Purification of methioine hydroxy analogue hydrolyzate by electrodialysis

• US 4,419,198 A
• Filed: 06/22/1981
• Issued: 12/06/1983
• Est. Priority Date: 06/22/1981
• Status: Expired due to Term

• Current Assignee: Novus International, Inc. (Nippon Soda Company Limited)
• Original Assignee: Monsanto Company (Bayer AG)
• Inventors: Keating, Kenneth B., Breda, Ernest J.
• Primary Examiner(s): Niebling, John F.
• Application Number:
  US06/275,670
• Time in Patent Office: 897 Days
• Field of Search: 204/180 P, 204/151, 204/131
• US Class Current: 204/522
• CPC Class Codes: B01D 61/44 Ion-selective electrodialysis
• CPC Class Codes: C07C 323/00 Thiols, sulfides, hydropolysulfides or polysulfides substituted by halogen, oxygen or nitrogen atoms, or by sulfur atoms not being part of thio groups
• CPC Class Codes: Y02P 20/10 Process efficiency

Abstract

A process for separating anions, such as sulfates, chlorides and phosphates, and cations, such as ammonium and hydrogen ion, from methionine hydroxy analogue hydrolysate in solution by passing a direct electric current through an electrodialysis cell, said process producing substantial environmental benefits and energy savings over existing methods of manufacture.

Claims

1. A process for separating anions and cations from a reaction mixture obtained by acid hydrolysis of MHBN to MHBA comprising:

(i) introducing the reaction mixture into an electrolytic cell, said cell having at least three compartments, an anode compartment containing anolyte and having an anode in contact with said anolyte, a cathode compartment containing catholyte and having a cathode in contact with said catholyte, separated by at least one process compartment into which said reaction mixture is introduced, an anion-exchange membrane separating said anode compartment from said process compartment, and a cation-exchange membrane separating said cathode compartment from said process compartment;

said anolyte and said catholyte being selected from water or aqueous sulfuric acid containing up to about 10% sulfuric acid;

(ii) applying a direct current of electricity through the cell such that up to about 450 Ampere-hours of electrical charge are passed per liter of reaction mixture, the current being driven by an applied voltage of about 2 to 20 volts per cell; and

(iii) recovering the purified MHBA reaction mixture.

2. The process of claim 1 where sulfate and ammonium ions are removed from a reaction mixture obtained by sulfuric acid hydrolysis of MHBN to MHBA.

3. The process of claim 2 where the concentration of sulfate ion in the process compartment or compartments exceeds that in the anode compartment.

4. The process of claims 1, 2 or 3 where the anolyte and catholyte are aqueous sulfuric acid containing about 0.4 to 0.6% sulfuric acid.

5. The process of claim 1 where the reaction mixture is introduced into a multi-compartment electrolytic cell in which the anode compartment and the cathode compartment are separated by a series of alternating process and receiving compartments, all compartments are separated from one another by alternating anion- and cation-exchange membranes, the reaction mixture being introduced into the process compartments, and an electrolyte selected from water or aqueous sulfuric acid containing up to about 10% sulfuric acid being introduced into the anode, cathode and receiving compartments.

6. The process of claim 5 where sulfate and ammonium ions are removed from a reaction mixture obtained by sulfuric acid hydrolysis of MHBN to MHBA.

7. The process of claim 6 where the concentration of sulfate ion in the process compartments exceeds that in the anode and receiving compartments.

8. The process of claims 5, 6 or 7 where the electrolyte is aqueous sulfuric acid containing about 0.4 to 0.6% sulfuric acid.