Biogas to power pork production

An innovative biogas system, developed at NIWA Hamilton, New Zealand, has been embraced by the Australian pork industry. It provides an alternative electricity and heating source.

The Australian pork industry association, Australian Pork Limited (APL), has collaborated with NIWA and several pork producers to design and build covered anaerobic pond based biogas systems. So far, four systems are currently at various stages of construction.

NIWA worked in collaboration with the New Zealand Pork Industry Board and Energy Efficiency and Conservation Authority (EECA) on the New Zealand prototype.

NIWA identified that anaerobic digestion in covered waste ponds holds significant potential to reduce odour and greenhouse gas (GHG) emissions, while providing biogas as a local energy resource.

Australian pig farmers are incentivised to use the technology to reduce farm GHG emissions. The recently introduced Carbon Farming Initiative (CFI) allows farmers and land managers to earn carbon credits by storing carbon or reducing greenhouse gas emissions from the agricultural sector. These credits can then be sold to businesses with an emission liability, such as fossil fuel power plants or chemical processors.

“The system makes good sense,” says NIWA research engineer Stephan Heubeck, who has driven the development of the technology. “Anaerobic digestion in covered ponds holds significant potential to reduce odour and greenhouse gas emissions from the farming sector. At farm scale, this energy resource can be used for heating and/or to generate electricity.”

The first pond based biogas system that NIWA designed was a purpose-built 7000m3 covered anaerobic pond for Steve Lepper’s piggery in Taranaki, New Zealand.

NIWA’s simple and low cost design has proven effective and reliable over the last two years. At the Lepper piggery, the biogas is used for electricity generation and heating in a combined heat and power unit (CHP). As well as providing the majority of the piggery’s electricity needs during daytime, waste heat from the generator is used in a reticulated hot water system for keeping young pigs warm.

More information is available at: http://www.waikatoregion.govt.nz/effluentexpo

Bioenergy but not at the expense of food

FAO has just released a suite of guidance documents and policymaking tools that governments can use to help rural communities benefit from bioenergy development and ensure that biofuel crop production does not come at the expense of food security.

Materials released by FAO's Bioenergy and Food Security Criteria and Indicators (BEFSCI) Project include: methodologies for assessing the environmental and socioeconomic impacts of bioenergy production, indicators that can be measured when doing so, recommended good practices, and policy measures for promoting sustainable bionenergy development.

"In a few months the international community will gather for the Rio+20 conference to explore new ways to combat rural poverty and promote sustainable development. Undertaken responsibly and where appropriate, bioenergy production can offer farmers and rural people the opportunity to take part in building a new green economy, and can help counter the effects of decades of underinvestment in developing world agriculture and rural areas," said Alexander Mueller, FAO Assistant Director-General for Natural Resources Management and Environment.

But bioenergy development must avoid undermining food security, Mueller stressed. And deforestation due to the conversion of new lands to bioenergy crops as well as impacts on indigenous peoples are also issues of concern.

"Development of bioenergy must be carefully managed, and meeting social goals like sustainable rural development, poverty alleviation and food security should be guiding principles," he said.