The assessment of a Novel Nitration of Benzene and Toluene

• Main Authors: Chun-ming Yan, 顏俊明
• Other Authors: James I. Chang
• Format: Others
• Language: zh-TW
• Published: 2002
• Online Access: http://ndltd.ncl.edu.tw/handle/81186803109090519097

碩士 === 國立高雄第一科技大學 === 環境與安全衛生工程所 === 90 === ABSTRACT Nitroaromatic compounds are widely used as the feedstocks for a great many materials, such as pharmaceuticals, dyes, perfumes and plastics. Since the conventional nitration processes that occur in the mixture of concentrated nitric and sulfuric acids are highly dangerous and produce excess waste acids difficult to recover, it is ideal to find alternative processes. Recently a few studies show that acetyl nitrate prepared from a stoichiometric quantity of nitric acid and acetic anhydride was an effective nitration agent and used zeolite CP-814E as a catalyst. This alternative process is definitely worth of further investigation. The purpose of this research program is to study the physical chemical properties, of a such as reaction thermal assessment, kinetics analysis, reaction parameters（temperature, speed of agitate）effect of the zeolite catalyzed nitration of benzene and toluene. The program will provide necessary data for future scale-up and development work, accelerate the commercialization process, and promote the R & D of green chemistry. Benzene and toluene are nitrated in excellent yields （more than 95﹪）with high regioselectivity under mild conductions using zeolite CP-814E as the catalyst and a stoichiometric quantity of nitric acid and acetic anhydride. Nitration of toluene gives a quantitative yield of mononitrotoluenes, of which 45﹪is 4-nitrotoluene. The reaction calorimeter experimental data show that the zeolite CP-814E can reduce the activation energy. In the benzene nitration, the reaction was 1.2 order on benzene and the heart of reaction was 115.6 kj/mole; in the toluene nitration, the reaction was 1.4 order on toluene and the heart of reaction was 135.67 kj/mole. The new process has several advantages. The zeolite CP-814E can be recycled; the products can be separated by vacuum distillation and the only byproduct is acetic acid, which can be used to make acetic anhydride at higher temperature. Since acetyl nitrate will decomposes at 55℃, the reaction temperature has to be controlled below 30℃.