Abstract: Process and plant for the synthesis of ammonia from a hydrocarbon feedstock, comprising: primary reforming with steam and air-fired secondary reforming wherein primary reforming is performed at a temperature and pressure of at least 790° C. and 50 bar, and secondary reforming is carried out substantially in absence of excess air, the so obtained make-up synthesis gas having a H2 to N2 molar ratio in the range 2.5 to 3.

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: 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: Process for manufacturing a hydrogen-containing synthesis gas from a natural gas feedstock, comprising the conversion of said natural gas into a raw product gas and purification of said product gas, the process having a heat input provided by combustion of a fuel; said process comprises a step of conversion of a carbonaceous feedstock, and at least a portion of said fuel is a gaseous fuel obtained by said step of conversion of said carbonaceous feedstock, and the Wobbe Index of said fuel is increased by a step of carbon dioxide removal or methanation.

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: A process for producing ammonia synthesis gas from a hydrocarbon-containing feedstock, with steps of primary reforming, secondary reforming with an oxidant stream, and further treatment of the synthesis gas including shift, removal of carbon dioxide and methanation, wherein the synthesis gas delivered by secondary reforming is subject to a medium-temperature shift (MTS) at a temperature between 200 and 350.degree. C., and primary reforming is operated with a steam-to-carbon ratio lower than 2. A corresponding method for revamping an ammonia plant is disclosed, where an existing HTS reactor is modified to operate at medium temperature, or replaced with a new MTS reactor, and the steam-to-carbon ratio in the primary reformer is lowered to a value in the range 1-5-2, thus reducing inert steam in the flow rate trough the equipments of the front-end.

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 process for producing ammonia synthesis gas from a hydrocarbon-containing feedstock in a front-end, comprising the steps of steam reforming of said feedstock, obtaining a synthesis gas comprising hydrogen, carbon monoxide and carbon dioxide; a treatment of said synthesis gas including shift of carbon monoxide and subsequent removal of carbon dioxide, wherein the shift of the synthesis gas includes high-temperature shift with an iron-based catalyst and at a temperature greater than 300° C. and the global steam-to-carbon ratio of the front end is 2.6 or less; a corresponding plant and a method for revamping a front-end of an ammonia plant are also disclosed.

Abstract: Process for making a hydrogen-containing synthesis gas (105) from a hydrocarbon feedstock (101), comprising the reforming of said hydrocarbon feedstock and purification of raw synthesis gas, said purification comprising shift conversion of carbon monoxide into carbon dioxide and subsequent absorption of carbon dioxide into an absorbing medium (7a, 14), resulting in a stream of a CO2-rich medium (5), and regeneration of said medium with recovery of CO2 absorbed therein, wherein said raw synthesis gas (102) is produced by the reforming step at a pressure of at least 45 bar, said regeneration of the CO2-loaded medium includes a step of chemical regeneration and the CO2-loaded medium has a temperature of at least 150° C. during said chemical regeneration.

Abstract: A process for producing ammonia synthesis gas from a hydrocarbon-containing feedstock, with steps of primary reforming, secondary reforming with an oxidant stream, and further treatment of the synthesis gas including shift, removal of carbon dioxide and methanation, wherein the synthesis gas delivered by secondary reforming is subject to a medium-temperature shift (MTS) at a temperature between 200 and 350° C., and primary reforming is operated with a steam-to-carbon ratio lower than 2. A corresponding method for revamping an ammonia plant is disclosed, where an existing HTS reactor is modified to operate at medium temperature, or replaced with a new MTS reactor, and the steam-to-carbon ratio in the primary reformer is lowered to a value in the range 1-5?2, thus reducing inert steam in the flow rate trough the equipments of the front-end.

Abstract: Process for the synthesis of ammonia from a make-up gas containing hydrogen and nitrogen, said process comprising: generation of a synthesis gas (8) containing hydrogen and nitrogen in a molar ratio lower than 3, inside a front-end section (2); a first cryogenic purification, designed to remove nitrogen and raise said molar ratio; conversion of the synthesis gas into ammonia (13) inside a high-pressure synthesis loop (6), with extraction from said loop of a purge stream (14) containing hydrogen and inert gases; wherein at least a portion of said purge stream (14) undergoes a further purification in order to recover at least part of the hydrogen contained therein, obtaining at least one stream (15, 15a, 16, 18) containing recovered hydrogen which is recycled to the process.

Abstract: An ammonia plant is disclosed, where ammonia purge gas (20), is sent to a cryogenic recovery unit, said recovery unit comprising means of cooling (102, 202, 302, 402, 502) and a high-pressure phase separator (103, 203, 303, 403, 503) operating at loop pressure; inside said unit the purge gas (20) is cooled to a cryogenic temperature, and a partial liquefaction of methane and argon is achieved; the high-pressure phase separator separates the cooled stream into a gaseous stream and a bottom liquid; the gaseous stream is reheated in a passage of a heat exchanger; the unit is then capable to export a gaseous stream (123, 223, 323, 423, 523) containing nitrogen and hydrogen at loop pressure, that can be reintroduced at the suction side of the circulator (4) of the loop.

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: 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 process and a related equipment for producing ammonia synthesis gas from a hydrocarbon-containing feedstock (20), the process comprising the steps of: primary reforming with steam (21), secondary reforming with an oxidant stream (23), and purification of the effluent of said secondary reforming, said purification comprising a step of shift conversion (13) of carbon monoxide, wherein the synthesis gas (25) produced by said secondary reforming is subject to a medium-temperature shift over a copper-based catalyst, and the global steam to carbon ratio of the process is not greater than 2.

Abstract: Process and plant for the synthesis of ammonia from a hydrocarbon feedstock, comprising: primary reforming with steam and air-fired secondary reforming wherein primary reforming is performed at a temperature and pressure of at least 790° C. and 50 bar, and secondary reforming is carried out substantially in absence of excess air, the so obtained make-up synthesis gas having a H2 to N2 molar ratio in the range 2.5 to 3.

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.

Abstract: Process for manufacturing a hydrogen-containing synthesis gas from a natural gas feedstock, comprising the conversion of said natural gas into a raw product gas and purification of said product gas, the process having a heat input provided by combustion of a fuel; said process comprises a step of conversion of a carbonaceous feedstock, and at least a portion of said fuel is a gaseous fuel obtained by said step of conversion of said carbonaceous feedstock.

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 vapor or supercritical product stream (20), and energy is recovered by expanding said vapor 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.