Abstract:
To meet the rapid and increased demand for animal protein, intensive poultry and livestock farming units are growing quickly in many developing countries in Asia. To access the markets, such production units are primarily located in peri-urban areas where available land for manure treatment and/or recycling back to the soil is limited, thus leading to serious environmental pollution. Although poultry manure from these farms is readily used as organic fertiliser for the production of cash crops, pig manure is usually washed and discharged, with or without treatment, into nearby streams and rivers. Efficient treatment of wastewater from pig farms with limited land is very expensive as it normally requires some degree of artificial aeration. Although it has long been proven that the biogas produced from the anaerobic lagoons can be converted to reusable fuel for heating and/or the generation of electricity for the farm, the technology has not been well received by farmers because they have easy access to other cheap energy sources. However, due to the opportunity of gaining extra monetary return from carbon credit trading under the initiative of the Kyoto Protocol, many pig farmers are beginning to show interest in this technology. From a recent feasibility study conducted in Malaysia to assess the technical and economic viabilities of converting biogas from pig farms into electricity, the following challenges were identified: (i) the organic content of the wastewater generated from the pig farm was far below that required for the efficient production of biogas; (ii) the high costs required for the modification of the existing farm infrastructures and additional equipment made the project economically unattractive; (iii) the potential amount of electricity generated from such a project does not match the daily fluctuating electricity demand on-farm; (iv) current governmental policies and infrastructural supports to buy back the extra electricity generated from such a project are inadequate; (v) the misconception by farmers that recovery of biogas from an anaerobic lagoon will enhance the efficiency of wastewater treatment and thus improve the quality of their wastewater at endpoint to meet the governmental requirements for discharge; and (vi) the quantum sharing of the carbon fund by farmers and the carbon credit trading company.