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
  • C10G11/00—Catalytic cracking, in the absence of hydrogen, of hydrocarbon oils
  • C10G11/14—Catalytic cracking, in the absence of hydrogen, of hydrocarbon oils with preheated moving solid catalysts
  • C10G11/18—Catalytic cracking, in the absence of hydrogen, of hydrocarbon oils with preheated moving solid catalysts according to the "fluidised-bed" technique
• • 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
  • C10G51/00—Treatment of hydrocarbon oils, in the absence of hydrogen, by two or more cracking processes only
  • C10G51/06—Treatment of hydrocarbon oils, in the absence of hydrogen, by two or more cracking processes only plural parallel stages only
• • 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
  • C10G2300/00—Aspects relating to hydrocarbon processing covered by groups C10G1/00 - C10G99/00
  • C10G2300/10—Feedstock materials
  • C10G2300/1037—Hydrocarbon fractions
  • C10G2300/1048—Middle distillates
• • 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
  • C10G2300/00—Aspects relating to hydrocarbon processing covered by groups C10G1/00 - C10G99/00
  • C10G2300/40—Characteristics of the process deviating from typical ways of processing
  • C10G2300/4056—Retrofitting operations
• • 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
  • C10G2400/00—Products obtained by processes covered by groups C10G9/00 - C10G69/14
  • C10G2400/02—Gasoline
• • 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
  • C10G2400/00—Products obtained by processes covered by groups C10G9/00 - C10G69/14
  • C10G2400/04—Diesel oil

Definitions

• the present invention belongs to the field of fluid catalytic cracking (FCC) processes and concerns the maximization of medium distillates. More specifically, the present invention describes a heavy or mixed-load FCC process which proposes the use of two distinct pivoting converters, one of which is dedicated to producing better quality LCO (Light Cycle OH). and the other converter dedicated to reducing unwanted (decanted oil) or unspecified (naphtha) currents generated in the first converter. Furthermore, the invention describes the benefit of using low contact time as a method for reducing reaction severity in the converter aimed at producing quality LCO. The process seeks both to maximize LCO production and improve its quality and to produce gasoline of the required quality and reduce fuel oil production, eliminating the typical problems of maximum LCO operation.
• FCC fluid catalytic cracking
• LCO Light Cycle OH
• TRX low reaction temperature converter
• the proposed invention relates to a fluid catalytic cracking (FCC) process comprising two pivotally operating converters.
• Converter here and throughout the text, means a set of equipment that enables: the occurrence of load cracking reactions including the use of finely particulate catalyst for the reaction mechanism to be catalytic; regeneration of spent catalyst; and transporting the fluidized catalyst with the rheological characteristics of a powder between the reaction zone and the regeneration zone.
• the converter itself contains a single catalyst formulation in its inventory.
• the proposed process seeks to maximize both LCO production and quality, and in addition produces the required quality gasoline and reduces fuel oil production, eliminating typical LCO operation problems.
• Fluid bed catalytic cracking plays a vital role in oil refining, especially when processing of heavy hydrocarbons, therefore difficult to distillation.
• the main characteristics of the process are: possibility of adjusting production according to the real market needs and reusing low commercial value fractions from other refinery processes.
• the FCC unit processes intermediate and heavy petroleum fractions, generating lighter products (gasoline and lighter intermediates) of higher added value through chemical breakdown reactions via zeolitic catalysts. This type of cracking occurs at controlled temperatures and lower than thermal cracking.
• Coke is a high molecular weight material consisting of hydrocarbons which typically contains from 4% to 9% by weight of hydrogen in its composition.
• the coke-coated catalyst At the end of the riser reactions, the coke-coated catalyst, generally referred to as the "spent catalyst", must be separated from the cracking products. This separation operation is typically performed on cyclones contained in a vessel called a “separator vessel”.
• Applicant's separation technology object of patent documents PI 9303773-2 (comprising a riser end rapid separation system), PI 0204737-3 (comprising an improvement of the rapid separation system by introducing manifolds of hydrocarbon vapors to the system) and PI 0704443-7 (comprising the application of the rapid separation system for converters with two or more risers), incorporated herein by reference, is the preferred technique for use in the present process.
• the spent spent catalyst still contains some amount of noble cracking products dragged between the catalyst particles or adsorbed on its surface and should therefore be rectified for recovery of this residual hydrocarbon.
• This operation occurs in the rectifier, equipment in general combined with the separator vessel.
• the rectifying fluid is generally steam and it flows countercurrent to the spent catalyst flow. Rectifier trim allows for closer contact between catalyst particles and grinding vapor.
• GC fuel gas - process inert, H 2 S, H 2 and C1 and C2 hydrocarbons
• LPG liquefied gas - C3 and C4 hydrocarbons
• Acid waters sum of all vapor streams injected into the reaction zone and top system of the fractionation section and containing high levels of contaminants such as H 2 S;
• GLN cracked naphtha specified as gasoline - C5 + hydrocarbons to boiling end point (PFE) of 220 ° C, typically;
• LCO light cycle oil - PIE hydrocarbons from 220 ° C to PFE of 340 ° C, typically;
• the cracked naphtha stream can be fractionated into light naphtha (NL) and heavy naphtha (NP), the cutting temperature being in the interest of the refiner. Additionally, in some configurations a circulating reflow current from the tower, intermediate between LCO and OD, the heavy cycle oil (HCO) stream is removed as product.
• NL light naphtha
• NP heavy naphtha
• HCO heavy cycle oil
• the spent catalyst at the rectifier outlet containing only non-rectifiable carbonaceous material is subsequently sent to a regenerating vessel.
• this vessel which operates under high temperature, the coke that is deposited on the surface and in the pores of the catalyst is burned. Coke elimination through combustion allows for recovery of catalyst activity and releases sufficient heat to meet the thermal needs of catalytic cracking reactions.
• Fluidization of catalyst particles by gas streams allows the transport of catalyst between the reaction zone and the regeneration zone and vice versa.
• the catalyst in addition to fulfilling its essential function of catalyzing chemical reactions, also acts as a means of transporting heat from the regenerator to the reaction zone.
• the art contains many descriptions of hydrocarbon catalytic cracking processes in a fluidized catalyst stream, with catalyst transport between the reaction zone and the regeneration and coke burning zone in the regenerator.
• the Fluid Catalytic Cracking (FCC) process is primarily geared towards the production of high octane gasoline and is also responsible for the production of LPG.
• the average distillate (LCO) produced in this conventional process represents from 15% to 25% by weight of the total yield. Normally LCO has a high concentration of aromatics, exceeding 80% of the total composition, which makes it difficult to incorporate it into the diesel pool.
• Aromatics in the LCO range degrade its quality by reducing the cetane number (index based on the chemical formula C 16 H 34 linear paraffinic hydrocarbon used as a standard in assessing diesel igniter properties) and increasing density, a feature that cannot be be fully reversed by hydrotreatment. Minimizing aroma formation in the FCC is therefore an important strategy in maximizing middle distillates.
• Aromatics in FCC products may come directly from the charge through dealkylating reactions of larger aromatic molecules, or may be formed from cyclizing olefins and then undergo hydrogen transfer reactions. The formation of aromatics from olefins occurs in side reactions and the low reactivity of aromatics causes these molecules to eventually concentrate on products as conversion progresses and removes other more reactive species from the environment. reactionary. The undesirable aromatic formation reactions, which are undesirable to obtain a better quality middle distillate, are favored by high severity conditions such as: high reaction temperature and high contact time between the load and the riser catalyst.
• the FCC process was originally designed for the production of high octane gasoline, the intrinsic flexibility of the process allows it to be adapted for different production purposes, such as maximizing medium distillates for diesel or even of light olefins (present in GC and LPG) for the petrochemical industry.
• Medium maximization and light olefin maximization are diametrically opposed types of operation. In medium operation, low conversions are sought in order to preserve the yield of LCO (boiling point range 220 ° C - 340 ° C), which is higher at conversion levels below those commonly practiced in typical FCC operation.
• the light olefins maximization operation seeks very high conversions by entering the gasoline overdrive region. For this reason, the task of simultaneously obtaining high yields of better quality light olefins and LCO in a single reaction zone is made difficult.
• the most commonly used solution for maximizing LCO production is to minimize the severity of reactions by operating the converter with a low reaction temperature between 450 ° C and 500 ° C, using a low activity catalyst. . Under these conditions the production of LCO is increased and its quality improved. The problem is that, along with this solution, some undesirable factors appear, such as increased production of DO and a deterioration in the quality of cracked naphtha, making its introduction into the gas pool unfeasible. Generally another associated undesirable factor caused by reduced reaction severity is the reduction in LPG production and, consequently, light olefins in the LPG range.
• a negative consequence usually from the operation of the FCC for maximizing averages by reducing the reaction temperature is the excessive coke deposition observed in the reaction zone and the grinding zone. It is normal to observe under low reaction temperature riser coke deposition, separator vessel cyclones, transfer line and rectifier bottom. This problem reduces the operational reliability of the unit and often requires its complete stop for coke removal and cleaning.
• Excessive coke deposition is mainly caused by incomplete vaporization of the load, due to the low temperature resulting in the mixing zone between the load and the catalyst, as a result of the lower reaction temperatures practiced for maximizing midrange.
• regenerator phase temperature Another negative consequence usually resulting from the operation of the FCC for the maximization of averages by reducing the reaction temperature is the temperature trigger in the regenerator whose operating range should be between 670 ° C to 730 ° C in the dense catalyst bed (dense regenerator phase temperature). Excessive rise in regenerator temperature is detrimental by increasing the unit's catalyst inventory shutdown rate and bringing the regenerator vessel closer to its design metallurgical limits. In addition it has the undesirable effect of significantly increasing the potential cracked naphtha gum as a result of the higher thermal cracking to which the load is subjected to mixing with the hottest catalyst from the regeneration zone despite the lower TRX.
• the temperature trigger in the regenerator during operation with reduced reaction temperature has as its main cause the increase of hydrocarbon drag to the regenerator.
• Hydrocarbon drag increases, in turn, due to the lower rectification efficiency caused by both the low temperature in the rectifier that accompanies the reaction temperature and the higher concentration of higher molecular weight components in the gas entering the rectifier from the lower load conversion and the largest non-vaporized portion of the load, as a result of the lower mixing temperature at the riser base, which follows the reaction temperature.
• Regenerator temperature correction can be accomplished by installing catalyst cooler equipment (catalyst cooler, or catcooler) in the regenerator vessel.
• the catcooler receives a current of hot vessel catalyst, exchanges heat with tubular beams through which water flows and in which saturated steam is generated, and returns to the regenerator a cooled catalyst current, keeping the regenerator's dense phase temperature in the proper operating range.
• Catalyst cooler or catcooler
• the catcooler receives a current of hot vessel catalyst, exchanges heat with tubular beams through which water flows and in which saturated steam is generated, and returns to the regenerator a cooled catalyst current, keeping the regenerator's dense phase temperature in the proper operating range.
• its use has the disadvantage of increasing the air demand for the regeneration zone due to the increase in total coke yield resulting from its effects on the overall energy balance of the converter.
• Another method for correcting the regenerator temperature is to inject a quench coolant stream into the riser, preferably at a point above the main charge injection, as taught in patent application PI 0504854-0.
• Quench injection leads to an increased energy demand for the riser, which results in increased catalyst circulation from the riser to the regenerator.
• This additional removal of hot catalyst from the regenerator indirectly contributes to the reduction of the temperature in the dense regenerator catalyst bed.
• Another benefit of quenching is the riser base temperature increase (to the same final reaction temperature), which contributes to better load vaporization (especially important for heavy loads) and bottom cracking, reducing the production of OD and also reducing the coke deposition on the converter internals by the presence of non-vaporized load. Similar to the catalyst cooler, this alternative has the disadvantage of increasing the total coke yield of the unit, which consequently requires the use of a higher combustion air flow.
• delta coke is the ratio of the coke weight yield of the charge to the mass ratio of catalyst circulation / charge flow (catalyst / oil ratio, or C / O).
• C / O translates to the unit mass of catalyst per unit mass of charge.
• delta coke indicates the amount of catalyst required to produce a certain amount of coke, defined by the converter's thermal demand.
• the lower the delta coke value the greater the catalyst circulation (higher C / O) must be to generate a given coke yield in the unit, which ultimately means that the lower delta coke cools the regenerator (leads to a lower dense phase temperature) by promoting increased catalyst circulation, which removes heat from the regenerator to the riser.
• Reduced contact time leads to a reduction in delta coke because under these conditions the coke yield required to meet the converter's thermal balance is only achieved from increased catalyst circulation (higher C / O), which compensates for this. the shortest reaction time available in the riser.
• Applicant's patent application PI 0504321-2 discloses a process aimed at eliminating the drawbacks of increased OD production and loss of specification of gasoline resulting from reduced severity operation.
• the process is characterized by the use of a single converter with two distinct reaction sections associated with two separate fractionation sections.
• the load (current 10) is fed into the converter in the less severe reaction section in a riser with a temperature of 460 ° C to 520 ° C (maximum mode LCO).
• the reaction products are separated into a fractionator, from which "LCO for Diesel" (current 66) and unspecified cracked naphtha (current 64) and OD (current 68, high yield due to low severity) currents are removed.
• the operational reliability of the converter is reduced due to the problems related to coke deposition in the reaction and rectification section equipment associated with the lower temperature riser.
• the application of this process may be restricted to the processing of lighter loads.
• Patent application PI 0605009-3 discloses a double riser converter with the differential that no current is recycled. Risers operate at different severities, and therefore the production profile and product qualities are distinct between the two risers.
• the advantage of this design is the increase in the unit's fresh load processing capacity, which represents an increase in funds conversion to the refiner, as the second riser is not captive to the current riser reprocessing.
• the disadvantage is that unspecified naphtha production and higher OD in the first riser.
• US patent application 2006/0231458 discloses an FCC process that claims to use low riser contact time, focusing on increasing the production of gasoline and middle distillates. In this process a single riser is used and the contact time is 1 to 5 seconds (however, generally the short contact time is characterized by times less than 2 seconds). Some of the advantages of low contact time are cited in this document, such as the reduction of non-selective reactions and the reduction of unwanted hydrogen transfer reactions that lead to the formation of aromatics in cracking products. Reduction in fuel oil production is achieved by selective DO recycling, ie from an OD stream whose triaromatic compounds (hydrocarbons with more than three aromatic rings) have already been removed.
• WO 01/60951 discloses a two-riser FCC process, the second riser being exclusively for the reprocessing of the OD from both the first and the second riser itself.
• the FCC process of WO 01/60951 has some disadvantages, such as:
• the first riser LCO and naphtha currents are not separated in the fractionator associated with this riser, but are mixed with the same cuts obtained in the second OD riser. With this, the LCO and naphtha obtained in the first riser are mixed with those obtained in the second riser fractionator. If the severity in both risers is low, the resulting LCO is of good quality, but OD reprocessing loses its effect, and the process has the usual drawback of high OD (and low quality naphtha) production.
• US 6,416,656 describes a process for increasing the overall diesel and LPG yield by using a riser. In this process, the gasoline is depressed to increase the LPG yield, being injected at a point lower than the nozzle, the site subjected to the highest severity in the riser, both in the reaction temperature and in the ratio of catalyst mass unit per unit. load mass (C / O ratio).
• the process load is injected at multiple points along the riser, reducing contact time and thereby increasing LCO yield;
• the temperature is already lower, as well as the C / O ratio (due to the injection of more load in the riser), which also favors the yield and quality of the LCO.
• a quench is injected at the top of the riser in order to cease secondary reactions.
• Lower severity in the load cracking region may lead to an undesired increase in OD production, but the patent indicates the possibility of recycling OD along with the cargo.
• the disadvantages of this technique are:
• a catalytic system for low severity load cracking objective of maximizing quality LCO
• another catalytic system for naphtha cracking under specific conditions objective of correcting quality
• the technique still requires a mixed charge fluid catalytic cracking process aimed at the production of medium distillates that maximizes the quality of the LCO obtained in the load cracking, isolating this high quality LCO stream from other CSF streams from the reprocessing of cracked fractions that, due to their chemical nature and higher reaction severity, generate a lower quality CSF.
• the invention provides a process that utilizes two distinct converters that work together in a pivotal manner for diesel maximization by independently cracking naphtha and OD streams for specified gasoline production and reducing fuel oil production by converting it into diesel fuel.
• lighter products in addition to providing the specification as Aromatic Residue (RARO) of its remaining fraction due to the high aromaticity obtained by shrinkage, presenting a benefit superior to that obtained with only one converter.
• RARO Aromatic Residue
• This technique can be extended to refineries that have two FCC units by modifying the equipment and aligning the units by adjusting one converter under low severity and the other under high severity. Catalytic systems would be distinct and appropriate for each objective.
• the high quality LCO stream would be produced and in the second, the naphtha and OD currents of the first one would be reduced, besides the unit load.
• naphtha could be lowered into an independent riser.
• the OD would be mixed to the load. If a single riser is available on the second converter, the naphtha could alternatively be lowered in the lift section below the injection of the DO load mixture.
• the use of the present technique further provides the refiner with the desired flexibility in changing local demand for derivatives.
• the second converter will be used to crack part of the load flow of the first, since the increase in thermal demand of the first will limit the load processing in it.
• Using both converters will allow the refiner to process the same full charge flow regardless of the operating mode selected.
• a more restricted application refers to its use in a refinery with only one converter and which chooses not to build a second converter to handle unspecified naphtha current and decanted oil surplus from the converter operating to maximum LCO.
• the refiner enjoys all the benefits of reducing the reaction severity in his converter via low contact time maintaining the highest TRX, and has the option of recycling part of naphtha at the riser base.
• the difficulty of coping with the higher production of decanted oil will remain: if you choose to recycle some of the DO or not to reduce reaction severity so much as not to increase the yield of DO, the consequence will be a deterioration in LCO quality and lower incorporation of this current into the diesel pool, the initial objective of the converter operation to medium maximums.
• the present invention relates to a heavy or mixed-load FCC process comprising two distinct pivoting converters.
• a first converter operates with low riser contact time from 0.2s to 1.5s (preferably 0.5s to 1.0s) allowing a higher reaction temperature even at low severity from 510 ° C to 560 ° C (preferably from 530 ° C to 550 ° C) and with a suitable catalyst for maximizing LCO.
• a second converter has a high activity catalytic system, suitable for naphtha cracking and OD, and utilizes conventional contact time (greater than 1.5s).
• reaction temperatures of each are adjusted to the most recommended range to maximize cracking of each of the currents: 530 ° C to 560 ° C for the OD riser; and 540 ° C to 600 ° C for the naphtha riser.
• the process seeks both to maximize LCO production and quality and to produce quality gasoline. required and reduces fuel oil production, eliminating the traditional problems the refiner encounters when operating in LCO maximization.
• the use of the low contact time on the first converter allows for a higher quality LCO even at higher reaction temperatures, thus enjoying all the benefits associated with the higher TRX. The end result translates into increased operational reliability and a favorable thermal balance, which makes room for increased load temperature and for residual load processing.
• Figure 1 schematically illustrates a flowchart of the proposed invention in its preferred embodiment, in which the second converter is provided with two risers, for naphtha and OD independent shrinkage on each riser.
• Figure 1 illustrates the design of a new diesel-driven FCC unit at the refinery, as well as the application of the present invention to a refinery that already has two FCC converters, one of which has two risers.
• Figure 2 schematically illustrates a flowchart of an alternative solution of the present invention for application in a refinery that already has two FCC converters, where both have only one riser and in case a second riser is not chosen for one of the two. converters. It should be noted that, in this case, the condition of naphtha and OD (in the same riser) is not optimized; However, Figure 2 reflects a lower investment decision to implement this proposal.
• Figure 3 illustrates a block diagram of the invention applied to an existing FCC unit.
• the present invention deals with an FCC process for maximizing of medium distillates from mixed hydrocarbon loads, where it is proposed to use two separate converters, operating in an articulated manner, to maximize diesel, specified gasoline production and reduction of fuel oil production, with the resulting benefit exceeding that obtained with only one converter.
• FIG 1 schematically illustrates the proposal of the invention in its preferred embodiment.
• converter “A” (1) comprises a riser "2", a separating vessel (3), a rectifier (4), a spent catalyst standpipe (5), a regenerator (6) and a regenerated catalyst standpipe (7)
• a load (50a) consisting of heavy diesel or atmospheric residue (RAT) or a mixture of these streams is injected into the upper load spreader (8).
• RAT atmospheric residue
• the regenerated catalyst is initially dragged by a lift fluid (51), which is usually steam, to assist the upward flow of the catalyst in riser "I” (2) to the point of load introduction.
• the reaction products (52) of converter “A” (1) are hydrocarbons lighter than cargo (50a), such as gasoline, LPG, fuel gas (GC) and LCO, plus decanted oil (OD). These are sent to a fractionating tower “A” (1 1), from which the appropriate quality LCO stream (57) is withdrawn for incorporation into the diesel hydrotreating load pool. At the top of the fractionating tower "A” (11) comes a stream of light hydrocarbons (53) which is condensed and then sent to a top vessel (12). The top vessel (12) separates an unspecified naphtha (NNE) fraction (55) and a wet gas fraction (54), consisting primarily of GC and LPG strip components.
• NNE unspecified naphtha
• a wet gas fraction 54
• the fraction of NNE (55) is sent to the naphtha disperser (29) on the basis of a riser "II" (21) which is part of a second converter "B" (20).
• a fraction of NNE (56) may be sent to the disperser (10) at the base of riser ⁇ "(2) of converter” A "(1), in which case it would serve as a lift fluid (naphtha). lift) to the catalyst, which to reach the upper portion of the riser without load injection (which when vaporized ultimately contributes to the upward flow of the catalyst) requires a greater amount of lift steam (51).
• Converter “B” (20) comprises a riser “II” (21), a separating vessel (22), a rectifier (23), a spent catalyst standpipe (24), a regenerator (25), a catalyst standpipe (26) connecting the regenerator (25) to riser “II” (21), a regenerated catalyst standpipe (27) connecting the regenerator (25) riser “III” (28), and riser “III” (28).
• the OD (58) meets the hot regenerated catalyst from the regenerator (25) through the standpipe duct (27).
• the regenerated catalyst is initially entrained by a lift fluid (60), which is generally steam, to assist upward flow of the catalyst in riser "III" (28).
• a set of independent dispersors for load (50b) and OD (58) may be provided. If the operating mode is set to maximum petrol, the converter "A" (1) will produce a naphtha already specified and therefore it is not necessary to reduce this current in riser “II” (21) of converter “B” ( 20).
• a spreader (35) is provided in riser “II” (21) of converter “B” (20) load cracking 50c, consisting of heavy diesel or atmospheric waste (RAT), or a mixture of these currents, which may be the same as those used in converter "A” (1) and riser “M1” (28) of converter “B” (20), or even a segregated load of different quality from loads (50a) and (50b).
• the reaction products (61) of converter "B" (20) are sent to a fractionating tower “B” (31) from which a low quality LCO (65) current flows from the intermediate region of the tower to its destination. It is for refinery fuel oil diluent.
• a light hydrocarbon stream (62) which is condensed and then sent to a top vessel (32) which generates a stream (63) consisting mainly of GC track components and LPG.
• a stream (63) consisting mainly of GC track components and LPG.
• At the bottom of the vessel (32) comes an unstable naphtha stream (64).
• Sending streams 63 and 64 into the gas recovery area promotes GC and LPG separation as well as naphtha stabilization, which can then be incorporated into the refinery's Gasoline pool.
• the wet gas fraction (54) leaving the top vessel (12) of converter "A” (1) can be add to the wet gas fraction (63) leaving the top vessel (32) of converter "B” (20) and proceed to a common gas recovery area.
• Converter “A” (1) operates with low riser contact time ⁇ "(2), in the range of 0.2s to 1.5s (preferably 0.5s to 1.0s) and utilizes a suitable catalyst for maximizing LCO to minimize aromatic content in the LCO, thereby increasing its quality.
• the reaction products (52) are sent to the fractionating tower "A” (11) from which the quality LCO stream (57) of suitable quality for incorporation into the diesel hydrotreating load pool is drawn.
• Converter “B” (20) has a high-activity catalytic system suitable for cracking NNE (55) and OD (58), and since it has two separate risers, allows the reaction temperatures of each to be adjusted to the most recommended range to maximize cracking of each of the chains: 530 ° C to 560 ° C for the riser "III” (28) from OD (58) and 540 ° C to 600 ° C for the riser "II” (21) of the NNE (55).
• Converter “B” (40) comprises a riser (41), a separating vessel (42), a rectifier (43), a spent catalyst standpipe (44), a regenerator (45) and a regenerated catalyst standpipe (46).
• Reaction products (68) from converter “B” (40) are sent to a fractionating tower "B" (33) from which a low quality LCO (72) current flows from the middle of the tower, the destination of which It is for refinery fuel oil diluent.
• a light hydrocarbon stream (69) which is condensed and then sent to a top vessel (34) which generates a stream (70) consisting primarily of GC strip components and LPG.
• a stream (70) consisting primarily of GC strip components and LPG.
• Sending streams 70 and 71 into the gas recovery area promotes GC and LPG separation as well as naphtha stabilization, which can then be incorporated into the refinery's Gasoline pool.
• the "B” converter (40) has a high-activity catalytic system suitable for cracking NNE (55) and OD (58), but as it has no separate risers, it does not have the flexibility of independent temperature adjustment. of reaction for each current.
• the riser (41) should operate at a temperature of 530 ° C to 570 ° C in order to enable OD conversion, knowing that naphtha will be subjected to a greater severity because it is injected into the riser base (41).
• quench injection with a cooling fluid such as water at a point above the charge injections in any of the disclosed risers is an alternative that can be used as described in PI 0504854 -0 for the present case.
• a cooling fluid such as water
• HCO heavy cycle oil
• the block diagram as shown in Figure 3 illustrates the application of this innovation to a refinery that has an existing FCC unit.
• the scheme illustrates the innovation with charge inlet 50a such as vacuum heavy diesel (GOP) in an existing "A" converter (1).
• charge inlet 50a such as vacuum heavy diesel (GOP) in an existing "A" converter (1).
• reaction products (52) are generated which proceed to an existing fractionating tower "A” (11).
• the reaction products (52) of converter “A” (1) are hydrocarbons lighter than charge (50a), such as gasoline, LPG, fuel gas (GC) and LCO, plus OD.
• GC fuel gas
• LCO hydrocarbons lighter than charge
• the fractionating tower “A” (11) also separates unspecified naphtha (NNE) (55) and OD (58) streams as well as as a wet gas stream (54), consisting mainly of GC and LPG. NNE (55) and OD (58) currents flow to the new "B" converter (20) with two risers. After passing through the "B" converter (20), the reaction products (61) move to a new "B” fractionating tower (31), in which the wet gas fraction (63) consisting mainly of GC and LPG joins the wet gases (54) from converter "A" (1) and into an existing gas recovery area (36).
• NNE unspecified naphtha
• OD (58) currents flow to the new "B" converter (20) with two risers.
• the reaction products (61) move to a new "B” fractionating tower (31), in which the wet gas fraction (63) consisting mainly of GC and LPG joins the wet gases (54) from converter "A" (1) and into an existing gas recovery area (
• a second fraction leaving the fractionating tower "B" (31) is comprised of an unstable naphtha stream (64) which also proceeds to the gas recovery section (36), where it participates in the absorption of wet gases and, after stabilized, proceeds to the refinery's Gasoline pool.
• Two more fractions are produced from this "B" fractionating tower (31), which is the low-quality, high-aromatic LCO for diluent (65) and one fraction for OD (RARE OD) (66) .
• converter "A” (1) operates with GOP load (50a), with a reaction temperature of 520 ° C and a contact time of 0.5s, giving the following yield profile:
• the next example illustrates the benefit of using the low riser contact time as a method for reducing the reaction severity in the LCO to diesel converter.
• Race "A” represents a base case of operation using high activity catalyst and 530 ° C TRX.
• Races “B” and “C” represent the different routes of reaction severity reduction from the base case. In both the severity reduction occurs both by using a lower activity catalyst as well as by adjusting the operating condition, but differ in the process variable used for the adjustment: run “B” demonstrates the TRX reduction route, while that race “C” demonstrates the route of reducing contact time.
• race "C” the coke production clearance is 35% compared to the base case, significantly greater than that obtained by race “B”. This is because the low contact time route allows full utilization of all dense phase temperature cooling achieved by replacing the catalyst in the unit.
• contact time is a variable cited in the literature as one of the possible variables for adjusting reaction severity
• the approach that the use of low contact time allows working at a higher reaction temperature and reaping all the benefits from it. from the use of the low contact time / longer TRX pair even with the converter aimed at the midrange production (when most midrange FCC processes described in the literature follow the TRX reduction line) are not found in the literature. It is This approach, learned by the applicant during the development of its diesel maximizing FCC process, is a central aspect of the present invention, which will lead to a new riser design philosophy for FCC units that address cases of maximum LCO operation.
• the contact time variable acquires fundamental importance in this process.
• Existing units can be optimized for maximum LCO operation by installing higher-load cargo injectors on the dock. And in the case of new units, designed for blocked campaigns between maximum LCO or maximum gasoline, the use of injectors at different elevations is now considered (offering flexibility for the unit), adding to all the benefits of higher TRX use. (favorable thermal balance and operational reliability) even in the maximum LCO campaign.

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• 2011
  • 2011-04-15 JP JP2014504123A patent/JP6068437B2/ja not_active Expired - Fee Related
  • 2011-04-15 US US14/111,145 patent/US20140034551A1/en not_active Abandoned
  • 2011-04-15 WO PCT/BR2011/000108 patent/WO2012139181A1/pt active Application Filing
  • 2011-04-15 BR BR112013019604A patent/BR112013019604B1/pt active IP Right Grant
• 2012
  • 2012-04-13 AR ARP120101294A patent/AR086012A1/es active IP Right Grant

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