US-12623986-B2 - Synergistic use of phenol purification train in phenol production unit for processing phenolic water from bisphenol-a production unit

US12623986B2US 12623986 B2US12623986 B2US 12623986B2US-12623986-B2

Abstract

Systems and methods for recovering phenol have been disclosed. At least a portion of a wastewater stream from a bisphenol-A production process and a phenol stream that is produced by separating a crude phenol stream from a cumene based phenol production process are concurrently processed in a hydrocarbon removal unit to produce (i) a purified phenol stream comprising 95 to 99.9 wt. % phenol and (ii) an aqueous stream comprising water and byproducts of the phenol production process.

Inventors

Kadek Sumpena
Lara Galan-Sanchez
Frank Mostert
Kae Shin Wong

Assignees

SABIC GLOBAL TECHNOLOGIES B.V.

Dates

Publication Date: 20260512
Application Date: 20211008

Claims (15)

1 . A method of recovering phenol, the method comprising: concurrently processing, in a hydrocarbon removal unit, (1) a first phenol stream from a phenol production process and (2) at least a portion of a wastewater stream from a bisphenol-A production process under operating conditions sufficient to form: (i) a purified phenol stream comprising 95 to 99.9 wt. % phenol and (ii) an aqueous stream comprising water and byproducts of the phenol production process, wherein the hydrocarbon removal unit includes a hydro-extraction column configured to perform a liquid-liquid extraction to separate phenol from the byproducts of the phenol production process, wherein the hydro-extraction column is operated to provide an extraction temperature of 100 to 250° C. and an extraction pressure of 0.4 to 2 bar.
2 . The method of claim 1 , wherein the first phenol stream comprises (a) 85 to 99 wt. % phenol and (b) the byproducts from the phenol production process, and the first phenol stream is produced via a process comprising: separating an effluent stream from a cumene based phenol production process to form (i) a crude phenol stream comprising (c) 60 to 95 wt. % phenol and (d) byproducts from the cumene based phenol production process and (ii) a crude acetone stream comprising 10 to 30 wt. % acetone; and separating the crude phenol stream in a crude phenol distillation column to produce the first phenol stream.
3 . The method of claim 2 , wherein the byproducts from the cumene based phenol production process comprise hydrocarbons, α-methylstyrene, 2-methylbenzofuran, carbonyls, water, acetone, acetophenone, cumylphenol, α-methylstyrene dimers, high boilers, or combinations thereof.
4 . The method of claim 1 , wherein the wastewater stream from the bisphenol-A production process comprises 75 to 95 wt. % water and 5 to 20 wt. % phenol.
5 . The method of claim 4 , wherein the wastewater stream from the bisphenol-A production process is produced via separating an effluent stream from an acetone-phenol condensation reaction unit to form (i) a crude bisphenol-A stream comprising 5 to 25 wt. % bisphenol-A and (ii) the wastewater stream from the bisphenol-A production process.
6 . The method of claim 5 , wherein the wastewater stream from the bisphenol-A production process further comprises acetone, dimethylbenzofuran, cumene, alpha-methylstyrene, or combinations thereof.
7 . The method of claim 4 , further comprising: combining at least a portion of the wastewater stream from the bisphenol A production process with a wastewater stream from a phenol production process to form a dephenolation feed stream; processing the dephenolation feed stream in a dephenolation unit to form a second phenol stream comprising phenol; and recycling the second phenol stream to a phenol production process.
8 . The method of claim 7 , wherein the wastewater stream from the phenol production process comprises 2 to 10 wt. % phenol and 85 to 98 wt. % water.
9 . The method of claim 8 , wherein the wastewater stream from the phenol production process further comprises acetone, dimethylbenzofuran, cumene, alpha-methylstyrene, or combinations thereof.
10 . The method of claim 7 , wherein the dephenolation unit includes a solvent extraction unit.
11 . The method of claim 10 , wherein the dephenolation unit is operated using a solvent selected from the group consisting of cumene, ethylbenzene, toluene, and combinations thereof.
12 . The method of claim 1 , wherein the first phenol stream comprises 85 to 99 wt. % phenol.
13 . The method of claim 1 , wherein the water of the wastewater stream from the bisphenol-A production process is used as an azeotroping agent in the hydro-extraction column configured to form azeotrope with the byproducts of the phenol production process.
14 . The method of claim 1 , wherein the aqueous stream from the hydrocarbon removal unit further comprises phenol, and the method further comprises separating the aqueous stream in a dephenolation unit to recover additional phenol.
15 . The method of claim 1 , further comprising: processing the purified phenol stream in a finishing column under finishing conditions sufficient to produce a phenol product stream comprising 99.5 to 99.9 wt. % phenol.

Description

CROSS REFERENCE TO RELATED APPLICATIONS This application is a National Stage application of PCT/IB2021/059240, filed Oct. 8, 2021, which claims the benefit of priority of U.S. Provisional Patent Application No. 63/090,125, filed Oct. 9, 2020, both of which are hereby incorporated by reference in their entireties herein. FIELD OF INVENTION The present invention generally relates to producing to produce bisphenol-A (BPA) and phenol. More specifically, the present invention relates to a system and a method for processing wastewater coming from a BPA production unit, where such wastewater processing is carried out in a purification unit of a phenol production system. BACKGROUND OF THE INVENTION Bisphenol-A (BPA) is a precursor for various plastic materials, including polycarbonates, polysulfones, and epoxy resins. These plastic materials are used to manufacture water bottles, food containers, sports equipment, water pipes, etc. Thus, there is a large demand for BPA. Conventionally, BPA is produced by condensation reaction between acetone and phenol. The resulting effluent from the condensation reactor is then dehydrated, crystallized and prilled to produce purified BPA prills. In the conventional process for producing BPA, a recovery step is implemented to recover and recycle phenol and acetone from the wastewater stream produced at the dehydration step. Generally, the recovery step is conducted using a complex solvent extraction system, thereby resulting in relatively high capital expenditure and high energy consumption for the overall BPA production process. Overall, while the systems and methods for processing wastewater from the BPA production system exist, the need for improvements in this field persists in light of at least the aforementioned drawbacks of the conventional system and method. BRIEF SUMMARY OF THE INVENTION A solution to at least some of the above-mentioned problems associated with systems and methods for processing wastewater from a BPA production unit has been discovered. The solution resides in a method of recovering phenol from the wastewater stream of a BPA production unit including concurrently processing the wastewater stream of the BPA production unit and a phenol stream in a hydrocarbon removing unit of a phenol production unit. This is beneficial for at least simplifying operation due to removing of operation units and reducing the capital expenditure needed for producing BPA as the wastewater stream from BPA production unit can be processed in an existing unit of a phenol production system. Furthermore, at least a portion of the wastewater from the BPA production unit can also be processed in a dephenolation unit in the phenol production unit for recovering phenol, further optimizing the utilization of the processing capacity of the existing phenol production system, and resulting in lower work load for phenolic water purification system and reduced production cost for BPA. Therefore, the method and system of the present invention provide a technical solution to at least the aforementioned problems associated with the conventional system and method for processing wastewater and recovering BPA and/or acetone from the wastewater coming from a BPA production system mentioned above. Embodiments of the invention include a method of recovering phenol. The method comprises concurrently processing, in a hydrocarbon removal unit, (1) a first phenol stream from a phenol production process and (2) at least a portion of a wastewater stream from a bisphenol-A production process, under operating conditions sufficient to form: (i) a purified phenol stream comprising 95 to 99.9 wt. % phenol and (ii) an aqueous stream comprising water and byproducts of the phenol production process. Embodiments of the invention include a method of recovering phenol. The method comprises separating an effluent stream coming from a cumene based phenol production process to form (i) a crude phenol stream comprising (a) 60 to 95 wt. % phenol and (b) byproducts from the cumene based phenol production process and (ii) a crude acetone stream comprising 10 to 30 wt. % acetone. The method comprises separating the crude phenol stream in a crude phenol distillation column to produce a first phenol stream. The method comprises concurrently processing, in a hydrocarbon removal unit, (1) the first phenol stream and (2) at least a portion of a wastewater stream from a bisphenol-A production process under operating conditions sufficient to form: (i) a purified phenol stream comprising 95 to 99.9 wt. % phenol and (ii) an aqueous stream comprising water and byproducts of the phenol production process. Embodiments of the invention include a method of recovering phenol. The method comprises reacting acetone and phenol in an acetone-phenol condensation reaction unit of a bisphenol-A (BPA) production process under reaction conditions sufficient to produce BPA. The method comprises separating an effluent stream from the acetone-phenol c