the water authority's five sewage treatment works and cut down on electricity costs that now run into several billions of dollars each month.

If revived, the digesters also have the capacity of producing enough energy to drive several other industrial operations that require large amounts of power.

According to water experts Crowborough wastewater in Kuwadzana, currently consumes almost 215 000 kilowatts each month, costing the water authority billions of dollars yet it has the potential of producing about 12 500-cubic metres of biogas a day.

Zinwa spokesperson Mrs Marjory Munyonga, who took the media and several engineers on a tour of the wastewater facilities last week, said studies done on Crowborough revealed that the gas produced has a chemical composition of 66,4 percent methane, 32,2 percent carbon dioxide and the rest hydrogen sulphide.

"Only a third of the gas produced in the digesters is used in gas boilers for heating digested sludge for stabilisation purposes and the rest of the gas is captured and disposed of as waste gas.

"We are inviting all those interested in biogas-related projects to come forward and work with us," Mrs Munyonga said.

Zinwa wastewater management manager Engineer Simon Muserere, who was part of the entourage, said the revival of the digesters had various advantages.

"The opportunities of utilising the plant are immense and these include using gas-run vehicles that can also be used as service vehicles at the sewage treatment plants," he said.

11 February 2008

South African Rural Biogas Programme Could Benefit 20 000 Households

From: Creamer Engineering News Feb, 2008

A national biogas feasibility study, which was com- pleted in November last year, will be used by the Department of Minerals and Energy (DME) to undertake planning for a national biogas programme, Agama Energy director Greg Austin tells Engineering News.

Biogas, a type of biofuel that is a product of the anaerobic digestion, or fermentation of biodegradable materials, such as manure or sewage, municipal waste and energy crops, can be used for electricity production, water and process heating.

Austin comments that biogas is a frequently overlooked source of fuel in spite of the excitement surrounding the use of biofuels as an alternative source of energy.

“This is very surprising given that it is the most sustainable of all the biofuels, being derived essentially from waste materials,” says Austin. While energy crops can be grown for biogasification, outside of that context, all resources used in anaerobic digesters are derived from biodegradable wastes.

In the ‘South African National Rural Domestic Biogas Feasibility Assessment’ report, Austin and Jabenzi director James Blignaut comment that rural areas involved in the study demonstrated a great reliance on renewable sources of biomass in the form of fuel wood. This reliance, however, results in environmental degradation in the form of deforestation and soil erosion.

The existing unsustainable consumption of fuel wood represents about 8% of the total primary energy supply in South Africa, most of which is consumed as a household thermal fuel in rural areas.

The study also shows that provinces with the best technical potential for implementation of biogas and high demand for the fuel are the Eastern Cape, KwaZulu-Natal, and Limpopo provinces.

Although there is no policy specifically relating to rural energisation using biogas, the DME’s white paper on energy policy suggests biogas as a means to achieve rural energisation.

23 January 2008

Bluster and Biofuels - The Biofuels Con?

We thought that you might be interested in this investor's view on Biofuels and the Audit Committe report. I am sure Gary won't object to our potentially feeding him signups to his report page by printing this!

The Environmental Audit Committee has got it right says Smart Commodities UK editor, Garry White. Biofuels are currently a net negative for the environment...

Bluster and Biofuels
By Garry White

So, could this be the end of the biofuels con..? Let’s hope so…

The all-party Environmental Audit Committee headed by Tim Yeo will today say that the target to more than double the amount of biofuels used in the UK should be scrapped.

Yeo said: “Biofuels can reduce greenhouse gas emissions from road transport but at present most biofuels have a detrimental impact on the environment overall”.

The committee wants a moratorium on the biofuel targets. They have considered the whole cycle rather than just a part of it. They said that biofuels produced less greenhouse gases than fossil fuels when burned, but these savings are negated by the use of fertilisers, deforestation and the energy needed to process them into fuel. I could not agree more.

There are, however, dissenters form this point of view – notably the National Farmers Union (NFU).

The NFU rejected the committee’s calls for a moratorium.

“Biofuels represent the only renewable alternative for replacing fossil fuels in transport and a way of tackling the one quarter of UK carbon emissions which transport is responsible for” said NFU President, Peter Kendall.

“UK Biodiesel reduces greenhouse gas emissions by 53% and UK wheat bioethanol by 64% compared with their fossil fuel equivalents.

“Those savings can and should be improved. But for the committee to conclude that, because the savings are small, they are not worth having at all, is illogical and ill-informed.

“Of course, biofuel crops must be produced sustainably, both at home and abroad, and of course we should be developing more efficient biofuel technologies and encouraging motorists to take other measures to reduce transport emissions.

“And to criticise biofuels for using land that could otherwise be growing food when, in virtually the same breath, the Committee calls for land to be taken out of food production and given over to forestry and habitat creation shows just how muddled their thinking is.

“The best thing for the Government to do with this report is to consign it to the dustbin of history and focus instead on the infinitely more balanced and better informed report published by the Royal Society on 14 January 2008.”

The problem with this however, is that the Royal Society fudged the issue. I was at the press conference last week and one thing was made clear before it started; the report was not going to give any clear answers. The chairman said there would be no “yes” or “no” answers to anything, even though he accepted that was what the audience wanted.

This may be regarded as “good science” but when the world is looking for a solution to a major problem, sitting on the fence can do more harm than good. It’s time for people to nail their colours to the mast. I salute the Environmental Audit Committee for doing just this.

Regards,

Garry White
for The Daily Reckoning [Links removed because this page has been deleted from thelinked website.]

The Anaerobic News Blog is always interested to hear your views on the future of biofuels. One good place to post your views is at the Anaerobic Digestion Forum.

22 January 2008

UK Anaerobic Digestion Plants are to Get ROCs Subsidy Boost

BERR ROC Government Response to be included in the Energy Bill

BERR have released the government's response to the Renewables Obligation Consultation, and the proposal is to give Anaerobic Digestion the boost it was hoping for at 2.0 ROCs/MWh.

Their document summarises the responses and sets out the Government's intentions in the light of them. The government is seeking through the Energy Bill to secure the necessary primary legislative powers to make the proposed changes. The detail will be implemented through a new Renewables Obligation Order.

[Sorry. This page has been removed from the Government Website.] More information is here where the BERR pdf can be downloaded in full.

Anaerobic digestion has been placed in what is described as the "emerging" brand, and other technologies are included. Here is an excerpt from BERR's text:-

"Wave; tidal stream; fuels created using an advanced conversion technologies (anaerobic digestion; gasification and pyrolysis); dedicated biomass burning energy crops (with or without CHP); dedicated regular biomass with CHP; solar photovoltaic; geothermal, tidal Impoundment (e.g. tidal lagoons and tidal barrages (<1gw blockquote="" microgeneration.=""> - all get 2.0 ROCs/MWh, starting 1 April 2009.

Sewage gas was seen as an area for substantial increases in Anaerobic Digestion generation capacity, and existing and new anaerobic digesters, future expansion was suggested to be possible up to 0.8 TWh by 2010 by fitting new digesters to sewage treatment works which were not equipped with these at present.

It is all good news for AD, but still not I understand, up to the level of security of price for sale of the electricity given by the German government. Your comments are welcomed!

08 January 2008

Uganda: The Fuel from Human Excreta

New Vision (Kampala) - Africa Uses Anaerobic Digestion

2 January 2008
John Kasozi
Kampala

HUMAN excreta and urine are now an asset to farmers because they are a cheap source of biogas energy. The two offer the best biogas followed by pig and cattle dung.

Banana peels, poultry droppings, water hyacinth and algae are the other organic raw materials that generate biogas. Banana peels and water hyacinth should be mixed with cow dung and poultry droppings to give off good gas after putting them out to dry under the sun for two days to reduce the amount of sap.

Andrew Ndawula, a technician subcontracted by Heifer International Uganda (HIU), revealed this during the recent tour of Heifer biogas beneficiaries by Dr. Sahr Lebbie, the Heifer International vice president of the Africa programme, based in USA.

Heifer International is a worldwide NGO whose mission is to work in partnership with others to end hunger and poverty and to care for the earth through sharing livestock and knowledge. Its main goal is to improve food security and the income of needy households, while focusing on the family, gender and environmental protection through sustainable agriculture.

In conjunction with its partners, HIU has initiated the construction of biogas plants among beneficiaries after realising that deforestation is a serious threat to the environment.

"Biogas will slow down the rate of deforestation and its by-products are utilised to improve soil fertility," said Lebbie. He added that biogas also indirectly reduces the burden of women and children fetching firewood from long distances.

Biogas is an inflammable gas produced by bacteria during bio-digestion fermentation of organic materials. This occurs under airless condition in an air tight container called a digester. It is composed of methane gas (60-65%) and carbon dioxide (35-40%). Biogas from animal excreta contains 60-90% methane and is combustible if the methane is more than 50%. In this range, biogas burns without further purification.

"There are three models and different sizes of biogas plants: floating, polythene tubular system and the Chinese fixed dome. "The fixed dome is the most common and economical plant constructed for HIU beneficiaries," said Ndawula.

The smallest size of fixed dome is 6-cubic metres (cu/m), and the largest is 100cu/m. Thirty cu/m and above are for institutions or large farms. The fixed dome is of two types; bricks/blocks type and cast systems. The price of cement, bricks and galvanised pipes put the total cost of the plant high.

The 6 and 8cu/m plants pressure prepares a simple meal in 24 hours if both the cow and plants are well fed and maintained. The digester should not be under- or over-fed by raw materials in order to have constant pressure supply to the house. The 12cu/m plant can be maintained by two or three well fed zero-grazed cows. Gas can light one lamp and a twin-burner for a family of 8-10 people.

However, the 16cu/m plant can be maintained by three to six cows. Its pressure can run three burners and two lamps. People owning animal farms should go for 30cu/m plant. Ten and more cows can sustain the plant that runs about five lamps, a canteen burner (commercial) and a twin-burner. This type of plant has two expansion chambers that maintain constant pressure.

Ndawula noted that 75 to 100cu/m have been built in Kenya and Tanzania by institutions such as universities. "I have approached a number of institutions in Uganda to put up similar plants, but they are skeptical," he added.

In China, Kenya and Tanzania institutions mix human and animal excreta, giving off good grade methane, while some institutions in China make biogas from only human excreta.

Africans are making good use of Anaerobic Digestion

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