Method for preparing attapulgite solid alkali for synthesizing biodiesel from waste oil and fat

Abstract

The invention discloses a method for preparing attapulgite solid alkali for synthesizing biodiesel from waste oil and fat. The method for preparing the attapulgite solid alkali sequentially includes steps of purifying attapulgite; modifying the attapulgite by acid; modifying the attapulgite by coupling agents; and preparing the attapulgite solid alkali. Raw materials of the attapulgite solid alkali are low in cost, a preparation process is simple, the obtained attapulgite solid alkali is used for synthesizing the biodiesel from the waste oil and fat, a little amount of water generated in a reaction process can be effectively absorbed, the frequency of 'poisoning' of the solid alkali caused by acidic molecules such as CO2 is reduced, the service life of the solid alkali is prolonged, the solid alkali can be separated from a product easily, and higher than 80% of the activity of the solid alkali is kept after the solid alkali is reused by five times.

Description

technical field [0001] The invention relates to a preparation method of a solid base catalyst, in particular to a preparation method of an attapulgite solid base used for synthesizing biodiesel from waste oil. Background technique [0002] The transesterification method is currently the main method for producing biodiesel. The most common catalysts used are homogeneous acid and basic catalysts. There are catalysts that seriously corrode the equipment, cannot be reused, the product needs to be washed many times, and the process is relatively complicated. Disadvantages such as producing a large amount of waste liquid. The solid catalyst has the advantages of easy separation of the catalyst from the reaction system, easy regeneration of the catalyst after the reaction, and little corrosion of the catalyst to the reaction equipment. [0003] There have been many studies on the solid base used in the preparation of biodiesel. The publication number is CN101024189A "a magnetic so...

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Problems solved by technology

[0003] There are many studies on the solid base used for biodiesel preparation, the publication number is CN101024189A "a magnetic solid base catalyst and its preparation method and application", and the application publication number is CN101811038A's patent "A Method and Application of Solid Gold Catalyst for Synthesizing Biodiesel" and the like have all studied the solid base used for biodiesel preparation, but there are many solid base catalysts used to catalyze the synthesis of biodiesel from waste oil The following defects: the quality of waste oil is low, often contains more fatty acids, it is easy to saponify during the transesterification process, a small amount of water is produced, and the solid alkali is easy to absorb H2O and CO2 "Poisoned" by acidic molecules

Therefore, solid base catalysts are mostly used in the preparation of biodiesel from oils with better catalytic quality, and acid catalysis or two-step acid-base catalysis are mostly used in the preparation of biodiesel from waste oils and fats, and the process is more complicated.