Talk of renewable energy technologies, particularly anaerobic digestion (AD), is spreading around the world like a green wave — a potential benefit to pig farmers.

Countries are devoting time and resources to alternative energy production and reducing greenhouse gas emissions because of international concern over global warming and climate change — and the uncertainty over the future availability and price of  oil supplies.

UK farmers optimistic

The United Kingdom is currently promoting AD not only as a means of helping pig farmers turn their slurry into energy and money-earning opportunities, but also as a way to help it deal with all its municipal debris and food waste. At the same time contributing to efforts to cut greenhouse emissions and reduce its national carbon footprint.

The UK government has appointed a special Biogas Task Force to work with stakeholders from the waste industry, local authorities and agriculture to see if it can develop a blueprint which will enable the country to build a network of AD plants to heat and power the nation economically, while at the same time help it to dispose of its waste safely in the new Green Age.

It is not yet known when the task force will complete its deliberations and report back to the government. No indication of when work on any proposals will start, but farmers in the UK are optimistic, describing the talks as the first step toward a renewable energy policy for the country.

And it’s not only Britain which is thinking this way. Countries such as Northern Ireland, Poland, the Czech Republic and Hungary as well as Canada and China are pushing forward including developing other technologies to help meet their future energy needs.


Pilot biogas plant

A pilot biogas plant is being used as a demonstration and education unit for pig farmers in Lithuania and other Baltic states.They are all following in the footsteps of major pig-producing countries such as Germany and Denmark, where AD is commonplace on many pig farms. It is used as a way of dealing with pig muck and excess energy crops such as maize (to enhance biogas production), as well as generating heat and power and reduce pollution.

Farmers in those countries have also found that after the slurry is degraded in the AD plant, the nitrogen (N) is in a form that is more readily available to plants, which mean more N is available for uptake in the early growing following field application after all the gas has been removed.

In addition to improving crops, this could also save money, reduce pollution and improve soils in the long term.

Not so easy

However, pig farmers have been reminded that AD is not quite as easy as it sounds. You can’t just bung something into a tank and hope you will be able to collect biogas through an extraction pipe after a few days.
A technician at the University of Aarhus’s biogas research station in Denmark, explained, One really needs a professional engineer to get the best out of AD. All the slurry and other waste used in the process must be properly stirred up and mixed to form a smooth liquid that flows easily. This prevents the whole system clogging up and also produces more gas more quickly.

At the same time one can spend many hours perfecting the right recipe of pig slurry, fibre and fatty content to produce the most gas. This all takes time and effort, so farmers who are thinking of investing in AD must be prepared to get involved with the process and devote enough time to it to ensure success.

The production of substrate (or feedstock) for optimum anaerobic digestion and biogas output requires thorough pre-treatment before it is pumped into the reactor plant. Different mediums and biomass must be mixed up completely and all harsh dry particles must be copped up to form a smooth liquid consistency.

The European Union is already firmly behind these moves, according to EU agriculture commissioner, Mariann Fischer Boel, “We need to find good pragmatic solutions to help farmers adapt to changing weather conditions whilst emitting less greenhouse gases. The overall vision of the European Commission is to create conditions that allow us to use, without using up.”

And with the United Nations Climate Change Conference in Copenhagen, Denmark, in December 2009, one can only hope this view prevails and gives farmers the confidence to invest in AD – a technology that allows them to turn their waste into power and plug the world into a sustainable source of heat and power.