Diffusion mechanism of hydrocarbons within zeolite in high pressure liquid phase and supercritical fluid

2018 Fiscal Year Final Research Report

• Project/Area Number: 17K14856
• Research Category: Grant-in-Aid for Young Scientists (B)
• Allocation Type: Multi-year Fund
• Research Field: Reaction engineering/Process system
• Research Institution: Hokkaido University
• Principal Investigator: NAKASAKA Yuta 北海道大学, 工学研究院, 助教 (30629548)
• Research Collaborator: KUBOTA yoshihiro ; INAGAKI satoshi ; MASUDA takao
• Project Period (FY): 2017-04-01 – 2019-03-31
• Keywords: 拡散機構 / ゼオライト / 亜臨界・超臨界流体 / 芳香族化合物

Outline of Final Research Achievements

In this study, measurement method for diffusivity of aromatics within zeolite pore under sub- and super-critical conditions by constant volumetric method was established. Above 200 degree C, diffusivities of these cyclic hydrocarbons within pure silica zeolite (silicalite-1 and Si-beta) were decreased with increasing measured temperature and took minimum value around critical temperature of solvent. Generation of diffusion molecule-solvent cluster enhanced diffusion resistance at pore mouths leading to decrease the diffusivity. Toluene diffusivity within K-ZSM-5 was increased with increasing acid site of zeolite. Formation of diffusion molecule-solvent molecular cluster is considered to be suppressed by toluene adsorption on zeolite acid site.

Free Research Field

化学工学

Academic Significance and Societal Importance of the Research Achievements

これまで未解明であった高温高圧液相～亜臨界・超臨界流体中でのゼオライト結晶内拡散係数を測定することに成功するとともに，拡散機構を検討した．本測定手法を活用することで，液相および亜臨界・超臨界流体中におけるゼオライト内における様々な物質の拡散係数，拡散機構の情報が明らかにできる．本研究を通して得られる知見を活用することにより，これまでは経験的に行われてきた亜臨界・超臨界流体が関わるゼオライト触媒を用いた反応プロセスや触媒の設計に貢献できると期待される．