| abstract |
The invention provides a process system for preparing biodiesel by a step counter-current continuous enzymatic method, which is characterized by comprising a multistage enzymatic reaction device, an acid reducing device, a mixing tank and a grease raw material tank, wherein the multistage enzymatic reaction device comprises at least one enzymatic reaction unit, the enzymatic reaction unit comprises a reactor provided with a raw material inlet, a centrifuge 21 connected with the reactor, a heavy phase membrane filter and an oil phase membrane filter which are connected with the centrifuge in parallel, the oil phase membrane filter is provided with a methyl ester discharge port used for discharging methyl ester into the acid reducing device and a methanol return port used for returning methanol to the mixing tank, the heavy phase membrane filter is provided with a glycerin discharge port and a biological enzyme return port used for returning biological enzyme to the mixing tank, so as to solve the problems that the reaction rate of the biodiesel prepared by the biological enzymatic method is slow, the reaction is incomplete and the acid value of a product does not reach the standard, energy conservation and consumption reduction. |