阅读说明：本技术 用于控制废催化剂的部分再生的方法 (Method for controlling partial regeneration of spent catalyst ) 是由 约翰·J·塞内塔 于 2019-08-12 设计创作，主要内容包括：本发明公开了一种控制废催化剂从含氧化合物-烯烃反应区再生以提供部分再生的催化剂的方法。部分再生的催化剂具有介于1重量％至4重量％、或1重量％至3重量％、或2重量％至3重量％之间的焦炭。通过调节传递到再生区的燃烧气体中的空气与再循环烟气的比率来控制再生。烟气中的CO在CO氧化区中被去除,该CO氧化区接收氧气以将CO氧化成CO-2。(A method of controlling the regeneration of spent catalyst from an oxygenate to olefin reaction zone to provide partially regenerated catalyst is disclosed. The partially regenerated catalyst has between 1 wt% to 4 wt%, or 1 wt% to 3 wt%, or 2 wt% to 3 wt% coke. Regeneration is controlled by adjusting the ratio of air to recirculated flue gas in the combustion gases delivered to the regeneration zone. The CO in the flue gas is removed in a CO oxidation zone which receives oxygen to oxidize the CO to CO 2 。)

1. A method for controlling catalyst regeneration in a catalyst regeneration zone, the method comprising:

introducing an oxygen-containing gas (26) into the catalyst regeneration zone (14);

partially regenerating a stream of spent catalyst (10) from an MTO reaction zone (12), said spent catalyst (10) comprising coke;

separating a regenerated catalyst (28) from a flue gas (30), the regenerated catalyst (28) having a reduced amount of coke, and the flue gas (30) comprising carbon monoxide and carbon dioxide;

recycling a portion (44) of the flue gas (30) to the catalyst regeneration zone (14) with the oxygen-containing gas (26); and

maintaining a ratio of carbon dioxide to carbon monoxide in the flue gas (30) of at least 0.5.

2. The process of claim 1 wherein the ratio of carbon dioxide to carbon monoxide is maintained by adjusting the oxygen content of the oxygen-containing gas (26) introduced into the catalyst regeneration zone (14).

3. The method of claim 2, wherein the oxygen content is adjusted by controlling a ratio of air (48) to flue gas (44) in the oxygen-containing gas (26).

4. A method according to any one of claims 1 to 3, wherein the ratio of carbon dioxide to carbon monoxide in the flue gas (30) is maintained to be greater than 2.

5. The method according to any one of claims 1 to 3, wherein the flue gas (30) further comprises oxygen, and wherein the method further comprises:

maintaining an amount of oxygen in the flue gas (30) of less than 2 vol%.

6. The method of any of claims 1-3, wherein the regenerated catalyst (28) comprises between 1 wt% to 4 wt% coke.

7. The method of any of claims 1-3, further comprising:

maintaining an amount of oxygen in the flue gas (30) of less than 2 vol%.

8. A process according to any one of claims 1 to 3, wherein the oxygen utilization in the catalyst regeneration zone (14) is at least 90%.

9. The method of any of claims 1-3, further comprising:

adjusting process conditions associated with said MTO reaction zone (12); and

adjusting a ratio of air (48) to flue gas (44) in the oxygen-containing gas (26) in response to the adjusted process conditions of the MTO reaction zone (12).

10. The method of any of claims 1-3, further comprising:

the ratio of air (48) to flue gas (44) in the oxygen-containing gas (26) is adjusted to maintain a constant velocity of the spent catalyst (10) particles within the reactor (16) of the catalyst regeneration zone (14).

Technical Field

The present invention relates to a process for controlling the regeneration of spent catalyst used in oxygenates for an olefin conversion process and more particularly to a process for controlling various parameters to obtain a partially regenerated catalyst having a desired amount of coke.

Background

Light olefins are used as feeds for the production of a variety of chemicals and are traditionally produced by steam or catalytic cracking processes. However, the cost of producing light olefins from petroleum sources has steadily increased due to the limited availability and high cost of such petroleum sources.

The search for alternative materials for light olefin production has led to the use of oxygenates such as alcohols, and more particularly to the use of methanol, ethanol, and higher alcohols or their derivatives. Molecular sieves such as microporous crystalline zeolite and non-zeolitic catalysts, particularly Silicoaluminophosphates (SAPO), are known to promote the conversion of oxygenates to hydrocarbon mixtures in reactors. A number of patents describe this process for various types of these catalysts: U.S. patent nos. 3,928,483; 4,025,575, respectively; 4,052,479, respectively; 4,496,786, respectively; 4,547,616, respectively; 4,677,242; 4,843,183, respectively; 4,499,314, respectively; 4,447,669, respectively; 5,095,163, respectively; 5,191,141; 5,126,308; 4,973,792, respectively; 4,861,938, respectively; 7,309,679, respectively; and 9,643,897.

When the catalyst is exposed to an oxygenate such as methanol to promote reaction with olefins, carbonaceous material (coke) is generated and deposited on the catalyst. The accumulation of coke deposits interferes with the catalyst's ability to promote the reaction. As the amount of coke deposits increases, the catalyst loses activity and less feedstock is converted to the desired olefin product. The regeneration step removes coke from the spent catalyst by combustion with oxygen, thereby restoring the catalytic activity of the catalyst. The regenerated catalyst may then be exposed to an oxygenate again to promote conversion to olefins.

Recently, partial regeneration of spent catalyst has been shown to provide selectivity advantages in Methanol To Olefin (MTO) conversion processes. Thus, it is believed that the amount of coke on the regenerated catalyst can be adjusted based on various reactor conditions to maximize light olefin yield.

Partial regeneration of MTO catalyst presents challenges to controlling the extent of regeneration. Fluidized bed regeneration requires a specific range of superficial velocities to achieve adequate gas-solid contact and recovery of entrained fines from the flue gas. Therefore, once the regenerator is designed, the amount of air supplied to the regenerator can only be controlled to a small extent. Therefore, there is a need for a method of controlling the extent of catalyst regeneration to achieve the desired coke on the regenerated catalyst.

Disclosure of Invention

One or more methods for controlling the regeneration of spent catalyst to achieve a regenerated catalyst that includes some coke have been invented. As noted above, partial regeneration is desirable because utilizing a partially regenerated catalyst improves selectivity to light olefin production. In one or more of the processes of the present invention, regeneration is controlled with combustion gases by varying and adjusting the amount of fresh air that is mixed with the amount of recirculated flue gas that is recirculated to the regeneration zone. One or more process conditions in the regeneration zone or reactor are monitored and the composition of the combustion gases is adjusted in a predictive or responsive manner.

Accordingly, in at least one aspect, the invention may be characterized by providing a method for controlling catalyst regeneration in a catalyst regeneration zone by: introducing an oxygen-containing gas into the catalyst regeneration zone; partially regenerating a stream of spent catalyst from an MTO reaction zone, said spent catalyst comprising coke; separating a regenerated catalyst from a flue gas, the regenerated catalyst having a reduced amount of coke, and the flue gas comprising carbon monoxide and carbon dioxide; recycling a portion of said flue gas to said catalyst regeneration zone with said oxygen-containing gas; and maintaining a ratio of carbon dioxide to carbon monoxide in the flue gas of at least 0.5.

It is contemplated that the ratio of carbon dioxide to carbon monoxide is maintained by adjusting the oxygen content of the oxygen-containing gas introduced into the catalyst regeneration zone. The oxygen content can be adjusted by controlling the ratio of air to flue gas in the oxygen containing gas. The ratio of carbon dioxide to carbon monoxide in the flue gas can be maintained at greater than 2.

It is also contemplated that the flue gas further comprises oxygen, and the method further comprises maintaining an amount of oxygen in the flue gas to less than 2 vol%.

It is also contemplated that the regenerated catalyst comprises between 1 wt.% to 4 wt.% coke.

In another aspect, the invention may be characterized generally as providing a method for controlling catalyst regeneration in a catalyst regeneration zone by: introducing an oxygen-containing gas into the catalyst regeneration zone; partially regenerating a stream of spent catalyst from an MTO reaction zone, said spent catalyst comprising coke; separating a regenerated catalyst from a flue gas, the regenerated catalyst having a reduced amount of coke, and the flue gas comprising oxygen; recycling a portion of said flue gas to said catalyst regeneration zone with said oxygen-containing gas; and maintaining the amount of oxygen in the flue gas to be less than 2% by volume.

It is envisaged that the amount of oxygen in the flue gas is maintained by adjusting the oxygen content of the oxygen-containing gas introduced into the catalyst regeneration zone. The oxygen content can be adjusted by controlling the ratio of air to flue gas in the oxygen containing gas.

It is also contemplated that the regenerated catalyst comprises between 1 wt.% to 4 wt.% coke. The flue gas may comprise carbon dioxide and carbon monoxide and the method may comprise maintaining a ratio of carbon dioxide to carbon monoxide in the flue gas of at least 0.5. The ratio of carbon dioxide to carbon monoxide in the flue gas can be maintained at greater than 2.

In yet another aspect, the invention may also be generally characterized as providing a process for partially regenerating catalyst from an MTO reaction zone by: passing an oxygen-containing gas stream to a catalyst regeneration zone; passing a stream of spent catalyst from the MTO reaction zone to the catalyst regeneration zone, the spent catalyst comprising coke; combusting coke from the spent catalyst to provide a partially regenerated catalyst comprising between 1 wt.% to 4 wt.% coke; recycling a portion of a flue gas stream to said catalyst regeneration zone as said oxygen-containing gas; and controlling the ratio of air to flue gas in the oxygen-containing gas by maintaining at least one of the following parameters in order to achieve the partially regenerated catalyst: the amount of oxygen in the flue gas is less than 2% by volume; the ratio of carbon dioxide to carbon monoxide in the flue gas is at least 0.5; or the oxygen utilization in the catalyst regeneration zone is at least 90%.

It is expected that the ratio of carbon dioxide to carbon monoxide remains greater than 2.

It is also contemplated that the process includes adjusting process conditions associated with the MTO reaction zone and adjusting the ratio of air to flue gas in the oxygen-containing gas in response to the adjusted process conditions of the MTO reaction zone.

It is contemplated that the method further comprises at least one of: sensing at least one parameter of the method and generating a signal or data from said sensing; generating and transmitting a signal; or generate and transmit data. The method may include receiving a signal or data and adjusting a ratio of air to smoke in response to the received data or signal.

It is contemplated to control the air to flue gas ratio in the oxygen-containing gas by maintaining at least two of the following parameters in order to achieve a partially regenerated catalyst: the amount of oxygen in the flue gas is less than 2% by volume; the ratio of carbon dioxide to carbon monoxide in the flue gas is at least 0.5; or the oxygen utilization in the catalyst regeneration zone is at least 90%.

It is also contemplated to control the air to flue gas ratio in the oxygen-containing gas by maintaining the following parameters in order to achieve a partially regenerated catalyst: the amount of oxygen in the flue gas is less than 2% by volume; the ratio of carbon dioxide to carbon monoxide in the flue gas is at least 0.5; and an oxygen utilization in the catalyst regeneration zone of at least 90%.

It is also contemplated that the process includes adjusting the ratio of air to flue gas in the oxygen-containing gas so as to maintain a constant velocity of the spent catalyst particles within the reactor of the catalyst regeneration zone.

Additional aspects, embodiments and details of the invention, all of which can be combined in any manner, are set forth in the following detailed description of the invention.

Drawings

One or more exemplary embodiments of the invention will now be described in conjunction with the following figures, which illustrate a process flow diagram for MTO reaction and catalyst regeneration in accordance with one or more aspects of the invention.

Detailed Description

As noted above, the present invention provides one or more methods for partially regenerating spent catalyst from an MTO reaction zone, as well as methods for controlling the partial regeneration. In view of these general principles, one or more embodiments of the present invention will be described with the understanding that the following description is not intended to be limiting.

An exemplary MTO conversion process having a regeneration zone is illustrated wherein a spent catalyst stream 10 is passed from an oxygenate reaction zone 12 to a regeneration zone 14 having a regenerator 16. Oxygenate reaction zone 12 preferably includes an MTO reactor 18 wherein a methanol-containing feedstock 20 is contacted with a catalyst comprising a molecular sieve under conditions suitable to convert methanol to light olefins in an effluent stream 22. The catalyst can be a Silicoaluminophosphate (SAPO) having a framework of tetrahedral units forming a plurality of pores for optimal contact with the methanol feed during conversion to olefins.

The MTO conversion process may be a gas phase, fluid catalytic process that converts methanol to olefins, primarily ethylene and propylene. The feedstock 20 may be commercial grade methanol, crude methanol, or any combination of the two. The crude methanol may be an unrefined product from a methanol synthesis unit. The feedstock 20 having a blend of methanol and water may have between 65 wt.% and 100 wt.%, or between 78 wt.% and 99 wt.%, or 95 wt.% methanol. MTO reactor 18 is known in the art from, for example, U.S. patent nos. 6,166,282 and 7,423,191, which are incorporated herein by reference in their entirety.

As noted above, coke is typically a byproduct of the MTO process that accumulates on the catalyst as a result of contact with compounds from the oxygenate-containing feedstock 20. When coke deposits accumulate on the catalyst, the catalyst's ability to convert oxygenates, i.e., methanol, to olefins is reduced. Thus, the spent catalyst stream 10 from the MTO reactor 18 may be regenerated to maintain the desired activity of the catalyst.

At least a portion of the spent catalyst may be continuously withdrawn from the oxygenate reaction zone 12 for regeneration in the spent catalyst stream 10. Prior to regeneration of the spent catalyst, hydrocarbons may be stripped from the spent catalyst and the stripped spent catalyst in stream 10 is then passed to regenerator 16 in regeneration zone 14.

The regenerator 16 may be of a bubbling or turbulent bed type design comprising a vessel containing a distributor 24 fed by a stream 26 of combustion gas. As described below, the combustion gas 26 includes oxygen (O)₂) Or other oxidizing agents. The regenerator 16 is operated under conditions such that when the spent catalyst is contacted with oxygen from the combustion gas 26, coke from the spent catalyst is combusted as the spent catalyst passes upwardly in the regenerator 16. This results in the production of regenerated catalyst (i.e., catalyst with a lower amount of coke). Suitable conditions for regenerator 16 are known and may include a pressure of 255kPa (37psig) and a temperature of 650 ℃ (1202 ° f).

After separating the regenerated catalyst from any entrained gases, the regenerated catalyst falls to the bottom of the regenerator where additional gases may be stripped, and then a stream of regenerated catalyst 28 may be returned to the oxygenate reaction zone 12. An exemplary regenerator 16 is described in more detail in U.S. patent No. 7,423,191.

As noted above, the regenerated catalyst 28 is preferably a partially regenerated catalyst, meaning that when the amount of coke on the spent catalyst is reduced, the regenerated catalyst 28 returned to the oxygenate reaction zone 12 contains an average of between 1 wt.% to 4 wt.%, or 1 wt.% to 3 wt.%, or 2 wt.% to 3 wt.% coke. If the active component is SAPO-34, SAPO-18, ZSM-5, etc., the regenerated catalyst 28 may comprise between 3 wt.% and 15 wt.% of coke on the active component of the regenerated catalyst 28. Accordingly, the present invention provides a method of controlling the regenerator 16 to achieve a desired level of regeneration fraction by controlling the mixture of recirculated gas from the flue gas of the regenerator 16 and (fresh) air used as combustion gas 26 in order to achieve or maintain one or more operating conditions of the regenerator 16.

The flue gas of regenerator 16 contains nitrogen (N)₂) Oxygen (O)₂) Carbon monoxide (CO) and carbon dioxide (CO)₂) And water (H)₂O). An exemplary flue gas may have the following composition: 72.7% N by volume₂；11.6％H₂O；10.2％CO₂(ii) a 4.4% CO; and 1.0%O₂. However, the CO should be removed from the flue gas before the flue gas is directed back to the regenerator.

Thus, as shown, a flue gas stream 30 from the regenerator 16 may be passed through a control valve 31 to reduce the pressure of the flue gas before being passed to a CO oxidation zone 32. The CO oxidation zone 32 generally includes a burner 34 that is supplied with a supplemental fuel 33 and air 35 to substantially oxidize most, if not all, of the CO in the flue gas stream 30. Alternatively, CO oxidation zone 32 may include a catalyst containing a catalyst that promotes the combustion of CO to CO₂The catalyst of (1).

The CO oxidation zone 32 reduces the amount of CO recycled to the regenerator 16. In addition, the CO oxidation zone 32 facilitates heat recovery from the flue gas 30. If the CO is recycled back to the regenerator 16, oxygen is consumed in the regenerator to combust the CO to CO₂. This requires higher oxygen requirements for the regenerator 16, resulting in higher flow rates of combustion air, and a larger regenerator where the amount of heat removed from the regenerator 16 is increased to control the regenerator temperature. Thus, the removal of CO from the flue gas 30 in the CO oxidation zone 32 increases the ability to use the flue gas 30 as a recycle to the regenerator 16. Oxygen provided in air stream 35 is introduced into CO oxidation zone 32 to convert CO to CO₂The conversion of (a) provides oxygen.

A CO-lean flue gas stream 36 is recovered from the CO oxidation zone 32 and may be passed to a filtration zone 38 configured to remove catalyst fines from the CO-lean flue gas stream 36. A portion 40 of the gas stream from the filtration zone 38 may be discharged, while a second portion 42 of the gas stream may be used as a recycle stream 44 for the combustion gas 26 passed to the regenerator 16. Specifically, second stream 42 is passed to blower 46 to control the volume of recycle stream 44 that is returned to regenerator 16. The recycle stream 44 is mixed with a fresh air stream 48, also provided by a blower 50, to form the combustion gas stream 26.

As noted above, in various aspects of the inventive process, control of catalyst regeneration is achieved by adjusting and varying the ratio of air 48 to recycle stream 44 in the combustion gas stream 26. The ratio is controlled by adjusting the conditions of one or both of the blowers 46, 50, which may be in wired or wireless communication with a computer 52. Adjusting may include, for example, manipulating valves at the inlet and/or outlet of the blowers 46, 50, or may include controlling blower speed, or other ways of varying flow rates while maintaining sufficient pressure.

According to one or more methods, the ratio of air 48 to recycle stream 44 in the combustion gas stream 26 is controlled to achieve, maintain, CO in the flue gas 30₂the/CO ratio is greater than 0.5 (i.e., 1:2), preferably greater than 2 (i.e., 2:1), or both. CO greater than 0.5 or greater than 2 is believed₂the/CO ratio is reduced or, in some cases, excessive gas phase temperature rise (post-combustion) is prevented in which the catalyst in the regenerator 16 downstream of the fluidized bed is reduced.

Similarly, in one or more processes, the ratio of air 48 to recycle stream 44 in the combustion gas stream 26 is controlled so as to achieve, maintain, or both, an oxygen concentration in the flue gas 30 of less than 2 vol%. It is also believed that this concentration decreases or in some cases prevents excessive temperature rise in the downstream reduction catalyst (post-combustion).

The ratio of air 48 to recycle stream 44 in the combustion gas stream 26 is controlled so as to achieve, maintain, or oxygen utilization of 90% or more. "oxygen utilization" is the fraction of oxygen consumed in the entire regenerator fluidized bed.

In some methods, the ratio of air 48 to recycle stream 44 is controlled or adjusted to achieve the desired CO₂the/CO ratio, and the desired oxygen concentration or the desired oxygen utilization.

Additionally, in one or more processes, the ratio of air 48 to recycle stream 44 in the combustion gas stream 26 can be controlled in order to achieve, maintain, or both, a constant fluidization velocity of the spent catalyst in the regenerator 16. For example, the amount of air 48 in the combustion gas stream 26 may be reduced while increasing the amount of recycle stream 44 in the combustion gas stream 26 to provide a stream with less oxygen while maintaining a desired velocity of the spent catalyst rising within the regenerator 16. The velocity of the spent catalyst will affect not only the residence time of the spent catalyst in the combustion zone of the regenerator 16, but also the height of the catalyst bed and the temperature of the regenerator 16.

In accordance with the method of the present invention, the ratio of air 48 to recycle stream 44 in combustion gas stream 26 may be adjusted based on changes in processing conditions associated with MTO reactor 18. In other words, while some methods may measure temperature, flue gas composition, etc. to adjust or maintain the ratio of air 48 to recycle stream 44, it is also contemplated to adjust the ratio of air 48 to recycle stream 44 before certain processing conditions are measured or obtained. For example, the ratio of air 48 to recycle stream 44 may be adjusted based on changes in the composition or flow rate of feedstock 20. Similarly, the temperature of MTO reactor 18 may be adjusted. At the same time, the ratio of air 48 to recycle stream 44 is adjusted in a predictive manner to offset temperature and flow rate variations in MTO reactor 18.

Any of the above-described lines, conduits, units, devices, containers, surroundings, areas, or the like may be equipped with one or more monitoring components, including sensors, measurement 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 tool. 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, such as computer 52. The computing device or system and the computer 52 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 related to at least one piece of equipment or data 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.

Those of ordinary skill in the art will recognize and appreciate that various other components, such as valves, pumps, filters, coolers, etc., are not shown in the figures, as it is believed that their specifics are well within the purview of one of ordinary skill in the art and their description is not necessary to the implementation or understanding of the embodiments of the present invention.

Detailed description of the preferred embodiments

While the following is described in conjunction with specific embodiments, it is to be understood that this description is intended to illustrate and not limit the scope of the foregoing description and the appended claims.

A first embodiment of the present invention is a process for controlling catalyst regeneration in a catalyst regeneration zone, the process comprising introducing an oxygen-containing gas into the catalyst regeneration zone; partially regenerating a stream of spent catalyst from an MTO reaction zone, said spent catalyst comprising coke; separating a regenerated catalyst from a flue gas, the regenerated catalyst having a reduced amount of coke, and the flue gas comprising carbon monoxide and carbon dioxide; recycling a portion of said flue gas to said catalyst regeneration zone with said oxygen-containing gas; and maintaining a ratio of carbon dioxide to carbon monoxide in the flue gas of at least 0.5. An embodiment of the invention is one, any or all of prior embodiments in this paragraph up through the first embodiment in this paragraph wherein the ratio of carbon dioxide to carbon monoxide is maintained by adjusting the oxygen content of the oxygen-containing gas introduced into the catalyst regeneration zone. An embodiment of the invention is one, any or all of prior embodiments in this paragraph up through the first embodiment in this paragraph wherein the oxygen content is adjusted by controlling the ratio of air to flue gas in the oxygen-containing gas. An embodiment of the invention is one, any or all of prior embodiments in this paragraph up through the first embodiment in this paragraph wherein the ratio of carbon dioxide to carbon monoxide in the flue gas is maintained at greater than 2. An embodiment of the invention is one, any or all of prior embodiments in this paragraph up through the first embodiment in this paragraph wherein the flue gas further comprises oxygen, and wherein the method further comprises maintaining an amount of oxygen in the flue gas to less than 2 vol%. An embodiment of the invention is one, any or all of prior embodiments in this paragraph up through the first embodiment in this paragraph wherein the regenerated catalyst comprises between 1 wt% to 4 wt% coke.

A second embodiment of the present invention is a process for controlling catalyst regeneration in a catalyst regeneration zone, the process comprising introducing an oxygen-containing gas into the catalyst regeneration zone; partially regenerating a stream of spent catalyst from an MTO reaction zone, said spent catalyst comprising coke; separating a regenerated catalyst from a flue gas, the regenerated catalyst having a reduced amount of coke, and the flue gas comprising oxygen; recycling a portion of said flue gas to said catalyst regeneration zone with said oxygen-containing gas; and maintaining the amount of oxygen in the flue gas to be less than 2% by volume. An embodiment of the invention is one, any or all of prior embodiments in this paragraph up through the second embodiment in this paragraph wherein the amount of oxygen in the flue gas is maintained by adjusting the oxygen content of the oxygen-containing gas introduced into the catalyst regeneration zone. An embodiment of the invention is one, any or all of prior embodiments in this paragraph up through the second embodiment in this paragraph wherein the oxygen content is adjusted by controlling the ratio of air to flue gas in the oxygen-containing gas. An embodiment of the invention is one, any or all of prior embodiments in this paragraph up through the second embodiment in this paragraph wherein the regenerated catalyst comprises between 1 wt% to 4 wt% coke. An embodiment of the invention is one, any or all of prior embodiments in this paragraph up through the second embodiment in this paragraph wherein the flue gas further comprises carbon dioxide and carbon monoxide, and wherein the process further comprises maintaining a ratio of carbon dioxide to carbon monoxide in the flue gas of at least 0.5. An embodiment of the invention is one, any or all of prior embodiments in this paragraph up through the second embodiment in this paragraph wherein the ratio of carbon dioxide to carbon monoxide in the flue gas is maintained at greater than 2.

A third embodiment of the present invention is a process for partially regenerating catalyst from an MTO reaction zone comprising passing a stream of an oxygen-containing gas to a catalyst regeneration zone; passing a stream of spent catalyst from the MTO reaction zone to the catalyst regeneration zone, the spent catalyst comprising coke; combusting coke from the spent catalyst to provide a partially regenerated catalyst comprising between 1 wt.% to 4 wt.% coke; recycling a portion of a flue gas stream to said catalyst regeneration zone as said oxygen-containing gas; controlling the ratio of air to flue gas in the oxygen-containing gas by maintaining at least one of the following parameters in order to achieve the partially regenerated catalyst: the amount of oxygen in the flue gas is less than 2% by volume; the ratio of carbon dioxide to carbon monoxide in the flue gas is at least 0.5; or the oxygen utilization in the catalyst regeneration zone is at least 90%. An embodiment of the invention is one, any or all of prior embodiments in this paragraph up through the third embodiment in this paragraph wherein the ratio of carbon dioxide to carbon monoxide is maintained at greater than 2. An embodiment of the invention is one, any or all of prior embodiments in this paragraph up through the third embodiment in this paragraph further comprising adjusting process conditions associated with the MTO reaction zone; and adjusting the ratio of air to flue gas in the oxygen-containing gas in response to the adjusted process conditions of the MTO reaction zone. An embodiment of the invention is one, any or all of prior embodiments in this paragraph up through the third embodiment in this paragraph, 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 generate and transmit data. An embodiment of the invention is one, any or all of prior embodiments in this paragraph up through the third embodiment in this paragraph, further comprising receiving a signal or data. And adjusting the ratio of air to smoke in response to the received data or signal. An embodiment of the invention is one, any or all of prior embodiments in this paragraph up through the third embodiment in this paragraph wherein the ratio of air to flue gas in the oxygen-containing gas is controlled by maintaining at least two of the following parameters in order to achieve the partially regenerated catalyst: the amount of oxygen in the flue gas is less than 2% by volume; the ratio of carbon dioxide to carbon monoxide in the flue gas is at least 0.5; or the oxygen utilization in the catalyst regeneration zone is at least 90%. An embodiment of the invention is one, any or all of prior embodiments in this paragraph up through the third embodiment in this paragraph wherein the ratio of air to flue gas in the oxygen-containing gas is controlled by maintaining the following parameters in order to achieve the partially regenerated catalyst: the amount of oxygen in the flue gas is less than 2% by volume; the ratio of carbon dioxide to carbon monoxide in the flue gas is at least 0.5; and an oxygen utilization in the catalyst regeneration zone of at least 90%. An embodiment of the invention is one, any or all of prior embodiments in this paragraph up through the third embodiment in this paragraph further comprising adjusting the ratio of air to flue gas in the oxygen-containing gas so as to maintain a constant velocity of spent catalyst particles within the reactor of the catalyst regeneration zone.

Without further elaboration, it is believed that one skilled in the art can, using the preceding description, utilize the present invention to its fullest extent and can readily ascertain the essential characteristics of the present invention without departing from the spirit and scope thereof, to make various changes and modifications of the invention and to adapt it to various usages and conditions. Accordingly, the foregoing preferred specific embodiments are to be construed as merely illustrative, and not limitative of the remainder of the disclosure in any way whatsoever, and is intended to cover various modifications and equivalent arrangements included within the scope of the appended claims.

In the foregoing, all temperatures are shown in degrees celsius and all parts and percentages are by weight unless otherwise indicated.

While at least one exemplary embodiment has been presented in the foregoing detailed description of the invention, it should be appreciated that a vast number of variations exist. It should also be appreciated that the exemplary embodiment or exemplary embodiments are only examples, and are not intended to limit the scope, applicability, or configuration of the invention in any way. Rather, the foregoing detailed description will provide those skilled in the art with a convenient road map for implementing an exemplary embodiment of the invention, it being understood that various changes may be made in the function and arrangement of elements described in an exemplary embodiment without departing from the scope of the invention as set forth in the appended claims and their legal equivalents.