| This problem task is a subject funded by Henan natural science fundation. Methylhydroquinone is a new kind of important product of fine chemical engineering , which has a prosperous future in many fields, such as liquid crystal, medicine and organic synthesis. As an important organic intermediate, the real problem, which is anxious to settle, is how to put it into commercial process as soon as possible to meet the demand in the develop of fine chemical industry. From which, we can see that commercial process of methylhydroquinone has not only practical significance, but also remarkable benefits in economy and society.There are no literature or report on the field of synthetic process of methylhydroquinone in the country, except the elementary progeny in the research of this laboratory. By consulting reference literature, we find that there are investigative reports about synthesizing methylhydroquinone in the countries of Japan, the U.S.A. France, and so on. But in these reports, some processes are difficult to realize because of hard reacting conditions; some have complex operation and the conditions are difficult to control; some has ordinary program, but the yields are too low; and so on. Because of all of this, there are seldom reports about commercial process, up to now. This text does some farther researches towards the existed problem in the original technical process, which has been sexploited successfully to use para-methylnitrobenzene as the basic crude materials to synthesize methylhydroquinone.At first, according to the characteristics of the physical properties of the component involved, cooling suction screening method is adopted to pass over the concerned steps of decompressed distillation and extraction, which reduces the quantity of the water added to half, and recycle the raw material unreacted in the reacting mixed-liquid. The technical process improved not only shorters the original manufacture! cycle to third, debase the energy consuming greatly, but also easies the operation, which is easier to put into industrialization.Secondly, under the help of the orthogonal design method, the key factors in the optimized technical peocess are confirmed which effect this complex reaction, the influences of every factor towards this synthesis reacting are discussed, the Quantitative Correlation Equation is established. According to the established equation, the optimum conditions of this technics are got. The maximum yield of methylhydroquinone under the optimum conditions is 56.11 %, which is identical approximately with the original technical process. Compared with the yield abroad, under the same condition, this one has raise 5 %.Thirdly, the key approach in this process has been in further discussion, which is production extraction. In the process of distilling methylhydroquinone, using ethyl oxide as solvent, self-designed laboratorial equipment of extraction and phase-balance is adopted. The mensuration of balance-solubility of the ternary systerm is carried out, which is composing of H2O, C7H8O2 and C4H10O, under the temperature of 25C. Through which, the data of balance-phase is gained. The distributive curve of methylhydroquinone in ethyl oxide and water is protracted, as well as H2O-C7H8O2-C4H10O ternary balance-phase diagrams of the system. Through which, a certain of designing data and technical proof for engineering design and industrialized process are provided.In addition, through mass of literature consulting and sample analysis using gas phase chromatography. a new kind of means to quantificationally analyze methylhydroquinone is fixed on, using external reference method, combined with subtraction method of mass conservation.In a word, in this text, we put forward a new kind of technical process to syntheticmethylhydroquinone. In the experiment, the solubility data of methylhydroquinone in ethyl oxide and water is measured, H2O-C7H8O2-C4H10O ternary balance-phase diagrams of the system is protracted, concerned analyzing method is established. Through which, nec... |
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