The invention relates to a novel desulfurization method of
biodiesel. The method comprises the steps that
sulfur-containing compounds in the
biodiesel are removed through two stages of high
vacuum distillation, crude
biodiesel is pumped into a first-stage desulfurization
tower for first-stage high
vacuum distillation, the
tower top of the first-stage desulfurization
tower is rich in light components of the
sulfur-containing compounds; desulfurized biodiesel at the kettle bottom of the first-stage desulfurization tower is pumped into a second-stage desulfurization tower through a pump for second-stage high
vacuum distillation, biodiesel reaching the standard is steamed out from the tower top of the second-stage desulfurization tower, the content of
sulfur in the biodiesel reaching the standard is lower than 10 ppm, biological
asphalt heavy components are obtained in a tower kettle of the second-stage desulfurization tower, the absolute operation pressure of the desulfurization towers ranges from 10 Pa to 1,000 Pa, and the tower kettle
heating temperature ranges from 200 DEG C to 300 DEG C. The method is simple in technological process, low in equipment
investment cost and capable of obtaining the biodiesel meeting the standard stably; compared with a traditional
petrochemical oil product desulfurization method, a high-temperature catalytic reaction is not related, new substances are not introduced, therefore, the process is
safer, the oil product structure is not destroyed, and it is guaranteed that the
oil quality is stable.