Processing device with flexible heat integration scheme

Abstract

A thermal configuration for use in a vulcanization process and operation may include the following heating steps: (a) heating a process feed through a charge heater, (b) heating a process feed stream or a recycle oil stream by exchanging heat with a process effluent, (c) heating the process feed stream or recycle oil stream after heating in the charge heater, and (c) cooling the process feed stream or recycle oil stream after heating in the charge heater. A process feed stream or a recycle oil stream is heated by exchanging heat with the process feed. Furthermore, these steps can be made independent of one another by controlling the ratio of the streams to (b) or (c), controlling the amount of feed or recycle oil stream heated by bypassing (b) or (c), and controlling the temperature of step (a).

Description

Technical Field

[0001] The present invention relates to a method of controlling process temperature during catalyst activation and during operation, taking into account efficient capital and operating costs. Background Art

[0002] Activation of base metal catalysts by sulfidation is an important factor affecting the performance of hydroprocessing processes, and an efficient sulfidation process is also a relevant aspect of cost. Using ex situ presulfided catalysts is an option, but this involves additional costs, especially in processes with short catalyst cycles, where in situ sulfidation is desirable.

[0003] Additionally, controlling the temperature is critical for optimal activation of the catalyst, so a configuration that supports optimal heat distribution during the sulfidation process is also important. Summary of the invention

[0004] The present invention proposes to optimize the sulfidation by using a charge heater (which may be fired or electric) and recovering the heat by heat exchange with an upstream flow. To further optimize the thermal conditions, the charge heater can heat the stream above the required temperature and transfer this excess heat to another process stream by heat exchange, thus enabling fine control of the temperature so that all reactors receive the sulfiding medium at the optimal temperature.

[0005] In addition, it is proposed to provide a means for controlling the flow so as to convert the upstream reactor into the downstream reactor during the vulcanization process, thereby minimizing the excessive heating required when in-situ vulcanization is selected.

[0006] Finally, a process scheme is proposed to further optimize the heat distribution for cost-effective and efficient operation.

[0007] definition

[0008] The terms: Start of Run (SOR), Middle of Run (MOR) and End of Run (EOR) refer to the design conditions (mainly temperature and reaction yield, but in principle all conditions) of the reactor loaded with fresh catalyst (SOR), the reactor at the end of guaranteed operation (EOR) and the reactor between these time points (MOR). Usually, the design temperature of the EOR will be higher than that of the SOR, because the catalyst activity is expected to decrease.

[0009] Unless otherwise indicated, the term catalyst activation by sulfidation is understood to be a method of converting nickel, cobalt, molybdenum and tungsten into metal sulfide forms. Before activation by sulfidation, the base metal may be in oxide form or elemental form. Activation may generally involve contacting the catalyst with a liquid or gas containing sulfur, such as sulfide-containing hydrocarbons, dimethyl disulfide (DMDS) and other H2S precursors, and with an elevated temperature, and generally also with a certain amount of hydrogen to support the formation of metal sulfides. Sulfidation does not mean the absolute percentage of the metal in sulfide form, but rather means the amount of sulfide sufficient for commercial operation.

[0010] Unless otherwise indicated, the terms process operation, conversion and production mean the feeding of a feedstock into a process flow for the purpose of chemically converting the feedstock to produce products of different properties, such as converting a hydrocarbon feedstock (including oxygenate feedstocks derived from biological sources or thermal decomposition) into hydrocarbons more suitable for use as transportation fuels or as raw materials for subsequent processing.

[0011] A heat exchanger is understood to be a device in which the thermal energy in one stream is transferred to a second stream, the two streams being physically separated in the heat exchanger. The stream with the highest inlet temperature is designated as the "hot side" and the stream receiving the thermal energy is designated as the "cold side" of the heat exchanger.

[0012] A material having catalytic activity in a chemical reaction such as hydrodeoxygenation or hydrocracking is understood to be a material having significant catalytic activity and preference for the chemical reaction under the conditions used. As the skilled person will appreciate, most reactions will exhibit a certain amount of side reactions, but unless otherwise indicated, the term "material having catalytic activity in a chemical reaction" is understood to be a combination of material and conditions under which a commercially relevant amount of conversion will occur with a selectivity greater than that of any other chemical reaction.

[0013] Technical issues

[0014] Hydroprocessing of reactive feedstocks is usually done in three steps; a diolefin saturation reactor, operating at 100-190°C with a temperature increase of 10-50°C. This reactor is followed by a guard reactor, at a temperature of about 250-300°C to capture impurities, and then the charge is heated to about 300-400°C for exothermic hydroprocessing of the purified feedstock, with an effluent temperature of about 300-350°C, where all temperatures are examples at the beginning of a run with fresh catalyst, but at the end of a run the catalyst will have deactivated, so the required temperature may be 50-90°C higher. Normally, all catalysts in a process will deactivate at a similar rate, and processes are designed under this assumption, allowing simple thermal control, simply increasing the temperature at one location to compensate for the reduction in activity of all reactors in a related manner. However, if one reactor deactivates at a different rate than the others, the required temperature compensation will be irrelevant, so independent thermal control is preferred to optimize catalyst life.

[0015] The catalysts used in the above three steps are usually sulfided base metal catalysts, which must be activated by sulfidation before operation. Sulfidation can be performed ex situ, which provides a ready-to-use catalyst at an increased cost, or can be performed in situ, which requires the presence of appropriate activation conditions in the processing equipment.

[0016] In-situ sulfiding of hydroprocessing catalysts is preferably carried out in a fairly narrow temperature range, such as 300-350°C or even 310-330°C, to maximize the quality of sulfiding and minimize the time required for sulfiding. For exothermic processes, the process inlet temperature required in the initial stage is much lower, perhaps 100-180°C, and the released process heat provides sufficient temperature for downstream reactions, so initial charging heaters may not be provided considering conventional operations. In order to realize such processes, it is necessary to load presulfided catalyst in some reactors, or to provide heaters at multiple locations to heat the presulfiding medium.

[0017] US 3,979,183 provides a process plant with feed preheating and process temperature control by controlling flow ratios.

[0018] Solution to the problem

[0019] The present invention discloses a process layout and process in which in-situ activation is achieved while minimizing heat exchange loads while ensuring optimal temperatures in all reactors.

[0020] The sulfidation of the catalyst is essentially adiabatic, therefore process equipment designed not to heat the feedstock, such as those operating for exothermic processes, may not be suitable for in situ sulfidation as sufficient heat will not be available.

[0021] By providing means for controlling flow so that an upstream reactor intended to operate at low temperatures, such as the above-mentioned diene hydrogenation reactor, is bypassed, by directing the flow for heat exchange with a hot process stream and directing the hot process stream to the diene hydrogenation reactor, a process scheme can be designed that can effectively sulfidize the catalyst at a moderate capital cost as well as a moderate operating cost.

[0022] Similarly, cases of uncorrelated deactivation of the catalyst can also be handled by uncorrelated thermal control, where flow control may be beneficial as it is less costly than adding a separate charge heater.

[0023] In general, the thermal arrangement according to the invention may involve the following multiple heating steps: (a) heating the process feed by means of a charge heater, (b) heating the process feed stream or recycle oil stream by heat exchange with process effluent, (c) heating the process feed stream or recycle oil stream by heat exchange with the process feed after heating in the charge heater. In addition, the steps can be made independent of each other by controlling the ratio of the streams directed to (b) or (c), controlling the amount of the heated feed stream or recycle oil stream bypassing (b) or (c), and controlling the temperature of step (a). The thermal arrangement can be carried out during activation by sulfidation or during process conversion. DETAILED DESCRIPTION OF THE INVENTION

[0025] Catalytically active materials containing base metals as active materials; molybdenum, tungsten, nickel or cobalt are most often used in their sulfided form during hydroprocessing. Since the materials are produced in elemental or oxide form, they must be activated by conversion to the sulfided form, which requires contacting them with a sulfur-rich material at a temperature sufficient to sulfidize the metal.

[0026] In practice, this can be carried out by directing a sulfiding medium, which is generally a gas / liquid mixed phase flow, which may comprise a gas phase with hydrogen and sulphur compounds and a liquid phase which may be a fossil feedstock or a sulphur-free feedstock inherently containing sulphur, which may be fossil hydrocarbons or hydrocarbons of renewable origin. In particular if the catalyst has a high activity, it may be beneficial to use hydrotreated hydrocarbons in order to minimize the risk of hydrogen depletion and / or thermal runaway and the associated coking of the catalyst. If the liquid phase is sulphur-free, a sulphur additive such as dimethyl disulfide - DMDS or other H2S precursors may be added to the liquid or gas. Depending on the availability and the specific catalyst, different sulphur compounds may be used for the sulphurization and the composition and additives of the sulphur-free feedstock may be selected to obtain an active and stable catalyst with reduced process downtime and lower reagent and energy costs.

[0027] One possible solution is to sulfid the catalyst ex situ and supply it to the reactor in presulfided form. This ex situ sulfidation has the advantages of well-defined sulfiding conditions and minimized downtime, but is associated with increased catalyst costs, making it unattractive.

[0028] Another solution involves in-situ sulphiding in the process equipment, operating as designed, usually recirculating the sulphiding medium until a significant concentration of sulphur is observed in the effluent. This is common practice, especially for processes with charge heating and little heat generation during the process, as this will correspond to the thermal profile of the sulphiding process, and it will be necessary to preheat the feedstock just as the sulphiding medium is preheated. If the thermal profiles are similar enough, a moderate change in the heating load can be allowed. In addition, in order to minimize the consumption of the sulphiding medium, it is usually recycled, which is usually done by keeping the gas and liquid phases separate.

[0029] For highly exothermic processes, the heat release during hydroprocessing is higher than that during sulfidation, so process heaters may not be provided as a necessity for the process. In this case, either presulfided catalyst needs to be provided for some reactors that are not equipped for adequate preheating, or process heating needs to be provided for use during sulfidation, which must be idle during operation. Both solutions are expensive, so an alternative is needed.

[0030] By modifying the existing charge heater to provide the appropriate amount of waste heat to the feed stream during the curing process and distributing it throughout the process, the heat required in the curing process can be efficiently provided. This can be achieved by providing heat exchange to cool the feed stream and heat the other streams.

[0031] By equipping the process equipment with flow control devices (such as valves and piping) so that an upstream reactor operating at a low inlet temperature during the hydroprocessing process temporarily receives a heated sulfiding medium in series or parallel with other reactors, even such reactors with low inlet temperatures can be economically and effectively sulfided in situ without the need for additional charge heaters.

[0032] In this way a slight excess of heating can be provided which is released from the process by heat losses.The effluent stream can also be used to heat the sulfiding medium by heat exchange before contacting any catalyst.

[0033] Additionally, during sulfiding, it may also be preferred to recycle a certain amount of the effluent sulfiding medium at an elevated temperature, whereas during hydroprocessing operations, it may be preferred to cool this recirculated oil stream to control the exotherm.

[0034] The process layout may also involve splitting the feed stream and, if recirculation is implemented, exchanging a certain amount of the recirculated oil stream with a stream from a charge heater (either flame-heated, electrically heated, or possibly heated by a hot process stream), another certain amount is heated by the process effluent, and combining the two recirculated oil streams after heating. Depending on the specific reaction, the temperature of the two streams will be different, and by controlling the amount of heating at each location, more flexible temperature control can be obtained. In sulfiding processes, as well as in hydroprocessing operations, regardless of the heat distribution used in the sulfiding process, such a scheme involves splitting the feed and / or recirculated stream, which is heated to two different temperatures at two different locations, which may be beneficial, especially to provide excess heat in the process heater, and it may be beneficial to transfer the excess heat to the feed stream and / or recirculated stream by heat exchange with a stream heated in the process heater.

[0035] During the process operation, the flexibility of thermal operation may also be required. For example, in order to control the selectivity between hydrocracking and isomerization, different process temperatures may be required to produce different products. This may also be related to raw materials with different reactivity, and finally different temperatures may be required at the beginning and end of the operation. In such an operation, in the case where the process needs to be cost-effective and flexible in thermal control, the process can be configured to optionally merge the feed stream with the recirculating oil stream and guide the stream to the main reaction, wherein the effluent of the main reaction is guided to the hot side for the second heat exchange with a certain amount of feed stream, recirculating oil stream or merging stream on the cold side. Another controllable amount of feed stream, recirculating oil stream or merging stream can be guided to the cold side of the first heat exchange to exchange heat with the main reaction feed stream on the hot side. The feed stream of the main reactor can be heated in a charge heater before the second heat exchange with the recirculating oil stream, and the charge heater can be designed to provide excess heat, thereby providing excess heat for heating another amount of feed stream, recirculating oil stream or merging stream in the first heat exchanger. If desired, the feed stream may be reacted in one or more pre-treatment steps, either before or after being combined with one or both recycle oil flows, and either before or after being heated by heat exchange with the main reaction effluent. The process may also be configured to allow controlled amounts of the feed stream or the pre-treated feed stream to bypass the first heat exchanger. Charge heaters may provide controlled amounts of heat to the feed stream, but the feed stream may also be heated by exothermic intermediate process steps.

[0036] By varying the controlled amount of one or more of the first feed stream, the recycle oil stream or the combined stream, and the controlled amount of one or more of the second feed stream, the recycle oil stream or the combined oil stream, the controlled amount of the bypass and the controlled amount of heat in the charge heater, a high degree of temperature flexibility can be established in the process reactor, so that the process has a high degree of flexibility in thermal control of the process. This may include processes for hydrotreating pretreatment and hydroprocessing, including hydrotreating as the main reaction, isomerization and hydrocracking, and may also include other processes.

[0037] BRIEF DESCRIPTION OF THE DRAWINGS

[0038] Figure 1 The process layout for hydroprocessing in three reactors is shown.

[0039] Figure 2 A process layout is shown for hydrotreating in three reactors, with flows in all three reactors configured for sulfiding.

[0040] Figure 1

[0041] Figure 1 A process layout for hydroprocessing in three reactors is shown. Solid process lines in the figure represent lines in flow, and dashed process lines represent lines where flow is blocked. The temperatures and reactions mentioned correspond to the operating start temperatures of the process for hydroprocessing pyrolysis oil derived from thermal decomposition of plastic waste, but since these are exemplary, these conditions may be different in other similar processes and should not be interpreted as limiting the scope of the claims.

[0042] A feedstock (100), for example pyrolysis oil originating from the thermal decomposition of plastic waste, is introduced into the process, combined with a hydrogen-rich gas (H2) and heated, for example, by steam (SH), and subsequently further introduced as an initial reactor feed (110) through an open valve to an initial reactor (RXA) for selective hydrogenation of dienes at a temperature of about 180°C. The outlet (112) of the initial reactor (RXA) is introduced to a three-way mixing valve providing a main stream (114) and a bypass stream (116), so that the main stream (114) is combined with a recycle gas (118) and a first recycle oil stream (122), providing a combined main stream (124), which is preheated by heat exchange in a first heat exchanger (HX1) and combined with the bypass stream (116) to form a first intermediate reactor feed stream (128). By increasing the amount of the bypass stream (116), less heating occurs in the first heat exchanger (HX1), which enables the temperature of the first intermediate reactor feed stream to be controlled.

[0043] The second recycle oil stream (130) is directed together with the recycle hydrogen to be preheated by heat exchange with the heated charge stream (136) in the second heat exchanger (HX2), and the second intermediate reactor feed stream (160) is combined with the first intermediate reactor feed stream (128) to provide the entire intermediate reactor feed stream (132). By controlling the flow rate of the second recycle oil stream (130) and the temperature of the heated charge (136), the temperature of the entire intermediate reactor feed stream (132) can be controlled.

[0044] The entire intermediate reactor feed stream (132) is directed to the intermediate reactor (RXB) to contact the catalyst (e.g., pollutant protection material) at a temperature of 280°C. This temperature is sufficient to release metal heteroatoms from the entire intermediate reactor feed stream (132), so that the heteroatoms are released and bonded to the surface of the pollutant protection material in the intermediate reactor. The process can be moderately exothermic, and the temperature of the intermediate reactor outlet stream (134) may be about 318°C. In order to support the hydroprocessing of the intermediate reactor outlet stream (134), it may be more preferable to increase the temperature to provide a heated charge stream (136), which is carried out in a charge heater (CH), which can be a flame heater, an electric heater, or heat exchange with a high temperature process stream. The heated charge stream (136) is directed to a second heat exchanger (HX2), and the cold side is the second recycle oil stream (130). Normally, the second recirculating oil flow (130) is zero, but if a temporary or permanent heating increase is required, the second recirculating oil flow (130) can be heated using superheating in the charge heater (CH).

[0045] The hot side outlet stream (138) of the second heat exchanger (HX2) is directed to the inlet of the main reactor (RXC). The temperature here is about 343°C, allowing efficient hydroprocessing with only a slight temperature increase of about 5°C, but depending on the nature of the feedstock, this temperature increase may be higher. The main reactor effluent (142) is cooled in the first heat exchanger (HX1), cooled here in a further cooler (C) and directed to a gas / liquid separation (SEP) and withdrawn as a product stream (150), which is optionally used for further processing; in this example, a certain amount of this main reactor effluent stream is directed to a recirculation pump (RP) as a recycle oil stream (152).

[0046] The process shown allows independent control of the three reactors because the heat energy in the steam heater (SH) will affect the initial reactor (RXA), the heat energy in the charge heater (CH) will affect the main reactor (RXC) and the intermediate reactor (RXB), more bypass flow (116) will bypass the first heat exchanger (HX1), thereby cooling the intermediate reactor (RXB), and the ratio between the two recirculating oil streams (122 and 130) will control the feed temperature of the intermediate reactor (RXB).

[0047] Figure 2

[0048] Figure 2 Shows the Figure 1 The same process layout, except that the flow is configured for the sulfidation of the reactor. In the figure, the solid process line represents the line in flow, and the dashed process line represents the line where the flow is blocked.

[0049] A sulfiding medium (200), for example hydrotreated oil, is introduced into the process, heated by steam (SH) and further introduced as sulfiding medium (206) via an open valve into a mixer to be combined with a first recirculating oil stream (222) to provide a combined main stream (224) which is preheated by heat exchange in a first heat exchanger (HX1).

[0050] A second amount of recycle oil (230), preheated by heat exchange with the heated charge in the second heat exchanger (HX2), is directed to be added to the first intermediate reactor feed stream (232) to provide the entire intermediate reactor feed stream (232). Controlling the flow of this stream and the temperature of the heated charge enables control of the temperature of the entire mid-body reactor feed stream (232). For sulfidation, this stream is preheated to 317°C, and the entire intermediate reactor feed stream (232) can be 313°C, which is optimal for sulfidation.

[0051] The entire intermediate reactor feed stream (232) is directed to the intermediate reactor (RXB) to contact the catalyst, such as the contaminant protection material, at a temperature of 313° C. This temperature is sufficient to effectively and deeply sulfidize the catalyst in the intermediate reactor (RXB). The outlet stream (234) of the intermediate reactor (RXB) is then directed to the initial reactor (RXA) through the initial reactor sulfidation line (262), and the outlet stream (212) of the initial reactor (RXA) is directed to the charging heater (CH) through the intermediate reactor bypass line (264).

[0052] The heated charge stream (236) is directed to the second heat exchanger (HX2) with the second recycle oil stream (230) on the cold side. For sulfidation, the second recycle oil stream (230) is preferably 25-50% of the total recycle oil stream (254) to ensure sufficient temperatures in the intermediate and initial reactors (RXB and RXA).

[0053] The hot side outlet stream (238) of the second heat exchanger (HX2) is directed to the inlet of the main reactor (RXC). The temperature here is about 329°C, which is the upper limit of the recommended sulfiding conditions, which allows effective sulfiding. The main reactor effluent (242) is cooled in the first heat exchanger (HX1) and directed to a gas / liquid separation (SEP), and a major amount of the main reactor effluent stream is directed to a recirculation pump (RP) as a recirculating oil stream (252). During the sulfidation process, hydrogen make-up gas (H2) is provided at multiple locations, and sulphur compounds (264) are also added to the process, for example before the recirculation pump (RP), until the sulfidation is completed. DETAILED DESCRIPTION OF THE INVENTION

[0055] A first specific aspect of the sulfidation of the present disclosure relates to a method of activating a first catalyst and a second catalyst by sulfidation, comprising the steps of:

[0056] directing a first amount of sulfiding medium to the primary side of the first heat exchange to provide a first amount of heated sulfiding medium having a first temperature,

[0057] directing a second amount of sulfiding medium to the primary side of the second heat exchange to provide a second amount of heated sulfiding medium having a second temperature,

[0058] combining the first heated sulfiding medium and the second heated sulfiding medium so that they contact the first material in the first reactor and withdrawing the intermediate sulfiding medium from the first reactor,

[0059] ● directing the intermediate vulcanizing medium so that it is heated by a heat source providing a certain amount of heat to provide a heated intermediate vulcanizing medium,

[0060] directing said heated intermediate vulcanizing medium to the primary side of the second heat exchange to provide a conditioned heated intermediate vulcanizing medium having a third temperature,

[0061] directing the conditioned intermediate sulfiding medium into a second reactor for contact with a second material and withdrawing an effluent from the second reactor,

[0062] directing the effluent to the secondary side of said second heat exchanger to provide a cooled effluent,

[0063] Therein, the ratio between the first amount of heated vulcanizing medium and the second amount of heated vulcanizing medium and the amount of heat provided by the heat source are controllable.

[0064] This has the benefit of providing a method for activating the base metal catalyst by in situ sulfidation even though the process operating conditions involve an exothermic process step in the first reactor, which eliminates the need for upstream process heaters during operation and is therefore not available during sulfidation.

[0065] A second specific aspect of sulfiding relates to a process according to the first specific aspect of sulfiding, wherein the heat source is from a fired heater, an electric heater or heat exchange with a process stream.

[0066] This has the associated benefit of providing the heat for the vulcanization process from an external source.

[0067] A third specific aspect of sulfiding relates to a process according to any specific aspect of sulfiding described above, wherein a recycled amount of the cooled effluent or a downstream stream derived from the cooled effluent is added to one or more of the sulfiding medium, the first amount of heated sulfiding medium, and the second amount of heated sulfiding medium.

[0068] This has the associated benefit of reducing consumption of the sulphiding medium. Advantageously, a sulphiding compound may be added to the recycled sulphiding medium to support sulphiding, wherein the sulphiding compound added varies with the sulphur concentration in the recycled sulphiding medium.

[0069] A fourth specific aspect of the vulcanization relates to a process according to any of the specific aspects of the vulcanization described above, wherein a third amount of the vulcanization medium is combined with the first amount of the heated vulcanization medium and the second amount of the heated vulcanization medium.

[0070] This has the associated benefit of further independent control of the process temperature by limiting the temperature by adding a certain amount of unheated vulcanizing medium.

[0071] A fifth specific aspect of the sulfiding relates to a process according to any specific aspect of the above sulfiding, wherein the third catalyst is present in a third reactor, and the sulfiding medium, the first amount of heated sulfiding medium, the second amount of heated sulfiding medium, the intermediate sulfiding medium, the heated intermediate sulfiding medium, and the effluent are directed so as to contact the third material in the third reactor.

[0072] This has the associated benefit of activating the third catalyst by directing the hot sulfiding medium to the third catalyst, placing the third catalyst at a downstream position during operation.

[0073] A sixth specific aspect of the sulfidation relates to a process according to any one of the first four specific aspects of the sulfidation described above, wherein the third catalyst is present in the third reactor, and wherein the third catalyst is pre-sulfided ex situ, and wherein less than 10% of the sulfiding medium, e.g., non-sulfiding medium, is directed to the third reactor during the sulfidation process.

[0074] This has the associated benefit that a process can be provided in which a controlled flow heat integration scheme is provided in only part of the process.

[0075] A first specific aspect of hydroprocessing relates to a process for hydroprocessing a feedstock comprising a sulfiding process according to any specific aspect of the sulfiding described above, followed by a subsequent hydroprocessing process for the hydroprocessed feedstock carried out in the same processing equipment, wherein the temperature at the inlet of the first reactor is at least 30°C or 50°C lower than the temperature at the inlet of the second reactor.

[0076] This has the associated benefit that a sulphide activation process can be provided in a process layout which would otherwise be designed for an exothermic process and whereby the feed heater would not have sufficient capacity to heat the sulphide medium.

[0077] A second specific aspect of hydroprocessing relates to the hydroprocessing process according to the first specific aspect of hydroprocessing in combination with the fourth or fifth aspect, wherein the flow control device is configured to allow the flow sequence of the reactors during sulfiding to be different from the flow sequence of the reactors during hydroprocessing.

[0078] This has the associated benefit of providing a process for activating, by sulfidation, a catalyst which would otherwise be at very low temperatures without this scheme for reconfiguring the flow sequence.

[0079] A third specific aspect of hydroprocessing relates to a process according to any of the above specific aspects of hydroprocessing or the specific aspects of sulfiding, wherein during the hydroprocessing, the first catalyst is operated under conditions where it is active for protection, and wherein the second catalyst is operated under conditions where it is active for hydroprocessing, and if present, the third catalyst is operated under conditions where it is active for diolefin saturation, and the feedstock comprises a renewable material containing oxygenates and / or thermal decomposition products of a solid feedstock, such as plastics, municipal waste, or biomaterials.

[0080] This has the associated benefit of providing a process suitable for in situ sulphur activation and subsequent operation. Since the cycle time of such a process is shorter, the cost savings from the inexpensive in situ activation will be more frequently achieved and therefore more valuable.

[0081] The sulfiding and hydroprocessing aspects involve a process for operating a first catalyst and a second catalyst, comprising the following steps:

[0082] The catalyst is activated by sulfidation.

[0083] directing the vulcanizing medium to be heated through the first heat exchanger to provide a heated vulcanizing medium having a vulcanizing temperature,

[0084] directing the heated sulfiding medium to combine with a first recirculating oil stream to contact a first material in a first reactor and withdrawing an intermediate sulfiding medium from the first reactor,

[0085] directing the intermediate vulcanizing medium to be heated through a second heat exchanger to provide a heated intermediate vulcanizing medium,

[0086] directing the heated intermediate sulfiding medium to contact a second material in a second reactor and withdrawing an effluent from the second reactor,

[0087] cooling the effluent by said first heat exchange to provide a cooled effluent,

[0088] directing at least a certain amount of the cooled effluent or a downstream flow derived from the cooled effluent as the first recirculated oil flow

[0089] After activating the material through sulfidation to make it an active catalyst,

[0090] The feedstock is hydrotreated by the following steps:

[0091] directing the feedstock, optionally combined with a first recycle oil stream, to contact the first catalyst in the first reactor at a first reactor inlet temperature to provide a pretreated product stream having a pretreated product temperature,

[0092] directing the pretreated product stream through the first heat exchange heating to provide a heated pretreated product stream,

[0093] directing the heated pretreated product stream to contact the second catalyst in the second reactor at a second reactor inlet temperature,

[0094] cooling the effluent of the second reactor by the first heat exchange to provide a cooled effluent,

[0095] directing at least a certain amount of said cooled effluent as said first recirculating oil stream,

[0096] Characterized in that, during the hydroprocessing process, the inlet temperature of the second reactor is at least 30°C or 50°C higher than the inlet temperature of the first reactor.

[0097] This has the associated benefit of providing a combined process for activating the catalyst and carrying out the conversion in a process that uses inexpensive process equipment while enabling efficient and flexible thermal control.

[0098] A first general aspect relates to a process for thermally controlling a chemical processing apparatus having two reaction steps, comprising the following process steps:

[0099] a. providing a first feed flow with a mass flow rate of m1 and a second feed flow with a mass flow rate of m2,

[0100] b. exchanging heat in a first heat exchanger the first feed stream as a main stream to provide a first heat exchange feed stream,

[0101] c. heating the second feed stream as a main stream in a second heat exchanger to provide a second heat exchange feed stream,

[0102] d. combining the first heat exchange feed stream and the second heat exchange feed stream and directing the combined heat exchange feed stream to the first reactor to provide an intermediate process stream at the outlet of the first reactor,

[0103] e. directing the intermediate process stream to a charge heat exchanger having a heat exchange duty to provide a first heat exchange intermediate process stream,

[0104] f. directing the first heat exchange intermediate process stream as a secondary stream to the first heat exchanger to provide a second heat exchange intermediate process stream,

[0105] g. directing the second heat exchange intermediate process stream to a second reactor to provide an effluent stream at the outlet of the second reactor,

[0106] h. directing the effluent stream as a secondary stream to the second heat exchanger to provide a heat exchange effluent stream,

[0107] i. wherein the ratio between the mass flow rate m1 and the mass flow rate m2 is controllable, and wherein the heat exchange duty of the charge heat exchanger is controllable.

[0108] This has the associated benefit of providing a process with a high degree of flexibility in heat distribution, with only a single charge heater.

[0109] A second general aspect relates to a process according to the above first general aspect, wherein the heat source is from a fired heater, an electric heater or heat exchange with a process stream.

[0110] A third general aspect relates to a process according to the first or second general aspect above, wherein an additional third feed stream having a mass flow rate m3 is diverted from the feed stream, and wherein the third feed stream is directed to the first reactor together with the first heat exchange feed stream and the second heat exchange feed stream.

[0111] This has the associated benefit of providing an additional independently controllable parameter by adding an unheated third stream to allow for additional thermal flexibility.

[0112] A thirteenth aspect relates to a processing device, comprising:

[0113] Raw material inlet and product outlet,

[0114] a first reactor including a catalyst and having an inlet and an outlet, and

[0115] a second reactor including a catalyst and having an inlet and an outlet,

[0116] The first heat exchange device has a cold side inlet, a cold side outlet, a hot side inlet and a hot side outlet,

[0117] The second heat exchange device has a cold side inlet, a cold side outlet, a hot side inlet and a hot side outlet,

[0118] The heating device has an inlet and an outlet,

[0119] A first flow control device has an inlet and two independently controllable outlets, which are respectively connected to the cold side inlet fluids of the first heat exchange device and the second heat exchange device,

[0120] The raw material inlet is fluidically connected to the inlet of the flow control device,

[0121] The cold side outlet of the first heat exchange device and the cold side outlet of the second heat exchange device are in fluid communication with the inlet of the first reactor,

[0122] wherein the outlet of the first reactor is in fluid communication with the inlet of the heating device, and no separation operation based on boiling point is involved,

[0123] The outlet of the heating device is in fluid communication with the hot side inlet of the second heat exchange device,

[0124] The hot side outlet of the second heat exchange device is fluidically connected to the inlet of the second reactor, without involving separation operation based on boiling point,

[0125] The outlet of the second reactor is in fluid communication with the hot side inlet of the first heat exchange device, and no separation operation based on boiling point is involved.

[0126] And the hot side outlet of the first heat exchange device is in fluid communication with the product outlet.

[0127] This has the associated benefit of providing a processing apparatus comprising only a single heating device, while having a high thermal flexibility.

[0128] A fourteenth aspect relates to a process according to the above thirteenth aspect, wherein the flow control device comprises a further third controllable outlet fluidly connected to the inlet of the first reactor.

[0129] This has the associated benefit of providing a bypass configuration, thereby providing further flexibility in heat distribution.

[0130] A fifteenth aspect relates to the processing apparatus according to the thirteenth or fourteenth aspect, further comprising a third reactor having an inlet and an outlet,

[0131] The second flow control device may be configured in any of the following configurations: configuration (a): providing fluid communication between the feedstock inlet and the inlet of the third reactor, and providing fluid communication between the outlet of the third reactor and the inlet of the second flow control device, or

[0132] Configuration (b): Fluid communication is provided between any one of the outlet of the second reactor, the outlet of the heating device and the hot side outlet of the second heat exchange device and the inlet of the third reactor, and fluid communication is provided between the outlet of the second reactor and the product outlet.

[0133] This has the associated benefit of providing an upstream reactor option that can be activated by in-situ sulfidation even if it is not equipped with an upstream charge heater. Example

[0134] Table 1 shows the temperatures and flow rates for two examples involving sulfurization activation under different thermal operating schemes.

[0135] Example 1-A shows that Figure 2 A process in which the split recycle oil stream (67% flowing in line 222 and 33% flowing in line 230 and corresponding to the first and second heat exchangers) and the charge heater temperatures are optimized to achieve similar temperatures in all three reactors. It can be seen here that in order to provide sufficient heat for sulfiding of the hydrotreating reactor catalyst and the guard catalyst, the charge heater must heat the feed stream to 346°C, but a certain amount of this heat is transferred to stream 260, which heats the feed entering the guard reactor by mixing with stream 228. In this way, the guard reactor catalyst can be sulfided at 313°C and the hydrotreating reactor at 329°C, i.e., within a range of only 16°C.

[0136] Example 1-B shows a similar process, where the second recycle oil stream is set to zero, i.e., demonstrating the effect of omitting the second heat exchanger. Here, the feed to the guard reactor is heated only by the effluent from the hydrotreating reactor. Since the same energy must be transferred to the stream, the feed heater must again heat the hydrotreating feed stream to 345°C to heat the feed entering the guard reactor to 311°C. This will result in sulfidation occurring at an elevated temperature of 345°C, but at the expense of catalyst life or activity, i.e., within a wider range of 34°C.

[0137] Table 2 shows a second example that illustrates the value of two heat exchangers and a flexible flow configuration in a hydroprocessing process.

[0138] In this example, the feeds and conditions of the diene hydrogenation reactor and the guard reactor result in a catalyst life (cycle length) that is only half the life of the hydrotreating catalyst. This means that in the time span in which the conditions of the diene hydrogenation catalyst and the guard catalyst are changed from the lowest temperature to the highest temperature, the hydrotreating catalyst is only changed from the lowest temperature to the intermediate temperature. In the following similar time span, the conditions of the diene hydrogenation catalyst and the guard catalyst will again be changed from the lowest temperature to the highest temperature, while the conditions of the hydrotreating catalyst are changed from the intermediate temperature to the highest temperature.

[0139] A process layout to achieve this heat distribution could be handled by two expensive separate charge heaters, but by including two heat exchangers and means to control the relative flows to the heat exchangers, lower capital costs will be possible.

[0140] Table 2 shows the effect of this approach, where Example 2-S corresponds to the start of the run. Figure 1 , Example 2-M corresponds to the mid-run Figure 1 , Example 2-E corresponds to the end of the operation Figure 1 It can be seen that at the start of the run, 75% of the diolefin hydrogenation reactor effluent (112) bypassed the first heat exchanger via line 116, so that only a small amount of this stream was heated in the first heat exchanger by the hydrotreating reactor effluent (142). In addition, the second heat exchanger was idle and there was no guard reactor feed in stream 130.

[0141] Example 2-M relates to mid-run, when the diolefin hydrogenation catalyst and guard catalyst are at the end of their cycle, the hydrotreating catalyst will be in "mid-cycle". This requires high temperatures to operate the diolefin hydrogenation catalyst and guard catalyst, while the hydrotreating catalyst is operated at an intermediate temperature. This can be achieved by having no bypass in line 116, 25% of the recycle oil being directed to be heated in the second heat exchanger, and providing additional heat in the charge heater. As a result, the diolefin hydrogenation catalyst and guard catalyst can be operated at elevated end-of-run temperatures without overheating the hydrotreating catalyst.

[0142] In Example 2-E, at the end of the run, operation can be carried out without bypassing pipeline 116 and without diverting the recycle oil flow, so that all the energy of the charge heater is directed to the hydroprocessing catalyst, and therefore, all three catalysts are operated at the highest temperature at the end of the run.

[0143] In this way, the use of bypass lines, diverter lines and additional heat exchangers provides a high degree of flexibility in the heating scheme of the process, which without this scheme would require operation with replacement of all catalysts after a minimum useful life.

[0144] Table 1

[0145]

[0146] Table 2

[0147]

Claims

1. A method for thermal control of a chemical processing device having two reaction steps, the method comprising the following process steps: a. providing a first feed flow with a mass flow rate of m1 and a second feed flow with a mass flow rate of m2, b. exchanging heat in a first heat exchanger the first feed stream as a main stream to provide a first heat exchange feed stream, c. heating the second feed stream as the main stream in a second heat exchanger to provide a second heat exchange feed stream, d. combining the first heat exchange feed stream and the second heat exchange feed stream and directing the combined heat exchange feed stream to the first reactor to provide an intermediate process stream at the outlet of the first reactor, e. directing the intermediate process stream to a charge heat exchanger having a heat exchange duty to provide a first heat exchange intermediate process stream, f. directing the first heat exchange intermediate process stream as a secondary stream to the first heat exchanger to provide a second heat exchange intermediate process stream, g. directing the second heat exchange intermediate process stream to the second reactor to provide an effluent stream at the outlet of the second reactor, h. directing the effluent stream as a secondary stream to the second heat exchanger to provide a heat exchange effluent stream, i. wherein the ratio between the mass flow rate m1 and the mass flow rate m2 is controllable, and wherein the heat exchange duty of the charge heat exchanger is controllable.

2. The method of claim 1, wherein the heat source is from a fired heater, an electric heater, or heat exchange with a process stream.

3. The process according to claim 1 or 2, wherein an additional third feed stream having a mass flow rate of m3 is branched off from the feed stream, and wherein the third feed stream is directed to the first reactor together with the first heat exchange feed stream and the second heat exchange feed stream.

4. A method for activating a first catalyst and a second catalyst by sulfiding, the method comprising the method for thermal control of a chemical processing equipment having two reaction steps according to claim 1, 2 or 3, wherein a first feed stream and a second feed stream are branched from a sulfiding medium stream, and a recycled amount of the heat exchange effluent or a downstream stream derived from the heat exchange effluent is added to one or more of the sulfiding medium, the first amount of heated sulfiding medium and the second amount of heated sulfiding medium.

5. The method of claim 4, wherein the third amount of the sulfiding medium is combined with the first amount of the heated sulfiding medium and the second amount of the heated sulfiding medium.

6. The method according to claim 4 or 5, wherein a third catalyst is present in a third reactor, and one of an amount of a sulfiding medium, a first amount of a heated sulfiding medium, a second amount of a heated sulfiding medium, an intermediate sulfiding medium, a heated intermediate sulfiding medium, and an effluent is directed to contact the third material in the third reactor.

7. A process according to claim 4, 5 or 6, wherein a third catalyst is present in a third reactor, and wherein the third catalyst is subjected to ex situ pre-sulfiding, and wherein during sulfiding, less than 10% of the sulfiding medium, e.g., non-sulfiding medium, is directed to the third reactor.

8. A process for subjecting a feedstock to hydroprocessing, comprising a sulphurization process according to claim 4, 5, 6 or 7 above, followed by a hydroprocessing process for subjecting the feedstock to hydroprocessing, the hydroprocessing process being subsequently carried out in the same process equipment, wherein the temperature at the inlet of the first reactor is at least 30°C or 50°C lower than the temperature at the inlet of the second reactor.

9. A method for hydroprocessing according to claim 8 as appended to claim 4, 5, 6 or 7, wherein the flow control means is arranged so that the flow sequence of the reactors during sulphidation is different from the flow sequence of the reactors during hydroprocessing.

10. A process for hydroprocessing according to claim 8 or 9, wherein during hydroprocessing, the first catalyst is operated under conditions where it is active for protection, and wherein the second catalyst is operated under conditions where it is active for hydroprocessing, and if present, the third catalyst is operated under conditions where it is active for diolefin saturation, the feedstock comprising renewable materials containing oxygenates and / or thermal decomposition products of solid feedstocks, such as plastics, municipal waste or biomaterials.

11. A processing device comprising: Raw material inlet and product outlet, a first reactor comprising a catalyst and having an inlet and an outlet, and a second reactor comprising a catalyst and having an inlet and an outlet, a first heat exchange device having a cold side inlet, a cold side outlet, a hot side inlet and a hot side outlet, a second heat exchange device having a cold side inlet, a cold side outlet, a hot side inlet and a hot side outlet, a heating device having an inlet and an outlet, A first flow control device having an inlet and two independently controllable outlets, which are respectively connected to the cold side inlet fluids of the first heat exchange device and the second heat exchange device, The raw material inlet is fluidically connected to the inlet of the flow control device, The cold side outlet of the first heat exchange device and the cold side outlet of the second heat exchange device are in fluid communication with the inlet of the first reactor, wherein the outlet of the first reactor is in fluid communication with the inlet of the heating device, and no separation operation based on boiling point is involved, The outlet of the heating device is in fluid communication with the hot side inlet of the second heat exchange device, and no separation operation based on boiling point is involved. The hot side outlet of the second heat exchange device is fluidically connected to the inlet of the second reactor, and no separation operation based on boiling point is involved. The outlet of the second reactor is in fluid communication with the hot side inlet of the first heat exchange device, And the hot side outlet of the first heat exchange device is in fluid communication with the product outlet.

12. The processing apparatus of claim 11, wherein the flow control device comprises a further third controllable outlet in fluid communication with the inlet of the first reactor.

13. The process plant according to claim 11 or 12, further comprising a third reactor having an inlet and an outlet, The second flow control device can be configured in any of the following configurations: Configuration (a): providing fluid communication between the feedstock inlet and the inlet of the third reactor, and providing fluid communication between the outlet of the third reactor and the inlet of the second flow control device, or Configuration (b): providing fluid communication between any one of the outlet of the second reactor, the outlet of the heating device and the hot side outlet of the second heat exchange device and the inlet of the third reactor, and providing fluid communication between the outlet of the second reactor and the product outlet.

Images