Ammonia Synthesizer Patents (Class 422/148)
  • Patent number: 6896757
    Abstract: This invention relates to light transmitting filters comprising: (a) a light absorbing layer of material having a front surface and a back surface, (b) transparent microspheres embedded in the light absorbing layer and contacting the front surface of the light absorbing layer with portions of the microspheres protruding through the back surface of the light absorbing layer for transmitting light through the light absorbing layer, and (c) a conformed layer of optically clear material having a front surface and a back surface wherein the front surface of the conformed layer is in contact with and conforming in shape with the protruding portions of the microspheres, and wherein the back surface of the conformed layer has a textured finish. The invention also relates to methods of making these light transmitting filters.
    Type: Grant
    Filed: November 6, 2003
    Date of Patent: May 24, 2005
    Assignee: Avery Dennison Corporation
    Inventor: Michael Hannington
  • Publication number: 20040234426
    Abstract: A synthesis plant (200) includes a separation system upstream of a synthesis loop that removes excess nitrogen and other gaseous compounds from a feed gas having a ratio of hydrogen to nitrogen of less than 3:1, thereby producing a syngas with a ratio of hydrogen to nitrogen at about 3:1. Particularly preferred separation systems include a coldbox (270) with a refrigerant other than air, or a pressure swing absorption system.
    Type: Application
    Filed: June 14, 2004
    Publication date: November 25, 2004
    Inventors: Satish Reddy, Mukund Bhakta, Sunil Vyas
  • Patent number: 6811762
    Abstract: A method for synthesis of ammonia includes compressing a synthesis gas containing hydrogen and nitrogen in a multi-stage (50, 56 and 57) centrifugal compressor. The synthesis gas is compressed to a pressure of from about 800 to 900 psia in the first stage (50) of the compressor, and withdrawn therefrom and subjected to cooling and dehydration by contact with liquid ammonia in a dehydrator (54). The cooled, dehydrated synthesis gas is then returned to the compressor and introduced into the second stage (56) thereof. Because of this interstage cooling and dehydration, compressor speed may be reduced and significant savings in power consumption are attained because of the favorable effect of the dehydrator (54) on the last two stages (56, 57) of the compressor. Additional power saving is realized because refrigeration requirements for the synthesis loop are reduced.
    Type: Grant
    Filed: November 13, 2002
    Date of Patent: November 2, 2004
    Inventor: Dewey Oren Moore
  • Publication number: 20040208813
    Abstract: Processes and apparatus for quantitatively converting urea to ammonia on demand are disclosed. One process includes the steps of: receiving a demand rate signal for ammonia; feeding reactants including urea and water into a reactor to provide a reaction mixture; and controlling temperature and pressure in the reactor to produce a gaseous product stream including ammonia and carbon dioxide at substantially constant concentrations. Another process includes the steps of: feeding molten urea or solid urea to a reactor; feeding water (liquid or steam) to the reactor; and reacting the urea and water at elevated temperature and pressure to form a gaseous product stream including anmmonia and carbon dioxide.
    Type: Application
    Filed: May 6, 2004
    Publication date: October 21, 2004
    Applicant: The Chemithon Corporation
    Inventors: Burton Brooks, Walter A. Jessup, Brian W. MacArthur, W. Brad Sheats
  • Publication number: 20040096370
    Abstract: A vertical, fixed-bed ammonia converter wherein a fixed-bed catalyst zone is configured into two mechanically separated catalyst volumes and two gas streams that operate in parallel. The design maintains the ratio of gas flow to catalyst volume so that there is no catalyst effectiveness penalty. The catalyst beds and gas flow paths are configured so that gas flow is downward through each catalyst volume. Each fixed-bed catalyst zone in the present invention can hold the catalyst in an annular space formed between two concentric shrouds arranged around a shell and tube heat exchanger. The two catalyst beds associated with each zone are situated above one another along the length of an interstage heat exchanger. Pipes or conduits are disposed through the beds to effect the parallel gas flow configuration, or alternatively, annular flows are created via passages through the internal shrouds that contain the catalyst beds.
    Type: Application
    Filed: November 15, 2002
    Publication date: May 20, 2004
    Applicant: Kellogg Brown & Root, Inc.
    Inventor: Kenneth Lewis Blanchard
  • Patent number: 6696026
    Abstract: A process for the combined production of ammonia and urea of the type comprising an ammonia synthesis reactor (2), a urea synthesis reactor (5) and a urea recovery section (21) stands out for the fact of submitting at least a part of a flow comprising carbamate in aqueous solution coming from the urea recovery section (21) to a partial decomposition treatment, to obtain a flow comprising ammonia and carbon dioxide in vapor phase and a flow comprising diluted carbamate in aqueous solution, which is fed together with a gas flow comprising hydrogen, nitrogen and carbon dioxide, preferably obtained by hydrocarbons steam reforming, and a flow comprising ammonia coming from the ammonia synthesis reactor (2) to a carbamate synthesis section (3), where ammonia and carbon dioxide are caused to react, to obtain a flow comprising carbamate in aqueous solution and a gas flow comprising hydrogen and nitrogen.
    Type: Grant
    Filed: January 16, 2001
    Date of Patent: February 24, 2004
    Assignee: Urea Casale
    Inventors: Giorgio Pagani, Umberto Zardi
  • Publication number: 20030211026
    Abstract: A method for synthesis of ammonia includes compressing a synthesis gas containing hydrogen and nitrogen in a multi-stage (50, 56 and 57) centrifugal compressor. The synthesis gas is compressed to a pressure of from about 800 to 900 psia in the first stage (50) of the compressor, and withdrawn therefrom and subjected to cooling and dehydration by contact with liquid ammonia in a dehydrator (54). The cooled, dehydrated synthesis gas is then returned to the compressor and introduced into the second stage (56) thereof. Because of this interstage cooling and dehydration, compressor speed may be reduced and significant savings in power consumption are attained because of the favorable effect of the dehydrator (54) on the last two stages (56, 57) of the compressor. Additional power saving is realized because refrigeration requirements for the synthesis loop are reduced.
    Type: Application
    Filed: November 13, 2002
    Publication date: November 13, 2003
    Inventor: Dewey Oren Moore
  • Patent number: 6616901
    Abstract: This invention relates to pollution control requirements for fossil fuel burning facilities such as power plants, and, more particularly, to an apparatus for providing a safe and economical supply of ammonia, from a urea feedstock, when ammonia is desired or necessary to initiate, cause and/or supplement the removal of one or more pollutants from an exhaust gas stream.
    Type: Grant
    Filed: June 21, 2000
    Date of Patent: September 9, 2003
    Assignee: Hera, LLC
    Inventors: Vincenzo Lagana, Felix E. Spokoyny
  • Patent number: 6540971
    Abstract: Process and reactor for the preparation of ammonia at elevated pressure and temperature in an ammonia reactor, wherein a process stream of ammonia synthesis gas is successively passed through at least three catalyst beds with intermediate cooling of partially reacted synthesis gas leaving the catalyst beds by heat exchange in heat exchangers arranged between each catalyst bed. The process stream is obtained by combining prior to introduction into a first catalyst bed, a first feed stream of synthesis gas having been preheated through indirect heat exchange during the intermediate cooling of the partially converted synthesis gas and a second feed stream of synthesis gas for adjustment of temperature of the process stream. The first feed stream is passed successively through the interbed heat exchangers for cooling the partially converted synthesis gas and space velocity of the synthesis gas is adjusted to be substantially in the same range in all catalyst beds.
    Type: Grant
    Filed: February 5, 2001
    Date of Patent: April 1, 2003
    Assignee: Haldor Topsoe A/S
    Inventor: Erik A Gam
  • Patent number: 6482382
    Abstract: Process for the preparation of ammonia, wherein three separate streams of fresh ammonia synthesis gas are used. The ammonia converter contains at least two catalyst beds connected in series. The second and third synthesis gas streams are passed through heat exchanger steps, where they are heated by effluent streams from the first catalyst bed. The preheated streams are mixed with the first synthesis gas stream and are fed to the first catalyst bed. The partly converted synthesis gas is used to heat the second and third stream and is fed to at least the second catalyst bed.
    Type: Grant
    Filed: December 22, 2000
    Date of Patent: November 19, 2002
    Assignee: Haldor Topsoe A/S
    Inventors: Erik Andreas Gam, Bjarne Skak Bossen
  • Publication number: 20020077516
    Abstract: An improved process and apparatus for the destructive distillation or pyrolysis of rubber, such as used rubber tires, to produce liquid and gaseous hydrocarbons and a solid carbonaceous char. A heat transfer gas circulating in a circulation loop is used to cool the hot char produced in the distillation chamber of a distillation oven, the circulation loop having some means for removing the heat transferred to the heat transfer gas from the hot char. In one embodiment, two distillation ovens are operated in off-set, batchwise distillation cycles. The distillation cycles in the two ovens are coordinated so that a fresh charge of rubber feed is introduced into the distillation chamber of one of the ovens as the distillation of rubber in the other oven is concluded.
    Type: Application
    Filed: February 22, 2002
    Publication date: June 20, 2002
    Applicant: Gentech, Inc.
    Inventor: V. J. Flanigan
  • Publication number: 20020054840
    Abstract: A urea synthesis process starting from ammonia and carbon dioxide carried out under a pressure of 120×10 2 to 400×10 2 KPa and a temperature of 140 to 215° C., in which the reaction takes place in a reactor in which gaseous CO 2 is fed in the bottom of the reactor while liquid ammonia and the recycled ammonium carbamate aqueous solution are fed from the top of the reactor, and going downward the reactor, they meet in countercurrent the rising gaseous CO 2.
    Type: Application
    Filed: May 20, 1999
    Publication date: May 9, 2002
    Inventor: VINCENZO LAGANA
  • Patent number: 6299849
    Abstract: A Method for in-situ modernization of a heterogeneous exothermic synthesis reactor, comprising the steps of providing at least a first and at least a second catalytic bed (12, 13) in an upper (2a) respectively lower (2b) portion of the reactor, providing additionally a lowermost catalytic bed (14) in the lower portion (2b) of the reactor having a reaction volume smaller than the reaction volume of the second catalytic bed (13), and loading the lowermost catalytic bed (14) with a catalyst having an activity higher that the activity of the catalyst loaded in the other beds (12, 13). Thanks to the above steps, the present method allows to obtain a reactor with high conversion yield.
    Type: Grant
    Filed: March 19, 1998
    Date of Patent: October 9, 2001
    Assignee: Ammonia Casale S.A.
    Inventors: Giorgio Pagani, Ermanno Filippi
  • Patent number: 6274096
    Abstract: The retrofitting of an existing methanol or methanol/ammonia plant to make acetic acid is disclosed. The plant is retrofitted to feed carbon dioxide into a reformer to which natural gas and steam (water) are fed. Syngas is formed in the reformer wherein both the natural gas and the carbon dioxide are reformed to produce syngas with a large proportion of carbon monoxide relative to reforming without added carbon dioxide. The syngas is split into a first part and a second part. The first syngas part is converted to methanol in a conventional methanol synthesis loop that is operated at about half of the design capacity of the original plant. The second syngas part is processed to separate out carbon dioxide and carbon monoxide, and the separated carbon dioxide is fed back into the feed to the reformer to enhance carbon monoxide formation. The separated carbon monoxide is then reacted with the methanol to produce acetic acid or an acetic acid precursor by a conventional process.
    Type: Grant
    Filed: November 1, 1999
    Date of Patent: August 14, 2001
    Assignee: Acetex (Cyprus) Limited
    Inventors: Daniel Marcel Thiebaut, Kenneth Ebenes Vidalin
  • Publication number: 20010002245
    Abstract: A process for the combined production of ammonia and urea of the type comprising an ammonia synthesis reactor (2), a urea synthesis reactor (5) and a urea recovery section (21) stands out for the fact of submitting at least a part of a flow comprising carbamate in aqueous solution coming from the urea recovery section (21) to a partial decomposition treatment, to obtain a flow comprising ammonia and carbon dioxide in vapor phase and a flow comprising diluted carbamate in aqueous solution, which is fed together with a gas flow comprising hydrogen, nitrogen and carbon dioxide, preferably obtained by hydrocarbons steam reforming, and a flow comprising ammonia coming from the ammonia synthesis reactor (2) to a carbamate synthesis section (3), where ammonia and carbon dioxide are caused to react, to obtain a flow comprising carbamate in aqueous solution and a gas flow comprising hydrogen and nitrogen.
    Type: Application
    Filed: January 16, 2001
    Publication date: May 31, 2001
    Inventors: Giorgio Pagani, Umberto Zardi
  • Patent number: 6214296
    Abstract: The present invention discloses a method of catalytic reaction operated near the optimal temperature and an apparatus for its embodiment. The catalyst bed in the apparatus consists of two parts of catalyst located respectively in the cold tube layer and the adiabatic layer. The feed gas in the cold tubes, after having exchanged heat with the reactant gases in the catalyst layer outside of the tubes, are mixed with the feed gas from the heat exchanger. While the mixed gases flow axially, radially or convectively in the catalyst layer, the gases contact successively with the catalyst in the cold tube layer and that in the adiabatic layer, and react with each other.
    Type: Grant
    Filed: February 18, 1999
    Date of Patent: April 10, 2001
    Inventors: Shoulin Lou, Ren Lou
  • Publication number: 20010000094
    Abstract: An exhaust heat recovery boiler in which an exhaust gas discharged from a gas turbine into a boiler duct to recover a heat of the exhaust gas and ammonia is injected to and mixed with the exhaust gas to reduce nitrogen oxide contained in the exhaust gas, the exhaust heat recovery boiler comprising: a boiler duct of a horizontal installation type having an inner hollow portion along which an exhaust gas flows from an upstream side to, a downstream side; a superheater; an evaporator; a denitration reactor; and an economizer, which are disposed inside the boiler duct in this order from the upstream side to the downstream side of the exhaust gas flow therein. A drum is disposed outside the boiler duct and connected to the evaporator and a downcomer pipe extending from the drum into the boiler duct.
    Type: Application
    Filed: December 4, 2000
    Publication date: April 5, 2001
    Inventors: Hideaki Shimada, Norihide Egami, Takayuki Nagashima
  • Patent number: 6190632
    Abstract: A system for producing ammonia by integrating blast furnace ironmaking with ammonia production wherein cryogenic rectification links the two systems enabling the production of ammonia synthesis gas from blast furnace gas for use in the ammonia production.
    Type: Grant
    Filed: February 25, 1999
    Date of Patent: February 20, 2001
    Assignee: Praxair Technology, Inc.
    Inventors: Minish Mahendra Shah, Raymond Francis Drnevich
  • Patent number: 6171570
    Abstract: A vertical tubular reactor for converting ammonia synthesis loop purge gas to ammonia; a method for converting ammonia synthesis loop purge gas to form additional ammonia; and a method for retrofitting a conventional ammonia plant having a synthesis loop using an iron-based synthesis catalyst and having a purge gas stream, the method including a supplemental ammonia converter for the purge gas stream. The supplemental ammonia converter is a shell and tube reactor. The tubes are filled with a catalyst comprising a platinum group metal such as ruthenium. The tubes are maintained in a substantially isothermal condition by boiling water in the shell side. As a retrofit modification to an existing ammonia synthesis plant, the purge stream is passed through the supplemental ammonia converter on a once-through basis to form additional ammonia and reduce the amount of purge gas. Advantages of the retrofit modification include lower energy consumption, lower purge rates and higher ammonia production rates.
    Type: Grant
    Filed: October 12, 1998
    Date of Patent: January 9, 2001
    Assignee: Kellogg Brown & Root, Inc.
    Inventor: Thomas A. Czuppon
  • Patent number: 6132687
    Abstract: A method for modifying a standard two-bed horizontal ammonia converter to provide increased conversion and/or production capacity by placing the first secondary catalyst bed of the existing converter in parallel flow with the existing primary catalyst bed and replacing magnetite catalyst in the second secondary catalyst bed with high activity ruthenium-on-carbon catalyst.
    Type: Grant
    Filed: May 21, 1998
    Date of Patent: October 17, 2000
    Assignee: Kellogg Brown & Root, Inc.
    Inventor: Stephen Allen Noe
  • Patent number: 6106793
    Abstract: A process for ammonia and methanol co-production in a plant comprising a first primary reforming section (11) and a secondary reforming section (12) arranged in series, an ammonia synthesis section (13) and a methanol synthesis section (22), is distinguished by the fact that ammonia and methanol are produced in independent synthesis processes where the heat required for the reforming reaction in the methanol process is advantageously obtained by utilizing the high heat content present in the gas flow coming from the secondary reforming section (12) of the ammonia process.
    Type: Grant
    Filed: December 29, 1997
    Date of Patent: August 22, 2000
    Assignee: Methanol Casale S.A.
    Inventors: Marco Badano, Franco Fabbri, Ermanno Filippi
  • Patent number: 6096195
    Abstract: Described in a process for hydrotreating (HDT) a petroleum feedstock (1) that contains sulfur and nitrogen are the catalytic cracking of the ammonia, produced by the hydrotreating process, in a catalytic cracking furnace (F), the cooling (E2) and separating of the cracking effluent to produce an H.sub.2 S containing gas phase, the extraction of the hydrogen sulfide from said gas phase and from the hydrotreating purge gas in an amine washing unit (20), and the separation (SM) of the hydrogen from the resultant effluent. The recovered hydrogen is recycled to hydrotreating unit (HDT) via a pipe (17).
    Type: Grant
    Filed: August 24, 1998
    Date of Patent: August 1, 2000
    Assignee: Institut Francais du Petrole
    Inventors: Christian Streicher, Fabrice Lecomte, Christian Busson
  • Patent number: 6086840
    Abstract: Ammonia is made from a carbon-containing heterogeneous feedstock by partially oxidizing the feedstock at low pressure to generate a synthesis gas containing CO; isothermally shift reacting the synthesis gas with steam to form H.sub.2 ; cryogenically removing portions of the CO.sub.2 and Ar from the shifted gas; purifying the H.sub.2 in a pressure swing adsorber; mixing the purified H.sub.2 with high purity N.sub.2 ; and converting the H.sub.2 and N.sub.2 into ammonia. The tail stream from the pressure swing adsorber can be recycled with the synthesis gas for control purposes and/ or used as boiler fuel. The reduced volume of purge gas purged from the ammonia synthesis loop allows ammonia contained in the purge gas stream to be recovered by cryogenic condensing.
    Type: Grant
    Filed: November 25, 1998
    Date of Patent: July 11, 2000
    Inventors: John P. Whitney, Ashok D. Rao
  • Patent number: 6077459
    Abstract: Process and process unit for the preparation of ammonia synthesis gas from a hydrocarbon feedstock comprising sequentially primary and secondary catalytic steam reforming of the feedstock in a primary heat exchange steam reformer and in a subsequent secondary reformer, wherein an effluent stream of primary steam reformed gas is heated by indirect heat exchange with a hot product effluent of secondary reformed gas prior to introduction of the primary steam reformed gas into the secondary reformer.
    Type: Grant
    Filed: May 5, 1998
    Date of Patent: June 20, 2000
    Assignee: Haldor Topsoe A/S
    Inventors: Carsten Lau Laursen, Henrik Otto Stahl
  • Patent number: 6015537
    Abstract: Process for the preparation of ammonia at elevated pressure and temperature in an ammonia reactor, comprising passing a process stream of ammonia synthesis gas successively through at least three catalyst beds and reacting the synthesis gas in the beds;intermediately cooling of partially reacted synthesis gas leaving the catalyst beds by heat exchange in heat exchangers arranged between each catalyst bed and withdrawing a product effluent being rich in ammonia, wherein the process stream is obtained by combining prior to introduction into a first catalyst bed, a first feed stream of synthesis gas having been preheated through indirect heat exchange during the intermediate cooling of the partially converted synthesis gas, a second feed stream of synthesis gas having been preheated by indirect heat exchange with the product effluent, and a third feed stream of synthesis gas for adjustment of temperature of the process stream and wherein the first feed stream is passed successively through the interbed heat exch
    Type: Grant
    Filed: April 14, 1998
    Date of Patent: January 18, 2000
    Assignee: Haldor Topsoe A/S
    Inventor: Erik Andreas Gam
  • Patent number: 5997834
    Abstract: A process for the preparation of ammonia from a hydrogen- and nitrogen-containing synthesis gas having a combined compression step in the recirculation of synthesis gas from at least two ammonia synthesis loops. The process includes admixing to the synthesis gas a recycle gas from a first and a second ammonia separation step. The admixed gases are pressurized, and the gas is divided into a first make-up gas stream and a second make-up gas stream. The first make-up gas stream is introduced to a first ammonia reactor, and a first process stream rich in ammonia is withdrawn. The second ammonia make-up gas stream is introduced into a second ammonia reactor, and a second process stream rich in ammonia is withdrawn. Ammonia from the first and second process streams is separated. The remainders of the first and second process streams are recycled for admixing with the synthesis gas. The separated ammonia is combined and withdrawn as an ammonia product stream.
    Type: Grant
    Filed: May 5, 1997
    Date of Patent: December 7, 1999
    Assignee: Haldor Topsoe A/S
    Inventors: Niels Udengaard, John Skaanderup-Larsen
  • Patent number: 5882606
    Abstract: In a method of modernizing a heterogeneous exothermic synthesis reactor (1) of the type comprising an external shell (2), in which at least one catalytic bed (15, 16, 17) is supported, the catalytic bed (15, 16, 17) is connected to an external boiler (21), for generating high pressure steam, by means of a reacted gas outlet nozzle (4) and a conduit (29) extending in said nozzle (4) thereby forming an annular airspace (30). Advantageously, the airspace (30) defines an outlet flowpath of the gases cooled in the boiler (21) which avoids overheating of the nozzle (4).
    Type: Grant
    Filed: October 30, 1996
    Date of Patent: March 16, 1999
    Assignees: Ammonia Casale S.A., Umberto Zardi
    Inventors: Umberto Zardi, Giorgio Pagani, Ermanno Filippi
  • Patent number: 5779988
    Abstract: Method for the protection of the internal walls of the shell of Braun type converters, transformed into axial-radial reactors with insertion of a cartridge and a cylindrical perforated wall, characterized by the fact that cooling gas is circulated (FLU) at temperatures between 250.degree. and 300.degree. C. in the airspace (I) between cartridge (C) and (P).
    Type: Grant
    Filed: February 28, 1995
    Date of Patent: July 14, 1998
    Assignees: Ammonia Casale, S.A., Umberto Zardi
    Inventors: Umberto Zardi, Giorgio Pagani
  • Patent number: 5585074
    Abstract: A method for "in-situ" modernization of a reactor for effecting heterogeneous exothermic synthesis reactions, especially of the so-called Kellogg type, including the preliminary step of providing at least three radial or axial-radial catalyst beds (11, 12, 13), includes the steps of providing a first gas/gas heat exchanger (18) between the first (11) and second (12) catalyst beds and a second gas-gas heat exchanger (29) in the third catalyst bed (13). Thanks to the provision of two exchangers (18, 29) for cooling of the gases flowing between the catalyst beds by means of indirect heat exchange, the present modernization method allows to achieve a reactor with a high conversion yield.
    Type: Grant
    Filed: December 29, 1994
    Date of Patent: December 17, 1996
    Assignee: Ammonia Casale S.A.
    Inventors: Umberto Zardi, Giorgio Pagani, Ermanno Filippi
  • Patent number: 5520891
    Abstract: Disclosed are a fixed-bed, cross-flow catalytic reactor wherein reaction heat can be exchanged against a heat exchange medium circulating indirectly through the catalyst bed, and a catalytic process comprising operation of the cross-flow reactor. The reactor comprises a catalyst bed having internally embedded banks of heat exchange tubes. An inlet distributor distributes reactants along the axial length of the bed. The distributed fluid passes through the bed in a cross-flow path wherein a catalytic reaction occurs. The reaction effluent is then collected from the bed by an outlet product collector. A heat exchange medium circulated through the internal heat exchange tubes adds or removes reaction heat as required for enhanced conversion in the reactor. Multiple heat exchange tubes can be used, and inlet and discharge manifolds are provided for distributing the circulating heat exchange medium.
    Type: Grant
    Filed: February 1, 1994
    Date of Patent: May 28, 1996
    Inventor: Jing M. Lee
  • Patent number: 5484577
    Abstract: A catalytic hydrocarbon reformer operates at lower temperature and pressure relative to conventional reformers. Convective heat transfer between the hot combustion gas stream and the reactor tube is enhanced through use of a narrow gap heat transfer area, which induces turbulent flow of the combustion gas stream across the reactor tube. The reactor tube includes a catalyst fines collection tube to accumulate and retain catalyst particles or fines entrained in the reformate gas stream.
    Type: Grant
    Filed: May 27, 1994
    Date of Patent: January 16, 1996
    Assignee: Ballard Power System Inc.
    Inventors: Richard F. Buswell, Ronald Cohen, Joseph V. Clausi, Stanley L. Leavitt, David S. Watkins
  • Patent number: 5484582
    Abstract: A process and unit for the recovery of ammonia in ammonia production are disclosed. All or a portion of a high pressure liquid ammonia product stream is introduced into a syngas makeup stream to produce a mixed vapor-liquid refrigeration medium for condensing ammonia from a synthesis loop product stream. Following the product stream ammonia condensation step, the vapor component of the mixed vapor-liquid stream is compressed and cooled for condensing ammonia therefrom. Liquid ammonia separated from the low pressure mixed vapor-liquid stream can be withdrawn as a low pressure liquid ammonia product. An ammonia-lean makeup gas is then combined with the ammonia-containing product recycle gas stream from the synthesis loop and further compressed. The process preferably includes recycle of all or a portion of the low pressure liquid ammonia product as a supplemental refrigerant.
    Type: Grant
    Filed: October 27, 1993
    Date of Patent: January 16, 1996
    Inventor: Jing M. Lee
  • Patent number: 5409684
    Abstract: Process and apparatus for the combined production of ammonia synthesis gas and pure hydrogen. There is withdrawn (at 21) a flow of synthesis gas which is first treated in a permeation unit (24) with the return (at 28) of the non-permeated gas, while the permeate (32)is treated by adsorption (34) (35) (36), which permits producing (in 57) very pure hydrogen. The process has a high energy efficiency.
    Type: Grant
    Filed: June 7, 1993
    Date of Patent: April 25, 1995
    Assignee: L'Air Liquide, Societe Anonyme pour l'Etude et l'Exploitation des Procedes Georges Claude
    Inventor: Francois Fuentes
  • Patent number: 5352428
    Abstract: A process and apparatus are disclosed to achieve high per-pass synthesis conversion of ammonia. A nitrogen/hydrogen synthesis gas mixture is passed sequentially through a plurality of catalyst beds. The effluent from a subsequent catalyst bed is cooled by direct quench with a partially reacted gas which has passed through at least a first catalyst bed.
    Type: Grant
    Filed: August 21, 1992
    Date of Patent: October 4, 1994
    Assignee: C.F. Braun, Inc.
    Inventors: Mukund L. Bhakta, Bernard J. Grotz
  • Patent number: 5254316
    Abstract: Improved process to convert in situ conventional reactors with four catalytic beds with axial flow and with intermediate quenching (Kellogg reactor), Third and fourth original beds are combined thus obtaining a reactor with three beds through which the synthesis gas now flows with a substantially radial flow.
    Type: Grant
    Filed: April 3, 1992
    Date of Patent: October 19, 1993
    Assignees: Ammonia Casale S.A., Umberto Zardi
    Inventors: Umberto Zardi, Giorgio Pagani
  • Patent number: 5250270
    Abstract: A fixed bed, dual-zone radial flow catalytic reactor is disclosed. In particular, the catalyst bed configuration includes a first freeboard outwardly radial flow catalyst zone in series with a second inwardly radial flow zone separated by an interconnecting substantially impermeable catalyst chute to accommodate catalyst settling while preventing hot spots and/or fluidization in the freeboard area. A gas distributor divides the freeboard zone into segments including a bypass segment and one or more catalyst segments. The radial flow of gas through each segment is essentially unaffected by the level of catalyst so that the flow pattern is not adversely affected by catalyst setting in the freeboard zone.
    Type: Grant
    Filed: July 17, 1992
    Date of Patent: October 5, 1993
    Assignee: The M. W. Kellogg Company
    Inventor: Stephen A. Noe
  • Patent number: 5236671
    Abstract: An apparatus for the synthesis of ammonia having at least two synthesis reactors in series in which two high temperature heat sink tube bundles are combined in a single shell which is close coupled to the inlet and outlet of a reactor, the second tube bundle being disposed in an interior portion of the exchanger shell inside of the first tube bundle, the first tube bundle being connected for flow from its tubes to the reactor inlet, the second tube bundle being connected for flow to its tubes from the reactor outlet.
    Type: Grant
    Filed: September 24, 1990
    Date of Patent: August 17, 1993
    Assignee: C. F. Braun, Inc.
    Inventor: Bernard J. Grotz
  • Patent number: 5190731
    Abstract: A cooled reactor for exothermic catalytic conversion of gaseous materials, e.g. for the oxo synthesis, for the conversion of hydrogen and nitrogen to form ammonia and for the reaction of carbon oxides with hydrogen to form methanol, comprises a cylindrical pressure shell (10), distributor means (34) for synthesis gas, at least one tube sheet (30) and one or more catalyst beds (20) provided with cooling tubes (38) for the indirect cooling of reacting gas. Each cooling tube (38) consists of an outer tube (4) provided with a heat exchanging outer wall (7); this outer tube surrounds and is coaxial with an inner tube (2) and hence defines an annular space the inner wall of which is provided with perforations (8) to direct the stream of cooling gas, which may consist of or contain components of the synthesis gas, to the annular space and along the heat exchanging wall.
    Type: Grant
    Filed: August 15, 1991
    Date of Patent: March 2, 1993
    Assignee: Haldor Topsoe A/S
    Inventor: Henrik O. Stahl
  • Patent number: 5184386
    Abstract: Reactors for the catalytic conversion of carbon monoxide into carbon dioxide are advantageously modified in situ from axial flow reactors into substantially radial flow reactors, and more particularly into axial-radial flow reactors. To this end at least an external cylindrical wall perforated for its whole length and an internal wall preferably perforated for most of its length are inserted inside the conventional reactor shell and cartridge.
    Type: Grant
    Filed: March 26, 1991
    Date of Patent: February 9, 1993
    Assignees: Ammonia Casale S.A., Umberto Zardi
    Inventors: Umberto Zardi, Giorgio Pagani
  • Patent number: 5180570
    Abstract: An integrated process for making methanol and ammonia from a hydrocarbon feed stock and air is disclosed. An air separation unit is used to produce substantially pure oxygen and nitrogen gas streams. The oxygen gas is used in the secondary reformer to increase the operating pressure of the reformers so that compression to methanol synthesis pressure may be done by a single stage compressor. The nitrogen gas is used to remove carbon oxides impurities from a ammonia synthesis feed stream in a nitrogen wash unit in addition to supplying the nitrogen reactant in the ammonia synthesis gas. Use of nitrogen wash obviates the need for steam shift and methanation reactions used in prior art processes.
    Type: Grant
    Filed: January 23, 1992
    Date of Patent: January 19, 1993
    Inventors: Jing M. Lee, Joseph R. LeBlanc
  • Patent number: 5171543
    Abstract: Synthesis gas is reacted in several catalytic beds having axial-radial or radial flow. Reacted gas is collected at an outlet of a final catalytic bed and is transferred to a reaction heat recovery system situated at a top of a reactor. The reactor includes three catalytic beds, two or more beds having inverted, curved bottoms. A first quenching system is located in the reactor and includes a distributor situated inside a first, upper bed at a location immediately under an unperforated portion of an internal wall of that bed. A gas/gas heat exchanger is located centrally within one or more of two upper beds located within the reactor. A water pre-heater or boiler is located inside an upper bottleneck portion of a shell of the reactor and is fed with reacted gas collected from a lowermost catalytic bed.
    Type: Grant
    Filed: March 9, 1990
    Date of Patent: December 15, 1992
    Assignees: Ammonia Casale S.A., Umberto Zardi
    Inventors: Umberto Zardi, Giorgio Pagani
  • Patent number: 5167933
    Abstract: A process and apparatus for steam reforming of hydrocarbons. Heat from a product stream of reformed gas is utilized to supply heat required for endothermic reforming of a process gas of hydrocarbons and steam by indirect heat exchange between the product stream and process gas. The temperature of metallic materials of gas heated reactors used in the reforming is controlled so as to avoid metal dusting on tube walls of the gas heated reactors.
    Type: Grant
    Filed: January 31, 1991
    Date of Patent: December 1, 1992
    Assignee: Haldor Topsoe A/S
    Inventor: Jesper Norsk
  • Patent number: 5152977
    Abstract: In a process for exothermic and heterogeneous synthesis, for example of ammonia, in which the synthesis gas is reacted in several catalytic beds with axial-radial or only radial flow, the reaction gas is collected at the outlet from the last catalytic bed but one and is transferred to a system for heat recovery external to the reactor, and is re-introduced into the last catalytic bed.
    Type: Grant
    Filed: September 5, 1991
    Date of Patent: October 6, 1992
    Assignees: Ammonia Casale S.A., Umberto Zardi
    Inventors: Umberto Zardi, Giorgio Pagani
  • Patent number: 5135722
    Abstract: A converter for heterogeneous catalytic synthesis under pressure, consisting of an external shell in a single piece and inside this of at least a cartridge containing a catalyst arranged in one or more beds contained in catalyst-carrying baskets. An external wall of these baskets is provided with means that protrude from the closed bottom and are coupled, in order to be supported, with means protruding from the internal continuous face which extends substantially along the entire axial height of the converter and is the nearest to the internal wall of the baskets. An unflanged labyrinth seal is located between two centrally located heat exchangers contained within the converter.For reactions at high pressures, the wall holding the protruding support rings at the bottom of the baskets is a cartridge wall in a single piece that extends substantially along the whole shell and forms with this an airspace.
    Type: Grant
    Filed: December 22, 1988
    Date of Patent: August 4, 1992
    Assignee: Ammonia Casale S.A.
    Inventors: Umberto Zardi, Giorgio Pagani
  • Patent number: 5130098
    Abstract: A system for modernizing exothermic heterogeneous reactors used in the synthesis of ammonia, methanol and the like, which include a pressure shell, a wall for forming an airspace, a wall or cartridge for containing a catalyst bed, and catalyst-containing basket. An airspace-forming wall is formed of a single piece substantially the whole axial length of the reactor. A bed forming wall is distinct from, and unconnected to, the airspace forming wall, and it constitutes independent modules, each module containing at least one catalyst bed and each module resting either on an underlying module or on an extension of an inside gas distribution collector. The bed forming walls contain the catalyst and distribute gas therethrough. A portion of the catalyst contacts the airspace-forming wall.
    Type: Grant
    Filed: September 24, 1990
    Date of Patent: July 14, 1992
    Assignees: Ammonia Casale S. A., Umberto Zardi
    Inventors: Umberto Zardi, Giorgio Pagani
  • Patent number: 5080872
    Abstract: A reactor apparatus and method useful in regulating temperature in a heterogeneous reaction system is provided. The apparatus includes an elongated tube reactor packed with a bed of solid particles through which a reactant fluid phase is passed. A plurality of heat transfer medium passage tubes are disposed in the bed of solid particles with adjacent tubes spaced relative to each other about the longitudinal axis of the reactor and with the tubes being substantially transverse to reactant flow through the reactor. The temperature in the system may, in turn, be regulated by effecting flow of a heat transfer medium through the passage tubes.
    Type: Grant
    Filed: January 9, 1989
    Date of Patent: January 14, 1992
    Assignee: Amoco Corporation
    Inventors: James L. Jezl, Robert F. Blanks, Michael A. Stasi
  • Patent number: 5069886
    Abstract: Process and apparatus wherein nitrogen oxides NO.sub.x contained in waste gases produced by combustion of fossil fuels in a firing plant are removed by reacting the waste gases with ammonia NH.sub.3 to reduce the nitrogen oxides to elementary nitrogen N.sub.2 ; subjecting the waste gases after being so reacted to wet waste gas cleaning whereby the washing water removes the unreacted ammonia (slip) from the waste gas to produce slip enriched washing water; raising the pH value of the slip enriched washing water to a value of more than 10, introducing air into the pH raised slip enriched washing water to remove the slip from the water and produce an air-slip mixture and recycling the slip into the furnace to react with waste gases to lower the amount of ammonia discharged into the atmosphere.
    Type: Grant
    Filed: September 26, 1990
    Date of Patent: December 3, 1991
    Inventors: Ruedi Frey, Hans Ruegg
  • Patent number: 5059411
    Abstract: Methanol is catalytically cracked (at 4) then the essential portion of the components other than CO is removed by washing with water (at 5), selective adsorption (at 7) and permeation (at 8). The process and apparatus has application to the production of moderate quantity of carbon monoxide.
    Type: Grant
    Filed: March 2, 1990
    Date of Patent: October 22, 1991
    Assignee: L'Air Liquide, Societe Anonyme pour l'Etude et l'Exploration des Procedes Georges Claude
    Inventors: Rene Dupont, Pierre Gauthier
  • Patent number: 5032364
    Abstract: In an ammonia synthesis process a nitrogen-hydrogen gas is reacted partially over a catalyst at a pressure in the range 30.degree.-120.degree. C., ammonia is separated as liquid after cooling the reacted synthesis gas and unreacted synthesis gas is recycled. The liquid ammonia is evaporated in heat exchange with reacted synthesis gas to provide the required cooling effect. Such heat exchange is effected using a heat exchange surface (as in a plate-fin heat exchanger) of at least 1.5 m.sup.2 per kg mol per hour of ammonia to be condensed, with cold-end temperature approach of less than 80.degree. C. and a hot-end temperature approach of less than 5.degree. C. whereby exploit the heat effect of, inter alia, the non-ideality of ammonia to provide product gaseous ammonia at a convenient pressure with minimal mechanical refrigeration.
    Type: Grant
    Filed: June 5, 1987
    Date of Patent: July 16, 1991
    Assignee: Imperial Chemical Industries, PLC
    Inventor: Alwyn Pinto
  • Patent number: 5019356
    Abstract: The inventive apparatus for the execution of endothermic reactions between gaseous reactants at heightened temperture and increased pressure encompasses the following main components:an inner isolating hull (33) for conveying the feed substances from their inlet (E) along the clearance between the pressure wall (31) of the apparatus and the hull,a tube-bundle heat exchanger (39'), placed within the hull for the internal heat recovery, whereby the feed substances are outside of the tubes (39) of the heat exchanger,a catalyst material, disposed in the lower part of the heat exchanger and/or after it in flowing direction.heating means (37, 37") arranged within the catalyst material for the supply of heat energy to the reactants at the region of the final conversion, whereby the reaction products proceed inside of the tubes, with heat delivery to the entering feed substances to the outlet of the apparatus.Processes for producing a hydrogen-rich gas may be carred out by using an apparatus as indicated.
    Type: Grant
    Filed: January 22, 1988
    Date of Patent: May 28, 1991
    Inventor: Ludwig Silberring