Vapor-liquid-equilibrium (VLE) at normal pressure for the system formed by n-heptane, benzene and N-methyl-pyrrolidone (NMP) are investigated. The results show that NMP is a good extractive solvent that reverses the volatility of the binary system of n-heptane + benzene. A UNIFAC model is selected and proved that the group interaction parameters are reliable. A modified extractive distillation (MED) process, in which a little of water is added to lower the boiling point of reboilers in aromatics recovery column, is proposed on the basis of the original extractive distillation (OED) process. The process simulation shows that the proposed process raises the yield ratio of benzene from 94.2% to 98.2%. Since the modification is not complicated, the MED process have a lasting value in industry.

Oxidation of vanadium pyrophosphate (VPO) to the orthophosphatewas investigated by temperature programmed oxidation (TPO) and by weight gain measurements in a TGA unit as a model for the re-oxidation of a catalyst in a two-bed process in the partial oxidation of butane to maleic anhydride (MA). It was demonstrated by FTIR observations that the weight gain corresponds to the VPO oxidation. The results of separate measurements of a catalyst alternatively exposed to oxygen and to a stream containing butane should also be applicable to a VPO catalyst employed in a two-bed process. The VPO oxidation measurements demonstrate that re-oxidation of a VPO catalyst in a two-bed process should be carried out at a higher temperature than the butane partial oxidation. When this is carried out, significant performance improvements in the two-bed process are observed.

A new separation method of reactive extractive distillation is proposed for the separation of isopropanol and water, using the mixture of ethylene glycol (C2H6O2) and glycollic potassium (C2H5O2K) as an entrainer. Vapor-liquid-equilibrium (VLE) measurements confirmed that the entrainer was effective for this separation. Using a feed/solvent volume ratio of 1:1, isopropanol with a concentration over 96.0% weight fraction was obtained by the reactive extractive distillation process and the azeotropic point was eliminated. A novel process of separating isopropanol and water is designed on the basis of reactive extractive distillation to obtain the product with different concentrations, which may have a lasting value in industry.