Abstract: Reactor for catalytic chemical reactions comprising a catalyst bed with an annular-cylindrical form crossed by a radial flow or mixed axial-radial flow, wherein the bed is delimited by cylindrical walls made gas-permeable by means of slits and the catalyst bed is formed by particles of catalyst with a nominal minimum size such that: the ratio between a transverse dimension of the slits and the nominal minimum size of the particles of catalyst is smaller than or equal to 0.6; the catalyst bed contains no more than 3% by weight of particles with an actual size smaller than said nominal size.

Abstract: Process for synthesis of ammonia wherein the synthesis of ammonia is performed in a high-pressure synthesis loop which is partially fed with green hydrogen produced from a renewable energy source and hydrogen recovered from a purge stream of the loop is stored in a hydrogen storage to compensate for temporary lack of the green hydrogen when the renewable energy source is not fully available.

Abstract: Method for preparing a synthesis gas suitable for the synthesis of ammonia or methanol, the method comprises the step of feeding to the radiant portion of a primary reformer an oxygen-enriched air obtained by mixing air with an oxygen stream generated by water electrolysis.

Abstract: A multi-bed catalytic converter comprising: a plurality of catalytic beds which are traversed in series by a process gas, sequentially from a first catalytic bed to a last catalytic bed of said plurality, and at least one inter-bed heat exchanger (7) positioned between a first catalytic bed and a second catalytic bed of said plurality, wherein at least the last catalytic bed of said plurality is adiabatic and is made of fine catalyst with a particle size not greater than 2 mm.

Abstract: 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.

Abstract: A perforated-tray column wherein each tray comprises downcomer pipes for conveying a downwardly flowing liquid to a next tray, wherein the downcomer pipe includes: a first portion extending above the perforated tray, a second portion extending below the perforated tray towards the next perforated tray, and an end guard to prevent a gaseous phase from entering the downward pipe.

Abstract: Reactor for catalytic chemical reactions comprising a catalyst bed with an annular-cylindrical form crossed by a radial flow or mixed axial-radial flow, wherein the bed is delimited by cylindrical walls made gas-permeable by means of slits and the catalyst bed is formed by particles of catalyst with a nominal minimum size such that: the ratio between a transverse dimension of the slits and the nominal minimum size of the particles of catalyst is smaller than or equal to 0.6; the catalyst bed contains no more than 3% by weight of particles with an actual size smaller than said nominal size.

Abstract: A multi-bed catalytic converter comprising at least a first catalytic bed, a second catalytic bed and a heat exchanger arranged between said first bed and said second bed, wherein said heat exchanger is arranged to transfer heat from the hot effluent of the first bed to a cooling medium; said heat exchanger comprises a plurality of stacked round plates, wherein adjacent plates define gaps therebetween, and the effluent of the first catalytic bed and the cooling medium are respectively fed into alternate gaps.

Abstract: A method for revamping a CO2 removal section for removing carbon dioxide from a hydrogen-containing synthesis gas, wherein the CO2 removal section comprises an absorption section (2) wherein carbon dioxide is transferred to an absorbing solution and a stripping tower (3) for regeneration of the CO2-loaded solution, said stripping tower comprising an upper zone (4) where a first gaseous CO2 stream (10) and a partially regenerated semi-lean solution (11) are produced, and a lower zone (5) acting as a stripping zone where a second gaseous CO2 stream (12) and a lean regenerated solution are produced, the second CO2 stream (12) being a substantially pure stream containing less hydrogen and impurities than the first CO2 stream, and wherein the method of revamping provides the installation of sealing means (16) inside the stripping tower (3), arranged to isolate said second gaseous CO2 stream (12) from the first stream (10), so that the second stream (12) can be exported separately.

Abstract: A method for revamping an ammonia plant including a steam system, said steam system comprising at least a high-pressure section operating at a first pressure and a medium-pressure section operating at a second pressure lower than said first pressure, the revamping including: the provision of at least one additional heat recovery by means of a steam flow at a third pressure which is intermediate between said first and second pressure, and the provision of a steam export line arranged to export outside the ammonia plant at least a portion of said steam flow at said third pressure.

Abstract: A multi-bed catalytic converter comprising: a plurality of catalytic beds which are traversed in series by a process gas, sequentially from a first catalytic bed to a last catalytic bed of said plurality, and at least one inter-bed heat exchanger (7) positioned between a first catalytic bed and a second catalytic bed of said plurality, wherein at least the last catalytic bed of said plurality is adiabatic and is made of fine catalyst with a particle size not greater than 2 mm.

Abstract: A multi-bed catalytic converter comprising at least a first catalytic bed, a second catalytic bed and a heat exchanger arranged between said first bed and said second bed, wherein said heat exchanger is arranged to transfer heat from the hot effluent of the first bed to a cooling medium; said heat exchanger comprises a plurality of stacked round plates, wherein adjacent plates define gaps therebetween, and the effluent of the first catalytic bed and the cooling medium are respectively fed into alternate gaps.

Abstract: 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.

Abstract: A chemical plant comprising a refrigeration system including an absorption refrigeration unit, and a steam system including one or more steam producers, steam users, and at least one steam condenser, wherein a heat exchanger is arranged to intercept at least part of a steam flow directed to said steam condenser, and said heat exchanger transfers heat to a working fluid of said absorption refrigeration unit to provide at least part of a heat input required for operation of said refrigeration system.

Abstract: 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.

Abstract: A process for producing ammonia synthesis gas from a hydrocarbon-containing feedstock, with steps of primary reforming, secondary reforming with an oxidant stream, and further treatment of the synthesis gas including shift, removal of carbon dioxide and methanation, wherein the synthesis gas delivered by secondary reforming is subject to a medium-temperature shift (MTS) at a temperature between 200 and 350.degree. C., and primary reforming is operated with a steam-to-carbon ratio lower than 2. A corresponding method for revamping an ammonia plant is disclosed, where an existing HTS reactor is modified to operate at medium temperature, or replaced with a new MTS reactor, and the steam-to-carbon ratio in the primary reformer is lowered to a value in the range 1-5-2, thus reducing inert steam in the flow rate trough the equipments of the front-end.

Abstract: A process for producing ammonia synthesis gas from a hydrocarbon-containing feedstock, with steps of primary reforming, secondary reforming with an oxidant stream, and further treatment of the synthesis gas including shift, removal of carbon dioxide and methanation, wherein the synthesis gas delivered by secondary reforming is subject to a medium-temperature shift (MTS) at a temperature between 200 and 350° C., and primary reforming is operated with a steam-to-carbon ratio lower than 2. A corresponding method for revamping an ammonia plant is disclosed, where an existing HTS reactor is modified to operate at medium temperature, or replaced with a new MTS reactor, and the steam-to-carbon ratio in the primary reformer is lowered to a value in the range 1-5?2, thus reducing inert steam in the flow rate trough the equipments of the front-end.

Abstract: A method for revamping a CO2 removal section for removing carbon dioxide from a hydrogen-containing synthesis gas, wherein the CO2 removal section comprises an absorption section (2) wherein carbon dioxide is transferred to an absorbing solution and a stripping tower (3) for regeneration of the CO2-loaded solution, said stripping tower comprising an upper zone (4) where a first gaseous CO2 stream (10) and a partially regenerated semi-lean solution (11) are produced, and a lower zone (5) acting as a stripping zone where a second gaseous CO2 stream (12) and a lean regenerated solution are produced, the second CO2 stream (12) being a substantially pure stream containing less hydrogen and impurities than the first CO2 stream, and wherein the method of revamping provides the installation of sealing means (16) inside the stripping tower (3), arranged to isolate said second gaseous CO2 stream (12) from the first stream (10), so that the second stream (12) can be exported separately.

Abstract: 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.

Abstract: A method for revamping an ammonia plant including a steam system, said steam system comprising at least a high-pressure section operating at a first pressure and a medium-pressure section operating at a second pressure lower than said first pressure, the revamping including: the provision of at least one additional heat recovery by means of a steam flow at a third pressure which is intermediate between said first and second pressure, and the provision of a steam export line arranged to export outside the ammonia plant at least a portion of said steam flow at said third pressure.