Treatment and utilization of carbon dioxide have globally been an innovative direction of environment technologies. It is a worthy innovative technology that carbon dioxide stored inside deep geological reservoirs is converted to energy methane by methanogens. In the first year, the project is aimed to develop the basic technology of conversion of carbon dioxide to methane under 100 atm condition. According to the project, some results have been obtained: 1. Five freshwater methane-producing cultures FJ01、03、07、10 and 14 as well as 4 marine cultures KM1、2、3、5 and 9 were obtained in the project. The methane-producing culture FJ10 was chosen for further studies. 2. By fractional fractorial design yeast extract was identified to be a positively significant factor for FJ10 affecting the conversion of carbon dioxide to methane. Methane-producing culture FJ10 was found to had the optimal methane production when grown at the concentration of 5.0 g/L of yeast extract. 3. The methane-producing culture FJ10 was found to had the optimal methane production when grown at pH 8.0 and temperature 40oC. 4. When grown in the 150 ml-vessel with 150 ml medium, the methane-producing culture FJ10 had the optimal methane production rate of 1.452 μmole-CH4 /ml-medium/day. 5. When grown in the 30 ml- vessel with 29.7 ml medium, the methane-producing culture FJ10 had the optimal methane production rate of 1.075μmole-CH4/ml-medium/day and 0.976μmole-CH4/ml-medium/day under 100 atm and 1 atm, respectively.

carbon dioxide, greenhouse effect, methanogens