32results about How to "Resolve low activity" patented technology

The present application provides a method for improving the yield of biodiesel, comprising: contacting and reacting low-acid-value oil and fat with monohydric alcohol in the presence of metal oxide or sulfide catalyst, characterized in that carboxylic acid or high-acid-value oil and fat is additionally added. The method of the present application can effectively solve the problem of low activity of various metal oxide or metal sulfide catalysts when used for preparing biodiesel from low-acid-value oil raw materials, expand the application range of oxide or sulfide catalysts, obtain high-yield biodiesel at lower temperature and pressure, and greatly reduce the investment in devices since the reaction is carried out at low pressure.