PROCESS FOR THE ISOLATION OF LEVULINIC ACID

1 . A process for the isolation of levulinic acid with a predetermined purity, comprising the following steps:

a. performing acid catalyzed hydrolysis of a C6 carbohydrate-containing feedstock to obtain reaction product X,

b. purifying of reaction product X to provide a composition 1 , comprising at least 75 wt. % levulinic acid, at most 15 wt. % solvent and at most 10 wt. % impurities, based on the total weight of composition 1 ,

c. feeding composition 1 to a melt crystallization cycle,

d. repeating the melt crystallization cycle as many times as necessary to obtain as composition 2 levulinic acid with the predetermined purity, and

e. isolating the levulinic acid with the predetermined purity.

2 . The process according to claim 1 , wherein the melt crystallization cycle comprises the following steps:

i. Feeding composition 1 to a melt crystallizer, wherein composition 1 is cooled to the freezing point or below the freezing point of levulinic acid to crystallize the levulinic acid in composition 1 ,

ii. Separating a liquid 1 from the crystallized levulinic acid,

iii. Purify the crystals obtained according to step i, after separation of liquid 1 ,

iv. Melting the crystals obtained according to step iii, after separation of liquid 1 , to obtain a composition 2 .

3 . The process according to claim 1 , wherein the melt crystallization cycle comprises the following steps:

i. Feeding composition 1 to a melt crystallizer wherein composition 1 is cooled to at least one temperature Tc, wherein Tc (° C.)=1.23.(W1)−(a value between 94.5 and 109.5) to crystallize the levulinic acid, wherein W1 is the weight % of levulinic acid in composition 1 ,

ii. Draining a liquid 1 , wherein liquid 1 is 30-80 wt. % of composition 1 , based on the total weight of composition 1 ,

iii. Treating the crystals obtained in step i, after draining liquid 1 , at at least one temperature Tw (° C.)=1.23.(W1)−(a value between 84.5 and 101.5) to partly melt the crystals and to obtain a liquid 2 , wherein W1 is the weight % of levulinic acid in composition 1 ,

iv. Draining liquid 2 , wherein liquid 2 is 5-50 wt % of composition 1 , based on the total weight of composition 1 ,

v. Melting the crystals obtained according to step iii, after draining of liquid 2 , at at least one temperature Tm (° C.)=1.23.(W1)−(a value lower than 84.5) to obtain a composition 2 , wherein W1 is the weight % of levulinic acid in composition 1 .

4 . The process according to claim 1 , wherein the predetermined purity of levulinic acid in composition 2 is at least 98 wt. %, based on the total weight of composition 2 .

5 . The process according to claim 2 , wherein the melt crystallizer is a static melt crystallizer.

6 . The process according to claim 1 , wherein the melt crystallization cycle is repeated 0-6 times.

7 . The process according to claim 1 , wherein the melt crystallization cycle is repeated 1-4 times.

8 . The process according to claim 2 , wherein the cooling in step i is performed for 5 minutes to 24 hours.

9 . The process according to claim 3 , wherein step iii is performed for 5 minutes to 2 hours.

10 . An isolation section in a plant for the production of levulinic acid, comprising at least one melt crystallizer.

11 . The isolation section according to claim 10 , wherein the at least one melt crystallizer is a static melt crystallizer.

12 . Use of melt crystallization for the isolation of a levulinic acid composition, comprising at least 98 wt. % levulinic acid, based on the total weight of the composition.

13 . The process according to claim 3 , wherein the predetermined purity of levulinic acid in composition 2 is at least 98 wt. %, based on the total weight of composition 2 , and wherein the melt crystallizer is a static melt crystallizer.

14 . The process according to claim 3 , wherein the cooling in step i is performed for 5 minutes to 24 hours.