Reaction apparatus for production of alkanolamine and method for production of alkanolamine using the apparatus

Abstract

Selective production of a dialkanolamine is attained by controlling the volume preceding the entrance to a catalyst bed and the temperature prevailing under respectively fixed levels subsequent to the mixture of an alkylene oxide thereby repressing a reaction occurring in the absence of a catalyst and curbing the formation of trialkanolamine. The reactant fluid is prevented from generating a channeling by disposing an exportable structure in a reactor thereby creating the state of a false shell-and-tube type reactor. The reaction is initiated with the inlet temperature set at a higher level than the prescribed level and the alkylene oxide concentration set at a lower level than the prescribed level and thereafter the inlet temperature and the alkylene oxide concentration are gradually changed toward the respectively prescribed levels.

What is claimed is:  
     
         1 . A reaction apparatus for producing a dialkanolamine by causing an alkylene oxide to react with ammonia and a monoalkanolamine, comprising: 
 a mixer for mixing ammonia with the monoalkanolamine;    a pre-heater for heating the fluid flowed from the mixer;    an alkylene oxide mixer with a feed inlet for supplying an alkylene oxide and interposed between the pre-heater and a reactor for introducing the alkylene oxide via the feed inlet and mixing it into the fluid heated by the pre-heater; and    a reactor equipped with a catalyst bed packed with a solid catalyst for introducing the preheated mixture of ammonia, monoalkanolamine, and alkylene oxide flowed from the alkylene oxide mixer to react.    
     
     
         2 . An apparatus according to  claim 1 , wherein an available volume from the supply inlet for an alkylene oxide through the inlet of the catalyst bed is not more than 0.5 times the volume of the catalyst bed in the reactor.  
     
     
         3 . An apparatus according to  claim 1  further comprising a liquid-pervious inert material set on the upstream side in the interior of the reactor.  
     
     
         4 . A method for producing a dialkanolamine by causing an alkylene oxide to react with ammonia and a monoalkanolamine, which method comprises: 
 mixing the ammonia with monoalkanolamine;    preheating the resultant mixture;    mixing the alkylene oxide into the preheated liquid; and    feeding the mixture of alkylene oxide and the preheated liquid to a reactor including a solid catalyst.    
     
     
         5 . A method according to  claim 4 , wherein a molar ratio of the ammonia to the monoalkanolamine is in the range of 200:1 to 1:2.  
     
     
         6 . A method according to  claim 5 , wherein the molar ratio is in the range of 100:1 to 1:1.  
     
     
         7 . A method according to  claim 4 , wherein a molar ratio of the alkylene oxide to the monoalkanolamine is in the range of 1:0.01 to 1:20.  
     
     
         8 . A method according to  claim 7 , wherein the molar ratio is in the range of 1:0.05 to 1:10.  
     
     
         9 . A method according to  claim 4 , wherein a time required for the preheated fluid containing the alkylene oxide in reaching the catalyst is set at not more than 0.5 times the retention time in the catalyst bed.  
     
     
         10 . A method according  claim 4 , wherein a temperature of the fluid at the inlet of the catalyst bed is set at not less than 50° C. lower than the temperature at the outlet of the catalyst bed.  
     
     
         11 . A method according to  claim 4 , wherein a reactor containing the catalyst is a cascade type reactor and the temperature of the fluid at the inlet of the catalyst bed at the second or subsequent stage is cooled to not more than 50° C. below the temperature at the outlet of the catalyst bed at the immediately preceding stage.  
     
     
         12 . A method according to  claim 11 , wherein a time required for the preheated fluid containing the alkylene oxide in reaching the catalyst is set at not more than 0.5 times the retention time in the catalyst bed.  
     
     
         13 . A reactor for the production of an alkanolamine comprising a honeycomb structure disposed in the interior thereof.  
     
     
         14 . A reactor according to  claim 13 , wherein a plurality of the honeycomb structures are disposed therein.  
     
     
         15 . A method for packing a reactor for the production of an alkanolamine with a catalyst, which method comprises: 
 disposing a honeycomb structure in the reactor; and    filling the structure with the catalyst in solid particles.    
     
     
         16 . A method for packing an up-flow type reactor for the production of an alkanolamine with a catalyst, which method comprises: 
 packing a catalyst having a particle diameter of not more than 1 mm;    overlaying the resultant catalyst bed with inert particles having a particle diameter of 0.5 to 10 times the particle diameter of the catalyst; and    overlaying the superposed layer of the inert particles with inert particles having a particle diameter of 1.5 to 10 times the particle diameter of the inert particles in the superposed layer.    
     
     
         17 . A startup method for the production of an alkanolamine by the reaction of ammonia with an alkylene oxide using an adiabatic reactor in the presence of a solid catalyst, which method comprises: 
 initiating the reaction while setting the inlet temperature of the reactor at a higher level than the prescribed temperature and the alkylene oxide concentration at a lower level than the prescribed concentration; and    changing the inlet temperature and the alkylene oxide concentration toward the respectively prescribed levels gradually.    
     
     
         18 . A method according to  claim 17 , wherein the inlet temperature of the reactor at the start of reaction is higher by 20 to 100° C. than the prescribed temperature of 20 to 100° C.  
     
     
         19 . A method according to  claim 17 , wherein the alkylene oxide concentration at the start of reaction is in the range of 10 to 90 v/v % based on the prescribed concentration that the molar ratio of the ammonia to the alkylene oxide is 2 to 30:1.