Method for decoloring biodiesel prepared from gutter oil

Abstract

The invention relates to a method for decoloring biodiesel prepared from gutter oil. The method comprises the following steps: 1, preparing biodiesel from gutter oil through ester exchange; 2, decoloring: adding 100g of biodiesel to a 250ml flask, adding hydrogen peroxide which is 5-25% oil weight in mass percentage, wherein heating temperature is 70-90 DEG C, stirring, reacting for 18-25min, centrifuging and reserving an upper phase; 3, calculating a decolorization ratio: respectively adding the obtained grease in a 1.0cm cuvette, and implementing absorption spectrum scanning on 465nm, wherein the decolorization ratio is defined as a ratio of a difference in absorbance indexes before and after biodiesel decolorization to an absorbance index before decolorization. The method has the beneficial effects that the method, through a hydrogen peroxide oxidation process, has an obvious decolorization effect on deep-color biodiesel prepared from the gutter oil. And the decolorization method is simple to operate, high in decolorization speed and high in recovery efficiency, and the biodiesel decolorized by the method has no large difference with the biodiesel before decolorization in both physical and chemical property.

Description

technical field [0001] The invention relates to the field of chemical industry, in particular to a decolorization method for preparing biodiesel from waste oil. Background technique [0002] With the worldwide energy shortage and people's increasing emphasis on environmental protection, it is imminent to develop and research biodiesel (short chain alcohol esters of fatty acids), a green and environmentally friendly fuel, to replace the depleted petroleum energy. [0003] Waste oil is considered by more and more people as an ideal raw material for biodiesel because of its low price. After repeated high-temperature frying and use of cooking oil, phospholipids and proteins in the oil begin to decompose, denature or react with other substances to form a large amount of dark substances; When, colored substances or potentially colored substances are formed. Therefore, most of the waste oil is darker in color, and the biodiesel produced from it is also mostly dark brown. [000...

AI Technical Summary

Problems solved by technology

The traditional rectification or distillation purification method to produce biodiesel also has a certain decolorization effect on biodiesel, but the equipment cost and operation cost of simply using distillation or rectification for decolorization are relatively high, and the space-time yield is relatively low