Wednesday, August 20, 2014

New Low Temperature Anaerobic Digestion Process Reviewed

Low Temperature Anaerobic Digestion - It Is The Third Type Of AD Process

I was fascinated to discover a new company with their own stand at the AD & Biogas Association (AD&B) Exhibition and Conference 2014, which was held last month at the NEC Birmingham, UK.  Irish start-up NVP Energy was the company in question, and they were there to present their unique and innovative low temperature (< 20°C) Anaerobic Digestion (Lt-AD) wastewater (WW) treatment technology for medium to low-strength industrial effluents.

And, yes! You did just read “less than 20 degrees Centigrade”, so this is a truly ambient temperature process for use in our cold northern European climate, without costly insulation and heating.

If you have ever wondered why so many digesters in the UK (of the mesophilic and thermophilic variety), are a lot less productive than those un-insulated anaerobic digestion systems which seem miraculously easy to build and operate in hot climates, it has got an awful lot to do with our climate being too cold, and the cost of heating!

Watch our sponsored Lt_AD explainer video below:

To view this video on the YouTube website click here and watch Low Temperature Anaerobic Digestion being explained.

So, how remarkable to find that a spin-off technology, which has taken 15 years microbiological lab and pilot scale testing at the National University of Ireland, Galway is now available for the Food and Drink Wastewater (WW) industry. Not only that there are many other industries which produce similar strength organic effluents such as the Municipal WW industry, Pharmaceutical WW industry, and also the ethanol processing WW industry. All thse can now use this technology to treat their wastewater without the ever-rising energy (running) cost implications of current aerobic treatment systems.

But like all other anaerobic digestion based processes LT-AD has, is also by nature biogas plant, with all the implications that brings for net energy export (and revenue), reduced carbon footprint for the business, and even possible sales for other products such as CO2, and the digestate as a fertilizer.

Traditionally all these industries have used aerobic wastewater treatment systems, the Lt-AD technology does what those high energy consuming systems can do. It recovers the carbon in the WW and transforms it into biogas. This means that the NVP Energy technology is a carbon neutral and energy-positive process technology which is great news for the global environment. But, lets not forget the benefits to the bottom line for those that use this new process, due to those reduced carbon costs.

If you have been watching how quickly anaerobic digestion taking hold as the preferred treatment method of choice, then just take a look at this blog! Due to its clean green energy credentials Ad is leaping ahead, and this development should be very attractive to the Food and Drinks industry, plus all other businesses producing similar effluents.
AD-Lt Anaerobic digestion 3D Image cut-away
The NVP Energy process has been given the name of “Lt-AD technology” and they say that it can work equally well as a retrofit, an add-on technology to their client’s business expansion, or of course can be the core technology treatment method in any new build scenario.
For example, if you operate a Food & Drink plant that has an existing inefficient WWT system such as the activated sludge system, then their technology can:
  • Lessen the load on your current system and greatly reduce your aeration costs due to our high COD attenuation
  • Significantly decrease your sludge volumes. Their technology has been shown to generate up to 90% less organic sludge compared to the activated sludge process.
On the other hand, if you operate a Food & Drink plant that elutes all your wastewater to sewer, then their technology can:
  • Significantly reduce your trade effluent charge/Mogden charge due to high COD & TSS attenuation.
In both cases the biogas that is produced is 100% available for reuse on-site to generate heat and/or electricity thus reducing your operational expenditure.

They say that the system will prove very attractive to Food and Drink plant operators that currently discharge their wastewater to sewer.

Where this is the current disposal method they say that NVP Energy can significantly reduce the high trade effluent discharge costs that arise from the application of the “Mogden” calculation of TE Charges due to high chemical oxygen demand (COD), and total suspended solids (TSS) attenuation.

I spoke to Tracey Giles (NVP Energy, Design Engineer) who said:
“For Food and Drink plants that treat their wastewater on-site, NVP Energy can considerably decrease their aeration costs. In addition, the Lt-AD technology can reduce organic sludge volumes by up to 90% when compared to the activated sludge process thus reducing sludge management costs.”
“The technology is very attractive as it has produced effluent which adheres to effluent release standards, e.g. Urban Wastewater Directive (UWWD) COD release standards, without the need for post-treatment. This is proven from our pilot-scale trials using our “low-strength” effluent definition, a type of effluent that will apply to very many businesses”.
Benefits of Lt-AD are listed as:
  • Significantly reduced OPEX due to lower discharge costs through a high COD attenuation (approx. 80% removal rate) capability & reduced TSS levels (approx. 50% removal rate).
  • Reduced OPEX - up to 90% less organic sludge produced than the activated sludge system.
  • Energy Efficient - No WW heating or aeration required. Lt-AD has been successfully trialled at temperatures as low as 40C.
  • Potential savings from biogas production – can be used to generate electricity/heat that will offset use of fossil fuels.
  • Potential revenue from biogas production - FITs/RHIs for on-site energy generation.
  • Modular design allows flexibility in WW volumes.
  • Integrates easily with existing WW treatment systems.
  • Aids in adhering to specific discharge requirements e.g. UWWD.


NVP Energy offers an exciting new and innovative energy-positive, low temperature anaerobic digestion technology (Lt-AD).

Lt-AD treats wastewater (WW) highly efficiently at temperatures as low as 4°C and will significantly reduce low strength wastewater treatment costs and TE charges. The Lt-AD technology target markets are Food and Drink WW including Dairy, Brewing, Malting and Distilling applications; Municipal WW; certain pharmaceutical WW streams and also ethanol processing WW.

For more information visit: www.nvpenergy.com

Tuesday, August 12, 2014

New Schmack Carbotech Plant to Shows Extent of Swedish Commitment to Biogas Biomethane Production

Shmack carbotech biomethane upgrading
Schmack Carbotech Stockholm: Sweden’s role in bioenergy production, with the world's largest installed biogas upgrading capacity, is set to continue its march toward transport fuel sustainability ahead of other nations. That is because of the announcement that Schmack Carbotech has been signed-up as the "design and build" contractor for a 2000 Nm³/h biogas upgrading facility to be located to the south of Stockholm.

Schmack Carbotech’s innovative Pressure Swing Adsorption (PSA) technology will be used in a development that will enable the Swedish capital to produce pure methane (biomethane) from more biogas.

(Image: (c) Schmack)
This will increase the proportion of biomethane, it uses by 50%, this will provide biofuel for vehicles currently powered by natural gas. The biomethane produced will be a high purity gas leaving the PSA with a methane content in excess of 97 per cent.
Fed by organic waste and waste kitchen oil, the plant, which will be located in Sofielund, Huddinge, will produce biogas with an annual energy yield of nearly 100 million kilowatt hours. That's enough to supply approximately 5,000 vehicles clocking up an average of 20,000 km per year each.

Part of the Viessmann Group, Schmack Carbotech’s Pressure Swing Adsorption (PSA) principle distinguishes itself from other technologies because of its favourably low energy consumption, efficient heat extraction and high methane yield, as the company’s International Business Manager, Eberhart Wusterhaus Gomez, explains:
“This important new contract at Sofielund brings to bear all of our 30 years ‘experience in the development, engineering and manufacturing of turnkey gas upgrading plants.
“As industry pioneers and market leaders in biogas purification, we are very keen to play our part in delivering a low energy yet high yield technology that in this case fits in perfectly with the Swedish government’s long-term thinking to become the world’s first completely oil-free economy”.

(Image: (c) Schmack)

Setting new standards in biogas process efficiency, Sofielund’s new plant will be equipped with a CNG station, a Carbotech PSA plant, off-gas cleaning with high heat recovery system combined with a peak load boiler. The plant will also benefit from ultra-reliable VOC and Hydrogen Sulphide removal, making Carbotech’s robust technology ideal to produce biomethane from biogas, sewage gas and landfill gas for grid injection and CNG vehicle fuel. As well as being a specialist in upgrading biogas plants, the Viessmann Group is actively implementing complete biogas turnkey solutions worldwide. Installations include award-winning biological technology, with special wet fermentation (from Schmack Biogas) and batch-dry fermentation (BioFerm technology) now integral parts of more than 300 cogeneration and biomethane plants in Europe and beyond. This includes Europe’s largest dry-AD-from-organic-waste plant, located in Fife, Scotland.

The Viessmann Group is a leading international manufacturer of heating technology systems. Founded in 1917, the family company has around 11,400 employees with group sales of EUR 2.1 billion. Viessmann has an international presence with 27 production companies in 11 countries, sales companies and representations in 74 countries and 120 sales branches worldwide. 55 percent of sales are generated abroad.

For more information, contact:

Petra Krayl
Schmack Biogas GmbH
+49 (0) 9431 / 751-285

Thursday, July 31, 2014

Lukeneder Offers Biogas Plant Owners a Leap in Biogas Plant Efficiency Plant Efficiency - Iron Additive Dosing/53d2d3b33111e
The German Company Lukeneder recently added the UK to its list of countries to which it supplies its Deuto-Clear® Sulfo product, which is an iron dosing chemical. That means that UK anaerobic digestion plant operators can now obtain substantially improved biogas plant efficiencies, and raise the profitability of their operations.

View this description of the Lukender Deuto-Clear® Sulfo product on YouTube.

The Anaerobic Digestion industry tends to spend too much time scrubbing the biogas, when in most cases, a far better solution to producing a better quality of gas, is to tackle such problems at the source of the problem, in the digester. By doing it in the digester there are so many spin-off benefits. In fact, operators will end-up wondering why they did not previously pursue all avenues for optimizing the conditions in the reactor to suit the micro-organisms they want to encourage!

A policy of H2S prevention, combined with the avoidance of high (and biochemical process inhibiting) ammonia concentrations, not only helps to stabilise the whole methane production process, it also allows the healthier biomass that results, to produce more gas of a better quality. This is achieved, it is understood, without changing the feedstock, and occurs over a period of time.

This looks like a true “win-win” situation, and involves the daily dosing of the digester with Deuto-Clear® Sulfo. This according to the Lukeneder brochure:

"Is a ready-to-use solution containing metal salts and trace elements. It improves the performance of your biogas plant and its dosage will be adjusted to fit the specific needs of your digester. Deuto-Clear® Sulfo features a broad range of trace elements, minerals, and other agents to improve the quality and stability of the digestate."
Deuto-Clear® Sulfo removes hydrogen sulphide and ammonia gas from the digestate and adds nutritious trace elements and minerals to produce a healthy and productive environment for anaerobic bacteria.
 Added benefits are listed as:
To read our more comprehensive article go here.

For more information and copies of supporting documents contact:

Dr. Naoimh McMahon, UK Representative, Lukeneder GmbH (BIOGAS & ANIMAL HYGIENE)
Telephone: +44 (0)20.3151 0883

Wednesday, June 25, 2014

How to Stop Water Pollution Risks Leading to Water Pollution from Biogas and AD Plants

There was recently quite a serious UK biogas plant digestate tank failure at Harper Adams University recently, which we reported on in our last post. It led to digestate leaking into a bunded area, and because the right precautions were taken with containment it is extremely unlikely that any pollution has occurred.

That led us to consider what we could do to help those people who are responsible for Anaerobic Digestion and Biogas Plants to understand the UK legislation on watercourse and groundwater protection. Most will be familiar through their site environmental permitting arrangements anyway, but we wanted to provide an accessible reminder which would also be useful to our international readers who might view it as "good practice" worth following, even if similar local regulations don't exist in their location. 

The idea is that a better appreciation of the law in this area, and what causes most spillages, should help to ensure that those responsible, such as site managers and plant operators carry out what is in fact their legal duty (in the UK). That is to assess risks from their liquid storage installations and reduce all such risks to their minimum which in most cases (as for anaerobic digestion plants) means providing suitable containment.

The answer, we thought, would be to post the infographic image below which is based upon a UK Chartered Institute of Waste Management Fact File.

It provides the legal basis for compliance by owners/ operators of factories and other potentially polluting sites, making sure that they appreciate their legal liability should they fail to follow the guidance. It then provides a summary of some of the most important requirements for minimizing pollution risks from processes like anaerobic digestion, where collapse or even a leak can harm large areas of groundwater, or long stretches of rivers if either the mixed-liquor, stored digestate, or even uncontrolled maturation slab run-off reaches rivers, or soaks into the ground and into the groundwater.

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Here, in text, is what the CIWM said in their Fact File:

OPERATORS OF permitted facilities are responsible for complying with their environmental permit and for preventing pollution of air, land and water.
Waste management facilities have the potential to cause significant environmental harm, which could threaten water supplies, public health and wild life in the event of an environmental incident such as fire, explosion or spillage.
 A facility found guilty of causing a pollution incident could face a fine of up to £50000 in the Magistrates Court.
In order to prevent environmental harm you should be aware of the following:
The source of the contaminant;
  • the most common pollutant in the UK is oil 

The pathway 
  • this could be the site's surface water drainage system or via off-site surface drainage, direct run-off, foul drainage system or into the atmosphere 
The receptor
  • ie a river, groundwater, the local population. 

Potential causes of environmental incidents include: 
  • delivery and use of materials 
  • plant or equipment failure 
  • containment failure 
  • fire, explosion or failure to contain fire fighting water 
  • wrong connections of sewers and pipes 
  • discharge of partially-treated or raw effluent 
  • vandalism 
  • flooding of part or all of your site.

Those operating waste facilities need to assess the risk from every one of the above listed potential causes, in the context of the source (degree and nature of pollution), the pathway to the permeable ground, river, ditch or stream which would become the receptor

Tuesday, June 03, 2014

Harper Adams University Biogas Plant Explosion and Tank Collapse Produces 2nd Spill of Liquor at Troubled Green Power Facility

This is appalling news for a flagship UK anaerobic digestion plant which was put into operation less than 3 years ago.

As far as can be seen from the Shropshire Star report referenced below, there was an explosion which resulted in a digester tank collapse and that led to the contents of the tank being dropped on the ground around the plant.

We found the short video below on YouTube, briefly showing the clean-up:

There was also previous spill at the plant last year, which appears to be beset by incident.

Thankfully, we don't think there were any injuries on either occasion, but there may have been some of the biomass which entered the local stream, again the articles referenced below don't make it clear just what the effect was on the local water quality. Hopefully, there would not be expected have been any significant loss of liquor outside of the bunded area for the plant, and therefore the clean up will adequately remove any future risk of pollution.

Sludge power plant collapses in Shropshire

"A power plant using farm waste today exploded at Harper Adams University, spilling tonnes of slurry. A 200-metre exclusion zone was today put in place by police, who described it as a “chemical incident”."
The incident took place on Friday 30 May, and the following further article was published on Monday 2 June:
"The clean-up operation continues at the HarperAdams University anaerobic digestion plant today. The access road to the AD plant was fully cleared over the weekend. Digestate is now [contained]."

 Credits: Clean-up continues at Harper Adams anaerobic digestion plant - (press release)

Today the Farmers Guardian had more to say, as the staff worked on at the clean-up:
THE clean-up at the Harper Adams anaerobic digestion (AD) plant is continuing today (Tuesday) with specialist contractors working on limiting the impact of the spill on the environment. The university has been working to tackle the major leak since one ...

 Credits: Harper AD plant clean-up continues after major spill - Farmers Guardian

It is clear that this was a major explosion to cause this degree of damage, and from the articles the presence of watercourse pollution remains unknown while tests are carried out:
"A Harper Adams spokesman said: “The Environment Agency is also conducting routine monitoring of the local watercourse. No release of pollution has been detected so far.”
I would predict that the University will carry out an inquiry into the cause, and that in due course there will be lessons to be learnt for the UK biogas industry.
We have previously highlighted the potential for explosions at Anaerobic Digestion Plants on this blog, and the need for this to be heeded at all times both during design and construction, and throughout biogas plant operation.
In this case there does not appear to have been anyone present at the automatically operated plant when the incident took place simply because there is no mention of a staff, or maintenance contractor's presence at the time, so we would guess that an equipment failure of some sort is the most likely cause.
In the video below we see the biogas plant in happier times, on opening day in 2012:

Wednesday, May 07, 2014

Poo Power Infographic Taps Into Public Sensitivities About Biogas from Waste in Our Latest AD Blog Post

This post is about another web page, which we hope that you will want to visit. Read-on and you will discover why that is.

Here is the top part of the new infographic from that other page, which we have been given permission to use by Lanes for Drains – Drainage Contractor, through the embedding code they provide below this interesting infographic image, in its original location, on their website.

 From Poo to Power - Via Anaerobic Digestion!

The way the subject is handled won't meet the approval of some people (we apologize if that is you...) as the source of this very clean and environmentally sustainable "energy from poo" is something most of us would rather not dwell upon. 

However, the reason that "Lanes for Drains" commissioned this informational artwork in the way they have done, was very much one of publicizing anaerobic digestion to a new audience by using a novel way to communicate what most would otherwise consider to be a very dry subject.

If you visit our web page at you can see the full infographic which is unfortunately simply too large for us to embed it here on this blog page!

Below the infographic which tells the story of the growing number of (sewage sludge waste fed) Anaerobic Digestion Plants around the world, we have added a YouTube video which we really liked because it shows an experiment which demonstrates just how well a digestate culture can produce biogas in a simplified biogas reactor system.

It is just the sort of "hands-on" chemistry experiment which inspired me when I was at school and hopefully it will inspire many youngsters to consider studying science.

More and more schools are teaching children about how anaerobic digestion produces biogas and indeed GCSE teaching in the UK about biogas includes a course-unit in which it is explained. So we hope that this page will help continue that trend. More and more demonstrations of the unique combination of chemistry and biology which creates this useful, mostly methane (biogas) power source can only mean that the take-up of AD will grow further.

We are hoping that our page at the Anaerobic Digestion blog (see link above) will be seen very widely, so any help you can give when you go and check the infographic out. by "Liking" or "Sharing" the page using the buttons that we have provided, would be greatly appreciated. Now if you visit I'll see you there!

Thursday, April 24, 2014

Recent Biogas and Sewer Methane Explosion Incidents Worldwide

Thankfully, as far as we are aware, there have been few methane explosions reported recently worldwide, which is good news because there have been deaths in the past when biogas has exploded.

There was an explosion in India at the start of 2013 which caused at least one death, which was reported as follows:

Two labourers killed in Maharashtra gas explosion

Solapur (Maharashtra) : Two labourers were injured, one critically, in an explosion at a biogas factory while it was being constructed on the outskirts of the city, police said.
"Some labourers had undertaken drilling and welding work near a cement tank at the upcoming biogas plant Solapur Bio Energy Pvt. Ltd. However, they did not know of the gas in the tank," an official from Solapur's Jodbhave police station told IANS.
"An explosion took place after the gas leaked out due to drilling and welding near the tank. Two labourers have died and one is critically injured with severe burns," the official added.
Read more here.

There has also been an explosion in China, which was reported on March 30 2014, as follows:

Biogas explosion erupts in Xiamen sewer, no casualties reported

“The food stall was burning coals to cook soup in a pottery jar by the door at that time. Maybe its coal fire splashed into the sewer and caused the explosion,” he explained. However, the cause of the biogas explosion has not been confirmed. The case ...
A sewage gas explosion erupted in a sewer on Siming South Road in Xiamen on Friday morning, terrifying many residents around the site after hearing a loud bang caused by the explosion.

The explosion that occurred at 9:30 am has been brought under control. No casualties were reported, but the glass door of one nearby store and a section of the street was heavily damaged.

According to the work safety supervision bureau, the area of Siming South Road near the explosion is filled with food stalls. These stalls often dump their sewage and waster into the closed sewer, which easily produces a large quantity of highly flammable methane gas. 
Credits: Biogas explosion erupts in Xiamen sewer, no casualties reported - What's on Xiamen

Then there was our own report, on our sister blog, of on anaerobic digestion plant biogas explosion back in March of last year, which we wrote about :

Anaerobic Digester Plant Explosion

Nobody was hurt by this biogas incident...
Credits: Anaerobic Digester Plant Explosion Blamed on Gas Storage EPDM ...

Of course, if we look back in time a little further, there were the following biogas explosion incidents:

Four die in biogas plant explosion in Ernakulam

Aug 27 2009: By Staff Correspondent,. Kochi: Four people were killed and several others injured when a biogas plant exploded at Aluva in Ernakulam yesterday. About six people are reported to be missing. The explosion ... 
Credits: Four die in biogas plant explosion in Ernakulam |

And finally:
Investigators believe the powerful explosion that rocked Kirinyaga Road on Sunday was caused by biogas from an underground room of a petrol station.
Credits: Biogas in room likely cause of city explosion, say ... - The Standard
If any of our readers know of other recent biogas explosion incidents, please use our comments facility below to tell us what you know. These incidents need publicizing so that the both biogas businesses and the health and safety authorities responsible globally, never forget of this danger.