Classifications

• • C—CHEMISTRY; METALLURGY
  • C07—ORGANIC CHEMISTRY
  • C07C—ACYCLIC OR CARBOCYCLIC COMPOUNDS
  • C07C37/00—Preparation of compounds having hydroxy or O-metal groups bound to a carbon atom of a six-membered aromatic ring
  • C07C37/08—Preparation of compounds having hydroxy or O-metal groups bound to a carbon atom of a six-membered aromatic ring by decomposition of hydroperoxides, e.g. cumene hydroperoxide
• • C—CHEMISTRY; METALLURGY
  • C07—ORGANIC CHEMISTRY
  • C07C—ACYCLIC OR CARBOCYCLIC COMPOUNDS
  • C07C45/00—Preparation of compounds having >C = O groups bound only to carbon or hydrogen atoms; Preparation of chelates of such compounds
  • C07C45/51—Preparation of compounds having >C = O groups bound only to carbon or hydrogen atoms; Preparation of chelates of such compounds by pyrolysis, rearrangement or decomposition
  • C07C45/53—Preparation of compounds having >C = O groups bound only to carbon or hydrogen atoms; Preparation of chelates of such compounds by pyrolysis, rearrangement or decomposition of hydroperoxides
• • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
  • Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
  • Y02P—CLIMATE CHANGE MITIGATION TECHNOLOGIES IN THE PRODUCTION OR PROCESSING OF GOODS
  • Y02P20/00—Technologies relating to chemical industry
  • Y02P20/10—Process efficiency
• • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
  • Y10—TECHNICAL SUBJECTS COVERED BY FORMER USPC
  • Y10S—TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
  • Y10S203/00—Distillation: processes, separatory
  • Y10S203/06—Reactor-distillation

Definitions

• Phenol is an important organic chemical with a wide variety of industrial uses. It is used, for example, in the production of phenolic resins, bisphenol-A and caprolactam. A number of processes are currently in use for the production of phenol but the single process providing the largest proportion of the total production capacity is the cumene process which now accounts for over three quarters of the total U.S. production. The basic reaction involved in this process is the cleavage of cumene hydroperoxide into phenol and acetone:
• the reaction takes place under acid conditions with the yield of both phenol and acetone generally being 40 percent or more.
• the cumene hydroperoxide is usually treated with dilute sulphuric acid (0.5 to 25 percent concentration) at a temperature of about 50° to 70°C.
• the reaction mixture is separated and the oil layer distilled to obtain the phenol and acetone together with cumene, alpha-methylstyrene, acetophenone and tars.
• the cumene may be recycled for conversion to the hydroperoxide and subsequent cleavage.
• the phenol produced in this way is suitable for use in resins although further purification is required for a pharmaceutical grade product.
• U.S. Patent No. 5,055,627 to Smith, Jr., et al. discloses an alkylation process for preparing cumene from benzene and propylene in a zeolitic catalyst bed disposed in a distillation column reactor.
• the alkylated benzene is withdrawn from the distillation column reactor at a point below the fixed bed and unreacted organic aromatic compound may be taken off as an overhead.
• Steps v) and vi) can be used to control dilution of the cumene hydroperoxide feed, e.g., by setting the reflux rate of acetone through said column.
• the liquid flow of the diluted cumene hydroperoxide through the reactor is preferably maintained at a rate sufficient to keep the catalyst bed wetted, thereby maintaining catalyst temperature at or near the boiling point of the liquid to provide isothermal operation of the process.
• step vii) is optional, the presently claimed process includes operation under conditions of total reflux with all overhead product being returned to the column.
• the present invention relates to an apparatus for preparing phenol from cumene hydroperoxide which comprises: a) a reactive distillation column comprising at its upper portion a distillation column and its lower portion a catalyst bed; b) a lower outlet downstream of the catalyst bed for removing high boiling bottom products comprising phenol; c) an inlet at or near the bottom of said distillation column for introducing cumene hydroperoxide feed at a point upstream of said catalyst bed; d) an upper outlet for removing low boiling overhead products comprising acetone; e) a heat exchanger upstream of said upper outlet for cooling said overhead products; f) an overhead products receiver upstream of said heat exchanger having an outlet from which said overhead products are collected and/or returned to said distillation column; and g) overhead products inlet at an upper portion of said distillation column for introducing overhead products reflux from said receiver.
• the apparatus can further comprise an element selected from the group consisting of h) an overhead products inlet at a lower portion of said distillation column for introducing overhead products from said receiver to said distillation column at or near said inlet for introducing cumene hydroperoxide; i) an overhead products line which recycles overhead products to the cumene hydroperoxide feed upstream of said inlet for introducing cumene hydroperoxide; and j) an overhead products line which recycles overhead products to one or more portions of the catalyst bed.
• a reaction zone containing catalyst is fitted into a fractionation tower equipped with an overhead condenser, reflux pump, reboiler, overhead receiver and control instrumentation. Feed components are introduced above the catalyst bed. Products are continuously removed from the reaction zone by the distillation process.
• Catalytic distillation is suitable only for chemical reactions where the distillation of reaction components occurs in the same temperature range as the reaction. Thus, operation above the critical point can be a limitation, and the presence of azeotropes or close boiling components may cause difficulties.
• the reduced residence time in the reactive section of the column of the present invention will minimize the formation of byproducts. This is especially advantageous in the case of CHP decomposition as the dehydration of 2-phenyl-2-propanol leads to the formation of ⁇ -methylstyrene (AMS), a reactive intermediate that could undergo further reactions such as dimerization, oligomerization, and coke formation. Minimizing the formation of heavy compounds will extend catalyst life if a heterogeneous catalyst is employed for the reactive section of the column.
• AMS ⁇ -methylstyrene
• the preferred conditions for the decomposition reaction include temperature and pressure ranges that are suitable for use in a distillation column. Due to the high heat of reaction, decomposition preferably takes place under dilute CHP concentrations, of the order of less than 50 wt.%, preferably 0.1 to 25 wt.%, and most preferably 0.5 to 5 wt.% , e.g., about 3 wt.% CHP.
• the feed to the tower can range from 25 to 95 wt.%, preferably 75 to 85 wt.%, e.g., 80 wt.% CHP, and needs to be further diluted, preferably by acetone, to the above-noted levels. Control of the dilution level can be achieved by setting the reflux rate through the tower, or directly adding the recycled overhead containing acetone to the cumene hydroperoxide feed.
• Table 1 lists the normal boiling points for the major components involved in the decomposition of cumene hydroperoxide. Acetone has a significantly lower boiling point than all the other major components, thereby facilitating its separation in a reactive distillation column. Other low boiling components may also be present in the column, e.g., methanol, acetaldehyde, and benzene.
• Suitable heterogeneous catalysts for use in the cleavage of cumene hydroperoxide include solid acid catalysts such as zeolite beta, disclosed in U.S. Patent No. 4,490,565; a Constraint Index 1-12 zeolite, such as ZSM-5, disclosed in U.S. Patent No. 4,490,566; faujasite, disclosed in EP-A-492807; smectite clays, described in U.S. Patent No.
• the large pore crystalline molecular sieves which can be used in the present invention include those which have pores sufficiently large to physically absorb 2,2,4-tr ⁇ methylpentane
• Representative large pore crystalline molecular sieves include, for example the following zeolites ZSM-3, ZSM-4, ZSM-12, ZSM- 18, ZSM-20, zeolite Beta, zeolite L, mordenite, faujasite, zeolite Y, and the rare earth metal-containing forms of the above
• zeolite Y includes zeolite Y in its as synthesized form, as well as its variant forms including framework dealuminated zeolite, e g , ultrastable Y (USY) described in U S Pat No 3,293,192 and LZ-210 described in U S Pat No 4,503,023, hereby incorporated by reference
• the large pore zeolite selected for use in the process of this invention generally can possess an alpha value over a wide range of from less than 1 to over 1000 "
• the particular class of macroreticular acid cation exchange resins useful as catalysts in the present invention are characterized by substantial porosity, high surface area and a low surface acid concentration, generally less than about 0.5 milliequivalents of hydrogen ion per square meter surface area.
• the cation exchange resin can contain a small amount of water, generally between 0.5 and 20 percent by weight.
• the catalyst bed is an unstructured packed bed of solid catalyst.
• the catalyst is in the form of pellets, typically greater than 1/24" diameter, such that the catalyst bed void volume allows for liquid flow down the bed, and vapor flow up the bed.
• the catalyst is prepared as follows: five hundred parts of ZrOCI 2 .8H 2 0 are dissolved with stirring in 3.0 liters of distilled water. To this solution is added 7.6 parts of FeS0 4 -7H 2 0. Another solution containing 260 parts of concentrated
• Phenol and other heavies formed pass downwardly through the catalyst bed and are withdrawn from the reactive distillation column through lower outlet 140 and are sent for recovery in the distillation section of the plant (not shown).
• Overheads containing acetone pass upwardly through the column and through upper outlet 150 and thence to a heat exchanger such as condenser 160 and thereafter to overheads receiver 170.
• the acetone-containing overhead can be withdrawn from the receiver through line 180 or recycled as reflux to an upper portion of the distillation column 190.
• Dilution of cumene hydroperoxide feed with acetone is controlled by varying the amount of acetone recycled to the distillation column, i.e., setting the reflux rate through the tower.
• the compositions of the proposed feed and estimated product compositions are provided below in TABLE 2.
• phenol and acetone are produced from cumene hydroperoxide in a reactive distillation column 200.
• a cumene hydroperoxide-containing feed line 210 containing about 80 wt.% CHP introduces feed through inlet 220 at a point above catalyst bed 230 where it is mixed with a diluting portion of acetone derived from column overhead to provide a dilute cumene hydroperoxide mixture which passes through the catalyst bed 230 under cumene hydroperoxide decomposition conditions including a temperature of about 50 to 90°C, a pressure of 0 to 10 psig, and an LHSV of 0.3 to 5 hr "1 to provide a product comprising phenol and acetone.
• phenol and acetone are produced from cumene hydroperoxide in a reactive distillation column 300
• a cumene hydroperoxide-containing feed line 310 containing about 80 wt % CHP introduces feed through inlet 320 at a point above catalyst bed 330 where it is mixed with a diluting portion of acetone derived from column overhead to provide a dilute 3 wt % cumene hydroperoxide mixture which passes through the catalyst bed 330 under cumene hydroperoxide decomposition conditions including a temperature of about 50 to 90°C, a pressure of 0 to 10 psig, and an LHSV of 0 3 to 5 hr 1 to provide a product comprising phenol and acetone
• the catalyst bed is an unstructured packed bed of solid catalyst as described in Example 1 Phenol and other heavies formed pass downwardly through the catalyst bed and are withdrawn from the reactive distillation column through lower outlet 340 and are sent for recovery in the distillation section of the plant (not shown)

Landscapes

• Chemical & Material Sciences (AREA)
• Organic Chemistry (AREA)
• Organic Low-Molecular-Weight Compounds And Preparation Thereof (AREA)
• Low-Molecular Organic Synthesis Reactions Using Catalysts (AREA)
• Vaporization, Distillation, Condensation, Sublimation, And Cold Traps (AREA)

Priority Applications (4)

Applications Claiming Priority (2)

Publications (1)

Family

ID=23859932

Family Applications (1)

Country Status (8)

Cited By (6)

Families Citing this family (19)

Citations (2)

Family Cites Families (10)

• 1999
  • 1999-12-21 US US09/468,465 patent/US6410804B1/en not_active Expired - Fee Related
• 2000
  • 2000-12-20 EP EP00988249A patent/EP1242348B1/en not_active Expired - Lifetime
  • 2000-12-20 AT AT00988249T patent/ATE331702T1/de not_active IP Right Cessation
  • 2000-12-20 DE DE60029132T patent/DE60029132T2/de not_active Expired - Lifetime
  • 2000-12-20 JP JP2001546616A patent/JP5041354B2/ja not_active Expired - Fee Related
  • 2000-12-20 AU AU24477/01A patent/AU2447701A/en not_active Abandoned
  • 2000-12-20 WO PCT/US2000/034843 patent/WO2001046102A1/en not_active Ceased
  • 2000-12-20 ES ES00988249T patent/ES2267600T3/es not_active Expired - Lifetime
• 2001
  • 2001-11-14 US US09/991,831 patent/US6441252B1/en not_active Expired - Fee Related

Patent Citations (2)

Also Published As

Similar Documents

Legal Events