A process and a device for the production of ammonia at different pressure levels may involve removing gases that are inert (inert gases) or harmful with regard to ammonia synthesis from the process in a process step before the ammonia synthesis so that enrichment of these is decreased or suppressed. For example, with respect to a gas mixture that includes hydrogen, nitrogen, water, methane, carbon monoxide, and carbon dioxide, at least part of the water, at least part of the methane, at least part of the carbon monoxide, and at least part of the carbon dioxide may be removed from the gas mixture before the synthesis of the ammonia occurs.

A novel concept for a high energy and material efficient nitric acid production process and system is provided, wherein the nitric acid production process and system, particularly integrated with an ammonia production process and system, is configured to recover a high amount of energy out of the ammonia that it is consuming, particularly in the form of electricity, while maintaining a high nitric acid recovery in the conversion of ammonia to nitric acid. The energy recovery and electricity generation process comprises pressurizing a liquid gas, such as air, oxygen and/or N.sub.2, subsequently evaporating and heating the pressurized liquid gas, particularly using low grade waste heat generated in the production of nitric acid and/or ammonia, and subsequently expanding the evaporated pressurized liquid gas over a turbine. In particular, the generated electricity is at least partially used to power an electrolyzer to generate the hydrogen needed for the production of ammonia. The novel concepts set out in the present application are particularly useful in the production of nitric acid based on renewable energy sources.

A dual pressure process for the synthesis of ammonia from a make-up gas, wherein the make-up gas is reacted in two steps in series, the second step operating at a greater pressure than the first step, and wherein a portion of the effluent of the first step is recycled back to the first step, said portion containing unreacted make-up gas.

A renewable ammonia synthesis process is provided.

The invention relates to a method for the synthesis of ammonia, in which a fresh gas consisting largely of hydrogen and nitrogen is compressed via a compressor and subsequently fed to an ammonia converter for conversion into a converter product containing ammonia and comprising hydrogen and nitrogen. Upstream of the compressor, ammonia is evaporated into the fresh gas in order to cool the fresh gas and to produce a cold substance mixture comprising ammonia and the fresh gas. The substance mixture is heated in a heat exchanger against at least one process stream to be cooled, and subsequently compressed via the compressor, to obtain a compressed substance mixture comprising ammonia and the fresh gas. Upstream of the circuit cooler, a gas mixture consisting largely of hydrogen and nitrogen is fed to a substance stream comprising the fresh gas. The constituents of the gas mixture are separated from the converter product and/or from the compressed substance mixture comprising ammonia and the fresh gas.

Included are an ammonia synthesis column that synthesizes ammonia from a raw material gas, a discharge line that discharges a synthetic gas, a water-cooled cooler that cools the synthetic gas with a coolant, disposed in the discharge line, an ammonia separator into which a synthetic gas after cooling is introduced and which separates the ammonia gas and a liquid ammonia from each other, a raw material return line that returns a raw material gas containing the separated ammonia gas to the ammonia synthesis column side as a return raw material gas, and a compressor that compresses the return raw material gas, disposed in the raw material return line. An ammonia concentration in the return raw material gas is 5 mol % or more, and an ammonia synthesis catalyst that synthesizes the ammonia gas in the ammonia synthesis column is a ruthenium catalyst.

In a process for the production of ammonia in at least two reaction systems, in which ammonia is produced from a portion of the synthesis gas in each of the systems with a part-stream being withdrawn, the make-up gas is essentially inert-free, the downstream system is at the same pressure or at a higher pressure than the upstream system and the make-up gas is sent once through a make-up gas (MUG) converter unit, the residual synthesis gas coming from the MUG converter unit is optionally pressurized to a higher pressure before being sent to an inert-free synthesis loop. This way, an economically attractive production of ammonia is feasible with synthesis gases not containing inerts.

The invention relates to a method for operating an ammonia cooling circuit of an ammonia synthesis plant for preventing pressure variations in the cooling circuit due to varying load or outlet temperatures, wherein the method comprises: iii-1) adapting the liquid level of condensing ammonia inside the ammonia condensing unit of the cooling circuit according to the pressure of the compressed ammonia vapor stream, in which the ammonia condensing unit is a tube-shell heat exchanger; and/or iii-2) adapting the flow of cooling medium to the ammonia condensing unit according to the pressure of the compressed ammonia vapor stream of the cooling circuit; and/or iii-3) adapting the temperature of cooling medium directed to the ammonia condensing unit by recycling a portion of the cooling medium return stream. The invention relates also to an ammonia cooling circuit arranged for carrying out the method, its use for revamping an ammonia synthesis plant into a green ammonia synthesis plant, and an ammonia synthesis plant comprising the ammonia cooling circuit.

A method for treatment of process condensate (1) in an ammonia plant, wherein the ammonia plant comprises a front-end section producing a make-up gas and a synthesis section where the make-up gas is reacted to ammonia, and said process condensate (1) is collected from one or more equipment of the ammonia plant and is an aqueous solution comprising ammonia, carbon dioxide and methanol. Said method comprises: stripping said process condensate with low-pressure steam (4), obtaining a vapour phase (5) comprising ammonia, carbon dioxide and methanol stripped from the process condensate; condensing said vapour phase, obtaining a solution (11) enriched of ammonia and methanol; re-introducing a first portion (12) of said solution to said stripping environment; recycling a second portion (13) of said solution to said ammonia plant.

A method and an apparatus for producing ammonia, in which a first hydrogen/nitrogen fraction is provided at a time-varying flow rate in order to form an ammonia synthesis gas which is converted to ammonia in an ammonia synthesis, wherein the first hydrogen/nitrogen fraction is supplemented by a second hydrogen/nitrogen fraction in such a way that, during normal operation, the ammonia synthesis gas can always be supplied to the ammonia synthesis at a flow rate which exceeds a predefined minimum value. The characterizing feature is that ammonia produced in the ammonia synthesis is transferred in liquid form to a storage means from which ammonia is taken and split into hydrogen and nitrogen in order to obtain hydrogen and nitrogen so as to form the second hydrogen/nitrogen fraction.