Sorbent composition for an electrostatic precipitator

Patent metadata

Field	Value
Publication number	US-10898876-B2
Application number	US-201715657294-A
Country	US
Kind code	B2
Filing date	Jul 24, 2017
Priority date	Jul 24, 2017
Publication date	Jan 26, 2021
Grant date	Jan 26, 2021

Abstract

A powdery calcium-magnesium compound, sorbent composition is shown which is based on calcium-magnesium. The compound is used in flue gas treatment and has characteristics which make it particularly compatible with electrostatic precipitators used in flue gas treatment installations.

First claim

The invention claimed is:

1. A powdery calcium-magnesium compound comprising at least a calcium-magnesium carbonate content or a calcium-magnesium hydroxide content greater or equal to 80 weight %, doped with at least one metallic ion M, and at least one counter ion X,
wherein the at least one metallic ion M is selected from the group consisting of Cu 2+ , Fe 2+ , and Fe 3+ , Mn 2+ , Co 2+ Mo 2+ , Ni 2+ , Zn 2+ in an amount greater than or equal to 0.05 weight % and lower or equal to 5 weight %;
wherein the at least one counter ion X is selected from the group consisting of nitrates, nitrites and their mixtures at an amount greater than or equal to 0.05 weight % and lower or equal to 5 weight %,
said weight percentages being expressed with respect to the total weight of the powdery calcium-magnesium compound, and
said powdery calcium-magnesium compound presenting a resistivity at 300° C. (372° F.) (R 300 ) lower than 1E11 (1×10 11 ) Ohms·cm and higher than 1E7 (1×10 7 ) Ohms·cm.

2. A powdery calcium-magnesium compound according to claim 1 , presenting a maximum (Rmax) lower than 1E11 (1×10 11 ) Ohms·cm.

3. A powdery calcium-magnesium compound according to claim 1 , wherein the total weight of said metallic ion and said counter ion is greater than or equal to 0.1 weight % and lower than or equal to 5 weight % with respect to the total weight of the powdery calcium-magnesium compound.

4. A powdery calcium-magnesium compound according to claim 1 , further comprising sodium in an amount up to 3.5 weight % with respect to the total weight of the powdery calcium-magnesium compound, expressed as sodium equivalent.

5. A powdery calcium-magnesium compound according to claim 1 , wherein said metallic ion M is selected from the group consisting of Cu 2+ , Fe 2+ , Fe 3+ .

6. A powdery calcium-magnesium compound according to claim 1 , wherein said at least one counter ion X is nitrate.

7. A powdery calcium-magnesium compound according to claim 1 , presenting a BET specific surface area by nitrogen adsorption of at least 20 m 2 /g.

8. A powdery calcium-magnesium compound according to claim 1 , presenting a BJH pore volume for pores having a diameter lower or equal to 1000 Å by nitrogen desorption of at least 0.1 cm 3 /g.

9. A sorbent composition for flue gas treatment installation including an electrostatic precipitator comprising a powdery calcium-magnesium compound, the powdery calcium-magnesium compound comprising at least a calcium-magnesium carbonate content or a calcium-magnesium hydroxide content greater or equal to 80 weight %, said powdery calcium-magnesium compound being doped with at least one metallic ion M, and at least one counter ion X,
wherein the at least one metallic ion M is selected from the group consisting of Cu 2+ , Fe 2+ , and Fe 3+ , Mn 2+ , Co 2+ , Mo 2+ , Ni 2+ , Zn 2+ in an amount greater than or equal to 0.05 weight % and lower or equal to 5 weight %;
wherein the at least one counter ion X is selected from the group consisting of nitrates, nitrites and their mixtures at an amount greater than or equal to 0.05 weight % and lower or equal to 5 weight %,
said weight percentages being expressed with respect to the total weight of the powdery calcium-magnesium compound, and
said powdery calcium-magnesium compound presenting a resistivity at 300° C. (372° F.) (R 300 ) lower than 1E11 (1×10 11 ) Ohms·cm and higher than 1E7 (1×10 7 ) Ohms·cm.

10. A sorbent composition according to claim 9 , further comprising a compound selected from the group consisting of activated charcoal, lignite coke, halloysite, sepiolite, clays, bentonite, kaolin, vermiculite, fire clay, aerated cement dust, perlite, expanded clay, lime sandstone dust, trass dust, Yali rock dust, trass lime, fuller's earth, cement, calcium aluminate, sodium aluminate, calcium sulphide, organic sulphide, calcium sulfate, open-hearth coke, lignite dust, fly ash and water glass.

11. A sorbent composition according to claim 9 , further comprising a sodium additive comprising sodium in an amount up to 3.5 weight % with respect to the total weight of the powdery sorbent composition and expressed as sodium equivalent.

12. A sorbent composition according to claim 9 , wherein said calcium-magnesium compound is hydrated lime.

13. A sorbent composition according to claim 9 , further comprising water in such an amount that the sorbent composition is under the form of a suspension.

14. A sorbent composition according to claim 13 , where the sorbent composition is under the form of a milk of lime.

15. A process for manufacturing a sorbent composition comprising the powdery calcium-magnesium compound of claim 1 , the process comprising the steps of:
a) providing a calcium-magnesium compound to a reactor;
b) adding an additive or a mixture of additives, comprising at least one metallic ion M and/or a counter ion X with M being a metallic ion having an atomic number less than or equal to 74 and being a transition metal ion or a post-transition metal ion, and X being one of the counter ions selected from the group consisting of nitrates, nitrites, oxides O 2− , and hydroxide OH— and their mixture in an amount calculated to obtain between 0.1 weight % and 5 weight % of said metallic ion M and for counter ion X based on the weight of dry sorbent composition.

16. A process according to claim 15 , wherein said calcium-magnesium compound comprises at least a calcium-magnesium carbonate content greater or equal to 80 weight % with respect to the total weight of the dry calcium-magnesium compound.

17. A process according to claim 15 , wherein said calcium-magnesium compound comprises a calcium-magnesium hydroxide content greater or equal to 80 weight %, with respect to the total weight of the dry calcium-magnesium compound.

18. A process for manufacturing a sorbent composition according to claim 15 , characterized in that the said metallic ion M is selected from the group consisting Cu 2+ , Fe 2+ , Fe 3+ , Mn 2+ , Co 2+ , Mo 2+ , and Zn 2+ .

19. A process for manufacturing a sorbent composition according to claim 15 , characterized in that said metallic ion M is selected from the group consisting of Cu 2+ , Fe 2+ , Fe 3+ .

20. A process for manufacturing, a sorbent composition according to claim 15 , characterized in that said counter ion X is nitrate.

21. A process for manufacturing a sorbent composition according to claim 15 , characterized in that it comprises a step of adding another additive comprising sodium expressed as sodium equivalent in an amount calculated to obtain up to 3.5% of sodium equivalent in weight of the dry sorbent composition.

22. A process for manufacturing a sorbent composition according to claim 15 , characterized in that it further comprises a step of adding a compound selected from the group consisting of activated charcoal, lignite coke, halloysite, sepiolite, clays, bentonite, kaolin, vermiculite, fire clay, aerated cement dust, perlite, expanded clay, lime sandstone dust, trass dust, Yali rock dust, trass lime, fuller's earth, cement, calcium aluminate, sodium aluminate, calcium sulphide, an organic sulphide, calcium sulfate, open-health coke, lignite dust, fly ash and water glass.

23. A process according to claim 15 , wherein said step of providing a calcium-magnesium compound to a reactor comprises the steps of providing a quicklime to said reactor, slaking said quicklime with a predetermined amount of water to obtain said calcium-magnesium compound comprising at least a calcium hydr

Assignees

• Lhoist Rech Et Developpement Sa
• S A Lhoist Rech Et Development

Inventors

• Foo Rodney
• Filippelli Gregory Martin
• Heiszwolf Johan

Classifications

• B01J20/043 Primary

  Carbonates or bicarbonates, e.g. limestone, dolomite, aragonite · CPC title

• B01D2251/604

  Hydroxides · CPC title

• B01D2251/404

  of calcium · CPC title

• B01J20/041

  Oxides or hydroxides · CPC title

• B01J20/28071

  being less than 0.5 ml/g · CPC title