US 12,492,159 B2
Method for producing levulinic acid
Alok Satlewal, Faridabad (IN); Ruchi Agrawal, Faridabad (IN); Ravindra Kumar, Faridabad (IN); Ravi Prakash Gupta, Faridabad (IN); and Sankara Sri Venkata Ramakumar, Faridabad (IN)
Assigned to INDIAN OIL CORPORATION LIMITED, (IN); and DEPARTMENT OF BIOTECHNOLOGY, (IN)
Filed by INDIAN OIL CORPORATION LIMITED, Maharashtra (IN); and DEPARTMENT OF BIOTECHNOLOGY, New Delhi (IN)
Filed on Apr. 14, 2023, as Appl. No. 18/135,054.
Claims priority of application No. 202221023739 (IN), filed on Apr. 22, 2022.
Prior Publication US 2023/0339838 A1, Oct. 26, 2023
Int. Cl. C07C 51/487 (2006.01); C07C 59/185 (2006.01)
CPC C07C 51/487 (2013.01) [C07C 59/185 (2013.01)] 14 Claims
OG exemplary drawing
 
1. A process for producing levulinic acid from technical lignin, the process comprising:
a) treating technical lignin with a combination of formic acid and technical spirit in a high-pressure reactor (HPR) for obtaining cellulose and lignin;
b) subjecting the cellulose of step a) to a treatment with a catalyst to obtain a slurry;
c) centrifuging the slurry to obtain a levulinic acid containing liquid fraction;
d) mixing the levulinic acid containing liquid fraction with a solvent to obtain an organic mixture and an acidic aqueous liquid waste;
e) evaporating the solvent from the organic mixture to obtain levulinic acid; and
f) recycling the acidic aqueous liquid waste of step d) and solvent of step d) for a subsequent cycle of levulinic acid extraction and purification;
wherein the technical lignin comprises 10-25% cellulose, 0-5% hemicellulose, 25-55% lignin and 20-50% ash content.