Sunday, August 26, 2018

The Dangers of Biogas - 7 Known and 3 Unexpected AD Hazards

There are dangers of biogas just as there are dangers inherent in everything we do. The most obvious biogas dangers come from the fact that it is an explosive gas when mixed air in the right proportions.

However, there are also anticipated dangers of biogas plants which the public authorities and individuals raise during consideration of planning applications, which this article also discusses with examples, in section 2.

Finally, in section 3 below we have included three surprising unexpected dangers of biogas which few if any people have foreseen, with:

  • honey which became coloured due to an anaerobic digestion plant locally, and 
  • estrogen, antibiotics which persisted in dairy farm waste after AD treatment
  • worries about aluminium roof collapse if sulphur leaks out of the biogas.
Image - cartoon suggests the dangers of biogas.

1. Normally Accepted Biogas Hazards

The normally accepted dangers of biogas are summarized in the list of 7, below:

  1. Fire/Explosion
  2. Asphyxiation
  3. Disease
  4. Methane
  5. Carbon Dioxide
  6. Hydrogen Sulfide
  7. Ammonia.

Precautions to Limit the Normally Accepted Dangers of Biogas

Standard biogas plant safety procedures will major on the following actions to keep plant staff safe:

  • Observe All Manufacturer Warnings with Rigour, create Site Safety Policies and implement procedures to ensure all staff and each visitor is trained to avoid every biogas plant hazard which could cause injury or ill-health.
  • Conduct Safety Walk-Throughs/ Plant and Equipment Inspections Regularly
  • Use and Maintain Gas Sensors
  • Use the relevant Personal Protective Equipment via Biogas Safety

2. Dangers Raised During Biogas Plant Planning Discussions

Dangers of biogas production as an alternative energy source for rural areas

Biogas is a mixture of 55-65% Methane, 30-35% Carbon Dioxide and Moisture, Hydrogen Sulphide, Nitrogen and Hydrogen making up the balance.

Its heating value is around 600 B.T.U. per cubic feet. Biogas production is a biological process without oxygen in which organic matters are converted into biogas by bacteria, because organic matters are the food source for methane producing bacteria. About one cubic feet of biogas may be generated from one pound of cow dung at around 28°C.

This is enough to cook a day's meals for 4-6 people. In anaerobic process, the bacteria requires both Carbon and Nitrogen, but they consume Carbon roughly 30 times faster than Nitrogen.

Biogas is not poisonous, although this may be improved by filtering it through limewater to remove CO2, iron filings to absorb corrosive H2S and Ca2Cl to extract the water vapour.

The only danger is by the explosion of the plant and mixed with air and fire. Thus proper maintenance of the Biogas plant is important to prevent the leakage.

via Biogas production as an alternative energy source for rural areas

Villagers fear biogas plant in Canwick would cause ‘unnecessary danger’

February 2018: Plans for a new biogas plant in Canwick have provoked an angry response from fearful local residents, with even the Environment Agency and Lincolnshire Fire and Rescue weighing in to say that the development should not be approved in its current form. via Canwick danger’

THE Energy Regulatory Commission has not licensed any of the bottled biogas products which are ... are highly explosive, hence pose a lot of danger if not well handled. "The people bottling biogas need to get safety approval first," ERC director ... via Kenya: Traders Selling Bottled Biogas Illegally - Kenya: Traders

Anaerobic digester plans stymied in Franklin - News - Milford Daily News

After hearing the pleas of several concerned residents, Town Council on Wednesday tabled zoning changes that sited an anaerobic digester plant for a Pond Street property.

... The questions about anaerobic digestion, a biological process that converts organic waste into energy, overshadowed the positives of the burgeoning technology.

With support from the Economic Development Committee, Town Administrator Jeffrey Nutting and officials in the Department of Planning and Community Development had hoped to tweak the zoning to allow for an anaerobic digester facility on the former Pond Street sewer bed.

... a day after the Planning Board voted not to recommend the zoning changes, residents who live on or near Pond Street attended the council meeting ready to fight the prospect of an anaerobic digester in their backyard.

"I want you to take into consideration what anything seeping into the ground, or going into the air … could do to our community — the town we love so much," said Sandra Verhaegen. "Is the $500,000 to $1 million worth it? Probably not. Look to new businesses (to fill the property). Do we really want something in our community that isn’t tested?"

According to the Environmental Protection Agency, the "biogas" or gas produced when the anaerobic digester breaks down waste is comprised of methane, hydrogen sulfide, a highly toxic and flammable gas with a distinct rotten egg smell, and carbon dioxide.

Residents worried that problems [of the dangers of biogas] with the plant, such as a fire or leak, could put them in immediate danger. And they feared the increased truck traffic that would accompany the plant.

Councilors expressed the same concerns. via Anaerobic digester plans stymied

3. Unexpected Dangers of Biogas

Waste from M&M's Candy Causes Honey to Turn Green in France

M&M candies come in every color of the rainbow – but what if honey came in the color of M&Ms?

Distraught beekeepers in Northeastern France are facing just that conundrum, as honey from their apiaries has been turning up in shades of green and blue.

After weeks of perplexing investigation, the farmers found the candy colored honey to be caused by waste from nearby Agrivalor biogas plant, which has been processing M&M’s waste.

The farmers in Ribeauville, Alsace are just 2.5 miles away from the biogas plant, a short jaunt for their bees to travel and pollinate before returning to the hive. In the past the biogas plant threatened no danger to their business, but since processing waste from the colorful shells of M&M’s, the beekeepers felt an immediate effect. Bees from around twelve apiaries have been returning to the hive with blue and green debris, which gets directly transferred to the honey they yield.

Honey appearing in colors other than amber is needless to say, unsellable. The murky blue and green sweet stuff isn’t being packaged as a new M&M flavor, but instead is being thrown in the trash.

These beekeepers are already facing adversity, with increasing bee mortality rates killing off many of their producers they can’t afford to lose the honey they do make. Coupled with the effects of harsh winters, the apiaries are already in a jam.

[The AD plant operator] has been notified and has begun cleaning up the mess, but the beekeepers are still stuck with green honey. via Honey Green

Estrogen, antibiotics persisted in dairy farm waste after advanced treatment, study finds

When University at Buffalo chemists began studying waste disposal at a dairy farm in New York State, they thought that the farm's advanced system for processing manure would help remove estrogens and antibiotics from the excrement.

Instead, the scientists found that the chemicals largely persisted in the treated materials, which are typically reused as fertilizer and animal bedding on the farm.

The waste management process—an advanced anaerobic digestion system—also converted a less harmful form of estrogen in the manure into a form that may pose a greater ecological threat.

The study underscores how far waste treatment techniques have fallen behind the times.

Hormones and antibiotics, if not removed from waste, can migrate into the environment and threaten wildlife. Estrogens, for example, can enter rivers and lakes, causing male fish to develop female traits—a phenomenon that can harm reproduction. Rogue antibiotics pose a different kind of challenge, encouraging the spread of antibiotic resistance, in which disease-causing bacteria stop responding to drugs.

... "One of the messages of our work is that even anaerobic digestion, an advanced treatment, doesn't totally remove these chemicals which may pose a danger to the environment. We need to start looking closely at additional treatment techniques to identify better practices."

The research, funded by the New York State Pollution Prevention Institute, was published in two recent papers. via Estrogen, antibiotics persisted

Waste Not, Pollute Not 

This is part of IEEE Spectrum's special report: Critical Challenges 2002: Technology Takes On

Cow Power - Danger of Sulphur Precipitation to Aluminium Roof Corrosion and Potential Eventual Collapse

...each of DDI's three barns will be warmed by water pipes running under the concrete floor. The hot water, which will be heated by biogas power, will keep the manure flowing into the digester even in the dead of winter. So the electricity will keep flowing, too.

That electricity will be generated by four microturbines from Capstone Turbine Corp., Chatsworth, Calif. [see "Networking Assets," IEEE Spectrum, January 2001, p. 84]. ...DDI will still scrub the gas before it goes to the microturbines by passing it through iron-impregnated wood chips...

If the biogas is not scrubbed, the sulfur could precipitate out of the exhaust as an acid, a danger for surrounding equipment as well as the farm's 12 000 m2 of aluminum roofs.

via Waste Not, Pollute Not

Well there you have it! Biogas Dangers never imagined!

Tuesday, August 14, 2018

Applying Biogas Benefits Essential After Bad News for Climate Change in 2018

We consider that applying the biogas benefits in helping reduce climate change (global warming) is now more essential than ever after the bad news for climate change in 2018.

Just take a look at the trending news about climate change in the last 30 days, as summarized below:

Climate change: Our plans are in pieces as killer heat shreds records

(CNN) Deadly fires have scorched swaths of the Northern Hemisphere this summer, from California to Arctic Sweden and down to Greece on the sunny Mediterranean. Drought in Europe has turned verdant land barren, while people in Japan and Korea are dying from record-breaking heat.
Climate change is here and is affecting the entire globe -- not just the polar bears or tiny islands vulnerable to rising sea levels -- scientists say. It is on the doorsteps of everyday Americans, Europeans and Asians, and the best evidence shows it will get much worse.

This summer, 119 people in Japan died in a heat wave, while 29 were killed in South Korea, officials there say. Ninety-one people in Greece died in wildfires, and ongoing fires in California have taken at least eight lives. Spain and Portugal sweltered through an exceptionally hot weekend with a heat wave that has killed three people in Spain and pushed temperatures toward record levels. via heat shreds records

Biogas Benefits
Biogas Benefits - "Off the Chart "NCE Magazine - Warning!

Science Says: Record heat, fires worsened by climate change via Science

Record-breaking heat and fires are worsened by climate change, scientists say

Heat waves are setting all-time temperature records across the globe -- again. Europe suffered its deadliest fire in more than a century, and one of nearly 90 large fires in the U.S. West burned dozens of homes and forced the evacuation of at least 37,000 people near Redding, California. Flood-inducing downpours have pounded the U.S. East this week.
It's all part of summer -- but it's all being made worse by human-caused climate change, scientists say.
"Weirdness abounds," said Rutgers University climate scientist Jennifer Francis.
via Record-breaking heat

We think that the need to implement all possible means of reducing climate change which can be done using proven technologies, without incurring un-affordable costs, must surely now be implemented without delay.

Biogas Benefits are Now Proven - Time to Ramp Up AD Plant Construction

The global biogas industry has developed rapidly over the last 10 years, and now is the time to start ramping up anaerobic digestion plant construction.

Biogas offers a solution to helping protect our environment and meet ambitious climate change commitments. All of these critical functions – generating renewable energy, reducing solid wastes, managing nutrients, reducing GHGs and mitigating pollution risks – can be realized from a biogas facility in an economically sound and sustainable manner.

GHG Emission Reduction

The capturing and utilization of biogas is a powerful tool for reducing GHGs that are the principle cause of human-induced climate change. GHGs are reduced in two ways: first, the biogas produced is a source of renewable energy that can replace fossil fuels. Second, the capturing of biogas reduces methane, a very potent greenhouse gas that would otherwise be free to escape into the atmosphere. Biogas has the potential to reduce GHG emissions by 37.5 Mt CO2e, or 10% of the national target.

Methane Abatement

Biogas reduces two critically important greenhouse gases — carbon dioxide (CO2) and methane (CH4). Carbon dioxide emissions are reduced when biogas replaces fossil fuel use (i.e., coal, diesel or natural gas). This can be in the form of direct displacement in the pipeline by injecting RNG into the natural gas supply, or in transportation by replacing diesel with RNG. In addition to displacement, the biogas process is able to capture upstream methane emissions and convert it to renewable energy. Methane abatement strategies are critically important in agriculture for manure management, as well as at municipal landfills that flare their captured gas. There are multiple ways in which biogas can reduce methane emissions or displace other higher carbon intensive fuels with a lower-carbon solution.

Resource Recovery

Biogas offers a solution to waste management that ensures valuable organic material is not sent to landfill. The benefits resulting from diversion of organic materials, include the following:
  • Less food waste going to disposal means fewer GHG emissions associated with growing, manufacturing, transporting, and disposing of food;
  • Diverting organics from disposal avoids potential methane emissions from landfills;
  • Using the biogas produced from organic wastes as a source of energy reduces the need for fossil fuel energy sources, such as oil and natural gas;
  • Digestate (the product that comes from the anaerobic digestion of organic material) returns organic matter to the soil.
  • Digestate utilization reduces the extraction of peat, an important sink for CO2.
An additional societal and political benefit of organic material diversion includes preserving landfill space for “real” waste. For biogas system operators, these materials are essential for fueling their biogas systems and producing clean, green energy. via Canadian Biogas Association

Who Will Drive Accelerated AD Plant Development?

While some governments will undoubtedly raise their financial support for climate change reduction initiatives, after the heat-wave and fire events of summer 2018, many will not.

The best hope for rapid implementation of all forms of climate change mitigation will be most likely to come from big investment funds. These funds are becoming critically aware of the need for their investment funds to identify and only invest in sustainable companies, as their long-term pension funds can only prosper under a stable global climate.

How Big Investment Organisations Will Only be Able to Invest in Sustainable Businesses

“The next step for [large investment funds] will be to begin the process of identifying and quantifying the financial impacts of climate change, exploring how resilient their strategies are to different climate scenarios, and encouraging others to do the same.”
“Many of the biggest investors in infrastructure worldwide are signed up to the TCFD guidelines, requiring disclosure of the climate risks to their investments,” explains Mott MacDonald head of climate resilience Ian Allison.
“The consequence is that we will see investment diverted away from businesses or industries that are not making a positive contribution to the Paris Agreement,” Allison says.
The pace at which the financial sector is acting to understand its exposure to climate risk is fast and is beginning to make a real impact on infrastructure clients and their supply chains, says Mott MacDonald principal climate advisor Madeleine Rawlins. via NCE

Summary to Applying Biogas Benefits After the Bad News for Climate Change in 2018 

We consider that applying the biogas benefits in helping reduce climate change is now more essential than ever after the bad news for climate change in 2018. Climate change is here and is affecting the entire globe, not just the polar bears or tiny islands vulnerable to rising sea levels.

Spain and Portugal sweltered through one exceptionally hot weekend. Flood-inducing downpours have pounded the U.S. East, and terrifying fires are raging across the US. So, as we contend that the biogas benefits are now proven it's time to accelerate global AD Plant Construction.

But who will drive this accelerated AD Plant Development? Governments are unlikely to provide the needed push.

The best hope for rapid implementation of all forms of climate change mitigation will be most likely to come from big investment funds.

The pace at which the financial sector is acting to understand its exposure to climate risk is fast.

These institutions are beginning to make a real impact on infrastructure clients and their supply chains, insisting on sustainable projects such as biogas plant development for renewable energy from waste materials (not food crops).

See also our article at the AD Blog on Biogas Benefit and the Civil Engineer's Call to Action!

Friday, August 03, 2018

How the EU’s Circular Economy Package (CEP) Will Advance Anaerobic Diges...

Here is the article on which the above YouTube video is based, and we have titled the, "How the EU’s Circular Economy Package (CEP) Will Advance Anaerobic Digestion in the UK".

After many years of gestation, the legislative changes included in the EU’s Circular Economy Package (CEP) came into force last month (July 2018).

Here we explore the implications of these changes for UK Anaerobic Digestion.

One of the main headlines the sector talked about throughout negotiations on the Circular Economy Package (CEP) is the proposed increases in recycling targets.

Image showing how the EU’s Circular Economy Package will help Anaerobic Digestion development in the UK.
The final package (which came into force on 4 July 2018) does introduce new, higher targets, but, there are also many other ways it will affect UK waste collection and recycling practice.

In this video we will discuss only the affect on anaerobic digestion, and the news here is that the Circular Economy Package places a greater emphasis on waste prevention and reuse in general.

So, there will be a duty on member-states to promote food waste prevention and on the Commission to consider setting targets for reductions to this, and other waste streams.

The requirement for separate collection of waste is strengthened and the test as to whether separate collection isn’t technically, environmentally or economically practical (‘TEEP’) is made tougher.

The separate collection of bio-waste is required (by 2023), among other stipulated waste streams.

The overall targets for recycling of municipal waste are increased to 55% by 2025, 60% by 2030, and 65% by 2035.

Along with tightened ‘TEEP’ tests and the requirements on biowaste, etc, this is also likely to push more waste collectors towards separate collection in England, catching up with the direction of travel elsewhere in the UK.

For bio-waste, various changes promote the use of anaerobic digestion and in-vessel composting over incineration.

Alongside the changes to collection rules, this will push much more biowaste towards AD and IVC and, as highlighted above, strengthen the case for more UK-based reprocessing capacity.


The overall impact of the changes in the CEP will be to make the case for separate collection of food waste far stronger for English local authorities.

Once collected separately, this waste will need to be recycled (not landfilled or incinerated), which will drive demand for Anaerobic Digestion, and IVC until and unless food waste reduction actions bite or new technologies (such as biorefineries, etc) come along.

Text condensed from CIWM Journal Online article "Read It & TEEP" (2nd August 2018):