SOx/NOx sorbent and process of use
AssigneeW. R. Grace & Co.-Conn.
InventorsMichael S. Ziebarth, Michael J. Hager, Jean W. Beeckman, Stanislaw Plecha
Life of this patent
Estimating the term…
Abstract
An alumina sorbent capable of adsorbing NOx and SOx from waste gases and being regenerated by heating above 600.degree. C. is made by incorporating an alumina stabilizing agent into the sorbent. A preferred method is to add the stabilizer when the alumina is precipitated. The precipitated powder is formed subsequently into a slurry, milled and dripped to form the stabilizing spheroidal alumina particles. These particles are impregnated with an alkali metal or alkaline earth metal to form the stabilized sorbent. Alumina stabilizers include one or more of silica, lanthana, other rare earths, titania, zirconia and alkaline earths.
Claims22
An active ingredient containing stabilized alumina sorbent capable of adsorbing NOx and SOx and other impurities from waste gases and being regenerated by heating above 600.degree. C. comprising stabilized spheroidal alumina particles having
- a surface area of about at least 180 square per gram;
- a compacted bulk density of about 20 to about 45 pounds per cubic foot;
- an average crush strength of at least 4 pounds,
- an attrition loss measured by the Air Jet Attrition method of less than 2%;
- an alumina stabilizer selected from the group consisting of silica, lanthana, other rare earths, titania, zirconia, clay, alkaline earths and mixtures thereof in an amount from an effective amount up to about 30 mole %;
- and
- an active ingredient of a metal selected from the group consisting of alkali metals, alkaline earth metals and mixtures thereof and present in an amount of from about 1 to 20 wt %,
- said sorbent when subjected to the Sorbent Cycle Stability procedure having its surface area dropping less than 60 m.sup.2 /g from the 20th to the 100th cycle, and
- said sorbent when subjected to the Hydrothermal Stability procedure maintaining a BET surface area of at least 100 m.sup.2 /g.
A method of producing an active ingredient containing stabilized alumina sorbent capable of adsorbing NOx and SOx from waste gases and being regenerated by heating above 600.degree. C. comprising:
- co-precipitating alumina forming reactants and an alumina stabilizer material to form a stabilized alumina powder;
- reducing the particle size of said alumina powder to obtain an average particle size of less than 10 microns;
- forming substantially uniform spheroidal alumina particles by forming droplets of the slurry which are passed through air into a column containing an upper body of a water immiscible liquid and ammonia and into a lower body of aqueous alkaline coagulating agent;
- drying and calcining the particles;
- impregnating the calcined particles with an active ingredient selected from the group consisting of an alkali metal, alkaline earth metal and mixtures thereof;
- and
- drying and calcining the impregnated particles to form the sorbent.
A method of producing an active ingredient containing stabilized alumina sorbent capable of adsorbing NOx and SOx from waste gases and being regenerated by heating above 600.degree. C. comprising:
- forming a slurry of alumina powder, an alumina stabilizer material and reducing the particle size of the powder to obtain an average particle size of less than 10 microns;
- forming substantially uniform spheroidal alumina particles by forming droplets of the slurry which are passed through air into a column containing an upper body of a water immiscible liquid and ammonia and into a lower body of aqueous alkaline coagulating agent;
- drying and calcining the particles;
- impregnating the calcined particles with an alkali metal or alkaline earth metal;
- and
- drying and calcining the impregnated particles to form the sorbent.
A method of producing an active ingredient containing stabilized alumina sorbent capable of adsorbing NOx and SOx from waste gases and being regenerated by heating above 600.degree. C. comprising:
- forming a slurry of alumina powder and reducing the particle size of the powder to obtain an average particle size of less than 10 microns;
- forming substantially uniform spheroidal alumina particles by forming droplets of the slurry which are passed through air into a column containing an upper body of a water immiscible liquid and ammonia and into a lower body of aqueous alkaline coagulating agent;
- drying and calcining the particles;
- impregnating the calcined particles with the following two components
- a) an alumina stabilizer material, and
- b) an alkali metal or alkaline earth metal, said two components being either added together or sequentially in any order;
- and
- drying and calcining the impregnated particles to form the sorbent.
A method of producing an active ingredient containing stabilized alumina sorbent capable of adsorbing NOx and SOx from waste gases and being regenerated by heating above 600.degree. C. comprising:
- forming alumina particles from
- i) an alumina powder having a particle size less than 10 microns;
- ii) an alumina stabilizer selected from the group consisting of silica, lanthana, other rare earths, titania, zirconia, clay, alkaline earths and mixtures thereof in an amount from an effective amount up to about 30 mole %;
- and
- iii) an active ingredient of a metal selected from the group consisting of alkali metals, alkaline earth metals and mixtures thereof and present in an amount of from about 1 to 20 wt %;
- and
- calcining the particles to form the sorbent.
Dependencies are inferred from the claim text.