Process and device for gasification of crude glycerol

Abstract

The invention relates to a process as well as a device for continuous thermal decomposition (pyrolysis) of a mixture of substances (crude glycerol) ( 1 ) that contains glycerol, salts and water, whereby the crude glycerol ( 1 ) is heated in a reactor (pyrolysis reactor) (R) to a temperature (pyrolysis temperature) of more than 100° C. The pyrolysis of the crude glycerol ( 1 ) is performed at a pressure (pyrolysis pressure) that is higher than the vapor pressure of the water, present in the pyrolysis reactor (R), at pyrolysis temperature, and salts and other higher-boiling substances together with water are drawn off continuously from the pyrolysis reactor (R) as waste water ( 3 ).

1 . A process for continuous thermal decomposition of a crude glycerol mixture containing glycerol, salts and water, comprising:
 heating said crude glycerol mixture ( 1 ) in a pyrolysis reactor (R) to a pyrolysis temperature of more than 100° C., wherein pyrolysis of the crude glycerol mixture ( 1 ) is performed at a pyrolysis pressure that is higher than the vapor pressure of water present in said pyrolysis reactor (R), at said pyrolysis temperature, and   withdrawing continuously salts and other higher-boiling substances, together with water, from the pyrolysis reactor (R) as waste water ( 3 ).   
   
   
       2 . A process according to  claim 1 , wherein said process is performed at a pyrolysis temperature of 290° C.-370° C. 
   
   
       3 . A process according to  claim 1 , wherein said process is performed at a pyrolysis temperature of 290° C.-340° C. 
   
   
       4 . A process according to  claim 1 , wherein said process is performed at a pyrolysis temperature of 290° C.-310° C. 
   
   
       5 . A process according to  claim 1 , wherein said crude glycerol mixture ( 1 ) is thermally decomposed in the presence of acids and/or Lewis acids. 
   
   
       6 . A process according to  claim 1 , wherein the heat required for the pyrolysis is introduced into the pyrolysis reactor (R) by indirect heating via heating surfaces and/or by direct heating via high-pressure vapor ( 2 ). 
   
   
       7 . A process according to  claim 1 , wherein a pyrolysis gas, produced by pyrolysis of crude glycerol mixture in said pyrolysis reactor ( 1 ) is superheated to cleave long-chain compounds contained therein and thereby form hydrogen and/or carbon monoxide. 
   
   
       8 . An apparatus for thermal decomposition of a crude glycerol mixture ( 1 ) containing glycerol, salts and water, said apparatus comprising:
 a pyrolysis reactor (R) having a feed inlet (Z) for feeding of a crude glycerol mixture, a gas discharge outlet (H) for discharging a gaseous pyrolysis product, means for heating the crude glycerol mixture ( 1 ) to a pyrolysis temperature of more than 100° C.,   wherein said pyrolysis reactor (R) is a pressure vessel, in which a crude glycerol mixture ( 1 ) is gasifiable at a pressure higher than the vapor pressure of water present in the pyrolysis reactor, at the pyrolysis temperature, and   wherein said pyrolysis reactor (R) has a second discharge outlet for discharging waste water (A), via which salts and other higher-boiling substances together with water can be drawn off continuously from pyrolysis reactor (R) as waste water ( 3 ).   
   
   
       9 . An apparatus according to  claim 8 , wherein between the crude glycerol feed inlet (Z) and the second discharge outlet for discharging waste water (A), the pyrolysis reactor further comprises built-in components (T) that ensure a sufficiently long dwell-time of crude glycerol ( 1 ) in the pyrolysis reactor (R) to avoid premature removal of glycerol with the waste water ( 3 ). 
   
   
       10 . An apparatus according to  claim 8 , wherein said apparatus further comprises a device for superheating (U) the pyrolysis gas, in which pyrolysis gas can be heated to a temperature higher than the pyrolysis temperature. 
   
   
       11 . An apparatus according to  claim 8 , wherein said apparatus further comprises a feed means for introducing high-pressure vapor (D) into the pyrolysis reactor (R), whereby energy required for pyrolysis can be introduced into the pyrolysis reactor (R) via high-pressure vapor.