EVALUATION METHOD OF ENVIRONMENTAL EFFECT OF BIOGAS PLANT INTRODUCTION ON CARBON AND NITROGEN CYCLE

Abstract

 This paper proposes a method for quantifying environmental effects of introducing a biogas plant. This method quantifyies the effects of introducing a biogas plant by clarifying the details of the carbon cycle and nitrogen cycle in a dairy area and comparing GHG emissions and nitrogen leaching into the ground before and after introduction of biogas plants. In order to analyze the carbon and nitrogen cycles, calculation conditions for evaluation were assumed based on available statistics and filed data. The proposed model was applied to a virtual dairy area with 40,000 milk cows in Hokkaido to evaluate reduction of GHG emissions and increase of nitrogen leaching quantitatively. The validity of the proposed method was discussed to clarify items to improve evaluation accuracy.