Formation behaviors of CO2 hydrate in silica gels are investigated at various pressure and temperature conditions. In addition, a kinetic promoter of sodium dodecyl sulfate (SDS) is used in order to evaluate promotional effect on the formation behaviors in porous media. Formation rates and hydrate conversions are found to be large when higher pressure or lower temperature is used at a given temperature or at a given pressure, respectively. The formation rates are found to be affected more significantly when driving force larger than 1.0 MPa is applied. In addition, when the kinetic promoter is used, initial hydrate formation rates are found to increase so as to reach the final gas consumption more rapidly. Obtained results are expected to provide useful information for designing or evaluating a hydrate-based process using porous media. (C) 2009 Elsevier Ltd. All rights reserved.