Abstract: Integrated process for the production of urea and urea-ammonium nitrate, comprising: reacting ammonia and carbon dioxide to form a reaction mixture (4) containing urea and unconverted materials, and also comprising the recovery of unconverted materials in a first recovery stage at a first pressure and in a second recovery stage at a second pressure, wherein ammonia-containing offgas (19) released by said second recovery stage are condensed at said second pressure, and said condensed offgas (20) are recycled to said first recovery stage.

Abstract: A process for the finishing of urea comprising: (a) removing water from an aqueous urea solution in a first evaporation and condensation section, obtaining a urea melt; (b) subjecting said urea melt to a finishing treatment comprising granulation and resulting in solid urea and air contaminated with urea dust and ammonia; (c) subjecting said contaminated air to acid scrubbing, producing an aqueous solution comprising urea and ammonium salts; (d) subjecting at least part of said aqueous solution to evaporation in a second evaporation section, obtaining a liquid stream comprising urea and ammonium salts and a gaseous stream; (e) condensing said gaseous stream in a second condensation section, obtaining a recycle aqueous stream; (f) using at least a part of said recycle aqueous stream for the scrubbing of contaminated air; (g) converting at least a portion of said liquid stream comprising urea and ammonium salts into solid particles, and (h) using said solid particles as seeds for the granulation; a correspondin

Abstract: A process for producing ammonia synthesis gas from the reforming of hydrocarbons with steam in a primary reformer (1) equipped with a plurality of externally heated catalytic tubes and then together with air in a secondary reformer (2) is characterized in that the reaction of said hydrocarbons with said steam in said primary reformer (1) is performed at an operating pressure of more than 35 bar in the catalytic tubes, in that air is added to said secondary reformer in excess over the nitrogen amount required for ammonia synthesis and in that the excess of nitrogen is removed downstream the secondary reformer preferably by cryogenic separation or by molecular sieves of the TAS or PSA type. This process allows to obtain high synthesis gas production capacities and lower investment and energy costs.

Abstract: Vertical reactor (1) for chemical reactions, comprising a tube heat exchanger (6) immersed in a catalytic bed (5), wherein said tube exchanger (6) comprises a plurality of straight tube bundles (6.1, 6.2) with respective tube plates for feeding (9.1, 9.2) and collecting (10.1, 10.2) the heat exchange fluid, and wherein the tube bundles and the respective tube plates are vertically staggered so as to allow access to the shell side.

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: Vertical reactor (1) for chemical reactions, comprising a tube heat exchanger (6) immersed in a catalytic bed (5), wherein said tube exchanger (6) comprises a plurality of straight tube bundles (6.1, 6.2) with respective tube plates for feeding (9.1, 9.2) and collecting (10.1, 10.2) the heat exchange fluid, and wherein the tube bundles and the respective tube plates are vertically staggered so as to allow access to the shell side.

Abstract: Catalytic chemical reactor comprising a perforated wall (6) adjacent to a supporting wall of the reactor or of a catalytic cartridge contained in the reactor, wherein said perforated wall comprises a plurality of panels (7) and comprises first sectors (9) resting on the supporting wall and second sectors (10) spaced from said supporting wall defining a cavity (11), and wherein means are provided for local securing said gas-permeable wall to said supporting wall, said securing means comprising: a plurality of support elements (13) fixed to the supporting wall (4) and passing through respective openings (15) of the first sectors (9) of the gas-permeable wall and a respective plurality of locking elements (14) which can be associated with the said support elements, the panels of the gas-permeable wall being gripped between said supporting wall and said locking elements.

Abstract: A fluid bed granulation process and apparatus, wherein a suitable fluid bed of a particulate material is maintained in a granulator fed by an input flow comprising a growth liquid and by a flow of seeds adapted to promote the granulation, and wherein a part of said input flow is taken upstream the feeding of the fluid bed, and used in a seeds generator, to produce the seeds for the fluid bed.

Abstract: Shell and tube heat exchanger (1) comprising a first outer shell (2) and a tube bundle (3), inlet and outlet interfaces communicating with the shell side and with the tube side for a first fluid and for a second fluid respectively, wherein the exchanger comprises a second shell (4) which is inside said first shell (2) and surrounds said tube bundle (3); said second shell (4) comprises at least one releasable longitudinal joint (32) and a plurality of longitudinal sections connected by releasable joints; said second shell (4) delimits the shell side of the exchanger (1) around said tube bundle (3), and further defines a flushing interspace (5) communicating with said shell side, said first fluid flows through said shell side along one or more longitudinal passages, and said first fluid and said second fluid are counter-current along said one or more longitudinal passages.

Abstract: Catalytic chemical reactor comprising a perforated wall (6) adjacent to a supporting wall of the reactor or of a catalytic cartridge contained in the reactor, wherein said perforated wall comprises a plurality of panels (7) and comprises first sectors (9) resting on the supporting wall and second sectors (10) spaced from said supporting wall defining a cavity (11), and wherein means are provided for local securing said gas-permeable wall to said supporting wall, said securing means comprising: a plurality of support elements (13) fixed to the supporting wall (4) and passing through respective openings (15) of the first sectors (9) of the gas-permeable wall and a respective plurality of locking elements (14) which can be associated with the said support elements, the panels of the gas-permeable wall being gripped between said supporting wall and said locking elements.

Abstract: Method for revamping a multi-bed ammonia converter, wherein said converter comprises a plurality of adiabatic catalytic beds including a first catalytic bed and one or more further catalytic bed(s), said catalytic beds being arranged in series so that the effluent of a bed is further reacted in the subsequent bed; at least a first inter-bed heat exchanger arranged between said first catalytic bed and a second catalytic bed to cool the effluent of said first bed before admission into said second bed, and optionally further inter-bed heat exchanger(s) arranged between consecutive beds; said method involves the conversion of said first catalytic bed into an isothermal catalytic bed.

Abstract: A process for the purification of a melamine melt (5) containing melamine and by-products, comprising the steps of: (a1) 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 producing ammonia and a derivative of ammonia from a natural gas feed comprising conversion of natural gas into a make-up synthesis gas; synthesis of ammonia; use of said ammonia to produce said derivative of ammonia, wherein a portion of the natural gas feed is used to fuel a gas turbine; power produced by said gas turbine is transferred to at least one power user of the process, such as a compressor; heat is recovered from exhaust gas of said gas turbine, and at least part of said heat is recovered as low-grade heat available at a temperature not greater than 200° C., to provide process heating to at least one thermal user of the process, such as CO2 removal unit or absorption chiller; a corresponding plant and method of modernization are also disclosed.

Abstract: A method for revamping a front-end of an ammonia plant, said front-end comprising a reforming section (1, 2) with air-fired secondary reformer or autothermal reformer (2), a treatment section (3) of the effluent from said reforming section, and an air feed compressor (6), wherein an O2-containing stream (8) is directed to said reforming section (2) for use as oxidant, at least one nitrogen stream (9) is introduced at a suitable location of the front-end, to provide a desired molar ratio between hydrogen and nitrogen in the product gas, and at least part of said nitrogen stream (9) is compressed via said feed compressor (6).

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: In a method for preparing granules containing filamentary fungi, a filamentary fungi culture is mixed with at least one modified starch and a starchy flour, then fillers and possible nutrients are added to the obtained product, obtaining a paste that is subsequently subjected to granulation and drying.

Abstract: A process and a related equipment for making ammonia make-up synthesis gas are disclosed, where: a hydrocarbon feedstock is reformed obtaining a raw ammonia make-up syngas stream; said raw syngas is purified in a cryogenic purification section refrigerated by a nitrogen-rich stream produced in an air separation unit; the nitrogen-rich stream at output of said cryogenic section is further used for adjusting the hydrogen/nitrogen ratio of the purified make-up syngas; an oxygen-rich stream is also produced in said air separation unit and is fed to the reforming section.

Abstract: The invention discloses the use of Raman spectroscopy to analyze one or more process streams (5) of a urea synthesis production plant, where urea is synthesised from ammonia and carbon dioxide at high pressure (100-300 bar) and high temperature (50-250° C.). The radiation generated by the Raman scattering is analyzed to determine the concentration of components such as urea, ammonia and carbon dioxide in the process streams (5). A logic system implemented in a plant control unit (1) generates signals to target plant actuators to optimize the operation.

Abstract: Plant for the synthesis of urea, comprising: a synthesis section comprising at least one reactor, a compressor for supplying CO2 to said synthesis section, a gas turbine for the operation of said CO2 compressor and a heat recovery steam generator; the heat source of said heat recovery steam generator consists of the exhaust gases of said gas turbine, and at least one steam flow produced by said heat recovery steam generator is used as heat source for at least one component of said urea plant.

Abstract: A method for the production of nitric acid, comprising a step of oxidation of ammonia in the presence of a catalyst, comprising a step of monitoring the temperature of said catalyst by at least one contactless infrared sensor.