Method for producing biodiesel by using inferior grease as raw material

The invention relates to the technical field of chemical industry, and particularly discloses a method for producing biodiesel by using inferior grease as a raw material. The method comprises the following steps: (1), filtering the inferior grease to remove impurities; (2), mixing the inferior grease treated in the step (1) and alcohol, and reacting under the action of a composite catalyst; (3), standing a product obtained in the step (2) for layering, taking a biodiesel-containing layer, and distilling to obtain the biodiesel. With the method, the ester content of the biodiesel can be greatlyincreased and the iodine value of the biodiesel can be greatly reduced; embodiment data show that the biodiesel prepared with the method provided by the invention has the ester content of 88% or above 88% and the iodine value of 100 or below 100. 本发明涉及化工技术领域，具体公开了种以劣质油脂为原料生产生物柴油的方法。所述方法包含如下步骤：(1)将劣质油脂过滤除杂；(2)将经步骤(1)处理的劣质油脂和醇混合，在复合催化剂作用下进行反应；(3)将步骤(2)得到的产物进行静置分层，取含生物柴油层进行蒸馏，即得生物柴油。该方法能大幅提高生物柴油的酯含量以及大幅降低生物柴油的碘值，实施例数据表明，由本发