Thursday, March 22, 2012

Biogas in Danger - Will Misuse of the Term for Process Gas Methane Devalue its Sustainability Credentials?

Please read this and add your weight to the comments box below the full article if you care about "biogas" and "sustainability".

I have seen a couple of so called "biogas" articles published internationally recently which I must admit confused me greatly, and I have been taking in interest in the subject of anaerobic digestion and biogas for more than 5 years, and should know enough not to get confused by AD terminology!

The articles were about biogas production from fossil fuels, and much more about the methane content of what in my view would be correctly called "process gas", "syngas" "synthetic gas". Methane created through this route when the source is from mineral energy deposits is not considered to be sustainable due to the high contribution that the carbon dioxide emitted during combustion adds to climate changing greenhouse gases.

That left me thinking that others will surely also be wondering whether they had misunderstood the meaning of "biogas" as has been commonly accepted until now, and the experts should speak out about the confusing usage of "biogas" to non-sustainable methane production. After, all nobody hitherto has called "natural gas" "biogas", and to use the term in this way is truly nonsensical.

Googling for a definition of biogas immediately brings:

"Gaseous fuel, esp. methane, produced by the fermentation of organic matter."

and, similarly from Wikipedia:

"Biogas typically refers to a gas produced by the biological breakdown of organic matter in the absence of oxygen. Organic waste such as dead plant and animal ..."

Also, in defence of this assertion I would point to the fact that in the UK, the Trade Association for Anaerobic Digestion companies is called the AD and Biogas Association, and the official UK government sponsored Anaerobic Digestion web site ( ) says that: "Biogas is a mixture of gases produced by AD."

I am glad to be able say that Blog reader Ruzena Svedelius is of the same opinion, and has kindly agreed to my quoting from an email she sent me recently as follows, and in which and she takes my concerns a stage further:
Dear colleagues in [the] biogas field, 

[The] purpose of this message is to inform you about a big danger that will affect further development of biogas systems. Recently I discovered that the definition of biogas has been altered in an unacceptable manner when the product of thermal gasification is also called biogas, which in fact is synthetic gas, and [in such processes there are normally] several elements remaining in the tar and corrosive ash.  

Questions that I intend to send to various people in the EU [are]:  

What is actually happening with sustainability? Is there a danger that the fundamental meaning of sustainable development is lost because of low priority for ecological and social sustainability of our decision-makers compared to financial sustainability? 

As a conscious [concerned] citizen, I demand transparent answers to these questions. 
1) Where is the comparison between ecological, economic and social sustainability between two ways of converting bioenergy, i.e. the sun's energy that is biochemically bound in biomass and renewable organic material? 

a) Methane fermentation (Anaerobic Digestion), i.e. microbial fermentation to two valuable products BIOGAS containing mainly methane and carbon dioxide, and BIOFERTILIZER that is important for the recycling of plant nutrients and soil fertility. 

b) Thermal gasification process, i.e. where conversion is in progress under temperatures between 800 and 1200 °C and high pressure and the product is SYNGAS - gas consisting mainly of nitrogen, hydrogen and carbon monoxide, with trace amounts of methane and the rest is TAR and various levels of CORROSIVE ASH. 
2) Who is responsible for misleading definitions of BIOGAS presented at: a) b) 
3) Is it possible to fulfill the following objectives with basic knowledge overridden? 
a) The European Union is undergoing a profound transformation, in moving from an industrial to a knowledge-based society. 
b) Identify promotional and catalytic actions needed for delivery of a sustainable knowledge society. 
Do you agree with me and Ruzena that biogas, is NOT SYNGAS?

Do you agree that all authors that seek to publish scientific papers purporting to describe "biogas" should be asked to correct their use of this term unless it refers to biogas from fermentation/ the Anaerobic Digestion process?

PLEASE add your views to the comment box below, and help us avert this danger to the clear understanding by all that use of the term " biogas" should be for the sustainable product, in my definitions, and so that biogas can continue to be be easily understood to be so by the general public.

Ruzena is from the BTF-Biological TransFormation of Renewable Organic Material, Ruzena Svedelius AgrD, Nöbbelövs Torg 29, SE 226 52 Lund, and a member of the Board Member of Aktion Skåne-Miljö; NGO for protection of cultivated soils, Member of World Toilet Organization, Member of Soroptimist Club in Lund

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