Chloramine and chlorine removal material and methods for making the same
AssigneeCalgon Carbon Corporation
InventorsJason Mazzoccoli, Walter G. Tramposch, Ryan Walker, Robert H. Vaughn
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Abstract
Sorbent materials are described that have enhanced performance in removing chlorine and chloramine, among other toxic compounds. The sorbent materials are formed by a process which includes steps of oxidation, adding a nitrogen-containing compound, and calcining the sorbent. The processes of forming the sorbent materials are also disclosed. The sorbent materials have excellent performance as measured by a chloramine and/or chlorine destruction number, and the sorbents retain a high nitrogen edge concentration. The sorbent materials may also be incorporated into devices such as filter assemblies.
Claims36
A method for making a sorbent, comprising the steps of:
- (a) providing a sorbent feedstock which has not been exposed to a nitrogen containing precursor and selected from the group consisting of activated carbon,
- (b) oxidizing the sorbent feedstock to form an oxidized sorbent feedstock,
- (c) adding a nitrogen containing precursor to the oxidized sorbent feedstock, wherein the nitrogen containing precursor is a reduced nitrogen compound,
- (d) heating the oxidized sorbent feedstock exposed to nitrogen containing precursor in step (c) to a temperature of at least about 400° C. under an inert atmosphere to form a calcined sorbent feedstock, and
- (e) cooling the calcined sorbent feedstock under the inert atmosphere immediately after the heating step,
- wherein the steps (a) to (e) is conducted in the order from (a) to (e), and
- wherein the sorbent feedstock, oxidized sorbent feedstock, or calcined sorbent feedstock are not subsequently activated with one or more of H2O, CO2, O2, or any combination thereof.
A method for making a sorbent, comprising the steps of:
- (a) providing a sorbent feedstock,
- (b) oxidizing the sorbent feedstock to form an oxidized sorbent feedstock,
- (c) adding a nitrogen containing precursor to the oxidized sorbent feedstock, wherein the nitrogen containing precursor is a reduced nitrogen compound,
- (d) heating the oxidized sorbent feedstock exposed to nitrogen containing precursor in step (c) to a temperature of at least about 400° C. under an inert atmosphere to form a calcined sorbent feedstock, and
- (e) cooling the calcined sorbent feedstock under the inert atmosphere immediately after the heating step (d) without activation of the calcined sorbent feedstock with one of H2O, CO2, O2, or any combination thereof,
- wherein the steps (a) to (e) is conducted in the order from (a) to (e), and
- further comprising a step of adding a sorbent feedstock which has not been treated in the amount of about 5 wt. % to about 95 wt. % based on the total amount of the formed sorbent.
A sorbent formed by a method comprising the steps of:
- (a) providing a sorbent feedstock which has not been exposed to a nitrogen containing precursor and selected from the group consisting of activated carbon,
- (b) oxidizing the sorbent feedstock to form an oxidized sorbent feedstock,
- (c) adding a nitrogen containing precursor to the oxidized sorbent feedstock, wherein the nitrogen containing precursor is a reduced nitrogen compound,
- (d) heating the oxidized sorbent feedstock exposed to nitrogen containing precursor in step (c) to a temperature of at least about 400° C. under an inert atmosphere to form a calcined sorbent feedstock, and
- (e) cooling the calcined sorbent feedstock under the inert atmosphere immediately after the heating step,
- wherein the steps (a) to (e) is conducted in the order from (a) to (e), and
- wherein the sorbent feedstock, oxidized sorbent feedstock, or calcined sorbent feedstock are not subsequently activated with one or more of H2O, CO2, O2, or any combination thereof.
A sorbent formed by a method comprising the steps of:
- (a) providing a sorbent feedstock,
- (b) oxidizing the sorbent feedstock to form an oxidized sorbent feedstock,
- (c) adding a nitrogen containing precursor to the oxidized sorbent feedstock, wherein the nitrogen containing precursor is a reduced nitrogen compound,
- (d) heating the oxidized sorbent feedstock exposed to nitrogen containing precursor in step (c) to a temperature of at least about 400° C. under an inert atmosphere to form a calcined sorbent feedstock, and
- (e) cooling the calcined sorbent feedstock under the inert atmosphere immediately after the heating step (d) without activation of the calcined sorbent feedstock with one of H2O, CO2, O2, or any combination thereof,
- wherein the steps (a) to (e) is conducted in the order from (a) to (e), and
- further comprising a sorbent feedstock which has not been treated in the amount of about 5 wt. % to about 95 wt. % based on the total amount of the sorbent.
Dependencies are inferred from the claim text.