Executive Summary
What is this Report About?
Australia’s National Greenhouse Gas Inventory estimates that on-farm activities (excluding energy use) produce around sixteen percent of overall national emissions. This is more than all of Australia’s transport based emissions, making the agricultural sector the second largest source of greenhouse gases after electricity production. Methane is the dominant agricultural greenhouse gas in Australia, with methane from livestock representing twelve per cent of national greenhouse gas emissions.

Approximately one quarter of those emissions of methane are from animal waste.

Methane is produced during the anaerobic (i.e., without oxygen) decomposition of organic material in livestock manure management systems. Manure deposited on fields and pastures, or otherwise handled in a dry form, produces insignificant amounts of methane.

Reducing methane emissions is one of the most cost-effective ways to realise immediate environmental benefits due to methane’s potency as a greenhouse gas.

Who is the Report targeted at?
This Report has been prepared for researchers and industry with an interest in methane capture and use.

Background
Detailed information regarding research and development activities in Australia and New Zealand into the capture and use of methane in intensive livestock industries is hard to come by.

Aims of the Report
This report brings together available information about methane capture and use research and development applicable to the intensive livestock industries in Australia and New Zealand and makes recommendations as to where future research and development should be targeted.

Methodology
Information has been sought by discussing relevant research activities with:

• research providers;
• research funding agencies;
• industry associations;
• industry members; and
• any other source of relevant information.

Results
Traditionally the most common manure management systems used in Australia have been treatment by anaerobic lagoons and direct application of manure slurries to land. The capture and use of methane has not traditionally been a priority in the decision making process; the issue of minimising odour has been a greater priority. Priorities are now changing due to environmental considerations and the potential to generate new farm income streams or reduce costs through the capture and use of methane.

The two principal methods of capturing methane are the use of covered anaerobic lagoons or the use of an anaerobic digester.

The use of the methane thus collected can vary from simply flaring the gas, this provides a relatively cheap option, while still providing environmental benefits as flaring converts methane into the less harmful, in greenhouse terms, carbon dioxide.

The more expensive, in capital terms, but potentially more beneficial, use of methane is to generate energy and/or heat that can be utilised on the farm or sold to energy users.

Research activities have to date been concentrated in the following areas:

• the design of covered lagoons;
• digester design;
• integrated farming systems; and
• the flaring of methane.

Lagoon design guidelines are still however based on Barth’s Rational Design Standard for anaerobic lagoons, which were formulated in 1985. Research and modelling is required to assess whether these design guidelines are still appropriate.

Any proposal to capture and use methane becomes more economical if greater quantities of methane are available. Therefore there is a need to continue research into how to increase methane yields.

The flaring of methane may be the only viable option for minimising greenhouse emissions for smaller farms. However cost considerations, resulting from Australian design standards, can be prohibitive, to even this simplest method of minimising greenhouse emissions. Research into how flaring costs can be minimised is essential and is the subject of another current project commissioned by RIRDC’s “Methane to Markets in Australian Agriculture” Program.

Impurities within the gas collected are an additional cost within any system of methane use. Biogas scrubbing systems are expensive to purchase, install and operate. Research into improving existing or developing new scrubber systems to minimise overall operating costs could make significant impacts on the economics of methane collection and use.

At present most projects use modified diesel engines for electricity generation. These systems are expensive to purchase and need to be regularly rebuilt. Porous burners are an alternative, however this Australian invention is in its infancy and are currently more expensive than commercial generation systems. Further research is required to prove their effectiveness and reliability for agricultural application.

Another alternative to the use of modified diesel engines is the fuel cell. Fuel cells currently operate at landfills and wastewater treatment plants in the United States, proving they are a valid technology for reducing emissions and generating power from methane. Further research is required to prove their effectiveness and reliability for agricultural application.

The potential to have multiple enterprises jointly develop methane capture and use facilities has not been fully investigated in Australia. In Europe feedlots are often closely located offering the potential of a cooperative approach that provides an economic scale. Research is required to prove the economics and technical feasibility of multi-enterprise waste management systems in Australia.

Carbon trading, or emissions trading, is a recently developed, market-based scheme for environmental improvement that allows parties to buy and sell permits for emissions or credits for reductions in emissions of certain pollutants. The intensive livestock industry needs to continue to monitor developments in respect of carbon trading, in order to ensure it maximizes the economic benefit, to the industry, that may be available from such trading.

The Methane to Markets International Expo is being held in Beijing, China between 30 October and 1 November 2007. The timing of the Expo provides RIRDC’s “Methane to Markets in Australian Agriculture” Program with the opportunity to consider international methane capture and use research and development activities, and assess their application in, or adaptation to Australian conditions.

Implications
The intensive livestock industries and policy makers will be better informed on options, strategies and technologies for capture and use of methane from the intensive livestock industries.

Recommendations
In order to maximise the economic benefit from future research activity funded by RIRDC’s “Methane to Markets in Australian Agriculture” Program it is recommended that the priorities noted in this Report be considered in conjunction with international research activities expounded at the Methane to Markets International Expo.