MXPA06008234A

MXPA06008234A - Chemical production processes, chemical production systems, and methods for monitoring and altering reactor conditions.

Info

Publication number: MXPA06008234A
Application number: MXPA06008234A
Authority: MX
Inventors: Vimal Sharma; William R Lowery; Shaun E Mckay; Benny D Evers
Original assignee: Great Lakes Chemical Corp
Priority date: 2004-01-21
Filing date: 2004-01-21
Publication date: 2007-01-26
Also published as: EP1718951A1; EP1718951A4; CN1906475A; WO2005080942A1

Abstract

The present invention includes chemical production processes and systems as well as methods for monitoring and altering reactor conditions. A method for monitoring reactor conditions includes monitoring reactant recovery stream density and altering the condition when the density reaches a predetermined amount. A chemical production system is provided that includes a reactor unit receiving a reactant recovery stream from a separation unit where the stream can be monitored by a density monitor. A chemical process is also provided that includes reacting a reactant and a starting material in a reactor unit having reactor parameters and producing a product stream that includes the reactant, a product, and a by-product. A recycle stream comprising the reactant and the by-product can be separated from the product stream and returned to the reactor unit. The recycle stream density can be monitored at least periodically and the reactor parameters altered as the density indicates an increased concentration of the by-product in the recycle stream.

Description

CHEMICAL PROCEDURES OF PRODUCTION, CHEMICAL SYSTEMS OF PRODUCTION, AND METHODS TO MONITOR AND ALTER REACTOR CONDITIONS FIELD OF THE INVENTION The present invention relates to chemical production methods and systems and to methods for monitoring and altering reactor conditions.

BACKGROUND OF THE INVENTION Chemical manufacturing processes can include single or multiple reactor units and individual or multiple separation units. A continuous goal in chemical processing is to synchronize these units together in a way that makes the procedure efficient. An exemplary configuration of reactors and separation units includes the return of unused or excess reagents to a reactor unit from a separation unit. One of the benefits of this configuration is that the excess reagents are not discarded, but used to produce products efficiently. Configured in this way, a system of chemical procedure can be considered a closed chemical system of stable state. In a closed system like this, in some cases, the reduced product recovery may be an indication of the need for the replacement of consumables and / or the alteration of the parameters of the procedure. An example of a consumable replacement is the replacement of catalysts in the catalytic reactor. However, because the system is a closed system, the procedure can operate inefficiently until it is determined that a consumable requires replacement. The present invention provides methods for monitoring reactor catalysts and processes and chemical production systems. Although the invention is motivated by the pointing out of the previous concerns and challenges, it is not, of course, limited. This invention is limited only by the appended claims as they are written literally and appropriately interpreted in accordance with equitable doctrines.

BRIEF DESCRIPTION OF THE INVENTION The present invention includes chemical production methods and systems and methods for monitoring and altering reactor conditions. In one implementation, a method to monitor reactor conditions includes monitoring the current density of reagent recovery. The reagent recovery stream can be configured to return reagents to a reactor having a catalyst. The method further includes altering the catalyst when the density reaches a predetermined amount. One aspect of the present invention provides a production method that includes providing a chemical production system having at least one reactor unit and at least one separation unit. The reactor unit can have reactor parameters. The excess reagent is recovered from the separation unit as a recovery stream and provided to the reactor unit. The density of the recovery current is monitored and the parameters of the reactor are altered when the density reaches a predetermined amount. In an exemplary implementation, a chemical production system is provided that includes a reactor unit that receives a reagent recovery stream that comes from a separation unit, the current being monitored through a density monitor. In an implementation, a chemical process is provided which includes reacting a reagent and a starting material in a reactor unit and producing a product stream that includes the reagent, a product and a byproduct. The reaction can occur in the presence of the catalyst and can deplete the catalyst. The product stream can be separated into two different streams, one recycle stream comprising the reactant and the secondary product being one of the two different streams. The recycle stream can be returned to the reactor unit. The return may include monitoring the density of the recycle stream to determine when the depletion of the catalyst has passed a threshold level. Recycling density can be monitored at least periodically. The catalyst can be replenished as the density indicates an increased concentration of the secondary product in the recycle stream.

DETAILED DEPTION OF THE INVENTION The present invention includes methods for monitoring and altering the conditions of the reactor and chemical production processes and systems. An exemplary implementation of these methods, methods and systems will be debed with reference to Figure 1. Referring to Figure 1, a chemical production system 10 includes a reactor unit. 12 and a separation unit 14. The reactor unit 12 can include catalytic reactors and can be configured to receive and / or react a reagent 16 and a starting material 18. The reactor unit 12 can have reactor parameters that include , starting material and reactant compositions and feed rates, temperature and pressure of the reactor unit, as well as catalyst composition. Reagent 16 may include reagents such as halogen exchange reagents. An exemplary halogen exchange reaction is the reaction of the starting material CH2Cl2 (dichloromethane, R-30) with the halogen exchange reagent HF. This reaction can create a halogen exchange product CH2F2 (difluoromethane, R 32) and by-products such as CH2CIF (chlorofluoromethane, R-31) and HCI (hydrochloric acid). Catalysts can be used to improve reactions such as halogen exchange reactions. Exemplary catalysts for use in halogen exchange reactions include supported and unsupported chromium-containing catalysts. The reactor unit 12 may include a catalyst. The catalyst can be depleted through use during the reaction. The spent catalyst can be replenished. The replenishment of the catalyst, in one aspect, includes replacing some and / or all of the catalyst, and in another aspect, reactivating some part and / or all of the catalyst and in a further implementation, some part of the catalyst can be reactivated and some part it can be replaced. Referring again to Figure 1, the product stream 20 can transfer products from the reactor unit 12 to the separation unit 14. The product stream 20 can include excess reagent, such as the halogen exchange reagent and the starting material, as well as the product and / or secondary products. Portions of the product stream 20 may be removed in the separation unit 14. The separation unit 14 may include separation units, such as phase separation units and / or distillation apparatus, such as phase separation units. liquid-liquid. In an exemplary implementation, the separation unit 14 can separate the product stream including CH2F2 and excess HF into two streams, a final product stream 24 and a recovery stream 22. The final product stream 24 can include the product such as CH2F2. The recovery current 22 can be recovered from the separation unit 14. In one implementation, the recovery current 22 can be recovered from the bottom of a separation unit of a distillation apparatus. The recovery stream 22 may include excess reagent, such as HF. The recovery stream 22 may also include by-products such as CH2CIF and / or starting material such as CH2Cl2. In the exemplary illustration of Figure 1, recovery stream 22 is returned to the reactor unit 12. As illustrated, this can be considered a recycle and the recovery stream 22 can be considered as a recycle stream. However, the present invention is not limited to the recycling of excess reagents to a reactor unit. The present invention also includes implementations wherein excess reagents are recovered from other processes and transferred to separate process reactors. Referring again to figure 1, the recovery current 22 can be monitored through a monitoring device 26. In one embodiment, the present invention provides the monitoring of the recovery current density 22. In one implementation, the return of the recycle stream can include monitoring the density of the recycle stream to determine when the catalyst depletion has passed a threshold. The monitoring device 26 may include a densitometer or density meter. An exemplary densitometer or density meter includes a Micromotion Elite CMF 100 with a Hastelloy sensor available from Micro Motion, Inc., an Emerson Process Management Division, 7070 Winchester Circle, Boulder, Colorado 80301, USA. In one implementation, the density monitoring may indicate an increase in the concentration of the starting material and / or the secondary product in the recovery stream 22. In an exemplary implementation, the density of the recovery stream 22 may be periodically monitored or it can be monitored continuously. Only an increase in the concentration of the starting material in an exemplary aspect, can be indicated by a change in density and in one aspect, only an increase in the concentration of the secondary product can be an indication of change in the density of the current of recovery 22. The density may indicate a double increase in the concentration of the secondary product and / or a double increase in the concentration of the starting material of the recovery stream 22. In an exemplary aspect, the density may be used to determine when the depletion of the catalyst has passed a threshold level. The threshold level may be the level at which the catalyst is depleted, the catalyst will soon be depleted, and / or the level may be predetermined. In accordance with the present invention, the conditions of the reactor unit 12 can be altered in response to the density of the recovery stream 22. In an exemplary aspect, a predetermined density amount of the recovery stream 22 can promulgate the alteration of the reactor parameters of the reactor unit 12. In an exemplary implementation, when the density of the recovery stream 22 indicates a double increase of either the starting material and / or the secondary product, the reactor parameters can be altered . In a particular implementation when the reagent 16 is HF, the starting material is CH2Cl2, a recovery current density of 1.04 g / ml can dictate the replenishment of the catalyst within the reactor unit 12. In another implementation, a density of 1.01 g / ml recovery stream can dictate the replenishment of the catalyst within the reactor unit 12. As mentioned above, the catalyst that is replenished can include a supported chromium catalyst. The catalyst can be replenished by replacing and / or reactivating the catalyst. The catalyst can be reactivated by methods known to those skilled in the art. One such method includes heating the catalyst in the presence of a reagent such as HF. Additionally, the alteration of the reactor unit is not limited to the replacement or regeneration of the catalyst. The present invention also includes altering other reaction parameters such as the compositions and feed rates of the starting material and reagents, as well as the temperature and pressure of the reactor unit.

Claims

NOVELTY OF THE INVENTION CLAIMS 1. - A method for monitoring and altering reactor conditions, comprising: monitoring the density of the reagent recovery stream, the reagent recovery stream is configured to return reagents to a reactor having catalyst therein; and altering reactor conditions when the density reaches a predetermined amount. 2. The method according to claim 1, further characterized in that the stream comprises a halogen exchange reagent. 3. The method according to claim 2, further characterized in that the halogen exchange reagent is HF. 4. The method according to claim 2, further characterized in that the stream further comprises a secondary product of halogen exchange. 5. The method according to claim 4, further characterized in that the halogen exchange reagent comprises HF and the secondary product comprises CH2CIF. 6. - The method according to claim 1, further characterized in that the alteration comprises replacing the catalyst. 7. The method according to claim 1, further characterized in that the reactor is configured to react CH2Cl2 with HF in the presence of a catalyst. 8. The method according to claim 7, further characterized in that the stream comprises one or more of HF, CH2Cl2, and CH2CIF and the alteration comprises replacing the catalyst when the current density reaches 1.04 g / ml. 9. The method according to claim 7, further characterized in that the stream comprises one or more of HF, CH2CI2, and CH2CIF and the alteration comprises replacing the catalyst when the density of the stream reaches 1.01 g / ml. 10. A chemical process comprising: reacting a reagent and a starting material in a reactor unit and producing a product stream comprising the reagent, a product, and a secondary product, the reaction occurs in the presence of a catalyst and exhaust the catalyst; separating the product stream into two different streams, one of the two different streams is a recycle stream comprising the reactant and the byproduct; returning the recycle stream to the reactor unit, the return comprises monitoring the density of the recycle stream to determine when the depletion of the catalyst has passed a threshold level; replenishing the catalyst as the density indicates an increased concentration of the secondary product in the recycle stream. 11. The process according to claim 10, further characterized in that the reagent comprises HF, the starting material comprises CH2CI2, the product comprises CH2F2 and the secondary product comprises CH2CIF. 12. The process according to claim 11, further characterized in that the catalyst comprises a supported chromium catalyst. 13. The process according to claim 12, further characterized in that the separation comprises distilling the product stream and recovering the recycle stream as a residual product of the distillation. 14. The method according to claim 12, further characterized in that the replenishment comprises at least one of: replacing the catalyst; reactivate the catalyst; or reactivate some part of the catalyst and replace some part of the catalyst. 15. The process according to claim 10, further characterized in that the separation comprises distilling the product stream and recovering the recycle stream as a residual product from the distillation. 16. - The method according to claim 10, further characterized in that the reaction comprises combining the reagent and the starting material in the presence of a catalyst and the replenishment comprises replacing the catalyst. 17.- A chemical procedure, which comprises: reacting a starting material and a reagent to produce a product stream comprising the reagent, a product, and a secondary product, wherein the reaction is carried out in a reactor unit having reactor parameters. 18. The method according to claim 17, further characterized in that at least one of the parameters of the reactor includes reactor temperature, and wherein the alteration comprises changing the temperature of the reactor. 19. The method according to claim 18, further characterized in that the change comprises increasing the temperature of the reactor. 20. The process according to claim 17, further characterized in that the reagent comprises HF, the starting material comprises CH2CI2, the product comprises CH2F2 and the secondary product comprises CH2CIF. 21. The process according to claim 20, further characterized in that the reaction comprises combining the HF and CH2Cl2 in the presence of a catalyst and the alteration comprises changing the temperature of the reactor. 22. The method according to claim 21, further characterized in that the change comprises increasing the temperature of the reactor. 23. The method according to claim 21, further characterized in that the alteration comprises changing the temperature of the reactor as the density indicates a double increase in the concentration of the secondary product in the recycle stream. 24. The process according to claim 20, further characterized in that the product stream additionally comprises the starting material and the recycle stream further comprises a concentration of the starting material. 25. The process according to claim 24, further characterized in that the reaction comprises combining the HF and CH2Cl2 in the presence of a catalyst and the alteration comprises changing the temperature of the reactor. 26. The process according to claim 24, further characterized in that the density indicates an increased concentration of both the starting material and the secondary product in the recycle stream. 27. - The method according to claim 24, further characterized in that the density indicates an increased concentration twice the starting material in the recycle stream. 28. The method according to claim 17, further characterized in that the return comprises continuously determining the density of the recycle stream. 29. The method according to claim 23, further characterized in that the density indicates an increased concentration twice the secondary product.