過熱水蒸気を用いる炭水化物の炭化特性 <ノート>

Carbonization Characteristics of Hydrocarbons Treated in Superheated Steam

鈴木 寛一

伊藤 剛

羽倉 義雄

日本食品工学会誌

Three types of hydrocarbon (potato starch, glucose and cellulose) were carbonized by superheated steam treatment, and their carbonization characteristics and reaction kinetics were investigated. To minimize the influence of the rate of heat transfer into the materials, fine powdery samples were used. Carbonization temperatures ranged from 498 K (225°C) to 548 K (275°C). Potato starch melted and swelled at around 225°C, and carbonization proceeded with foaming of the sample. Glucose melted and swelled within a few minutes after treatment, and carbonization proceeded in a foamy state. Cellulose was carbonized without melting, and a powdery charcoal product was obtained. The carbonization rates of the three samples obeyed a first-order rate equation. The activation energies for carbonization, evaluated from the rate constants, were in the range 133~167 kJ/mol, which is almost the same as the activation energies for,thermal decomposition of starch and cellulose under nitrogen gas.

3種類の炭水化物(バレイショデンプン, グルコース, セルロース)を過熱水蒸気中で炭化させ, その炭化特性と炭化速度を検討した. 試料内部への伝熱速度の影響をできるだけ少なくするために, 試料を微粉末状にして実験に供した. 炭化は, 498K(225℃)から548K(275℃)の温度範囲で行った. バレイショデンプンは, 225℃付近で溶融・膨化し, 泡立ちながら炭化が進行した。グルコースは, 処理後数分で溶融・膨化し, 泡立ちながら炭化した. これに対してセルロースは, 溶融することなく, 粉末状態のまま炭化した. 各試料の炭化速度は, 一次反応速度式に従い, 速度定数から求めた炭化の活性化エネルギは133～167kJ/molの範囲であった. この値は, 窒素ガス中でのデンプンとセルロースの熱分解の活性化エネルギとほぼ同じであった.

superheated steam treatment

carbonization

hydrocarbons

rate constant

activation energy

製造工業 [ 580 ]

日本語

日本食品工学会

[ISSN] 1345-7942

[NCID] AA12076107