Catalyst and process for production of acrylic acid

Abstract

An object of the present invention is to provide: a catalyst for production of acrylic acid which is a catalyst usable for production of acrylic acid and is excellent in the catalytic performances such as catalytic activity and in the physical properties such as physical strength of the catalyst itself; and a process for production of acrylic acid using this catalyst. As a means of achieving this object, a catalyst for production of acrylic acid according to the present invention is a catalyst obtained by drying a mixed liquid of starting materials including molybdenum and vanadium as essential components to give a dried material, molding the dried material with a liquid binder, and calcining the resultant molding, with the catalyst being characterized in that an ignition loss ratio of the dried material is from 5 to 40% by mass. A process for production of acrylic acid according to the present invention comprises the step of: subjecting acrolein to a catalytic gas phase oxidation in the presence of a molecular oxygen, with the process being characterized in that the above catalyst for production of acrylic acid according to the present invention is used.

1 . A catalyst for production of acrylic acid, which is a catalyst obtained by drying a mixed liquid of starting materials including molybdenum and vanadium as essential components to give a dried material, molding the dried material with a liquid binder, and calcining the resultant molding, wherein an ignition loss ratio of the dried material is from 5 to 40% by mass, 
 with the proviso that the ignition loss ratio of the dried material is calculated according to the following formula based on masses of the dried material before and after heated, the dried material being heated until there is no mass change at 300° C. under air atmosphere:    ignition loss ratio (% by mass)=[(mass of dried material before heated (g)−mass of dried material after heated (g))/mass of dried material before heated (g)]×100.    
   
   
       2 . The catalyst for production of acrylic acid according to  claim 1 , wherein the liquid binder comprises water as an essential component, and is used in an amount of 2 to 20 parts by mass in terms of water relative to 100 parts by mass of the dried material.  
   
   
       3 . The catalyst for production of acrylic acid according to  claim 1 , which is supported on a particulate carrier.  
   
   
       4 . The catalyst for production of acrylic acid according to  claim 2 , which is supported on a particulate carrier.  
   
   
       5 . A catalyst for production of acrylic acid, which is a catalyst obtained by drying a mixed liquid of starting materials including molybdenum and vanadium as essential components to give a dried material, molding the dried material with a liquid binder, and calcining the resultant molding, wherein an attrition loss of the catalyst is less than 10% by mass, 
 with the proviso that the attrition loss is calculated according to the following formula based on a mass (g) of the resultant catalyst for production of acrylic acid initially charged into a stainless airtight vessel, which is in the form of a cylindrical drum of 150 mm diameter of circular section in perpendicular direction and 150 mm width in horizontal direction, and a mass (g) of the catalyst remaining on a 2.0 mm-mesh sieve after subjected to an operation comprising the steps of weighing out 200±1 g of the catalyst precisely, charging the weighed catalyst into the stainless airtight vessel, rotating the vessel for 30 minutes at 150 rpm around a horizontal central axis thereof, and then putting the catalyst through the sieve:    attrition loss (% by mass)=[(mass of catalyst initially charged into vessel (g)−mass of catalyst remaining on sieve (g))/mass of catalyst initially charged into vessel (g)]×100.    
   
   
       6 . A process for production of acrylic acid comprising the step of: subjecting acrolein to a catalytic gas phase oxidation in the presence of a molecular oxygen, wherein the catalyst for production of acrylic acid according to any one of  claims 1  to  5  is used.