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Ulster Researchers Turning Domestic Food Waste into Energy

13 February 2013

University of Ulster researchers are working on a more effective way to turn discarded food waste into gas for use in homes across Northern Ireland.

Working alongside researchers from the Tata Energy and Resource Institute (TERI) in India, a team from the School of the Built Environment is hoping to create an anaerobic digester, which will use solar energy over a sustained period of time to generate gas from domestic organic waste for small scale applications such as barbeques or heating greenhouses.

Generally, anaerobic digesters, which convert waste like vegetable and fruit peelings, work best when maintained at a constant temperature in hotter climates.

However the cooler climate in the UK and Ireland means that additional heat must be added to the bio-reactor.

The new Solar Augmented Anaerobic Digester – pioneered at the University of Ulster – harnesses solar energy to heat the bio-reactor and retains that heat for a longer period thanks to its innovative design.

Dr Mervyn Smyth, a Reader from the School of the Build Environment has been working on the project along with lecturers Dr Jayanta Mondol and Mark Anderson and Dr Aggelos Zacharopoulos, a Research Fellow in the Centre for Sustainable Technologies.

Dr Smyth has already had a great deal of success with his research into harnessing and retaining solar energy for the domestic market through the development by Ulster researchers of SolaCatcher – a a cost-effective, patent pending vacuum system, which acts much like a thermos flask and can be used to heat water supplies in homes.

This easily installed, passive system enables the collection of solar energy during the day and provides insulation to keep water warm for a sustained period of time.

Dr Smyth explained that while there are several good examples of large scale anaerobic digesters in Northern Ireland, the University team is hoping to break down the technology to adapt it for household use.

"My initial aim is to develop a small scale anaerobic digester which could potentially be placed at the bottom of a domestic garden,” he revealed.

“This type of system already exists all over India.

“There, householders collect food scraps and dispose of them in a bio-reactor tank. The naturally warm climate heats the anaerobic bacteria which breaks down the organic material over a prolonged period of time to produce two elements.

“Firstly, the process creates a gas which many families use for cooking, heating water and even for domestic lighting. Secondly, the residue is a good, organic fertiliser which is put back onto the land.

“With our SolaCatcher inspired knowledge and the technology already adapted in India during the past 15 years, we hope to create a system which controls the digestion process, breaks down the material more efficiently and, therefore, yields more gas in a shorter time.”

Dr Mondol is the project principal investigator and has over 10 years extensive research experience in the area of solar systems, thermal storage, solid fuel gasification and sustainable building products.

“The main benefit of working with TERI is they have a grounded, practical knowledge of anaerobic digesters,” he said.

“We can learn a lot from their experience, which will help us to develop a successful system to suit Northern Ireland’s needs and climate.

“By amalgamating the expertise from India with our expertise at Ulster, we will be able to explore a whole new range of anaerobic related, energy solutions.

“In the future, we also hope to forge a greater collaboration with TERI and to work with them in other areas of research into sustainable energy.”

Research is due to culminate within the next few months, when an expert from TERI will visit the University of Ulster on an industrial placement.

He will assist in setting up a prototype which will be tested in an outdoor environment.

Notes to Editors:

University of Ulster researchers are working alongside TERI in the UK-India Education and Research Initiative (UKIERI) project ‘Solar Accelerator Design for Small Scale Bio-gas Production’ which is funded by the British Council.

TERI is involved in the development of various technologies for solid and liquid waste treatment through anaerobic digestion.

The New Delhi-based group established the ‘TEAM’ system (TERI’s Enhanced Acidification and Methanation) which is used to break down a surplus of domestic waste, fruit and vegetable market waste and semi-solid municipal waste and convert it into gas and organic fertilizer.

TERI aims to develop solutions to global problems in the fields of energy, environment and current patterns of development, which are largely unsustainable.