Protection of solid acid catalysts from damage by volatile species

Abstract

The invention provides a method to avoid catalyst damage and achieve longer catalyst life by selecting appropriate materials for reactor spacers, liners, catalyst binders, and supports, in particular, by not using crystalline silica-containing and high phosphorus-containing materials, if the presence of even small amount of steam is anticipated. In addition, alkali metals and alkaline earth metals are avoided due to potential damage to the catalyst.

1 . A method of maintaining acid catalyst sites of a catalyst for a production of olefins said method comprising providing a catalyst environment in a reaction zone wherein deposition of catalyst contaminant from surfaces or contents within said reaction zone is reduced to a level that does not impair activity of said catalyst. 
   
   
       2 . The method of  claim 1  wherein said contaminant is selected from the group consisting of phosphorus, silicon, alkaline metals and alkaline earth metals. 
   
   
       3 . The method of  claim 2  wherein said alkaline metal is sodium, lithium or potassium and said alkaline earth metal is magnesium or calcium. 
   
   
       4 . The method of  claim 1  wherein said reaction zone is contained within a plurality of reactor surfaces wherein said reactor surfaces comprise a refractory material resistant in loss of said contaminant under operating conditions of said reaction zone. 
   
   
       5 . The method of  claim 1  wherein said reaction zone is selected from the group consisting of apparatus for conversion of methanol to olefins, olefin cracking and catalytic naphtha cracking reaction zones. 
   
   
       6 . The method of  claim 1  wherein said catalyst retains at least 60% of catalytic activity. 
   
   
       7 . The method of  claim 1  wherein said catalyst retains at least 80% of catalytic activity. 
   
   
       8 . The method of  claim 1  wherein said catalyst retains at least 95% of catalytic activity.