Reaseheath College AD plant
Gas Data, the Coventry-based gas monitoring company, is taking part in a project to assess the viability and use of an anaerobic digestion plant on an agricultural site. 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’) provide a practical example that farmers, students and industry can learn from. Gas Data have provided their fixed site biogas monitoring, the Click! System, and their portable biogas analyser, the GFM416. Which allows a basic comparison to be made 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.
All of the data provided by this fixed site gas monitoring system can be seen on-line by Reaseheath College using a password protected site. In brief, the geographic overview given on this secure page shows the amount of gas being produced by each digester and showing the percentages of:
- Methane – the prime energy source (55-65%)
- Carbon dioxide – an inert gas (35-45%)
- Oxygen – in small residual quantities (<0.5%)
- Hydrogen sulphide – always present, but large concentrations are very harmful to the plant’s engines (0-1%)
It is important to monitor each gas to ensure site optimisation and efficiency, importantly the hydrogen sulphide levels must be monitored so that any unusually high levels containing harmful acids can be prevented from reducing the performance and lifetime of engines.
Daniel Galloway, the College’s sustainable technologies specialist:
We’re trialling new methods and mixes so farmers can benefit from our successes without the risks. 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.
Gas Data have provided us with a remote system that uses online monitoring to look at the effects of not just the inputs to the AD unit but also those caused due to weather conditions. We are currently getting 35m³ of biogas per tonne of slurry – significantly higher than average.
Gas Data managing director, Chris Dakin, is pleased with the project so far:
The development of renewable energy by the AD industry is dependent on smaller scale operations being adopted by the agricultural community, so education reduces the risks for the farmers. Our equipment is allowing detailed analysis of which feedstocks are most profitable – essential knowledge for anyone considering the substantial investment involved.
Electricity produced from the system is directed to an on-site sub-station and will supply around 15% of Reaseheath’s total campus demand. The £900,000 demonstration plant was part financed by The Rural Development Programme for England and supported by Defra, the North West Regional Development Agency and the European Agricultural Fund for Rural Development: Europe investing in rural areas.