Market Potential of Power Production from Anaerobic Digestion of Animal Manure in Canada

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Objective(s)

This Natural Resources Canada (NRCan) project was divided into two parts namely, the evaluation of animal manure resources in Canada and the analysis of GreenHouse Gas (GHG) emissions from manure management systems. The objective of the first part of this project was to compile statistical information to provide an understanding of the distribution of livestock and associated manure quantities throughout Canadian provinces. The objective of the second part of this project was to acquire an understanding of the energy and GHG emission reductions from manure, using anaerobic digester technology.

Description

For the first part of this study, statistics were compiled to identify regions with current or future manure management issues. Livestock production, manure storage systems, manure production and intensity, and GHG emissions from manure management systems were examined. The structure of the hog and dairy industries and the agro-environmental regulatory framework were also of interest. The second part of this study involved examining the market potential of technologies generating power from animal manure. This consisted of reviewing Canada's GHG Emissions Inventory for agriculture, reviewing Environment Canada's calculations and methodology for GHGs from animal waste, and producing a schematic of GHG emission pathways from agro-systems.

The federal government's Technology and Innovation Research and Development (T&I R&D) Initiative has two areas of interest: distributed energy and biotechnology. Since NRCan requires ample information on animal manure in order to develop strategic documents, the compilation of statistics was imperative. Beef, dairy, and hog sectors were identified as the primary producers of Canada's manure. The distribution and quantity of beef cattle, dairy herds, and swine populations were determined; the use of manure storage systems including solid and liquid management systems were evaluated; and provincial manure producers were identified and classified in terms of low, medium, and high intensities of manure production. In general, it was determined that Canadian steer inventories are primarily prevalent in Alberta and Ontario, dairy in Ontario and Quebec, and swine in Quebec, Ontario, Manitoba, and Alberta, respectively.

Manure intensity (density) is a leading indicator of potential environmental or economic problems associated with its management and disposal. Manure intensity was evaluated in order to identify areas subject to economic and social benefits from advanced manure management technologies. Using Canada's GHG Inventory (2000) and IPCC (Intergovernmental Panel on Climate Change) (1997) emission factors, carbon dioxide emissions were calculated for the agricultural sector and compared with national emissions.

Canada's dairy industry operates within the context of a regulated supply-management system that focuses on domestic markets. This system was found to have removed many risks that are common to other sectors leading to a relatively stable and profitable industry. Canada's hog industry is heavily export driven and is based on a system of bilateral contracts and/or open market trading of hogs. The hog industry was found to be subject to many production and market risks particularly those associated with global international trade. Provinces with significant livestock production adopt comprehensive legislation to help manage various social and environmental factors associated with intensive livestock operations. Such regulations are intended to prevent the direct or indirect pollution of air, water, or soil; provide standards for siting of new operations; and direct manure management practices including storage and land application of animal wastes. Quebec was found to have adopted a phosphorus standard for manure disposal, "Limited Activity Zones", which effectively prohibits herd expansion without full treatment of animal wastes and the export of nutrient products out of these zones. No GHG emissions mitigation regulations were identified for farm operations. Through the Agricultural Policy Framework (APF), the Government of Canada in conjunction with provincial governments and the agriculture and agri-foods industry, initiated the development of a comprehensive agricultural policy intended to increase the profitability of the sector. Issues related to particulates, odours, and GHG emissions are of particular interest within this framework.

Based on the National Inventory System, approximately 9.5% of Canadian GHG emissions are attributed to agricultural production activities¹. Emissions from agriculture are primarily nitrous oxide associated with fertilizer and animal manure use, and methane associated with cattle and livestock manure. Areas showing promise to reduce GHG emissions include crop nutrient management, livestock nutrient management, manure management, and biofuel use. In general, Canadian agriculture operates in global markets with very narrow margins. Given these limitations, it was determined that the most viable means of achieving reduction in agricultural net GHG emissions is to create and promote technologies that increase profitability and that can be voluntarily adopted.

While some profit-making technologies that reduce GHG emissions do exist, the adoption strategy must conduct to discovering and to developing new cost-effective GHG reducing technologies. GHG emission reductions require both government and industry action. It was found that technology for capturing, flaring, and utilizing biogas for power generation in the 1MW-5MW range is well developed in the world and could be cost effective for large feedlot operations in Canada. Small farm operations with animal populations of less than 1000 head however, are better suited in power generation from biogas in the range of 1kW-100 kW. While there are a variety of technologies in this generation range, their ability to tolerate impurities while keeping costs at a minimum precludes most of them. Reciprocating engines, microturbines (commercially available), and stirling engines (an emerging technology) are suited for small farm operations and have their respective limitations. It was determined that CHP (Combined Heat and Power) demonstration projects for small farm operations in conjunction with microturbine manufacturers are needed in Canada.

A limiting factor of this research was the accuracy of estimates for GHG emissions associated with manure handling, storage, and land application as IPCC emission factors may not have been applicable in all cases as a result of the diverse characteristics of Canada's climate and livestock industry. The lack of knowledge of known effects of many technologies currently employed was also limiting.

Significant Outcomes

Statistics on current manure management practices help foster an understanding of common practices that are useful in the development of environmental baselines and assessment of the impact of policies that in turn encourage alternative practices. The agricultural sector has adopted technologies that have reduced GHG emissions for environmental and economic reasons. More efficient technologies will reduce direct GHG emissions. It is believed that the APF may also provide an excellent entry point to introduce and discuss management or technology initiatives related to GHG emissions from this sector.

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¹The approximation does not include the use of fossil fuels or indirect GHG emissions from fertilizer production.