微量成分を含む蒸留計算

Distillation Calculations with Trace Components

吉田 英人

山根 博

頼実 正弘

石油学会誌

蒸留塔内部での微量成分のピーク位置の予測および抜き出し手法を緩和法を用いて数値計算により検討した。抜き出し手法に関しては, 従来は単一段の液相をサイドカットした場合について論じられていたが, 複数段からサイドカットした場合, および気相をサイドカットした場合の特性を新しく検討した。

さらに気相側および液相側をサイドカットした場合の分離効率および熱力学的効率を検討し, 気相をサイドカットした方が分離効率および熱力学的効率が向上する領域が存在すること, およびサイドカット段を下げると熱力学的効率は良くなるという新しい知見を得た。

The relaxation method was used for the distillation calculations involving trace amounts of a component in the n-Butanol-Water-Methanol and n-Propanol-Water-Methanol systems.

Tables 2, 3 indicate that the temperature of the stage, where the amount of the component becomes maximum, is approximately constant and the mean value is 83.1°C for the n-Butanol-Water-Methanol system, and it is 77.9°C for the n-Propanol-Water-Methanol system. It is also found that these values are independent of the location of the feed stage.

In the case there is no side cut, the equilibrium ratio of the trace component at its maximum concentration, can be estimated by Eq. (8) and Eq. (10) at the stripping and rectifying sections, respectively. The calculated results are shown in Table 4 for different reflux ratios.

Figs. 4, 5, 6 show that concentration profiles of the trace component in the column are nearly equal whether the number of liquid side-cut stage is one or two when the total amount of side cut is the same.

Both Figs. 7, 8 give the relation between separation number defined by Eq. (11) and side cut stage for various side-cut flow rates. These figures show that there exist optimum values for the side-cut stage and side-cut flow rate.

The effective side-cut stage is an intermediate stage located between feed stage and the stage where the amount of the trace component becomes maximum for the no side-cut case.

Figs. 9, 10, 11 indicate that there exists a region where both the separation and thermodynamic efficiencies for the vapor side cut case are higher than those for the liquid side cut case.

Distillation

Calculation

Trace component

Side cut

Thermodynamic efficiency

化学工業 [ 570 ]

日本語

石油学会

Copyright (c) 1981 (社)石油学会

本文データはJournal@rchiveから複製したものである

[ISSN] 0582-4664

[NCID] AN00130954

[URI] http://www.journalarchive.jst.go.jp/japanese/jnlabstract_ja.php?cdjournal=jpi1958&cdvol=24&noissue=3&startpage=173