Method for Processing Solid and Liquid Wastes from the Production of Vegetable Oil

Abstract

A method for processing solid, organic wastes obtained in the production of vegetable oil, for example the production of palm oil, chiefly consisting of pressing residues of the oil plants and/or oil seeds and oil-containing waste water by hydrothermal carbonization (HTC), wherein the oil present in the waste water in emulsified form is sorbed by the solids rich in carbon, which are obtained from the solid wastes.

1 . A method for processing solid, organic wastes and waste water obtained in the production of vegetable oil, wherein the solid wastes comprise pressing residues of oil fruits or oil seeds and the waste water contains vegetable oil residues beside other organic impurities, which are present in the waste water in emulsified form, wherein the solid, organic wastes are comminuted and in a stirred, heated reactor mixed with the waste water to form a suspension, the pH value of the suspension is adjusted in the acidic range, the atmospheric oxygen is removed from the reactor by flushing with inert gas, the reactor is closed gas-tight and the suspension is heated to at least 170° C. and kept at elevated pressure for at least 0.5 hours, wherein the solid, organic wastes chiefly are converted to a solid material rich in carbon, and wherein the emulsion of waste water and vegetable oil residues is broken and the oil is sorbed by the obtained solid material rich in carbon, and wherein subsequently the suspension is cooled, removed from the reactor and separated into a solids and a waste water fraction. 
     
     
         2 . The method according to  claim 1 , wherein the solid, organic wastes are comminuted to a particle size of 2 to 5 cm. 
     
     
         3 . The method according to  claim 1  wherein the dry matter content of the suspension before heating is adjusted to 10 to 40%. 
     
     
         4 . The method according to  claim 1  wherein the pH value of the suspension, before heating, is adjusted to a value between 3.0 and 6.9. 
     
     
         5 . The method according to  claim 1   wherein inside the reactor, before heating, an elevated pressure of  5  to  15  bar is generated by introducing inert gas. 
     
     
         6 . The method according to  claim 1  wherein the suspension is heated to and maintained at temperatures between 170 and 320° C. 
     
     
         7 . The method according to  claim 1  wherein the suspension is maintained at over 170° C. for a time between 0.5 and 16 hours. 
     
     
         8 . The method according to  claim 1  wherein the separation of the suspension into a solids and a waste water fraction is effected by means of mechanical separation methods. 
     
     
         9 . (canceled) 
     
     
         10 . (canceled) 
     
     
         11 . The method according to  claim 4  wherein the pH value of the suspension, before heating, is adjusted to a value between 3.0 and 3.5. 
     
     
         12 . The method according to  claim 8  wherein the means of mechanical separation is decantation, filtration or centrifugation.