Abstract: Method for reducing the content of nitrogen oxides NOx and nitrous oxide N2O in an input gas, comprising the steps of: treating said gas with a first amount of a NOx reducing agent in a first de-NOx catalytic bed; treating the effluent of said first de-NOx catalytic bed in at least one de-N2O catalytic bed for removal of N2O; treating the effluent of said at least one de-N2O catalytic bed with a second amount of a NOx reducing agent in a second de-NOx catalytic bed.

Abstract: A burner system (100) for the combustion of a hydrocarbon feedstock with an oxidant, comprising at least one burner (1) and a cooling circuit (2), where in: the burner system (100) comprises a fuel side (3, 15) and an oxidant side (4, 14); the burner (1) comprises a cooling chamber (5) connected to said cooling circuit(2); said cooling circuit (2) comprises a reservoir tank(8) for said cooling fluid and a circulation pump(16); said system (100) comprises pressure equalizing line (15b) arranged to establish a fluid communication between the inside of said reservoir tank (8) and at least one of said fuel side and oxidant side.

Abstract: A method for the suppression of soot formation during the partial oxidation of a hydrocarbon-containing gaseous feed, in the presence of steam and in an ATR reactor or in a POX reactor, the method comprising the addition of gaseous carbon dioxide to the hydrocarbon-containing gaseous feed before entry into the reactor. A method for determining a minimum steam to carbon ratio required for scot-free operation is also disclosed.

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 partial oxidation is performed in a reactor which includes a reaction chamber and a burner assembly, wherein: the burner assembly has a single oxidant nozzle located within an fuel channel, said oxidant nozzle comprises a nozzle pipe and a nozzle outlet, the nozzle pipe and the fuel channel are arranged to produce a diffusion flame, the nozzle outlet has a shape with two or more elongate lobes projecting from a center of the nozzle pipe.

Abstract: Process for the synthesis of ammonia from natural gas comprising conversion of a charge of desulphurized natural gas and steam, with oxygen-enriched air or oxygen, into a synthesis gas, and treatment of the synthesis gas with shift reaction and decarbonation, wherein a part of the CO2-depleted synthesis gas, obtained after decarbonation, is separated and used as fuel fraction for one or more furnaces of the conversion section, and the remaining part of the gas is used to produce ammonia.

Abstract: Plant for the synthesis of urea comprising: a synthesis section (101), wherein ammonia (1) and carbon dioxide (2) react to give an aqueous solution (3) containing urea and ammonium carbamate; at least one recovery section fed with said depressurized aqueous solution and in a two-phase state, said recovery section comprising a separator (104,108) which processes said two-phase solution; a pre-decomposer (105, 109), a decomposer (106, 110) and a condenser (107, 111), wherein the gaseous streams obtained in the separator and in the decomposer are condensed in said condenser of the recovery section.

Abstract: Method for producing solid urea by granulation, wherein the granulation is fed with liquid urea having a purity greater than 98% by weight and not containing formaldehyde.

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 the production of ammonia and urea in an ammonia-urea integrated plant comprising an ammonia section and a tied-in urea section, wherein a hydrocarbon is reformed to produce ammonia make-up synthesis gas; said make-up gas is purified by shift conversion and removal of carbon dioxide; carbon dioxide is removed from the make-up gas by a first and a second CO2 removal sections; the first section removes CO2 by absorption with a suitable medium, and the second section removes CO2 by washing with a carbamate solution taken from the urea section; the make-up gas is reacted to produce ammonia; the CO2 removed from the make-up gas and at least part of the ammonia are used to produce urea.

Abstract: A process for synthesis of urea from CO2 and NH3 wherein a steam flow (13) produced in the condenser (3) of a high-pressure synthesis loop is compressed to raise its pressure and temperature before using the steam as a heat source for a downstream step of the process.

Abstract: A nitric acid production process, comprising tertiary abatement of N2O and NOx on a tail gas withdrawn from an absorption stage, said abatement including passing the tail gas over a sequence of a deN2O stage comprising a Fe-z catalyst and a deNOx stage comprising a V2O5-TiO2 catalyst in the presence of gaseous ammonia, wherein the tail gas at the inlet of deN2O stage and the tail gas at the inlet of deNOx stage have a temperature greater than 400° C.

Abstract: Combined apparatus (1) for the synthesis of urea from ammonia and carbon dioxide, comprising an internal wall (3) which delimits two coaxial zones (4) inside the apparatus, operating respectively as reaction (4) and condensation (5) zones, and optionally also comprising a stripping zone and/or a scrubber integrated in the same apparatus.

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: Integrated process for the synthesis of ammonia and nitric acid, comprising a synthesis of nitric acid including the following steps: a) subjecting a stream of ammonia (10) to catalytic oxidation, obtaining a gaseous stream containing nitrogen oxides (13); b) subjecting said gaseous stream to a process of absorption of nitrogen oxides, providing nitric acid (16) and a tail gas (17) containing nitrogen and residual nitrogen oxides; c) subjecting at least a portion of said first tail gas (17) to a process of removal of nitrogen oxides, providing a nitrogen oxides-depleted tail gas (18), and comprising a synthesis of ammonia by catalytic conversion of a make-up gas (126, 226) comprising hydrogen and nitrogen in an ammonia synthesis loop, wherein at least a portion (18b, 18d, 21) of said second tail gas is used as nitrogen source for obtaining said make-up gas (126, 226).

Abstract: Integrated process comprising: synthesis of methanol from a methanol synthesis gas (12); synthesis of ammonia from an ammonia make-up gas (25), and synthesis of carbon monoxide from a methane-containing stream, wherein: the synthesis of methanol provides a liquid stream of methanol (13) and a gaseous stream (14) of unreacted synthesis gas; a portion (14a) of said gaseous stream is separated as purge gas; said purge gas is subjected to a hydrogen recovery step, providing a hydrogen-containing stream (19) which is used as a hydrogen source for making the ammonia make-up gas, and a tail gas (20) which is used as a methane source for the synthesis of carbon monoxide by oxidation of a methane-containing stream.

Abstract: A process for the purification of a melamine melt (5) containing melamine and by-products, comprising the steps of: (a1) In quenching of said melamine melt; (a2) decomposition of by-products with alkali, providing an alkaline aqueous solution of melamine (26); (b) stripping of said alkaline aqueous solution of melamine (26); (c) crystallization of melamine with a first alkali-containing solution (6b) and separation of solid melamine (7) from a mother liquor (8); (d) treatment of said mother liquor, providing a waste water stream (11) containing carbonates; (e) decomposition of at least part of the carbonates contained in said waste water stream (11) into carbon dioxide and alkali, providing a second alkali-containing aqueous solution (30); (f) recycle of at least part of said alkali-containing aqueous solution (30) to at least one of said steps (a1), (a2) and (c).

Abstract: A process for the purification of a melamine melt (5) containing melamine and by-products, comprising the steps of: (a1) In quenching of said melamine melt; (a2) decomposition of by-products with alkali, providing an alkaline aqueous solution of melamine (26); (b) stripping of said alkaline aqueous solution of melamine (26); (c) crystallization of melamine with a first alkali-containing solution (6b) and separation of solid melamine (7) from a mother liquor (8); (d) treatment of said mother liquor, providing a waste water stream (11) containing carbonates; (e) decomposition of at least part of the carbonates contained in said waste water stream (11) into carbon dioxide and alkali, providing a second alkali-containing aqueous solution (30); (f) recycle of at least part of said alkali-containing aqueous solution (30) to at least one of said steps (a1), (a2) and (c).

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: Process for the synthesis of ammonia comprising the steps of reforming of a hydrocarbon feedstock into a raw product gas, purification of said raw product gas obtaining a make-up synthesis gas, conversion of said synthesis gas into ammonia; said purification includes shift conversion of carbon monoxide into carbon dioxide and the reforming process requires a heat input which is at least partially recovered from at least one of said step of shift conversion, which is carried out with a peak temperature of at least 450° C., and said step of conversion into ammonia.