Abstract: A process to delignify biomass, said process comprising the steps of: providing a vessel; providing biomass comprising lignin, hemicellulose and cellulose fibers into said vessel; providing a aqueous acidic composition comprising a sulfuric acid component; providing a peroxide component; exposing said biomass to said sulfuric acid component and peroxide component, creating a reaction mass; allowing said sulfuric acid component and peroxide component to come into contact with said biomass for a period of time sufficient to a delignification reaction to occur and remove over 90 wt % of said lignin and hemicellulose from said biomass; and controlling the temperature of the delignification reaction to maintain it below 55° C.

Abstract: A process to perform a controlled exothermic delignification of biomass comprises providing a system having a first vessel and a second vessel, providing a biomass comprising lignin, hemicellulose and cellulose fibers placed into the first vessel, providing an aqueous acidic composition comprising a sulfuric acid component, providing a modifier component and providing a peroxide component. The biomass is exposed to the sulfuric acid component and peroxide component, thereby creating a reaction mass. The reaction mass is mixed and the sulfuric acid, modifier and peroxide components are allowed to come into contact with the biomass for a period of time sufficient for a delignification reaction to occur and to remove a predetermined amount of the lignin from the biomass. The predetermined amount is assessed by testing a first kappa number of the biomass. When the first kappa number of the biomass is reached, the biomass is transferred to the second vessel.

Abstract: A process to delignify biomass, said process comprising the steps of: providing a vessel; providing biomass comprising lignin, hemicellulose and cellulose fibers into said vessel; providing a aqueous acidic composition comprising a sulfuric acid component; providing a peroxide component; exposing said biomass to said sulfuric acid component and peroxide component, creating a reaction mass; allowing said sulfuric acid component and peroxide component to come into contact with said biomass for a period of time sufficient to a delignification reaction to occur and remove over 90 wt % of said lignin and hemicellulose from said biomass; and controlling the temperature of the delignification reaction to maintain it below 55° C.