A system for producing nitric acid at reduced power consumption, comprising: • an air compressor for compressing air, comprising an inlet and an outlet, to provide in a compressed air stream; • a source of pressurised oxygen-rich gas having a pressure higher than the pressure of the compressed air stream, such as a high pressure water electrolyzer, in fluid communication with the compressed air stream, thereby yielding an oxygen-rich gas/compressed air stream mixture; • a mixing apparatus for mixing the oxygen-rich gas/compressed air stream mixture with an ammonia gas stream, to provide in an ammonia/oxygen-enriched air mixture; an ammonia converter for oxidising ammonia in the ammonia/oxygen-enriched air mixture, to provide in a NO x gas/steam mixture, comprising water and nitric oxide; • means for measuring the temperature in the ammonia converter; • means for regulating the concentration of ammonia and of oxygen in the ammonia converter; • a steam turbine or an electric motor and means for converting steam into electricity, for converting steam into power, in fluid communication with the ammonia converter or the NO x /gas steam mixture; • a water cooler/condenser, for separating and condensing steam from NO x gas in the gaseous NO x gas/steam mixture, thereby generating an aqueous diluted nitric acid mixture and a gaseous NO x stream; • a NO x gas compressor for compressing the gaseous NO x stream, to provide in a compressed NO x gas stream; • an absorption tower downstream the NO x gas compressor for absorbing the NO x gases from the compressed NO x gas stream in water, to provide in a stream of raw nitric acid-containing residual NO x gas and a tail gas comprising NO x gases, comprising an absorption tower tail gas outlet for evacuating the tail gas; and • a tail gas expander for expanding the tail gas, thereby generating an expanded tail gas, downstream of the absorption tower comprising a tail gas expander inlet in fluid communication with the absorption tower tail gas outlet and a tail gas expander outlet; characterised in that: the system further comprises: • means for splitting the tail gas into a first tail gas stream in fluid communication with the tail gas expander inlet and a second tail gas stream, having a pressure P1 or adjusted to a pressure P1, in fluid communication with the compressed air stream; and • means for adjusting the amount of tail gas being split into the first tail gas stream in fluid communication with the tail gas expander inlet and the second tail gas stream in fluid communication with the compressed air stream. • an air compressor for compressing air, comprising an inlet and an outlet, to provide in a compressed air stream; • a source of pressurised oxygen-rich gas having a pressure higher than the pressure of the compressed air stream, such as a high pressure water electrolyzer, in fluid communication with the compressed air stream, thereby yielding an oxygen-rich gas/compressed air stream mixture; • a mixing apparatus for mixing the oxygen-rich gas/compressed air stream mixture with an ammonia gas stream, to provide in an ammonia/oxygen-enriched air mixture; an ammonia converter for oxidising ammonia in the ammonia/oxygen-enriched air mixture, to provide in a NO x gas/steam mixture, comprising water and nitric oxide; • means for measuring the temperature in the ammonia converter; • means for regulating the concentration of ammonia and of oxygen in the ammonia converter; • a steam turbine or an electric motor and means for converting steam into electricity, for converting steam into power, in fluid communication with the ammonia converter or the NO x /gas steam mixture; • a water cooler/condenser, for separating and condensing steam from NO x gas in the gaseous NO x gas/steam mixture, thereby generating an aqueous diluted nitric acid mixture and a gaseous NO x stream; • a NO x gas compressor for compressing the gaseous NO x stream, to provide in a compressed NO x gas stream; • an absorption tower downstream the NO x gas compressor for absorbing the NO x gases from the compressed NO x gas stream in water, to provide in a stream of raw nitric acid-containing residual NO x gas and a tail gas comprising NO x gases, comprising an absorption tower tail gas outlet for evacuating the tail gas; and • a tail gas expander for expanding the tail gas, thereby generating an expanded tail gas, downstream of the absorption tower comprising a tail gas expander inlet in fluid communication with the absorption tower tail gas outlet and a tail gas expander outlet; characterised in that: the system further comprises: • means for splitting the tail gas into a first tail gas stream in fluid communication with the tail gas expander inlet and a second tail gas stream, having a pressure P1 or adjusted to a pressure P1, in fluid communication with the compressed air stream; and • means for adjusting the amount of tail gas being split into the first tail gas stream in fluid communication with the tail gas expander inlet and the second tail gas stream in fluid communication with the compressed air stream. • means for splitting the tail gas into a first tail gas stream in fluid communication with the tail gas expander inlet and a second tail gas stream, having a pressure P1 or adjusted to a pressure P1, in fluid communication with the compressed air stream; and • means for adjusting the amount of tail gas being split into the first tail gas stream in fluid communication with the tail gas expander inlet and the second tail gas stream in fluid communication with the compressed air stream.