Process for the manufacture of levulinic acid and esters

• US 4,236,021 A
• Filed: 05/07/1979
• Issued: 11/25/1980
• Est. Priority Date: 05/07/1979
• Status: Expired due to Term

• Current Assignee: Goodrich Corporation (Raytheon Technologies Corporation d/b/a RTX)
• Original Assignee: Goodrich Corporation (Raytheon Technologies Corporation d/b/a RTX)
• Inventors: Chasar, Dwight W., Hsu, Chin C.
• Primary Examiner(s): Garner, Vivian
• Application Number:
  US06/036,718
• Time in Patent Office: 568 Days
• Field of Search: 560/174, 562/577, 203/57, 203/60
• US Class Current: 560/174
• CPC Class Codes: C07C 51/09 from carboxylic acid esters or lactones
• CPC Class Codes: C07C 59/185 Saturated compounds having only one carboxyl group and containing keto groups
• CPC Class Codes: C07C 67/00 Preparation of carboxylic acid esters
• CPC Class Codes: C07C 67/39 by oxidation of groups which are precursors for the acid moiety of the ester
• CPC Class Codes: C07C 67/54 by distillation
• CPC Class Codes: C07C 69/716 Esters of keto-carboxylic acids or aldehydo-carboxylic acids

Abstract

An improved process for the manufacture of levulinic acid which comprises esterification of furfuryl alcohol in the presence of a different alcohol selected from unsubstituted primary and secondary carbon-chain or carbon-ring alcohols containing 1 to 10 carbon atoms in the presence of a small amount of acid as a catalyst, purification of the resulting levulinate ester by vacuum distillation of a mixture of the levulinate ester and a high boiling solvent and hydrolysis of the purified levulinate ester in the presence of water and a small amount of strong acid catalyst to yield levulinic acid-water mixture. The improvement resides in the purification being carried out prior to hydrolysis and in using a high boiling solvent in the purification step to prevent the formation of a solid resin.

Claims

1. In the process for the manufacture of a levulinic acid ester which comprises the esterification of furfuryl alcohol with a different alcohol selected from the group consisting of unsubstituted primary and secondary carbon-chain aliphatic and carbon-ring cycloaliphatic alcohols of 1-10 carbon atoms in the presence of a strong acid catalyst, the improvement comprising purification of the crude levulinate ester by vacuum distillation of said levulinate in admixture with at least 3 percent by volume of the levulinate of a solvent which (a) has the boiling point of at least 20°

C. higher than the boiling point of the levulinate ester, (b) dissolves the by-product polymer tar and (c) is miscible with the levulinate ester.

2. A process of claim 1 wherein the difference between the boiling point of the levulinate ester and the boiling point of the solvent is at least 50°

C.

3. A process of claim 1 wherein said solvent is selected from the group consisting of triacetin, dimethyl phthalate, di-n-butyl phthalate and diethyl phthalate.

4. A process of claim 3 wherein furfuryl alcohol is esterified with an aliphatic alcohol.

5. A process of claim 3 wherein the solvent is used in the amount of from 4 to 10% by volume of the crude levulinate ester.

6. A process of claim 5 wherein the distilled levulinate ester is hydrolyzed to yield pure levulinic acid.

7. A process of claim 1 wherein furfuryl alcohol is esterified with n-butanol and the solvent is di-n-butyl phthalate.

8. A process of claim 1 wherein the distilled levulinate ester is hydrolyzed to yield pure levulinic acid.