Study On Preparation Of 2-Undecanone By Gas-Solid Catalysis

It is a kind of important reaction to prepare ketones through gas-solid catalysis. In the presence of catalysts, using same aliphatic acids or different acids as raw materials, ketones can be prepared in one step.2-undecanone , also called methyl-n-nonyl ketone , is a key intermediate to synthesize houttuynium, and 2-undecanone also can be used in organic synthesis and production of flavor. Because of the relatively high yield and easy operation, the most economical method for production of ketones is vapour phase decarboxylation of the corresponding acids.This dissertation deals with the preparation of 2-undecanone through gas-solid catalysis, and discusses the corresponding effect factors. Under appropriate conditions, the most efficient catalyst has been found. Using catalyst MgO-CeO₂/SiO₂, under the optimum conditions the highest conversion of capric acid is 100% and the molar yield of 2-undecanone is 87.2%. Orthogonal test has been rationally applied to arrange experiments. The results can help us to select more efficient catalysts quickly.Chapter one: The origin, pharmacological effects and kinds of medicament in present have been reviewed. The effect factor and mechanism of the reaction have been summarized. At last, the reason that selecting this theme is expatiated.Chapter two: The experiment methods, including catalysts preparation, experimental equipment and the procedure of gas-solid catalytic reaction etc, have been introduced.Chapter Three: The carriers of catalysts have been studied. Sol-gel method has been applied in catalysis abroad. This treatise studies the application of sol-gel method in preparation of ketones. The carriers made by sol-gel method and the carriers from the market have been experimented under different temperature. The result is that the carrier which has been enlarged pore size is not good as the hypothesis. Contrast to the carriers from the market, the carriers made by sol-gel method does not improve molaryield.Chapter four: The system of mono-component-catalyst has been studied. Through orthogonal tests, the optimum conditions have been found, which are: reaction temperature is 390°C, n (acetic acid) :n (capricacid) =6:1, space velocity is 36 h'1.Chapter five: The system of multiply-component-catalyst has been studied. At first, the system of two-component-catalyst is studied. Under the optimum conditions, using CeO2, MnO2, CaO as assistant catalysts, the experiments are arranged. The result is that it is advantage to induct assistant catalysts. When using 10.0wt.%CeO2 as assistant catalyst, the result is the best. Contrary to mono-component-catalyst system, molar yield of 2-undecanone has been increased 11.5 %. Then four-component-catalyst system has been studied. But the result is not good at present.Chapter six: The treatise is summarized, and advices about how to study further are given.