• Biotechnology and Bioprocess Engineering:BBE
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• v.5 no.3
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• pp.196-201
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• 2000

Lactic acid is of interest as the raw materials of polyactide that is a biodegradable polymer. For an effective purification of acid, batch distillation with the simultaneous reactions was used. Two Oldershow colums and reboilers were usde for fractionation of methanol and reactions. Two Oldershaw columns and reboilers were used for fractionation of methanol and reactions. Esterification reaction of lactic with methanol produced methyllactate and water. The productes of the esterification reaction, methl lactate and water were transported to the reboiler of the reproysis part. In hydroduced in the hydrolysis part and nureacter method lactic acid and methanol. Methanol produced in the hydroysis part and unreacted method lactic acid and methanol in the esterification part were separated by distillation and recycled to the revoiler of the esterification part so that the esterification reaction would be stimulated. Thus, pure lactic acid solution remained in the reboiler of the hydroysis part. The effect of the number of stages in column on the recovery yield was also inverstigated. In the operation with colums improved the fractionation of componets and stimulated the reactions in two parts.

• Applied Chemistry for Engineering
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• v.33 no.6
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• pp.588-593
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• 2022

The effects of P₂O₅-doped on the surface of MgO particles on hydrolysis, water repellency, and insulation behavior were investigated. P₂O₅-doped MgO has exhibited a unique electrical property, which is significant insulation behavior due to both the suppression of the hydrolysis reaction by P₂O₅ and water repellency. Therefore, the insulation behavior was inversely proportional to the hydrophilicity and the Mg(OH)₂ and OH^-charge transfer ratio by the surface hydration reaction of MgO. The insulation of MgO according to aging was strongly influenced by the surface hydration reaction, the band gap of the added dopant species, and the hydrophilicity and hydrophobicity of the dopant. Finally, it was to show electrical insulation by inhibiting the surface hydration reaction of the hydrophilic MgO, which has a great potential for use in heat transfer medium applications.

• Applied Chemistry for Engineering
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• v.10 no.7
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• pp.1020-1027
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• 1999

Heteropoly acid(HPW) catalysts supported on three different carriers, an amorphous silica, MCM-41 and MCM-48, with different loadings and calcination temperatures have been prepared and characterized by X-ray diffraction, nitrogen physorption, infrared spectroscopy, and $^{31}P$ magic angle spinning NMR. From the result of IR and NMR, it was shown that HPW retains the Keggin structure on the supported catalysts. No HPW crystal phase was developed even at HPW loadings as high as 35 wt % on the MCM-41 and 65 wt % MCM-48. Thus, HPW appeared to form finely dispersed species. In the hydrolysis reaction of di, bis, tri-pentaerythritol, HPW/MCM-41, 48 exhibited higher catalytic activity than $HPW/SiO_2$ or HPW.