摘要:
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.
摘要:
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.
摘要:
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 (11); 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.
摘要:
A method for revamping an absorption refrigeration system, comprising: an evaporator (2), wherein a liquid refrigerant (20) evaporates providing a gaseous refrigerant (21); an absorber (3), wherein said gaseous refrigerant (21) is absorbed in a suitable lean solution (23) providing an enriched solution (24) and releasing heat, said heat being removed by a cooling medium; a desorber (4), wherein said enriched solution (24) is heated causing the refrigerant to evaporate providing a gaseous refrigerant (27) and the lean solution (23); an air cooler, wherein the gasesou refrigerant leaving the desorber (4) is condensed by thermal exchange with cooling air providing said liquid refrigerant (20). The method of revamping provides for replacing the air cooler with an evaporative condenser (5).
摘要:
Reactor (1) for catalytic chemical reactions comprising a catalyst bed (3) with an annular-cylindrical form crossed by a radial flow or mixed axial-radial flow, wherein the bed is delimited by cylindrical walls (4, 5) made gas-permeable by means of slits (10) and the catalyst bed is formed by particles of catalyst with a nominal minimum size (di) 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.
摘要:
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.
摘要:
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.
摘要:
A refrigeration system comprising an absorption refrigeration unit (3) and a chiller (2) wherein: the chiller receives a liquid refrigerant (20) from the absorption unit and provides a refrigerant vapours (21) and a liquid blowdown (22); the absorption refrigerating unit (3) comprises an absorber (4) wherein said gaseous stream (21) is contacted with a solution (24) of said refrigerant into an absorbent; wherein the absorber (4) is positioned at a greater elevation ( h1 ) than the chiller (2) and the system comprises means (13) downstream of the chiller (2) which pressurizes said liquid blowdown (22) and a flowline which directs the pressurized liquid blowdown to the absorber (4).
摘要:
A process for selective removal of at least a gaseous reaction product (P) from a gaseous system, the molecule of said reaction product having a non-zero electric dipole moment and the other gaseous components of said gaseous system having molecules with electric dipole moment which is null or negligible compared to the electric dipole moment of molecule of said reaction product; a non-uniform electric field (4) being generated between at least a positive electrode (2) and a negative electrode (1), said positive electrode and negative electrode being located at opposite sides of at least one permeation membrane (3), the selective passage of said reaction product through said membrane being enhanced by said electric field.
摘要:
A process for producing ammonia (2) in an ammonia synthesis converter (19) with co-production of steam (40) from the recovery of process heat generated in the synthesis converter, the process includes producing power (44) from expansion of said steam (40) in a steam turbine (42) which is mechanically coupled to a reversible motor/generator (43) and to a compressor so to form an assembly which can be selectively operated in a first mode of operation and in a second mode of operation wherein: in said first mode, mechanical power (44) is transferred from said steam turbine (42) to said reversible motor/generator (43) and to said compressor whilst in said second mode, mechanical power (44) is transferred to said compressor from said steam turbine (42) and from said reversible motor/generator.