Optimization of chemical consumption in biomass delignification

A process to perform a controlled exothermic delignification on a batch of lignocellulosic biomass, said process comprising:

• providing a system comprising at least a first vessel and a second vessel;
• providing biomass comprising lignin, hemicellulose and cellulose fibers into said first vessel;
• providing an aqueous acidic composition comprising an acid selected from the group consisting of:
• sulfuric acid;
• an alkylsulfonic acid;
• an arylsulfonic acid and combinations thereof;
• providing a modifier component;
• providing a peroxide component;
• exposing said biomass to said acidic composition, said peroxide component and said modifier component to create a reaction mass;
• mixing said reaction mass;
• allowing said acidic composition and peroxide component to come into contact with said biomass for a period of time sufficient for a delignification reaction to occur and remove a pre-determined amount of said lignin from said biomass to form a first treated biomass, wherein said pre-determined amount is assessed by determining a first remaining peroxide concentration in the reaction mass, with a suitable apparatus, when said first remaining peroxide concentration is reached, the first treated biomass is transferred to said second vessel;
• allowing a temperature of the first treated biomass to increase during the residence time of said first treated biomass in said second vessel to a second temperature;
• and
• allowing said acidic composition, said modifier component and said peroxide component to continue said delignification reaction at said second temperature and remove a second pre-determined amount of said lignin from said first treated biomass to form a second treated biomass, wherein said second pre-determined amount is assessed by testing a second remaining peroxide concentration in the first treated biomass, when said second remaining peroxide concentration is reached, the second treated biomass is removed from said second vessel.