Method of removing ammonia from fly ash and fly ash composition produced thereby
View Patent ↗A method of treating fly ash and fly ash treated thereby, the method involving contacting ammonia-laden fly ash with an organic base-containing treatment composition, where the organic base causes the ammonia within the fly ash to evolve from the fly ash. The treatment composition preferably includes an effective amount of one or more amines. The treatment compound may be applied to the fly ash in any manner effective to disperse the treatment compound among the fly ash.
1. A method for reducing the ammonia content of ammonia-laden fly ash, comprising the steps of
supplying an ammonia-laden fly ash;
supplying a treatment composition one or more amines; and
contacting the ammonia-laden fly ash with the treatment composition to reduce the ammonia content of the ammonia-laden fly ash.
2. The method of claim 1 , wherein the treatment composition is a non-aqueous composition.
3. The method of claim 1 , wherein the one or more amines are selected from the group consisting of amines with a pK b value of less than 4.75.
4. The method of claim 1 , wherein the one or more amines include one or more amines selected from the group consisting of cycloamines, diamines, polyamines, and compounds represented by formula (I)
where R 1 and R 2 are independently selected from hydrogen, C 1 -C 8 alkyl, C 1 -C 4 hydroxyalkyl, aryl, and hydroxyaryl, wherein the alkyl, hydroxyalkyl, aryl and hydroxyaryl groups may be substituted or unsubstituted and branched or unbranched, and R 3 is selected from C 1 -C 18 alkyl, C 1 -C 4 hydroxyalkyl (including alkoxylated hydroxyalkyl), aryl, hydroxyaryl, and C 2 -C 4 alkenyl, wherein the alkyl, hydroxyaryl, aryl, hydroxyaryl and alkenyl groups may be substituted or unsubstituted and branched or unbranched.
5. The method of claim 4 , wherein the one or more amines includes one or more amines selected from the group consisting of compounds represented by formula (I)
wherein R 1 is selected from hydrogen and C 1 -C 8 alkyl wherein the alkyl groups may be substituted or unsubstituted and branched or unbranched; R 2 is selected from hydrogen, C 1 -C 8 alkyl and C 1 -C 4 hydroxyalkyl, wherein the alkyl and hydroxyalkyl groups maybe substituted or unsubstituted and branched or unbranched, and R 3 is selected from C 1 -C 18 alkyl, C 1 -C 4 hydroxyalkyl (which may be alkoxylated with 1-3 oxyalkylene groups), aryl, and C 2 -C 4 alkenyl, wherein the alkyl, hydroxylalkyl, aryl and alkenyl groups may be substituted or unsubstituted and branched or unbranched.
6. The method of claim 4 , wherein the one or more amines are selected from the group consisting of monoethanol amine, diethanol amine, triethanol amine, 1-amino-2-propanol, 2-amino-2-methyl-1-propanol, 3-amino-1-propanol, 2-(methylamino)-ethanol, 2-(2-aminoethyoxy)ethanol, ethylenediamine, and diethylenetriamine.
7. The method of claim 4 , wherein the one or more amines selected from the group consisting of cycloamines, diamines, polyamines, and amines represented by formula (I) includes one or more amines with a pK b value of less than 4.75.
8. The method of claim 4 , wherein the one or more amines selected from the group consisting of cycloamines, diamines, polyamines, and amines represented by formula (I) includes two or more amines with a pK b value of less than 4.75.
9. The method of claim 4 , wherein the one or more amines selected from the group consisting of cycloamines, diamines, polyamines, and amines represented by formula (I) includes one or more amines with a pK b value of less than 4.75 and one or more amines with a pK b value of more than 4.75.
10. The method of claim 1 , wherein the water content in the treatment composition produces a treated fly ash having less than 1.5 wt % water, based on the total wt % of the fly ash.
11. The method of claim 1 , wherein the treatment composition is supplied as a liquid spray.
12. The method of claim 1 , wherein the treatment composition is supplied as a vapor.
13. The method of claim 1 , further comprising the step of
agitating the combined fly ash and the treatment composition to facilitate commingling of the fly ash and the treatment composition.
14. The method of claim 1 , wherein the step of contacting the ammonia-laden fly ash with the treatment composition comprises the step of
determining the amount of the treatment composition to be applied to the ammonia-laden fly ash based on the flow rate of the fly ash.
15. The method of claim 1 , wherein the step of dispersing the treatment composition into the fly ash comprises the steps of
pressurizing the treatment composition prior to contacting the treatment composition with the fly ash.
16. The method of claim 1 , further comprising the step of
contacting the fly ash with a treating fluid comprising an agent selected from the group consisting of sacrificial agents, surfactants, dispersants, chemical activators, coating compositions, and combinations thereof.
17. The method of claim 1 , wherein the treatment composition further comprises at least one alkaline salt.
18. The method of claim 17 , wherein the treatment composition further comprises at least one alkaline salt selected from the group consisting of sodium carbonate, sodium aluminate, and sodium silicate.
19. A method for reducing the ammonia content of ammonia-laden fly ash, comprising the steps of
supplying an ammonia-laden fly ash;
supplying a treatment composition comprising one or more organic bases having a pK b value of less than 4.75; and
contacting the ammonia-laden fly ash with the treatment composition to reduce the ammonia content of the ammonia-laden fly ash.
20. The method of claim 19 , wherein the treatment composition is a non-aqueous composition.
21. The method of claim 19 , wherein the treatment composition comprises one or more amines.
22. The method of claim 21 , wherein the one or more amines include one or more amines selected from the group consisting of cycloamines, diamines, polyamines, and compounds represented by formula (I)
where R1 and R2 are independently selected from hydrogen, C1-C8 alkyl, C1-C4 hydroxyalkyl, aryl, and hydroxyaryl, wherein the alkyl, hydroxyalkyl, aryl and hydroxyaryl groups may be substituted or unsubstituted and branched or unbranched, and R3 is selected from C1-C18 alkyl, C1-C4 hydroxyalkyl (including alkoxylated hydroxyalkyl), aryl, hydroxyaryl, and C2-C4 alkenyl, wherein the alkyl, hydroxyaryl, aryl, hydroxyaryl and alkenyl groups may be substituted or unsubstituted and branched or unbranched.
23. The method of claim 22 , wherein the one or more amines includes one or more amines selected from the group consisting of compounds represented by formula (I)
wherein R 1 selected from hydrogen and C 1 -C 8 alkyl wherein the alkyl groups may be substituted or unsubstituted and branched or unbranched; R2 is selected from hydrogen, C1-C8 alkyl and C1-C4 hydroxyalkyl, wherein the alkyl and hydroxyalkyl groups maybe substituted or unsubstituted and branched or unbranched, and R3 is selected from C1-C18 alkyl, C1-C4 hydroxyalkyl (which may be alkoxylated with 1-3 oxyalkylene groups), aryl, and C2-C4 alkenyl, wherein the alkyl, hydroxylalkyl, aryl and alkenyl groups may be substituted or unsubstituted and branched or unbranched.
24. The method of claim 22 , wherein the one or more amines are selected from the group consisting of monoethanol amine, diethanol amine, triethanol amine, 1-amino-2-propanol, 2-amino-2-methyl-1-propanol, 3-amino-1-propanol, 2-(methylamino)-ethanol, 2-(2-aminoethyoxy)ethanol, ethylenediamine, and diethylenetriamine.
25. The method of claim 22 , wherein the one or more amines selected from the group consisting of cycloamines, diamines, polyamines, and amines represented by formula (I) includes two or more amines with a pK b value of less than 4.75.
26. The method of claim 22 , wherein the one or more amines selected from the group consisting of cycloamines, diamines, polyamines, and amines represented by formula (I) includes one or more amines with a pK b value of less than 4.75 and one or more amines with a pK b value of more than 4.75.
27. The method of claim 19 , wherein the water content in the treatment composition produces a treated fly ash having less than 1.5 wt % water, based on the total wt % of the fly ash.
28. The method of claim 19 , wherein the treatment composition is supplied as a liquid spray.
29. The method of claim 19 , wherein the treatment composition is supplied as a vapor.
30. The method of claim 19 , further comprising the step of
agitating the combined fly ash and the treatment composition to facilitate commingling of the fly ash and the treatment composition.
31. The method of claim 19 , wherein the step of contacting the ammonia-laden fly ash with the treatment composition comprises the step of
determining the amount of the treatment composition to be applied to the ammonia-laden fly ash based on the flow rate of the fly ash.
32. The method of claim 19 , wherein the step of dispersing the treatment composition into the fly ash comprises the steps of
pressurizing the treatment composition prior to contacting the treatment composition with the fly ash.
33. The method of claim 19 , further comprising the step of
contacting the fly ash with a treating fluid comprising an agent selected from the group consisting of sacrificial agents, surfactants, dispersants, chemical activators, coating compositions, and combinations thereof.
34. The method of claim 19 , wherein the treatment composition further comprises at least one alkaline salt.
35. The method of claim 34 , wherein the treatment composition further comprises at least one alkaline salt selected from the group consisting of sodium carbonate, sodium aluminate, and sodium silicate.