Method for blending and loading solid catalyst material into tubular structures

Abstract

The present invention relates to a method for blending and loading solid material into vessels, such as into the tubes of shell and tube reactors, in a manner which maximizes compositional homogeneity and consistency of quantities and configurations of the blended solid materials. The solid materials comprise one or more solid catalyst materials, one or more solid inert materials, or blends thereof.

1 . A method for blending solid materials to be placed in the tubes of a shell and tube reactor, said method comprising:
 (A) identifying a packing schedule which lists the types and amounts of solid materials needed to form different batches of solid materials for arranging in the tubes and forming desired regions in the shell and tube reactor, wherein each of said batches comprises one or more materials selected from the group consisting of: solid catalyst materials, solid inert materials, and blends thereof;   (B) using a combinatorial weighing machine to produce at least one of the different batches, wherein types and amounts of solid catalyst materials and solid inert materials blended for each batch of solid materials are selected based on the packing schedule;   (C) collecting at least one of the batches of solid materials in a plurality of containers, wherein each container of said plurality contains the same amount and proportion of the one or more solid materials, said amount being determined based upon the packing schedule, and each of said plurality comprising a total number of containers, said total number being determined by the number and size of the tubes of the shell and tube reactor; and   
     
     
         2 . The method according to  claim 1 , further comprising:
 (D) loading said batches of solid materials from each of said containers into corresponding tubes of the shell and tube reactor, according to a predetermined order dictated by the packing schedule, to form said desired regions within the reactor which are consistent and homogeneous.   
     
     
         3 . The method according to  claim 1 , wherein the combinatorial weighing machine comprises adjustable vibrating means for changing the rate at which solid materials are moved through the machine and blended with one another. 
     
     
         4 . The method according to  claim 1 , wherein the combinatorial weighing machine comprises dust collection means for collecting and removing dust from the solid materials, thereby preventing unwanted accumulation of dust in the tubes of the shell and tube reactor. 
     
     
         5 . The method according to  claim 1 , wherein the containers are bags and a bagging machine is used with the combinatorial weighing machine to accomplish the step of collecting each of the batches of solid materials in a plurality of containers. 
     
     
         6 . The method according to  claim 2 , wherein the step of loading the batches of solid materials from each of said containers into corresponding tubes of the shell and tube reactor is accomplished using a solids loading machine having one or more tubular members aligned with corresponding tubes of the shell and tube reactor. 
     
     
         7 . The method according to  claim 1 , wherein the packing schedule provides a list of types and amounts of materials required to perform two-stage oxidation of an alkene to form a corresponding unsaturated carboxylic acid, and wherein the desired regions comprise a first reaction stage wherein the alkene is converted to an unsaturated aldehyde and a second reaction stage wherein the unsaturated aldehyde is further converted to the corresponding unsaturated carboxylic acid. 
     
     
         8 . The method according to  claim 7 , wherein the first reaction stage comprises at least one catalyst comprising a mixed metal oxide and being capable of catalyzing the conversion of an alkene to an unsaturated aldehyde, and the second reaction stage comprises at least one catalyst comprising a mixed metal oxide and being capable of catalyzing the conversion of an unsaturated aldehyde to an unsaturated carboxylic acid. 
     
     
         9 . The method according to  claim 8 , wherein said first reaction stage comprises a plurality of reaction zones. 
     
     
         10 . The method according to  claim 8 , wherein said second reaction stage comprises a plurality of reaction zones. 
     
     
         11 . The method according to  claim 8 , where the unsaturated carboxylic acid comprises (meth)acrylic acid. 
     
     
         12 . The method according to  claim 1 , wherein the packing schedule provides a list of types and amounts of materials required to produce vinyl acetate monomer from reactants comprising ethylene, oxygen and acetic acid. 
     
     
         13 . The method according to  claim 5 , wherein said amount of solid materials in each bag varies from bag to bag by not more than +/−1% by weight based on the total weight of each bag. 
     
     
         14 . The method according to  claim 1 , wherein the batches of solid materials are loaded into the tubes of the shell and tube reactor at a drop rate of not more than 30 seconds per liter. 
     
     
         15 . The method of  claim 1 , wherein at least one of said batches of solid materials comprises a blend of two or more solid catalyst materials having the same essential components but different catalytic activity. 
     
     
         16 . The method of  claim 1 , wherein at least one of said batches of solid materials comprises a blend of at least one solid inert material and at least one solid catalyst material. 
     
     
         17 . The method of  claim 15 , wherein said same essential components of the solid catalyst materials comprise molybdenum, bismuth and iron.