US 11,939,721 B2
Method for non-catalytic delignification of biomass inside an apparatus
Nitin Kolhe, Nasak (IN)
Assigned to LIGNOPURA AGROTECH PVT LTD., (IN)
Appl. No. 17/423,106
Filed by LIGNOPURA AGROTECH PVT LTD., Maharashtra (IN)
PCT Filed Jan. 13, 2020, PCT No. PCT/IB2020/050220
§ 371(c)(1), (2) Date Jul. 14, 2021,
PCT Pub. No. WO2020/148623, PCT Pub. Date Jul. 23, 2020.
Claims priority of application No. 201921002226 (IN), filed on Jan. 18, 2019.
Prior Publication US 2022/0136171 A1, May 5, 2022
Int. Cl. D21C 3/20 (2006.01); D21C 1/02 (2006.01); D21C 3/26 (2006.01); D21H 11/02 (2006.01); D21H 11/12 (2006.01)
CPC D21C 3/20 (2013.01) [D21C 1/02 (2013.01); D21C 3/263 (2013.01); D21H 11/02 (2013.01); D21H 11/12 (2013.01)] 9 Claims
OG exemplary drawing
 
1. A method for non-catalytic delignification of biomass, the method comprising the steps of:
adding a stream of water-washed cellulose-rich lignocellulosic biomass inside an apparatus; and
treating the stream with a treatment liquid in presence of an oxygen-containing gas in the apparatus at a temperature of 120-170° C. and at an initial pressure of 3 to 100 bar, wherein the treatment liquid is a mixture of water and an oxygenated solvent, wherein the treatment liquid comprises:
30-70% w/w of the oxygenated solvent comprising at least one of an ether, a ketone, and an ester group; and
30-70% w/w of water;
the oxygen-containing gas comprises 2 to 100% volume of oxygen, the oxygen-containing gas is either in the form of oxygen or air or a mixture of oxygen with an inert gas;
wherein the method produces pulp with a pulp quality of modified kappa number less than 15.