阅读说明：本技术 降低的氢气与烃的比率下的脱氢方法 (Dehydrogenation process with reduced hydrogen to hydrocarbon ratio ) 是由 克里斯托弗·迪吉利奥 克莱顿·C·萨德勒 于 2018-11-01 设计创作，主要内容包括：描述了用于使烃原料脱氢的方法。该方法可在较低H<Sub>2</Sub>/HC比率和较低RIT下运行,同时使焦炭产生保持在与较高H<Sub>2</Sub>/HC比率和较高RIT下的操作相同的水平,而不降低单程收率。当在0.01至0.40范围内的低氢气与烃的摩尔比以及500°–645℃范围内的反应器入口温度下操作该方法时,实现了可接受的焦炭水平。(A process for dehydrogenating a hydrocarbon feedstock is described. The method can be used at lower H 2 Operating at a lower RIT and/or HC ratio while maintaining coke production at a higher H 2 the/HC ratio and operation at higher RIT are at the same level without decreasing the single pass yield. At low hydrogen to hydrocarbon mole ratios in the range of 0.01 to 0.40 and reactor inlets in the range of 500 ° -645 ℃Acceptable coke levels are achieved when the process is operated at temperatures.)

1. A process for dehydrogenating a hydrocarbon feedstock, the process comprising:

passing a feed stream comprising hydrogen and paraffins to a dehydrogenation zone comprising at least one reactor comprising a dehydrogenation catalyst maintained at dehydrogenation conditions to produce a dehydrogenation zone product stream comprising hydrogen, paraffins, and olefins;

wherein the dehydrogenation conditions in the at least one reactor comprise a hydrogen to hydrocarbon mole ratio in the range of from 0.01 to 0.40 and a reactor inlet temperature in the range of from 500 ° to 645 ℃.

2. The process of claim 1, wherein the molar ratio of hydrogen to hydrocarbon is in the range of 0.01-0.35 and the reactor inlet temperature is in the range of 500 ° -640 ℃.

3. The process of any of claims 1-2, wherein the molar ratio of hydrogen to hydrocarbon is in the range of 0.01-0.25 and the reactor inlet temperature is in the range of 500 ° -630 ℃.

4. The process of any of claims 1-2, wherein the molar ratio of hydrogen to hydrocarbon is in the range of 0.01-0.15 and the reactor inlet temperature is in the range of 500 ° -620 ℃.

5. The process of any one of claims 1-2, further comprising separating the dehydrogenation zone product stream into a hydrocarbon-rich product stream and a hydrogen-rich product stream.

6. The process of claim 5, further comprising passing a portion of the hydrogen-rich gas stream to the dehydrogenation zone.

7. The process of any of claims 1-2, wherein the hydrocarbon feed comprises at least one paraffin having from 2 to 30 carbon atoms.

8. The process of any of claims 1-2, wherein the hydrocarbon feed comprises at least one paraffin having from 2 to 6 carbon atoms.

9. The process of any of claims 1-2, wherein the hydrocarbon feed comprises at least one paraffin having from 3 to 4 carbon atoms.

10. The method of any one of claims 1-2, further comprising at least one of:

sensing at least one parameter of the method and generating a signal or data from the sensing;

generating and transmitting a signal; or

Data is generated and transmitted.

Background

Due to the existing increasing demand for dehydrogenated hydrocarbons for the manufacture of various chemical products such as detergents, high octane gasoline, oxygenated gasoline blending components, pharmaceutical products, plastics, synthetic rubbers, and other products well known to those skilled in the art, hydrocarbon dehydrogenation is an important commercial hydrocarbon conversion process. A process for converting paraffins to olefins involves passing a paraffin stream over a high selectivity catalyst, where the paraffins are dehydrogenated to the corresponding olefins. The dehydrogenation reaction is effected under operating conditions selected to minimize loss of feedstock. Typical processes involve the use of reactors (e.g., radial flow reactors, fixed bed reactors, fluidized bed reactors, etc.) in which a paraffinic feedstock is contacted with a dehydrogenation catalyst under reaction conditions. One example of such a process is the dehydrogenation of isobutane to produce isobutene, which can be polymerized to provide tackifiers for adhesives, viscosity index additives for motor oils, and impact and oxidation resistant additives for plastics. There is also an increasing demand for isobutene for the production of government regulated oxygenated gasoline blending components to reduce air pollution from motor vehicle emissions.

The production of olefins by the catalytic dehydrogenation of paraffinic hydrocarbons is well known to those skilled in the art of hydrocarbon conversion processing. In addition, numerous patents have been published that generally teach and discuss the dehydrogenation of hydrocarbons. For example, U.S. Pat. No. 4,430,517(Imai et al) discusses a dehydrogenation process and the catalyst used therein.

Detailed Description

In paraffin dehydrogenation processes, hydrogen is typically co-fed to minimize the amount of carbonaceous material deposited on the catalyst and improve catalyst stability. Fruit of Chinese wolfberryIn practice, the amount of hydrogen co-feed is expressed as hydrogen/hydrocarbon (H)₂HC) ratio, calculated by dividing the hydrogen molar flow by the hydrocarbon molar flow. If more than one dehydrogenation reactor is present in series, it conveniently refers to H of the overall process₂the/HC ratio, which is calculated by dividing the hydrogen feed to the first reactor by the hydrocarbon feed to the first reactor. After that, H₂the/HC ratio is taken as H relative to the process₂the/HC ratio is synonymous and is more precisely defined as H of the mixed hydrogen-hydrocarbon feedstream entering the first of the at least one dehydrogenation reactor₂The ratio of/HC. While hydrogen reduces coking on the catalyst, it also changes the equilibrium conversion of paraffins to desired olefins at a given temperature and pressure. Thus, there is a tradeoff between minimizing catalyst coking and maximizing conversion.

Some dehydrogenation processes utilize a Continuous Catalyst Regeneration (CCR) system to burn off coke. However, there are practical limits to how quickly the catalyst can be circulated through the regenerator system and how much coke can be burned off of the catalyst.

Thus, H₂the/HC ratio is an important design parameter for balancing catalyst coking and achieving the most efficient design.

For example, if H₂the/HC ratio is reduced and the Reactor Inlet Temperature (RIT) is kept constant, or if RIT is increased and H is maintained₂the/HC ratio remains the same, and an increase in coke on the catalyst is expected.

However, it has surprisingly been found that by simultaneously reducing H₂HC ratio and RIT, coke production can be maintained at a higher H₂the/HC ratio and operation at higher RIT are at the same level without reducing the single pass Yield (YPP) -which is a key parameter affecting the overall profitability of the dehydrogenation process. The single pass yield is calculated by dividing the mass flow of olefin (e.g., propylene) produced on the reactor section by the mass flow of paraffin (e.g., propane) in the feed.

At lower H without lowering YPP₂the/HC ratio operation results in a lower volumetric flow through the reactor section, thus reducing this section of the processThe utility of (1). When H is substituted₂The reduction in the/HC ratio and RIT, when combined with low coke catalyst, will be less in temperature than conventional commercial catalysts that allow operation at higher YPP, and further increase the profitability of the process.

It has been found that low H₂The coke index of the/HC ratio can be determined as a function of the reactor inlet temperature and the molar ratio of hydrogen to hydrocarbon of 0.01 to 0.40. It has been surprisingly found that acceptable coke levels are achieved when operating at these low hydrogen to hydrocarbon mole ratios.

Low H is determined by measuring coking over a series of combinations of reactor inlet temperatures and hydrogen to hydrocarbon mole ratios₂HC Coke index. Then, a correlation between reactor inlet temperature and molar ratio of hydrogen to hydrocarbon can be determined. This correlation and the selected molar ratio of hydrogen to hydrocarbon can be used to determine a desired reactor inlet temperature, and the reactor can be adjusted to the determined reactor inlet temperature. Alternatively, the correlation and the selected reactor inlet temperature can be used to determine a desired hydrogen to hydrocarbon molar ratio, and the hydrogen to hydrocarbon molar ratio can be adjusted to the determined hydrogen to hydrocarbon molar ratio. Alternatively, the coke index may be determined for a selected reactor inlet temperature and a selected hydrogen to hydrocarbon mole ratio.

One aspect of the invention is a process for dehydrogenating a hydrocarbon feedstock. In one embodiment, the method comprises: passing a feed stream comprising hydrogen and paraffins to a dehydrogenation zone comprising at least one reactor comprising a dehydrogenation catalyst maintained at dehydrogenation conditions to produce a dehydrogenation zone product stream comprising hydrogen, paraffins, and olefins; wherein the dehydrogenation conditions in the at least one reactor comprise a hydrogen to hydrocarbon mole ratio in the range of from 0.01 to 0.40 and a reactor inlet temperature in the range of from 500 ℃ to 645 ℃.

In some embodiments, the molar ratio of hydrogen to hydrocarbon is in the range of 0.01 to 0.35, and the reactor inlet temperature is in the range of 500 ° to 640 ℃.

In some embodiments, the molar ratio of hydrogen to hydrocarbon is in the range of 0.01 to 0.25, and the reactor inlet temperature is in the range of 500 ° to 630 ℃.

In some embodiments, the molar ratio of hydrogen to hydrocarbon is in the range of 0.01 to 0.15, and the reactor inlet temperature is in the range of 500 ° to 620 ℃.

In some embodiments, the process further comprises separating the dehydrogenation zone product stream into a hydrocarbon-rich product stream and a hydrogen-rich product stream.

In some embodiments, the process further comprises passing a portion of the hydrogen-rich gas stream to the dehydrogenation zone.

In some embodiments, the hydrocarbon feed comprises at least one paraffin having from 2 to 30 carbon atoms. In some embodiments, the hydrocarbon feed comprises at least one paraffin having from 2 to 6 carbon atoms. In some embodiments, the hydrocarbon feed comprises at least one paraffin having from 3 to 4 carbon atoms.

In some embodiments, the method further comprises at least one of: sensing at least one parameter of the method and generating a signal or data from the sensing; generating and transmitting a signal; or generate and transmit data.

Another aspect of the invention is a process for dehydrogenating a hydrocarbon feedstock. In one embodiment, the method comprises: passing a feed stream comprising hydrogen and paraffins to a dehydrogenation zone comprising at least one reactor comprising a dehydrogenation catalyst maintained at dehydrogenation conditions to produce a dehydrogenation zone product stream comprising hydrogen, light ends, paraffins, and olefins; wherein the dehydrogenation conditions in at least one reactor comprise a hydrogen to hydrocarbon molar ratio, a reactor inlet temperature, and a coke index, wherein the hydrogen to hydrocarbon molar ratio is in the range of 0.01 to 0.4, and wherein one dehydrogenation condition is adjusted based on the other two dehydrogenation conditions.

In some embodiments, the reactor inlet temperature is adjusted based on the selected hydrogen to hydrocarbon mole ratio and coke index, or the hydrogen to hydrocarbon mole ratio is adjusted based on the selected reactor inlet temperature and coke index.

In some embodiments, the coke index is in the range of 0 to 250.

In some embodiments, the coke index is determined by measuring coking at a series of reactor inlet temperatures and combinations of hydrogen to hydrocarbon molar ratios and determining a correlation between the reactor inlet temperatures and hydrogen to hydrocarbon molar ratios; and wherein the correlation and the selected molar ratio of hydrogen to hydrocarbon are used to determine a desired reactor inlet temperature, and wherein the reactor inlet temperature is adjusted to the determined reactor inlet temperature; or wherein the correlation and the selected reactor inlet temperature are used to determine a desired hydrogen to hydrocarbon molar ratio, and wherein the hydrogen to hydrocarbon molar ratio is adjusted to the determined hydrogen to hydrocarbon molar ratio.

In some embodiments, the hydrocarbon feed comprises at least one paraffin having from 2 to 30 carbon atoms. In some embodiments, the hydrocarbon feed comprises at least one paraffin having from 2 to 6 carbon atoms. In some embodiments, the hydrocarbon feed comprises at least one paraffin having from 3 to 4 carbon atoms.

In some embodiments, the process further comprises separating the dehydrogenation zone product stream into a hydrocarbon-rich product stream and a hydrogen-rich product stream.

In some embodiments, the process further comprises passing a portion of the hydrogen-rich gas stream to the dehydrogenation zone.

In some embodiments, the method further comprises at least one of: sensing at least one parameter of the method and generating a signal or data from the sensing; generating and transmitting a signal; or generate and transmit data.

The dehydrogenation of paraffinic hydrocarbons is well known to those skilled in the art of hydrocarbon processing. In the dehydrogenation zone maintained under dehydrogenation conditions, the dehydrogenatable hydrocarbon is contacted with a dehydrogenation catalyst. The contacting can be accomplished in a fixed catalyst bed system, a moving catalyst bed system, a fluidized bed system, or the like, or in a batch operation. The dehydrogenation zone can include one or more separate reaction zones with heating elements between the reaction zones to ensure that the desired reaction temperature can be maintained at the inlet of each reaction zone. The hydrocarbon can be contacted with the catalyst bed in an upward, downward, or radial flow manner. Radial flow of hydrocarbons through the catalyst bed is preferred for moving catalyst bed systems. The radial flow reactor is configured such that the reactor has an annular structure and an annular distribution and collection device. The means for distributing and collecting incorporates some type of screen-like surface. The mesh-type surface serves to hold the catalyst bed in place and to assist in the pressure distribution across the reactor surface to facilitate radial flow through the reactor bed. The screen may be a mesh of wires or other material, or a perforated plate. For a moving bed, the screen or mesh provides a barrier to prevent loss of solid catalyst particles while allowing fluid flow through the bed. Solid catalyst particles are added at the top, flow through the apparatus, and removed at the bottom, while passing through a closed housing that allows fluid to flow through the catalyst. For example, screens are described in U.S. patent No. 9,266,079 and U.S. patent No. 9,433,909(Vetter et al).

Hydrocarbons that may be dehydrogenated include dehydrogenatable hydrocarbons containing 2 to 30 or more carbon atoms, including paraffins, alkylaromatics, naphthenes, and olefins. One class of hydrocarbons that can be dehydrogenated with the catalyst are normal paraffins having from 2 to 30 or more carbon atoms. The catalyst is particularly useful for the dehydrogenation of paraffins having from 2 to 15 or more carbon atoms to the corresponding mono-olefins, or for the dehydrogenation of mono-olefins having from 3 to 15 or more carbon atoms to the corresponding di-olefins. The catalyst is especially useful for reacting C₂-C₆Paraffins (mainly propane and butane) are dehydrogenated to mono-olefins.

Light paraffin dehydrogenation utilizes a highly selective platinum-based catalyst system. One example of a suitable catalyst for the dehydrogenation of light paraffins is disclosed in U.S. patent No. 6,756,340, which is incorporated herein by reference. The dehydrogenation of heavier paraffins uses a selective platinum catalyst.

The dehydrogenation conditions include a temperature of from about 400 ℃ to about 900 ℃, a pressure of from about 0.01 to 10 atmospheres absolute, and about 0.1hr^-1To 100hr^-1Generally, the lower the molecular weight, the higher the temperature required for comparable conversion for normal paraffins the lower the pressure in the dehydrogenation zone is kept as low as possible, meeting equipment constraints, thereby taking advantage of the chemical equilibriumAnd (4) maximizing.

The effluent stream from the dehydrogenation zone will typically contain unconverted dehydrogenatable hydrocarbon, hydrogen, and products of the dehydrogenation reaction. The effluent stream is typically cooled, optionally compressed and passed to a hydrogen separation zone to separate a hydrogen-rich gas phase from a hydrocarbon-rich liquid phase. Generally, the hydrocarbon-rich liquid phase is further separated by means of a suitable selective adsorbent, a selective solvent, one or more selective reactions, or by a suitable fractionation scheme. Unconverted dehydrogenatable hydrocarbons are recovered and can be recycled to the dehydrogenation zone. The products of the dehydrogenation reaction are recovered as end products or as intermediates in the preparation of other compounds.

In general terms, the dehydrogenation Process may include one or more dehydrogenation reactors, fired heaters, heat exchangers, quench towers, compressors, cryogenic separation systems, processing systems, fuel gas production systems, light ends recovery systems, adsorption systems, fractionation towers, catalyst treatment/regeneration equipment, as known in the art and described in the Handbook of Petroleum Refining, 4 th edition, Chapter 4.1 (Handbook of Petroleum Refining Process,4 th edition, 4. f^thEdition, Chapter 4.1) "is discussed further.

Any of the above lines, conduits, units, devices, containers, surroundings, areas, or the like may be equipped with one or more monitoring components, including sensors, measuring devices, data capture devices, or data transmission devices. The signals, process or condition measurements, and data from the monitoring components can be used to monitor conditions in, around, and associated with the process plant. The signals, measurements, and/or data generated or recorded by the monitoring component may be collected, processed, and/or transmitted over one or more networks or connections, which may be private or public, general or private, direct or indirect, wired or wireless, encrypted or unencrypted, and/or combinations thereof; the description is not intended to be limited in this respect.

The signals, measurements, and/or data generated or recorded by the monitoring component may be transmitted to one or more computing devices or systems. A computing device or system may include at least one processor and memory storing computer-readable instructions that, when executed by the at least one processor, cause the one or more computing devices to perform a process that may include one or more steps. For example, one or more computing devices may be configured to receive data relating to at least one device associated with the process from one or more monitoring components. One or more computing devices or systems may be configured to analyze the data. Based on the data analysis, one or more computing devices or systems may be configured to determine one or more recommended adjustments to one or more parameters of one or more processes described herein. One or more computing devices or systems may be configured to transmit encrypted or unencrypted data including one or more recommended adjustments to one or more parameters of one or more processes described herein.