Microwave apparatus and method of extracting essential oils, essence, and pigments with gas flow

Abstract

Extraction apparatus and method for obtaining essential oils, essence, and pigments from odorous raw materials (e.g., plant materials and Chinese medicinal herbs) by microwave radiation heating have advantages of easy operation, higher extracting temperature and efficiency. The microwave chamber has a power level of 100 W to 1,500 W and its microwave radiation has a frequency at 915 MHz or 2,450 MHz. The extraction process can be performed without any preheating necessary. A condenser is operated at temperatures between −20° C. and 15° C. for cooling the gas flowing out of the extraction cartridges. Because both volatile fragrant compounds and pigments of the odorous raw materials can be extracted successfully by the top-down extraction fashion, the extracted essence is colorful. Since the extraction process by microwave heating is free from adding any organic solvent and/or any artificial chemical compound, the extraction apparatus and method are environmentally friendly.

1 . An extraction method of obtaining essential oils, liquid essence, and pigments from plant raw materials comprising the steps of:
 preparing wherein an odorous raw material to be extracted is filled in each of a plurality of extraction cartridges, each of the extraction cartridges has top and bottom openings and is affixed in a microwave chamber by securing a cap to the top opening thereof and securing its bottom opening to a bottom of the microwave chamber, and a condenser has an inlet connected to the bottom openings of the extraction cartridges, and an outlet;   flushing wherein a gas supply opens to flow a pressurized gas to each of the extraction cartridges via a channel of each of the caps in a top-down fashion;   heating wherein the microwave chamber is turned on to heat each of the extraction cartridges for a predetermined period of time to vaporize fragrant compounds out of the odorous raw material while the gas is flowing downward; and   cooling wherein cooling water is continuously circulating through the condenser to condense the fragrant compounds into essential oils, liquid essence, and pigments which are collected by a collecting reservoir.   
     
     
         2 . The extraction method of  claim 1 , wherein the microwave chamber is adapted to heat the extraction cartridges uniformly with a continuously distribution mode. 
     
     
         3 . The extraction method of  claim 1 , wherein the microwave chamber has a microwave radiation with a frequency at 915 MHz or 2,450 MHz. 
     
     
         4 . The extraction method of  claim 1 , wherein the microwave chamber has a power level of 100 W to 1,500 W. 
     
     
         5 . The extraction method of  claim 1 , further comprising at least one check valve, each of the at least one check valve adapted to adjust the pressure of the gas flowing out of the gas supply to a range between 110 KPa and 210 KPa. 
     
     
         6 . The extraction method of  claim 1 , wherein the microwave heating process is sustained for 5 minutes to 150 minutes. 
     
     
         7 . The extraction method of  claim 1 , wherein the gas is air. 
     
     
         8 . The extraction method of  claim 1 , wherein the gas is nitrogen. 
     
     
         9 . The extraction method of  claim 1 , wherein the gas is helium.