Biogas Success - Weltec Biopower To Build Piddlehinton AD Plant 1.1 MW Extension

Weltec Biopower Awarded 1.1 MW Piddlehinton AD Plant Extension

A highly successful food waste biogas plant constructed by Weltec, after only 2 years of operation is being enlarged. Now there's confidence in the profitability of food waste anaerobic digestion!

Watch our video on this project below:

Press release · Communiqué de presse

Vechta, September 2014: 

WELTEC BIOPOWER receives order for 1.1 MW extension in Dorset

Award-Winning AD plant processes food waste to energy

Weltec Biopower (UK) Ltd, based in Stoneleigh, Warwickshire, UK, has been granted the contract to extend the award-winning food waste AD plant in Piddlehinton, Dorset. Plant owners Eco Sustainable Solutions Ltd. are expanding with a further 1.1MW of food waste processing capacity. 

This follows on from the Weltec successes of commissioning two other plants in early 2014. The original Eco-Dorset AD plant was also built by WELTEC and was commissioned in 2012. After two years of successful operation, the operator assigned WELTEC with the extension. The extension will be completed in autumn 2014. 

Another advantage core to WELTEC’s continued success in industrial and agricultural applications is the fact that the digesters and digestate storage tanks are constructed from stainless steel. Aside from being a higher-quality product, stainless steel and is corrosion resistant to aggressive materials and offers a faster construction time, which is increasingly important to all developers with the FIT framework deadlines providing tight construction windows. 

Watch our new video "How Does a Biogas plant Work?"

After two years of successful operation, the operator assigned WELTEC with the extension. The extension will be completed in autumn 2014. The plant is fed by local authority food waste as well as out of date food products which prior to digestion are unpackaged, sorted and pasteurised at the site. After the extension, approximately 37,000 tpa of food waste will generate an electrical output of 1.6 MW. 

The Eco-Dorset approach is an excellent example of the benefits of intelligent design, co-location and mutually beneficial plant integration. Electricity generated at the plant as well as excess gas is fed to an adjacent feed mill. When the mill is not operational, the power is fed to the National Grid. The digestate produced by the plant, which is in the process of gaining PAS 110 accreditation, is collected and used by local farmers. 

Despite the latent renewable energy in commercial and municipal food wastes, much of this valuable resource still ends in landfill. Much of it also ends in composting plants, which use expensive imported energy to bio-stabilise (or destroy) what, when processed in an AD plant, is a valuable renewable energy resource. After all, one tonne of organic waste processed through AD, could be converted into 600 to 800 kilowatt hours of energy – enough to power five refrigerators for one year. 

The equivalent tonne of waste through a composting plant costs energy and money to process. As energy demand and prices continue to rise and security of supply concerns worsen, more and more Local Authorities and private waste companies look set to follow the excellent example set by Eco Sustainable Solutions Ltd. and capitalize on the excellent income generation opportunity that organic waste presents. 

WELTEC understands the needs of every client and tailors the most cost-effective solution on a case by case basis. The partnership between the plant manufacturer and his clients also maintain after the design and build phase. “We recognize that an AD plant is a 20 year partnership and that maintaining solid trust-based working relationships with our clients is crucial to our ongoing success. 

Therefore we now have a dedicated UK-based Service and Maintenance capability with locally available spare parts”, sales manager Kevin Monson explains. 

Company Portrait

In 2014, WELTEC BIOPOWER GmbH, one of the first manufacturers of biogas plants, celebrated its 13th anniversary. WELTEC is one of the pioneers of the constructors of biogas plants. 

Based on the modern approach of experienced engineers, the company from Vechta, Germany with its expertise of a staff of close to 80, offers complete biogas plants from one source and has developed to a leading constructor of biogas plants in the world. As the hydrogen sulphide and ammonia compounds contained in biogas corrode unprotected parts, WELTEC builds the digesters from stainless steel. This ensures a long useful life of the plant. The manufacturing depth also guarantees a consistently high standard regardless of the location and ensures an export rate that is far above the industry average. 

The plants have a modular structure. WELTEC uses only proven system components and develops most of the technologies along the entire value chain internally: digester technology, mixing technology, control technology, hygienisation systems, and digestate processing solutions originate from the company. 

By means of its comprehensive services, WELTEC ensures the technical and economic stability of the biogas plants. The CHP service guarantees stable output, the biological supervision ensures continuous monitoring of the relevant parameters, and systematic repowering makes sure that the biogas plant is always up to date. 

Operators can choose from a range of service packages of different types and scope. One of the main strengths of WELTEC is the ability to deliver individual and flexible solutions worldwide – from compact plants to large computer-controlled plants in the megawatt range, waste recycling plants, and biogas parks with gas processing technology.

Ann Börries

Marketing

Phone: +49 4441/99978-220

Email: presse@weltec-biopower.de

How to Anaerobically Digest Biomass and Produce Biogas in 7 Simple Actions

Just how do you eat an elephant? The traditional response to that question is, "Just one bite at a time!" Actually, it is the same answer for how to complete any large task. When you look at the whole thing all at once, it appears to be impossible. Break it down into parts, steps or sub-tasks, and each of these is not nearly so formidable. Your specific steps can each be relatively simple, something that's no big deal, that can be done. And when you have done every one of the small-task steps, you gaze back and find out that now you have the entire formidable-task thing done. That's just exactly how it is with how to anaerobically digest biomass and produce biogas. Here is a method to tackle the formidable task of anaerobically digest biomass and produce biogas, in 7 simple steps.

Step 1. The waste is delivered to the plant and is initially sorted mechanically to remove remaining non-biodegradable contaminants. With this you will need to involve screens, air classifiers or magnets. In the event you neglect this or don't do it, you should expect a poor quality of feedstock delivery into the digester, and potential for blockages of the digester, causing downtime.

Step 2. The organic waste is then shredded and mixed with water and pumped to an enclosed vessel (reactor) known as the biogas digester. This step is important because the right mixture must be created for pumping into the digester ).

Step 3. In the digester it is heated, stirred, and held for up to three weeks whilst the bacteria digest the waste and emit a gas consisting of about two thirds methane and one third carbon dioxide. This will mean that during that period bacteria and other organisms are fermenting the organic material. This could also mean that biogas methane is produced, and this is the main product of, and reason for operating the process.

Step 4. After this the solid digested material is pressed to recover the added water. This will probably involve a mechanical press system.

Step 5. The solid digestate is placed in piles to aerate for for anything between two weeks and twelve weeks. Once the digestate has been aerated it can be used as a soil improver or growing media constituent in the same way as compost. A key point you will want to remember here is going to be that there may be regulations which limit the use of digestate due to concerns about possible transmission of infection, and other possible contaminants. The reason why this will be significant is, for example, that this limits the uses and value of digestate. If the material is derived from mixed wastes sources additional sorting may also be required to remove contaminates.

Step 6. The liquid fraction can be recirculated in the process but some excess is generated and depending of the feedstock this can be used as a fertiliser or if the waste is contaminated it has to be disposed of to sewer.

Step 7. The gas that's generated after a basic cleaning stage to get rid of hydrogen sulphide and water, can be burnt in gas engines to create electricity or in boilers to provide steam.

Or, in some locations it can make good business sense to purify the gas further by removing the CO2 so that the gas may be employed to fuel autos like automobiles, buses or vans, or the purified gas can also possibly be piped in to the natural gas network.. You are now almost there! Remember, that environmental groups and many governments are very keen to promote the use of Anaerobic Digestion due to its carbon neutral and renewable energy nature.

When you take the steps explained above, the massive elephant-problem you had will likely be "eaten up" one step at a time, "devoured" and dealt with. You will succeed in completing your project and can enjoy the fruits of victory and accomplishment! Congratulations on your victory! You took on a big challenge, conquered it and won, one step at a time!

Discover the best way to build and operate a biogas digester by going to the Biogas Digestion eBook Resources site

Steve Symes regularly writes on renewable energy issues. He feels that the environmental debate is too important to leave to the boffins. If you think so too then visit a Blog on the subject at Renewable Energy News.