報告書番号

W00020

タイトル（和文）

石炭チャーのガス化反応速度解析 -第３報 二酸化炭素によるガス化反応における炭種の影響-

タイトル（英文）

The Gasification Rate of Coal Char with Carbon Dioxide- Influence of Coal Types on Gasification of Char -

概要 （図表や脚注は「報告書全文」に掲載しております）

加圧式粒子落下型気流層管状炉（PDTF）を用いて、二酸化炭素によるガス化実験を３炭種の瀝青炭チャーに対して実施し、高温高圧下におけるガス化反応速度を測定した。供試チャーはDTFを用いて1400℃の窒素気流中で微粉炭を急速熱分解することにより調製した。ガス化実験条件は、空気吹き２段噴流床石炭ガス化炉の炉内条件を想定し、温度1100～1400℃、圧力0.2～2 MPa、二酸化炭素分圧0.005～0.3 MPaとして、温度や圧力の依存性を明らかにした。細孔モデル Random Pore Model を用いた解析を行い、反応速度パラメータを得た。炭種により反応速度は１０倍程度の違いがあり、また、高温で粒子内拡散律速となり安い石炭となり難い石炭があった。これらの理由を炭素構造、細孔構造、鉱物質の触媒効果の観点からこの炭種による違いから検討した。

概要 （英文）

Three coal chars were gasified with carbon dioxide using a Pressurized Drop Tube Furnace (PDTF) at high temperature and pressurized conditions to simulate the inside of an air-blown two-stage entrained flow coal gasifier. Chars were produced by rapid pyrolysis of pulverized bituminous coals using a DTF in a nitrogen gas flow at 1670 Kelvin. Gasification temperatures were from 1370 K to 1670 K, pressures were from 0.2 to 2 MPa and partial pressures of carbon dioxide were from 0.05 to 0.3 MPa. As a result, influence of temperature and pressure on gasification reaction rate was made clear. The reaction rate was analyzed with the random pore model was used, and the kinetic parameters for char gasification with carbon dioxide were obtained. It was observed that chars had difference of ten times in reaction rate, and at high temperature as the reaction rate with carbon dioxide is about 0.03 s-1, the reaction rate of one char was controlled by pore diffusion, while that of another coal char was controlled by surface reaction. Surface pore structure of char particle, catalytic activity of mineral and crystal structure of carbon in char was analyzed to discuss the reason of these differences between coal types.

報告者

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