Abstract: A process for producing ammonia synthesis gas from a hydrocarbon source, comprising: conversion of the hydrocarbon source into a raw synthesis gas (14) in ATR or POX reactor (11) which is fired with oxygen (12) or oxygen-enriched air (28); a water-gas shift treatment of the raw synthesis gas (14), which consist of a medium-temperature shift (15) at a temperature of 200-300° C., thus obtaining a shifted synthesis gas (16); purification of said shifted synthesis gas (16) including at least a step of pressure-swing adsorption (17) to remove residual carbon oxides and methane from the synthesis gas, obtaining a purified synthesis gas (18), and optionally, addition of nitrogen (19) to said purified synthesis gas (18), thus obtaining ammonia synthesis gas with a desired hydrogen to nitrogen ratio.

Abstract: A multi-bed catalytic converter (1) with inter-bed heat exchangers, comprising a plurality of superimposed catalytic beds and a common heat exchanger (5) which is shared between two or more consecutive catalytic beds, said common heat exchanger including heat exchange bodies such as a tube bundle (6), and a wall system (9, 10) to define a tube side and a shell side respectively, and the shell side comprising at least a first space (12) and a second space (13), wherein the first space (12) receives the product gas leaving the first of said consecutive beds, and the inter-cooled gas leaving said first space (12) is admitted in the second bed (3-3) for further conversion, and a sealing means (14) preventing a direct gas passage from said first space to said second space.

Abstract: A methanation section for producing substitute natural gas (SNG) by reacting a fresh syngas, the methanation section comprising adiabatic reactors connected in series, with heat removal and reacted gas-recirculation, wherein the fresh syngas is fed in parallel to said adiabatic reactors. In a preferred embodiment the reacted gas is recirculated to the first reactor and further dilution of the fresh gas at the inlet of the first and second reactor is achieved by steam addition.

Abstract: A system (8; 9; 50) is described of walls for catalytic beds of synthesis reactors (1), in which there is a wall (14) in direct contact with a catalytic bed (7) for containing it, said wall (14) having a plurality of portions (17) permeable to the gases and a plurality of portions (19; 54; 55) impermeable to the gases, said portions (17) permeable to the gases being equipped with slits (18; 52, 53; 60; 70) of a size such as to allow the free passage of the synthesis gases through them but not the passage of the catalyst, in which the slits are obtained with milling, water cutting or electro-erosion processing.

Abstract: A chemical isothermal reactor (1) with internal plate heat exchanger (10) having heat-exchange radial plates (11), and radial ducts (14, 15) parallel to sides (13i, 13s) of the plates (11) for distributing and collecting a heat exchange fluid, said radial ducts having a portion with a smaller cross section near the inner converging ends (14c, 15c).

Abstract: Process and plant for refining a stream of crude methanol (103), comprising: pre-treatment of the crude methanol in a topping stage (100), for the separation of volatile components, at a defined topping pressure (p1); distillation of methanol with at least one final distillation step of methanol at a defined distillation pressure (p4), in which said distillation pressure (p4) is greater than the topping pressure (p1), and in which a gaseous stream of distilled methanol (440), which is produced in the final distillation step, is used to supply at least part of the heat for the pre- treatment topping step.

Abstract: A method of revamping of an ammonia plant fed with natural gas comprising a primary reformer (11) and a secondary reformer (12), the method comprising at least the following interventions: reducing the outlet temperature of the gas (17) flowing out from said primary reformer; adding a feeding line of substantially pure oxygen (30) directed to said secondary reformer (12) to at least partially replace the comburent process air; adding a nitrogen injection line (31) in an amount necessary to obtain a make-up gas suitable for ammonia synthesis.

Abstract: A reforming process for synthesis gas (12) production from a mixture of hydrocarbons (14) comprises a first step, or pre-reforming step, in which a process mixture 18), comprising said mixture of hydrocarbons :14: and steam (16), is subjected to a preliminary catalytic conversion reaction, obtaining a partial conversion product (22) comprising hydrogen, carbon oxides and hydrocarbons, and a second step, or main reforming step, in which said partial conversion product (22) is subjected to a conversion completion reaction, obtaining said synthesis gas (12), said pre-reforming step being carried out in pseudo-isothermal conditions.

Abstract: A steam cooled chemical reactor (1) comprising a vertical vessel (2), a plate heat exchanger embedded in a catalytic bed, to cool the catalytic bed by evaporation of a cooling water flow, wherein a water inlet and a steam outlet are located underneath the heat exchanger, and the plates and related piping are arranged so that the path of the cooling flow comprises a first ascending path from bottom to top of the catalytic bed, and a second descending path from top to the bottom of catalytic bed, and wherein internal evaporation channels of the plates provide the second descending or the first ascending path, and water upcomers or respectively steam downcomers provide the other of said first and second path.

Abstract: The present invention concerns 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 in a secondary reformer (2) together with an oxidant gas. In this process, the reaction of said hydrocarbons with said steam in said primary reformer (1) is performed at an operating pressure of at least 45 bar in the catalytic tubes and a flow of essentially pure oxygen or oxygen-enriched air is added to said secondary reformer as oxidant gas for substantially reforming together with said all the hydrocarbons content of said product gas exiting the primary reformer (1). In the case essentially pure oxygen is used as oxidant gas, a flow of nitrogen is added downstream the secondary reformer (2) to reach a N2/H2 molar ratio corresponding to or close to the stoichiometric ratio for ammonia synthesis.

Abstract: A process for producing ammonia make-up synthesis gas and a procedure for revamping a front-end of an ammonia plant for producing ammonia make-up synthesis gas are disclosed, wherein the make-up synthesis gas is produced by means of steam reforming of a hydrocarbon gaseous feedstock; said front-end includes a primary reformer, a secondary reformer, a shift conversion section, a CO2 removal section and optionally a methanation section; a shell-and-tube gas-heated reformer is installed after said secondary reformer, and a portion of the available feedstock is reformed in the tubes of said gas-heated reformer, and heat is provided to the shell side of said gas-heated reformer by at least a portion of product gas leaving the secondary reformer, possibly mixed with product gas leaving the tubes of said gas-heated reformer.

Abstract: A radial-flow plate heat exchanger (5) embedded in the catalytic bed of an isothermal chemical reactor (1) has heat exchange plates (10) comprising fluid passages (13) between a first metal sheet (20) and a second metal sheet (21) joined by perimeter weld seams (23) on a first surface (A) of the plate, a feeding channel (14) and a collecting channel (15) for the heat exchange fluid are formed with suitable metal sheets which are seam welded (25) directly to the opposite surface (B) of the plate, this structure allows the manufacturing of the plate (10) with an automated seam welding process, such as laser beam welding.

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: A process and equipment for removing carbon dioxide from a process gas (G), with a solid adsorbent and temperature swing adsorption, where the carbon dioxide is removed from process gas in either a first bed (B1) or a second bed (B2) of adsorbent, while the other bed is regenerated with heat furnished by the incoming hot process gas; the beds are contained in vessels (V1, V2) with heat exchange tubes or plates (T1, T2), so that the removal of CO2 takes place by contacting the process gas with the bed in the shell side, and regeneration of a bed takes place by passing the hot process gas inside the tubes.

Abstract: A process for producing ammonia synthesis gas from a hydrocarbon source, comprising: conversion of the hydrocarbon source into a raw synthesis gas (14) in ATR or POX reactor (11) which is fired with oxygen (12) or oxygen-enriched air (28); a water-gas shift treatment of the raw synthesis gas (14), which consist of a medium-temperature shift (15) at a temperature of 200-300° C., thus obtaining a shifted synthesis gas (16); purification of said shifted synthesis gas (16) including at least a step of pressure-swing adsorption (17) to remove residual carbon oxides and methane from the synthesis gas, obtaining a purified synthesis gas (18), and optionally, addition of nitrogen (19) to said purified synthesis gas (18), thus obtaining ammonia synthesis gas with a desired hydrogen to nitrogen ratio.

Abstract: Process and plant for refining crude methanol, comprising at least three distillation stages operating in cascade at decreasing pressures, wherein a first stage (200) operates at a maximum distillation pressure (p2), a second stage (300) operates at a medium distillation pressure (p3), and a final distillation stage (400) operates at a minimum distillation pressure (p4), wherein the first stage and the distillation stage each produce a respective gaseous stream (204, 304) of distilled methanol, and a respective solution containing methanol that is fed to the next distillation stage, and wherein at least one first gaseous stream of distilled methanol (204), produced in the first distillation stage, and a second gaseous stream of distilled methanol (304), produced in the second distillation stage, are used as heat sources to heat the second distillation stage and the final distillation stage, respectively.

Abstract: A method for modernizing an ammonia synthesis loop (1) with a first converter (10) and a second converter (11) in series, the first converter (10) comprises a cartridge with one or more catalyst beds, the second converter (11) comprises a catalyst bed in direct contact with said vessel, the method comprising the steps of removing the second converter, and boosting the first converter by replacing the cartridge with a high-efficiency cartridge comprising a plurality of adiabatic catalyst beds and inter-bed heat exchangers, or an isothermal catalyst bed, and by reducing the concentration of inerts in said first converter.

Abstract: A process for synthesis of methanol, where make-up syngas is reacted in a synthesis loop (10) obtaining crude methanol, and where a purge gas (20) taken from said synthesis loop is heated to 200-500° C. by indirect heat exchange with a high-temperature heat source, the heated purge gas (33) being expanded in a gas expander (34) to recover energy.

Abstract: A method for recovering waste heat in a process for the synthesis of a chemical product, particularly ammonia, where the product is used as the working fluid of a thermodynamic cycle; the waste heat is used to increase the enthalpy content of a high-pressure liquid stream of said product (11), delivered by a synthesis section (10), thus obtaining a vapour or supercritical product stream (20), and energy is recovered by expanding said vapour or supercritical stream across at least one suitable ex-pander (13); the method is particularly suited to recover the heat content of the syngas effluent after low-temperature shift.

Abstract: Plant for urea production from ammonia and carbon dioxide having a so-called high-pressure section which comprises a synthesis reactor and a condensation unit (7, 107) positioned inside the reactor, all substantially operating at the same pressure.