Processes and systems for using silica particles in fluid bed reactor
The present disclosure relates to fluid bed processes that utilize silica particles as a fluidization aid. The process comprises reacting one or more reactants in a reactor comprising a fluid bed to form a product. The fluid bed comprises a catalyst composition comprising a catalyst and an inert additive composition comprising silica particles from 0.5 wt % to 30 wt %, based on the total weight of the catalyst composition. The silica particles are discrete, inert particles that are mixed with the catalyst in the fluid bed.
1. A process comprising:
reacting one or more reactants in a reactor comprising a fluid bed to form a product;
wherein the fluid bed comprises a catalyst composition comprising a catalyst and an inert fluidization aid comprising from 0.5 wt % to 30 wt % of silica particles, based on the total weight of the catalyst composition,
wherein the silica particles have an equivalent median particle diameter ranging from 10 microns to 500 microns and a sphericity ranging from 60% to 99.9%.
2. The process of claim 1 , wherein the catalyst comprises one or more of antimony, uranium, iron, bismuth, vanadium, molybdenum, nickel, potassium, cobalt, oxides thereof, or salts thereof.
3. The process of claim 1 , wherein the catalyst has an equivalent median diameter ranging from 1 microns to 125 microns.
4. The process of claim 1 , wherein the silica particles have a real density ranging from 1.8 g/cm 3 to 2.8 g/cm 3 , and wherein the difference between the density of the silica particles and the catalyst is less than 75%.
5. The process of claim 1 , wherein the silica particles have a surface area less than 50 m 2 /g, and wherein the silica particles have a hardness ranging from 500 to 720 as measured by ASTM E384 (2018).
6. The process of claim 1 , wherein the catalyst composition further comprises alumina particles, wherein a weight ratio of alumina particles to silica particles is less than 1:1.
7. The process of claim 1 , wherein the fluidization aid comprises no alumina.
8. The process of claim 1 , wherein the process reduces consumption of the catalyst by greater than 5% per kilogram of product produced, as compared to an otherwise identical process using fluidization aids other than the silica particles.
9. The process of claim 1 , wherein the silica particles reduce erosion of the reactor by greater than 10% compared to an otherwise identical a similar process conducted without from 0.5 wt % to 30 wt % of the silica particles.
10. The process of claim 1 , wherein the process demonstrates a product yield greater than 0.2% greater than that of an otherwise identical a similar process conducted without from 0.5 wt % to 30 wt % of the silica particles.
11. The process of claim 1 , wherein the silica particles have a real density ranging from 2.1 g/cm 3 to 2.5 g/cm 3 , wherein the silica particles have a surface area less than 1 m 2 /g, wherein the silica particles have a hardness ranging from 500 to 720 as measured by ASTM E384 (2018), and wherein the product yield is greater than 70%.
12. The process of claim 1 , wherein the silica particles have an equivalent median particle diameter ranging from 20 microns to 100 microns, wherein the silica particles have a real density ranging from 2.1 g/cm 3 to 2.5 g/cm 3 , wherein the silica particles have a sphericity greater than 67%, wherein the silica particles comprise greater than 99 wt % silica, wherein the product yield is greater than 70%.
13. A process for producing an acrylonitrile product, the process comprising:
reacting one or more reactants in an ammoxidation reactor comprising a fluid bed under ammoxidation conditions to form the acrylonitrile product;
wherein the fluid bed comprises a catalyst composition comprising a catalyst and an inert fluidization aid silica particles having a density from 1.8 g/cm 3 to 2.8 g/cm 3 ,
wherein the silica particles have a sphericity ranging from 60% to 99.9%.
14. The process of claim 13 , wherein the difference between the density of the silica particles and the catalyst is less than 75%, wherein the process demonstrates an acrylonitrile product yield greater than 0.2% greater than that of an otherwise identical process conducted without the silica particles.
15. The process of claim 13 , wherein the one or more reactants comprises an olefin, ammonia, and an oxygen-containing gas.