Highlighting on: * Beneficial Use of Nitrous Oxide When Manufactured, and * Its Adverse Impact When Emitted In Traces With the Industrial Gaseous Effects and Other Human Activities

Highlighting on Beneficial Use of Nitrous Oxide When Manufactured  Introduction  Properties (colourless, critical temperature, critical pressure, boiling point…)  Uses of Nitrous oxide (medicine, semi conductor industry, …)  Nitrous oxide manufacture and market volume NH 4 NO 3 N 2 O + H 2 O 180 o C

Adverse Impact of Involuntarily Emitted Nitrous Oxide There are 2 major sources of N 2 O emissions : 1. Improper application of N-fertilizers in agriculture 2. Oxidation of ammonia for nitric acid manufacture

3. Development of the Nitric Acid Technology  Basic chemistry of nitric acid process has not changed in the last hundred years.  N.B. 4NH 3 + 5O 2  4NO + 6H 2 O 2NO + O 2  2NO 2 3NO 2 + H 2 O  2HNO 3 + NO 4NH 3 + 4O 2  2N 2 O + 6H 2 O 4NH 3 + 3O 2  2N 2 + 6H 2 O 4NH 3 + 6NO  5N2 + 6H 2 O

O 2 /NH 3 ratio O 2 /NH 3 ratio Fig. 1 Change I nitric oxide yield as a function of oxygen-to- ammonia ratio

Development in Nitric Acid Technology  Among various development in nitric acid technology the following milestones are cited:  Development of material of construction:  Construct larger ammonia converters  Construct of big absorption towers for N 2 O  Development of Catalyst:

Variance in N2O as % OMT pack optimized mass transfer Standard knitted pack N 2 O in ppm Yield in % N 2 O in ppm Yield in % Oxide formation is reduced as shown in this table

Development of abatement systems for NOx in general and N 2 O in particular  The boom in the measuring instrument made it possible to measure continuously NH 3 / NOx in the tail gas (or exhaust goal thus reducing excess ammonia to about)  The development in the catalysis (SCR selective catalytic reduction) made it possible to improve the performance of abatement reaction considerably. To less than 50 pm in tail gas

Development of abatement systems for NOx in general and N 2 O in particular  The latest development includes a catalyst and process of reducing N 2 O emissions at the top of the same reactor of NOx emissions The tail gas upstream of tail gas turbine is fed to the reactor first catalyst bed for catalytic thermal decomposition of N2O The tail gas upstream of tail gas turbine is fed to the reactor first catalyst bed for catalytic thermal decomposition of N2O N 2 O  N 2 + ½ O KJ N 2 O  N 2 + ½ O KJ Then the tail gas is mixed with ammonia before entering the second catalyst bed where NOx is catalytically reduced to N 2 & water vapor Then the tail gas is mixed with ammonia before entering the second catalyst bed where NOx is catalytically reduced to N 2 & water vapor 4NO + 4HH 3 + O 2  4N 2 + 6H 2 O-1628 KJ 4NO + 4HH 3 + O 2  4N 2 + 6H 2 O-1628 KJ 3NO 2 + 4NH 3  7/2 N H 2 O KJ 3NO 2 + 4NH 3  7/2 N H 2 O KJ