Biodiesel is an alternative to diesel fuel consisting of fatty acid alkyl monoesters from vegetable oils or tallow. At present, most biodiesel is produced from soybean oil, methanol and a basic catalyst (cholinesterase). However, most of the cheap fat that is not easily digested by the human body can be converted into biodiesel.
(1) physical refining: First, the oil hydration or phosphate treatment, remove the phospholipids, glial and other substances. And then the oil preheat, dehydration, degassing into the deacidification tower, to maintain residual pressure, access to excess steam, the steam temperature, the free acid and steam co-steamed, condensed precipitation, remove free fatty acids other than the net loss, In the free acid can be reduced to very low, the pigment can be broken down, so that the color lighter. All kinds of waste vegetable oil in the independent research and development under the action of DYD catalyst, the use of esterification, alcoholysis at the same time the reaction process to produce crude fatty acid methyl ester.
(2) methanol pre-esterification: First, the oil hydration degumming, with a centrifuge to remove phospholipids and plastic hydration formed when the floc, and then dehydration of oil. The raw oil is added with excess methanol and is pre-esterified in the presence of an acidic catalyst to convert the free acid to methyl ester. The methanol water was distilled off, and after fractionation, no free acid was separated from C12-16 methyl palmitate and C18 methyl oleate.
(3) ester exchange reaction: pre-treated fat and methanol together, adding a small amount of NaOH as a catalyst, at a certain temperature and atmospheric pressure transesterification reaction, which can produce methyl ester, the use of two-step reaction, through a specially designed The separator continuously removes the glycerol produced in the initial reaction, and the transesterification reaction is continued.
(4) Gravity sedimentation, washing and delamination.
(5) separation of glycerol with crude methyl ester.
(6) the release of water, the release of methanol, the removal of the catalyst and the extraction of refined biodiesel.
The entire process to achieve closed-circuit, all the comprehensive utilization of raw materials to achieve cleaner production. Roughly described as follows: raw material pretreatment (dehydration, deodorization, purification) —— reactor (alcohol + catalyst +70 ¡æ) —— stirring reaction 1 hour ——- precipitation separation Discharge ——- recovery of alcohol —— filter ——– finished product.
Biodiesel is a high quality clean diesel oil that can be extracted from a variety of biomass, so it can be said that inexhaustible energy, in the increasingly depleted resources today, is expected to replace oil as an alternative fuel.