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US 11,078,624 B2Granted
Method for isolating alpha cellulose from lignocellulosic materials
AssigneeKing Abdulaziz University
InventorSherif Shawki Zaki Hindi
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Abstract
The present invention involves an environmentally friendly process and apparatus for the delignification of lignin-containing materials, such as cardboard newspaper or agricultural or tree pruning wastes. This process produces cellulose using low temperatures and low concentrations of hydrogen peroxide. It can be performed using a column fitted with a semipermeable gasket that pressurizes the column by retaining oxygen released by action of the hydrogen peroxide on a lignin-containing material.
Claims16
A method for delignification of a ligno-cellulosic material comprising:
- blending a ligno-cellulosic material comprising cellulose and lignin with water to form an aqueous liquor,
- contacting the aqueous liquor with hydrogen peroxide under non-alkaline conditions in a reaction column, wherein oxygen generated during said contacting increases internal pressure relative to ambient atmospheric pressure, or increases partial internal O2 pressure relative to ambient partial O2 pressure during said contacting,
- removing dissolved lignin, and
- recovering cellulose;
- wherein a top of the column is closed to atmospheric pressure by a gasket, which gasket retains sufficient oxygen in the column to maintain a higher than atmospheric pressure in the column during said contacting;
- and
- wherein the gasket comprises a fiber plug or membrane which fits over an open top of the reaction column and prevents escape of sufficient oxygen molecules and oxygen radicals produced by said hydrogen peroxide treatment to enhance efficiency of delinification compared to an otherwise identical method that does not comprise the gasket.
4 more elements
Dependencies are inferred from the claim text.