Abstract: A burner (1) for the production of synthesis gas, configured to feed a reactant stream and an oxidant stream into a reaction chamber, the burner comprising at least one cooled component (11, 12), wherein said cooled component comprises channels (20) to convey a cooling medium, a cooling medium header (24) and a cooling medium collector (25), wherein said channels, said cooling medium header and said cooling medium collector are integrally formed within said cooled component of the burner.

Abstract: A dual-pressure plant for the synthesis of nitric acid comprising: a reactor (4) providing a gaseous effluent (15) containing nitrogen oxides; an absorption tower (6) nitrogen oxides react with water providing raw nitric acid and, said absorption tower operating at a pressure greater than the pressure of the reactor; a compressor (5) elevating the pressure of the reactor effluent (15) to the absorption pressure; said plant also comprising a first bleacher (37) and a second bleacher (7), said first bleacher (37) stripping with air (39) nitrogen oxides from the output stream (27) of the absorption tower (6) providing a partially stripped nitric acid stream (40) and a nitrogen oxides-loaded air stream (41), the former being fed to the second bleacher (7) and the latter being recycled to the delivery-side of said compressor (5).

Abstract: A process for the synthesis of ammonia from a hydrocarbon feedstock, wherein the process includes reforming the hydrocarbon feedstock to produce a make-up gas and converting said make-up gas into ammonia, the process is performed in an ammonia synthesis plant requiring an electric power for operation and also requiring a start-up power (Ps) for start-up, wherein a first electric power (P1) is internally produced in the ammonia plant, and a second electric power (P2) is imported, wherein said second electric power is equal to or greater than said start-up power (Ps).

Abstract: Method for determining the corrosion rate of a piece of equipment of a urea synthesis plant, the method comprises the provision of electrodes including a working electrode immersed in an aqueous solution containing ammonium carbamate, the method further comprises the determination of polarization data of the working electrode and the determination of the corrosion rate of said piece of equipment based on said polarization data.

Abstract: A process for the production of feed grade urea starting from a liquid urea melt, the process comprising processing the urea melt (6) to promote the formation of biuret until a concentration of at least 3% biuret, and subjecting the so obtained biuret-containing urea melt (8) to a shaping process to obtain a granular urea product.

Abstract: A process for the production of urea wherein: production of pure urea (U) includes the concentration of an aqueous urea solution (23) by crystallization; a urea crystallization purge aqueous phase (32) comprising urea, water and biuret, which is purged from the urea crystallization process, is used in a high-biuret urea processing section (34) for additional production of urea with a high content of biuret.

Abstract: A burner (1) for the production of synthesis gas, configured to feed a reactant stream and an oxidant stream into a reaction chamber, the burner comprising at least one cooled component (11, 12), wherein said cooled component comprises channels (20) to convey a cooling medium, a cooling medium header (24) and a cooling medium collector (25), wherein said channels, said cooling medium header and said cooling medium collector are integrally formed within said cooled component of the burner.

Abstract: Process for the preparation of urea granules comprising the steps of obtaining an aqueous urea solution from one or more synthesis and recovery steps wherein ammonia and carbon dioxide are reacted together, subjecting the aqueous urea solution to an evaporation step wherein water is removed to obtain a urea melt (1), processing and treating said urea melt in a granulation step (7) and optionally in a cooling section (10) to obtain solid urea granules (14); the process further comprises a scrubbing step (3) of granulation offgas and an atmospheric evaporation step (32) to recover a urea solution (2) and a water-saturated air stream (18): the water-saturated air stream is fed back to the scrubbing section (3) without condensation, and the recovered urea solution is conveyed to the granulation step (7).

Abstract: A process for purify ing a urea-containing aqueous stream, such as the aqueous stream from the recovery section of a urea plant. comprising a step of removing biuret from the urea-containing stream by reverse osmosis in one or more reverse osmosis stages.

Abstract: A process for the synthesis of urea and melamine, wherein urea synthesized in a urea plant is used to produce melamine in a melamine plant connected to the urea plant, according to a high-pressure non-catalytic melamine synthesis process, and offgas (16) liberated during the synthesis of melamine are returned to the urea plant after offgas processing (8) which includes a condensation and a urea formation step so that a urea-containing recycle stream (19) is returned to the synthesis section of the urea plant.

Abstract: A process for the production of biuret from urea wherein: a urea aqueous solution (24) withdrawn from the recovery section of a urea plant is processed to remove water and obtain a concentrated urea melt (25); said urea melt is processed under biuret-forming conditions to decompose urea into biuret and ammonia and obtain a high-biuret urea melt (26); said high-biuret urea melt (26) is diluted with water or with an aqueous stream obtaining a solution (28); the solution (28) is subject to crystallization and precipitation of a solid phase containing biuret which is separated from the aqueous phase.

Abstract: Process for the preparation of urea granules comprising the steps of obtaining an aqueous urea solution from one or more synthesis and recovery steps wherein ammonia and carbon dioxide are reacted together, subjecting the aqueous urea solution to an evaporation step wherein water is removed to obtain a urea melt (1), processing and treating said urea melt in a granulation step (7) and optionally in a cooling section (10) to obtain solid urea granules (14); the process further comprises a scrubbing step (3) of granulation offgas and an atmospheric evaporation step (32) to recover a urea solution (2) and a water-saturated air stream (18): the water-saturated air stream is fed back to the scrubbing section (3) without condensation, and the recovered urea solution is conveyed to the granulation step (7).

Abstract: A urea stripper or evaporator provided with fittings in the bottom liquid holder to reduce gas carryover wherein said fittings may include one or more of: perforated screens horizontally arranged or vertically in the bottom liquid holder; a sealed chamber arranged in the liquid holder to reduce the liquid collection volume in the liquid holder: a plurality of blades and/or vertical plates projecting from the inner surface of a bottom domed end of the apparatus to reduce speed of the liquid flow.

Abstract: A process for synthesis of urea from ammonia and carbon dioxide wherein: the urea synthesis is performed with a stripping process in a synthesis loop including at least a reactor (1), a stripper (2) and a condenser (3); the reactor effluent is treated in the stripper to remove unreacted ammonia and carbon dioxide; the urea solution (14) from the stripper is sent to a low-pressure recovery section (4); the stripper vapours are split into a first portion (151) directed to the reactor and a second portion (152) sent to the condenser; the condenser (3) is a shell-and-tube kettle condenser where condensation of stripper vapours is performed in the tube side (30); a carbamate-containing effluent (20) from the condenser is returned to the reactor.

Abstract: A dual-pressure plant for the synthesis of nitric acid comprising: a reactor (4) providing a gaseous effluent (15) containing nitrogen oxides; an absorption tower (6) nitrogen oxides react with water providing raw nitric acid and, said absorption tower operating at a pressure greater than the pressure of the reactor; a compressor (5) elevating the pressure of the reactor effluent (15) to the absorption pressure; said plant also comprising a first bleacher (37) and a second bleacher (7), said first bleacher (37) stripping with air (39) nitrogen oxides from the output stream (27) of the absorption tower (6) providing a partially stripped nitric acid stream (40) and a nitrogen oxides-loaded air stream (41), the former being fed to the second bleacher (7) and the latter being recycled to the delivery-side of said compressor (5).

Abstract: A process of granulation of a urea melt, comprising: adding a first additive containing carboxymethyl starch to one or more first stage(s) of the granulation process, to form a carcarboxymethyl starch containing inner layer of urea granules, and adding a second additive containing calcium lignosulfonate to one or more second stage(s) of the granulation process, downstream said first stages, to form granules with a coating containing calcium lignosulfonate.

Abstract: A process for the synthesis of methanol from an input stream of synthesis gas, comprising the following steps: subjecting a portion of said input stream as feed stream to an adiabatic reactive step, providing an effluent containing methanol and unreacted synthesis gas; quenching of said effluent with a further portion of said input stream, providing a quenched stream; subjecting said quenched stream to an isothermal reactive step, providing a methanol-containing product stream.

Abstract: A method for the control of nitrogen oxides content in the combustion fumes of a thermal power plant is disclosed; the method comprises the on-site production of ammonia by the steps of: electrolysis of water as a source of hydrogen; separation of air as a source of nitrogen, formation of a make-up gas and synthesis of ammonia in a suitable synthesis loop; said on-site produced ammonia, or a solution thereof, is used for a process of reduction of nitrogen oxides in the combustion fumes.

Abstract: Process for reducing the content of NOx and N2O from an input tail gas of a nitric acid process, said input tail gas having a temperature lower than 400° C., the process comprising an abatement stage at least including a deN2O stage and deNOx stage and providing a conditioned tail gas having a temperature greater than the input tail gas, wherein, prior to submission to said abatement stage, said input tail gas is pre-heated to a temperature of at least 400° C. by indirect heat exchange with at least a portion of said conditioned gas.

Abstract: A process for the production of urea wherein: production of pure urea (U) includes the concentration of an aqueous urea solution (23) by crystallization; a urea crystallization purge aqueous phase (32) comprising urea, water and biuret, which is purged from the urea crystallization process, is used in a high-biuret urea processing section (34) for additional production of urea with a high content of biuret.