Classifications

• • C—CHEMISTRY; METALLURGY
  • C10—PETROLEUM, GAS OR COKE INDUSTRIES; TECHNICAL GASES CONTAINING CARBON MONOXIDE; FUELS; LUBRICANTS; PEAT
  • C10G—CRACKING HYDROCARBON OILS; PRODUCTION OF LIQUID HYDROCARBON MIXTURES, e.g. BY DESTRUCTIVE HYDROGENATION, OLIGOMERISATION, POLYMERISATION; RECOVERY OF HYDROCARBON OILS FROM OIL-SHALE, OIL-SAND, OR GASES; REFINING MIXTURES MAINLY CONSISTING OF HYDROCARBONS; REFORMING OF NAPHTHA; MINERAL WAXES
  • C10G35/00—Reforming naphtha
  • C10G35/04—Catalytic reforming

Definitions

• This invention relates to catalytic reforming. More particularly, this invention relates to multi-stage, adiabatic catalytic reforming of petroleum feedstocks. The present invention relates especially to catalytic reforming of petroleum naphtha.
• Catalytic reforming is a well known process for upgrading petroleum fractions to more valuable products.
• Catalytic reforming finds particular application in upgrading petroleum naphtha fractions, i.e., petroleum fractions boiling between 100 and 400°F, to increase the octane value thereof for incorporation in gasoline motor fuels.
• lead additives such as tetraethyl lead
• catalytic reforming assumes an ever increasing importance.
• a feedstock material and hydrogen- containing gas are intimately mixed, before or after indirect heat exchange, and then passed through an alternating series of heaters and reaction zones.
• a heater By a heater is meant a device or arrangement for adding heat energy to the mixture directly or indirectly frcm a primary energy service such as a gas or oil burner.
• the nuriber of heaters is the same as the number of reaction zones and the mixture of feed material and hydrogen passes through a heater before entering the first reaction zone.
• Each reforming zone contains either a fixed or moving bed of suitable refoiming catalyst.
• Alumina based catalysts containing platinum and halogen are frequently utilized. Promoters such as rhenium, iridium or germanium may be incorporated in the catalyst with the platinum.
• Refoiming catalysts are well known in the art and will not be described in further detail here.
• feedstock material either before or after admixture with a hydrogen-containing gas, is passed through a heater to raise the temperature of the material to reforming temperatures prior to introducing the feedstock and hydrogen mixture into the first reaction zone.
• Effluent from the first reaction zone is reheated by passing it through a second heater before being introduced into the second reaction zone in the second stage of the reforming operation.
• effluent from the second reforming reaction zone is again reheated in a third heater before being introduced into the third reaction zone for the next stage of the reforming operation. Examples of such systems are disclosed in Webb, U.S. Patent No. 3,011,968; Greenwood et al. , U.S. Patent No.
• Another object of the present invention is to provide a process for catalytic reforming of petroleum naphtha wherein no heater is required to raise the temperature of the feedstock material and hydrogen prior to introducing then into the first stage refoiming reaction zone.
• Yet a further object of the present invention is to provide a catalytic reforming process which reduces the investment and operating costs of a reformer installation.
• a process for reforming a hydrocarbon feedstock comprising preheating said feedstock and a hydrogen-containing gas by indirect heat exchange to reforming conditions, passing said feedstock and hydrogen- containing gas in admixture successively through an alternating series of catalytic reaction zones maintained at reforming conditions and heaters; the number of heaters in said series being one fewer than the number of reaction zones in said series, and said admixture passing through the first reaction zone prior to entering the first heater.
• the petroleum naphtha feedstock and hydrogen-containing gas are passed in indirect heat exchange relation with the effluent fr ⁇ n the final reaction zone in the series of reaction zones in order to raise the initial temperature of the feedstock and hydrogen to reforming temperature.
• the reforming conditions in each subsequent reaction zone are more severe than the reforming conditions in the first reaction zone.
• the hydrocarbon feedstock and hydrogen-containing gas may be admixed prior to passage through the heat exchanger, or they may be preheated separately and then admixed.
• the reaction zones may each comprise an individual reactor or they may consist of separate zones in a single vessel.
• FIG. 1 is a schematic representation of a reforming installation 10 comprising a series of four reforming reaction zones represented by reactors 11, 12, 13 and 14.
• a petroleum feedstock such as petroleum naphtha is introduced into the refoiming installation through inlet line 15 by means of pump 16.
• a hydrogen-containing gas is supplied through line 17 and admixed with the feedstock.
• the mole ratio of hydrogen to feedstock may vary depending on the nature of the feedstock and the conditions of the reforming reaction. In most instances, the mole ratio of hydrogen to feedstock will lie between 1:1 and 10:1. For naphtha feedstocks processed according to the disclosed embodiment, it is preferred that the hydrogen/feedstock mole ratio lie between about 4:1 and about 6:1.
• the achiixed feed materials pass to a heat exchanger 18 in which the temperature of the feed materials is raised to at least 80CPF. Desirably, the temperature will be raised to between 825 and 85CPF.
• Fr ⁇ n heat exchanger 18, the feed materials pass through inlet line 19 and are introduced into the top of reactor 11.
• the feed materials pass through a bed of suitable reforming catalyst material, such as a platinum containing alumina based reforming catalyst in the reactor and react to produce an upgraded product.
• suitable reforming catalyst material such as a platinum containing alumina based reforming catalyst in the reactor and react to produce an upgraded product.
• the catalyst bed may be either fixed or moving and the flow through the catalyst bed in this and the succeeding reactors may be either radial or non-radial, as desired. Due to the strong endotheimic nature of the reforming reaction, the temperature of the feed mixture decreases rapidly. Depending upon the exact nature of the feed material, te ⁇ peratures in the first reactor may decrease anywhere from about 140 to about 200°F.
• the effluent from the reactor 11 is.withdrawn through line 20 and passed to a first heater 21 where it is reheated to reforming temperatures.
• the material will be heated to a temperature of at least 875°F.
• heater 21 will raise the temperature of the effluent from reactor 11 to a temperature of about 900°F. to 930°F.
• Inlet line 22 carries the reheated partially reformed feed to the top of second reactor 12. The feed material then passes through the catalyst bed in reactor 12 and is further reformed therein. The temperature of the mixture again drops significantly in reactor 12 in consequence of the endotheimic nature of the refoiming reaction.
• effluent fr ⁇ n reactor 12 has a ta ⁇ perature of not more than about 800°F.
• Effluent fr ⁇ n reactor 12 is conveyed through line 23, heater 24 and line 25 to reactor 13 where the same basic sequence of operations is repeated.
• the inlet temperature of the feed to reactor 13 is typically greater than 900PF, preferably, at least 935°F., and the outlet temperature is less than 90(PF.
• the partially reformed feed passes through line 26, heater 27 and line 28 to reactor 14, the final reactor in the series.
• the inlet te ⁇ p- erature for reactor 14 is typically at least about 940°F, and the outlet temperature is normally within 10°F. of the inlet temperature.
• the reforming reaction proceeds comparatively readily because of the comparatively high concentration of nonaromatic compounds in the feed mixture.
• concentration of nonaromatics becomesprogressively more dilute, and more strenuous reaction conditions are required.
• the reaction conditions in each succeeding reactor ordinarily ⁇ are made progressively more severe.
• the actual amount of reaction per unit of feed in each reactor becomes proportionately less, and conc ⁇ nitantly, the temperature drop in each successive reactor is usually less.
• the progressive reduction in the temperature decrease in each successive reactor facilitates heating the feed material to progressively higher te ⁇ peratures before introduction into each succeeding reactor.
• Pressures throughout the reactor system may be ambient or elevated. Desirably the refoiming reaction is carried out at elevated pressures ranging between 100 and about 600 psi. In the disclosed embodiment, pressures ordinarily range between about 150 and about 400 psig.
• Heat exchanger 18 may be an efficient counterflow-type exchanger such as a one pass feed_-one pass shell and tube heat exchanger with either stream on the tube side.
• the reformed naphtha and hydrogen-rich gas pass through line 30 to condenser 31 and thence through line 32 to a conventional separator 33 where the condensed refoimate is separated from the reformer off-gases.
• the reformate is transmitted fr ⁇ n the separator 33 via line 34 to such further processing units as may be desired, such as a stabilizer (not shown).
• Hydrogen-containing reformer off-gases leave separator 33 via line 35. A portion of the hydrogen-containing gases is recycled via compressor 36 and line 37 to the hydrogen-containing gas supply line 17.
• Hydrogen-containing reformer off-gases not required for recycle may be withdrawn via line 42 and collected or utilized as desired. • The catalyst material may be regenerated by known techniques.
• withdrawn catalyst may be regenerated externally. If stationary beds of catalyst are employed in the reforming reactors, the catalyst may be regenerated in situ by cyclic substitution of a spare reactor for a reactor in which the catalyst is being regenerated or by semi-cyclic shutdown of the entire regeneration systan while the catalyst in all the reactors is regenerated at one time. In the last mentioned case, it may be advantageous to first initiate regeneration in the final zone and preheat the oxygen-containing gas stream used to regenerate the first zone in the heat exchanger with the hot off gases from the final zone.
• a catalytic reformer comprising an alternating series of four reactors and three heaters, the heaters being disposed respectively between the first and second reactors, the second and third reactors and the third and fourth reactors, is charged with hydrocarbon naphtha feedstock at a rate of 17,000 barrels per stream day. Hydrogen-rich gas is also fed to the reformer at a rate sufficient to provide a hydrogen to hydrocarbon feed mole ratio of 5.0 to 1.
• the naphtha feedstock has a boiling range of 106°F to 39CPF and contains approxi ⁇ mately 52 percent paraffins and approximately 35 percent naphthenic compounds.
• the first three reactors each contain a 385 cubic foot
• Afc Wii-0 ⁇ bed of platinum containing alumina base refoiming catalyst; the fourth ⁇ reactor is larger and contains a 914 cubic foot bed of the catalyst.
• the naphtha feedstock and hydrogen-rich gas are intimately mixed and passed through a heat exchanger where the tetiperature of the admixture is raised to 825°F.
• the hot mixture is then passed through the first reactor wherein the temperature drops to 720 F.
• Effluent from the first reactor is heated to 938°F. in the first heater and then introduced into the second reactor wherein additional refoiming takes place and the temperature of the stream drops to 88CPF.
• the tempera- ture of the effluent from the second reactor is increased to 941°F.

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• Chemical & Material Sciences (AREA)
• Oil, Petroleum & Natural Gas (AREA)
• Engineering & Computer Science (AREA)
• Chemical Kinetics & Catalysis (AREA)
• General Chemical & Material Sciences (AREA)
• Organic Chemistry (AREA)
• Production Of Liquid Hydrocarbon Mixture For Refining Petroleum (AREA)
• Hydrogen, Water And Hydrids (AREA)

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• 1980
  • 1980-07-09 WO PCT/US1980/000900 patent/WO1981000415A1/en active Application Filing
  • 1980-07-09 GB GB8107166A patent/GB2070053B/en not_active Expired
  • 1980-07-09 JP JP55501860A patent/JPH0147519B2/ja not_active Expired
  • 1980-07-09 NL NL8020292A patent/NL8020292A/nl not_active Application Discontinuation
  • 1980-07-10 IT IT23360/80A patent/IT1131945B/it active
• 1981
  • 1981-02-24 EP EP80901564A patent/EP0031847A1/en not_active Withdrawn

Non-Patent Citations (1)

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