Producing Biogas from AD. Don’t fly blindfolded

With some sources predicting a boom in UK biogas production youd be forgiven for thinking that all of technical issues had been ironed out. In fact every biogas plant is different and it takes some skill and the availability of accurate and timely data to keep them efficient.

In the first of a short series of articles Chris Dakin, who has been at the heart of Gas Datas innovative gas analysis technology for over 20 years, takes a look at what needs to be measured and how.

Operating a biogas plant without gas quality and flow instrumentation is like trying to fly a plane blindfolded an experienced pilot may be able to keep the plane in the air for a while through sheer skill, feel and a few helpful hints from the control tower but landing safely on the right airfield will be more likely a miracle.

Where is your biogas plant going to land?

The technique of using bacteria under anaerobic conditions to convert a wide variety of carbon based bio-materials into methane gas has been used for decades yet its unappealing association with the treatment of sewage and animal slurry has left it largely ignored as a solution for clean, green energy generation. But that is changing dramatically on a global scale.

Almost daily, news about the need for secure and environmentally acceptable energy sources at competitive prices is to be found in the national and politicalpress. In 2010 the change of UK government brought a fresh emphasis on this technology and the race is on to catch the world leaders who are to be found predominantly in Germany. The aspirations of the Anaerobic Digestion and Biogas Association (ADBA) are for 2000 new biogas plants to be constructed in the UK by 2015.

Anaerobic Digestion tanks

Modern biogas plants require significant capital expenditure and are carefully planned around expected efficiencies and tariffs to predict both the return of capital and on going operating profits. It is typical for plants to target payback of capital within a three to five year period.

The attitude that energy from waste is energy for free is no longer the norm. Feedstocks all come at a price and operational costs need to be controlled. The prime energy gas from the anaerobic digestion process is methane. Depending upon the plant size, increasing the the methane quality by just 1% may easily equate to hundreds or thousands of pounds of extra revenue.

This means that understanding both output level and quality are essential in terms of plant management, operational effectiveness and financial reward. How do you do that? Well putting in place the measurement equipment and the right analysis processes is a good start.

In the next part of the series well explore the principles of accurate flow rate measurement and why that has implications for your financial calculations.

If you have any questions about the measurement and monitoring of biogas thencall us today on+44(0) 247 630 3311or via