Designer and manufacturer of gas analysis equipment, Gas Data, shows how to maximise investment in AD. Chris Dakin Gas Data’s managing director reports.
The key to making money out of AD is getting the analysis of biogas right.Even though anaerobic digestion has been around for over one hundred years, the actual process of harnessing energy from it is still relatively young, with new lessons being learnt every day.
Primarily people have taken to the anaerobic digestion industry because there is money to be made from renewable energy. It’s a great investment if you get your key principles right. And Coventry-based Gas Data has more than 18 years of experience within the design, engineering and production of gas analysis equipment.
With the industry still in its infancy, a practice has developed of buying top quality digesters and combined heat and power units, but the important gas analysis factor has sometimes been overlooked. But Gas Data argues that to make the most out of biogas, you need to know your exact levels of methane, carbon dioxide, oxygen and hydrogen sulphide. If you don’t know these accurately, your operation may not turn out to be as profitable as you had thought. This is where gas analysis can help you analyse your biogas to make sure your AD plant is operating at its optimum.
Methane, as the prime energy source is the obvious gas that everyone thinks about when it comes to profit as this is what makes electricity that can be used or sold to the Grid. But biogas will almost always contain sulphur in the form of hydrogen sulphide gas, says Chris. This gas is odorous, poisonous and is the source of metal corrosion when present in both its raw form and when combusted in the engine to form sulphur dioxide (SO2). Any unusually high levels containing harmful acids will make the engine break down. You only make money when your engine is running so reducing down time is essential.
The AD market is now growing to include smaller scale operations and the farming community is starting to engage beyond the early adopters we have seen so far. But failure to invest in good quality analysis equipment is short sighted because without it you cannot hope to ensure the greatest return on your investment.
Advantages of analysis
Another advantage of analysing biogas is that a comparison can be made between different materials to determine the most effective mix for maximum production of methane.
Gas Data customer, Reaseheath College near Nantwich in Cheshire, has built a demonstration facility based on two small scale, low capital systems that can be replicated commercially on farms or in horticultural businesses.
The AD plants (one Continuous Stirred Tank Reactor one ‘plug and play’) provides a practical example that farmers, students and industry can learn from. The gas analysis equipment enables a basic comparison between crops and slurry in the production of methane and a more sophisticated analysis of the gas output using a mix of different amounts of manure, silage, slurry and grain.
“We’re trialling new methods and mixes so farmers can benefit from our successes without the risks,” says the College’s sustainable technologies specialist Daniel Galloway. “If we can provide data on the optimum recipe for the maximum energy production it ensures farmers can make an informed judgement on their investment.”