27 June 2012

Round-Up of Recent Energy-from-Waste Contract News

Despite a double dip recession and UK infrastructure and general construction spending having dropped about 20% since the coalition government took up office in 2010, the waste section is not suffering nearly as much as you might expect. In addition, new Anaerobic Digestion Plants are being announced and coming on-stream.


That's due to EU waste reduction targets for landfill, and similar recycling targets which the UK has to meet, and which can only be achieved by a spend rate which was put as above £1bn annually, several years ago.

The government has therefore so far not cut substantially its plans for new waste facilities, and the following round-up shows just what progress is being made on new Energy-from-Waste facility construction right now (excerpts below are quoted from Edie.net):

The latest waste-to-energy developments across the UK involve a mix of technologies including gasification, anaerobic digestion and biomass for wood waste.
Origin Renewable Energy has submitted a planning application for a gasification combined heat and power (CHP) plant at Desborough, Northamptonshire.


The proposed 96,000 tonne facility will use technology from Energos and take residual waste from households and businesses. It will be sited at Magnetic Park and incorporate a visitors centre that will offer training, education and meeting facilities to the local community. 
Meanwhile biogas firm Tamar Energy is set to build its first anaerobic digestion (AD) plant at Holbeach Hurn, Lincolnshire, in conjunction with AH Worth, a family business whose major operating subsidiary is QV Foods, a multi-site produce packing and marketing operation. 
The plant will be located at one of the top-four potato processing sites in the UK supplying produce to national retailers. Discarded organic material from the packing lines and storage facilities will be diverted to the facility, which has capacity to treat 36,000 tonnes per year.
The plant is expected to be operational towards the end of 2013 and will have an electrical output of 1.5 MW. QV Foods will harness the large majority of the electricity production, with any surplus being delivered as green electricity to the National Grid.
Source edie newsroom

Visit : http://www.edie.net/news/news_story.asp?src=nl&id=22689 for the full article.

15 June 2012

Advances in Anaerobic Digestion


advanced anaerobic digestion
Anaerobic Digestion is a process carried out by bacteria in the absence of oxygen. The process has been developed to the level at which it produces substantially less sludge than aerobic treatment and converts organic matter to energy-rich biogas which can be used as a fuel, but further advances in the technology to reduce costs are still needed for it to be taken up on a large scale and for every farm of any size to have one.

There are only about 30 anaerobic digestion plants in Britain, compared with more than 4,000 in Germany. The Department for Energy and Climate Change (DECC) has said that the enhanced tarrifs for renewable energy from anaerobic digestion will improve its uptake, and it intends to pay 11.5p per kWh up to 500kWh, but the Renewable Energy Association REA has stated that most farmers with an average sized heard need at least double that to generate a commercial return on their investment.

Anglian Water is producing enough biogas from its new advanced digestion system to deliver 980kW of energy at the engine without any further fuel requirements and it is doing it by using advanced anaerobic digestion technology. Advanced digestion using Monsal enhanced enzymatic hydrolysis has been employed at two of their largest sites at Kings Lynn, Norfolk and Great Billing, Northants. The combined processing capacity of these plants is close to 60,000 tonnes dry solids per annum. Advanced digestion using biological hydrolysis maximises the biogas potential, which is achieved by bespoke pre-reactor design to complete the solubilisation reactions and generation of volatile fatty acids (VFAs) prior to mesophilic anaerobic digestion. High VFAs concentrations (10,000 mg/L) is produced, which is converted to biogas. The digesters convert VFAs primarily to biogas. The key innovation is the full use of the heat balance from the process in an optimal way. Low-grade heat from the combined heat and power unit is used in the first stage of the process, raising sludge temperature.

A further advance in the AD process is the use of steam autoclaves work like giant pressure cookers, heating mixed waste at high pressures to ensure the breakdown of organic material. The process ensures that more of the organic waste is captured for use in an energy generating anaerobic digestor, while the non-organic materials are cleaned and sterilised ready for recycling. As well as generating renewable electricity from the anaerobic digestor, waste heat from the process can be captured for re-use.

There is further good news that this advanced AD technology will help the industry become more established. It has been announced that waste management company Viridor has begun construction on a state-of-the-art anaerobic digestion facility near Bridgwater in Somerset. The £10m project is being developed by Viridor where Monsal are providing the technology which will convert food waste into renewable energy via their Advanced Digestion process. The plant will be Viridor’s first Food waste AD facility and will be located at its Walpole landfill site. The Somerset Waste Board agreed in September 2011 to develop the facility and the plant is expected to be operational by April 2013.

Another company which implements what it call its advanced biogas system is Oaktech Environmental. That company is an experienced developer of biological treatment solutions., and holds intellectual property rights to two advanced Anaerobic Digestion technologies designed for the treatment of a wide range of organic feedstocks including municipal solid waste, source separated wastes and commercial food. Oaktech’s proprietary technologies include the ArrowBio process for the treatment of residual waste and the Induced Bed Reactor (IBR) process for the treatment of source separated food waste, energy crops and farm slurries. Both technologies are commercially proven having undergone over 15 years development processes.

Advanced anaerobic digestion can also involve thermal pretreatment of sludge with resultant changes to sludge characteristics that have challenged pump designs, as offered by other Biogas Plant EPC Contractors. This is surely wonderful news for all those that are keen to see innovation in the biogas industry, as there are advantages in the use of autoclaving pretreatment in the manner in which it enables efficient separation of recyclates in a much healthier working environment, and provides pastuerisation for a saleable digestate at the same time. The industry must be wishing this venture every success, and watching keenly to see how well the process performs, especially the plant’s peformance in removal of enhanced calorific value from the autoclaved organic content during digestion.

Imtech Process is another delivery partner offoring Advanced Digestion in the UK and is one of an increasing number of companies which are descirbed as having a proven track record with some of the leading water companies. Plus having experience in food waste digestion and practical experience in beneficially recycling Class A biosolids for agricultural use.

With increasing pressure to find alternatives to the landfill disposal of waste, in a new development, one UK water company is using advanced anaerobic digestion in its wastewater treatment process to generate biogas – and is using this in an on-site CHP unit. So, at a time of heightened concerns about waste, climate change and the need for cleaner energy, it is worth pointing out that not some of the news is good. New technologies are redressing the balance, and one of these is advanced anaerobic digestion (AAD). AAD will not turn muck into brass, or indeed gold, but it does offer the potential to transform the sewage treatment process from a simple clean-up to one that recovers significant quantities of energy.

05 June 2012

Anaerobic Digestion News: Methane Explosion in China - Man Seriously Injured...

Anaerobic Digestion News: Methane Explosion in China - Man Seriously Injured...:


A father was very seriously injured by an exploding manhole cover in a China street after lighting a firecracker. (Article by Graham Smith of the Daily Mail on 16th February 2012). This should act as a warning to all biogas plant owners. Methane explosions occur rarely, but when they do the consequences are seldom minor, and can be tragic.

The pictures show how the shocking moment took place when a man is blown off his feet after lighting a firecracker on a manhole cover. The CCTV footage shows the man being thrown ten metres through the air by the force of the explosion.

Click on the title to read more.

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