Apparatus and process for conversion of ammonia into oxides of nitrogen
AssigneeDeepak Nitrite Limited
InventorSanjay Kumar Suman
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Abstract
Disclosed is an apparatus for conversion of ammonia into oxides of nitrogen which may comprise an adiabatic burner (108), a set of platinum/rhodium alloy catalytic gauzes (102A), (102B), and (102C), a waste heat recovery boiler (WHRB) (110), an absorption tower (302A), (302B), (302C), (302D) and (302E), a NaOH tank (306) and a surge tank (304). Further, the adiabatic burner may be configured to carry out catalytic oxidation of air and ammonia, using catalytic gauzes (102A), (102B), and (102C) of platinum/rhodium alloy. Further, the mixture of air and ammonia may be selectively oxidized to oxides of nitrogen, which may be absorbed in an alkali medium in the absorption tower (302A), (302B), (302C), (302D) and (302E), to yield sodium nitrites and nitrates.
Claims10
An apparatus for conversion of ammonia to sodium nitrite comprising;
- at least one adiabatic burner (108) used to carry out the oxidation of a mixture comprising air and ammonia, wherein the adiabatic burner (108) is enabled to maintain a pressure range between 1-4 bar and a temperature between 850° C.-950° C.;
- at least three pairs of catalytic gauzes (102A), (102B), (102C) enabled to carry out efficient oxidation of the air-ammonia mixture to selectively form nitrogen dioxide;
- at least one waste heat recovery boiler (WHRB) (110) equipped with the adiabatic burner (108), enabled to saturate the oxides of nitrogen by reducing the temperature of the oxides of nitrogen, and more specifically nitrogen dioxide;
- and at least one absorption tower unit (302A), (302B), (302C), (302D), and (302E) enabled to absorb the saturated nitrogen dioxide in an alkali media for selective formation of sodium nitrite.
A process (400) of conversion of ammonia into sodium nitrite, wherein the process comprises:
- introducing, (401) a mixture of air-ammonia gas into the adiabatic burner (108) at a temperature between 150° C.-170° C.;
- heating, (402) the air ammonia mixture in the burner (108) at a temperature up to 950° C. to carry out oxidation process;
- transmitting, (403) the mixture of air-ammonia through catalytic gauzes (102A), (102B),
- (102C);
- maintaining, (404) the required pressure and temperature of the adiabatic burner (108) to carry out the selective oxidation process, wherein the oxidation process is carried out at pressure between 1-4 bar and temperature between 850° C.-950° C. and for a pre-determined time period to selectively obtain nitrogen dioxide;
- transferring, (405) the composition of oxides of nitrogen to the waste heat recovery boiler (WHRB) (110) to saturate and cool the nitrogen dioxide composition to a set temperature, wherein the temperature of the composition is reduced from 950° C. up to 200° C.;
- passing, (406) saturated nitrogen dioxide from the bottom of the WHRB to absorption towers (302A), (302B), (302C), (302D), and (302E);
- and forming, (407) selectively a sodium nitrite by absorbing the composition of nitrogen dioxide in alkali medium.
The process as claimed in claim 8, wherein the process comprises an adiabatic burner (108) which is either a single type burner or double type burner.
The process as claimed in claim 8, wherein the gas flows into the adiabatic burner (108) at an inlet velocity between 15-20 m/s, wherein the gas is later oxidised to form oxides of nitrogen.
Dependencies are inferred from the claim text.