Abstract: The invention relates on a process for working-up a nitrous oxide comprising off-gas stream from a production process of adipic acid by decomposing the nitrous oxide contained in the off-gas stream into nitrogen and oxygen in a fixed bed reactor (21) of a N2O decomposition unit (9) at a temperature in the range from 430 to 800° C. to obtain a purified gas, wherein for controlling the N2O decomposition unit (9) a nonlinear model predictive control is used which is based on a reactor model of the fixed bed reactor based on equations of energy transport and species transport for nitrogen, oxygen and N2O.

Abstract: The invention relates to a process for decomposing nitrous oxide from a gas stream (1), comprising: (a) heating the gas stream (1) and splitting the gas stream (1) into at least two partial streams (3, 5) or splitting the gas stream (1) into at least two partial streams (3, 5) and heating the partial streams (3, 5); (b) feeding each of the partial streams (3, 5) into a separate decomposition reactor, wherein each reactor (31) comprises a catalyst; (c) decomposing the nitrous oxide into nitrogen and oxygen in the decomposition reactors to obtain purified streams (13, 15); (d) optionally feeding each purified stream (13, 15) into a unit (11) for decomposing nitrogen dioxide and/or nitrogen monoxide or combining at least two purified streams (13, 15) and feeding the combined purified streams into a unit (11) for decomposing nitrogen dioxide and/or nitrogen monoxide, wherein the catalysts of the decomposition reactors (31) are changed alternatingly and wherein one of the catalysts is changed when the arithmetic m

Abstract: The invention relates on a process for working-up a nitrous oxide comprising off-gas stream from a production process of adipic acid by decomposing the nitrous oxide contained in the off-gas stream into nitrogen and oxygen in a fixed bed reactor (21) of a N2O decomposition unit (9) at a temperature in the range from 430 to 800° C. to obtain a purified gas, wherein for controlling the N2O decomposition unit (9) a nonlinear model predictive control is used which is based on a reactor model of the fixed bed reactor based on equations of energy transport and species transport for nitrogen, oxygen and N2O.