Method for preparing magnetic solid acid catalyst for production of biodiesel

Abstract

The invention discloses a method for preparing a magnetic solid acid catalyst for the production of biodiesel. The solid acid catalyst is prepared by performing sulfonic acid group modification on zirconia-based Fe3O4 / ZrO2 compound. The preparation method comprises the following steps: after mixing ferrous chloride and ferric chloride, adding ammonia water or solution of sodium hydroxide to adjust the pH value of the mixture to between 10 and 12; ageing the mixture for 2 hours; washing the mixture by distilled water to be neutral to obtain a magnetic substrate; mixing the magnetic substrate and zirconium oxychloride in proportion, adding a certain amount of water to fully dissolve the zirconium oxychloride, uniformly oscillating the mixed solution, adjusting the pH value of the mixed solution to between 10 and 12 by ammonia water or the solution of sodium hydroxide; filtering and precipitating after ageing for 2 hours; fully washing the precipitate by deionized water until no Cl- exists; fully soaking the precipitate for 4 hours by ammonium sulfate or solution of concentrated sulfuric acid or solution of ammonium persulphate; and leaching and roasting a filter cake in a muffle furnace at the temperature of 500 DEG for 3 hours to obtain the magnetic catalyst.

Description

technical field [0001] The invention relates to a preparation method of a magnetic solid acid catalyst used for biodiesel production, and belongs to the application field of oleochemical catalytic materials. Background technique [0002] At present, the preparation technology of biodiesel is mainly based on the chemical method. The catalyst used in the chemical method is mainly liquid alkali, such as sodium methoxide or sodium hydroxide as the catalyst. Although the conversion efficiency is very high, as a homogeneous catalyst, it is very difficult to Difficult to separate it from the product. Another kind of catalyst uses liquid acid, such as concentrated sulfuric acid, as a catalyst to catalyze the transesterification reaction for the production of biodiesel, but the reaction speed of the acid catalyst is slow. [0003] With the advancement of technology, many preparation methods of solid catalysts have also appeared. Due to their heterogeneous reaction characteristics, ...

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Problems solved by technology

[0002] At present, the preparation technology of biodiesel is mainly based on the chemical method. The catalyst used in the chemical method is mainly liquid alkali, such as sodium methoxide or sodium hydroxide as the catalyst. Although the conversion efficiency is very high, as a homogeneous catalyst, it is very difficult to Difficult to separate it from the product

Another kind of catalyst uses liquid acid, such as concentrated sulfuric acid, as a catalyst to catalyze the transesterification reaction for the production of biodiesel, but the reaction speed of the acid catalyst is slow