Method of digesting lignocellulosic material

A method of digesting lignocellulosic material, said method comprising the steps of:

• A. providing the lignocellulosic material;
• B. providing a caustic composition having a pH of at least about 10 and consisting essentially of;
• (i) water,
• (ii) an alkaline- or alkaline earth-metal hydroxide present in an amount of from 7 to 20 parts by weight per 100 parts by weight of said caustic composition,
• (iii) about 0.2 to 0.3 percent by weight based on a total weight of the composition of a branched digestion additive having the structure;
• wherein A is at least one alkyleneoxy group and each alkyleneoxy group has from 2 to 3 carbon atoms, n is 1, B is a branched aliphatic hydrocarbon group having from 10 to 13 carbon atoms, X is H, and each m is independently an average value from 3 to 9;
• and
• a second digestion additive present in an amount up to 0.5 weight percent that is different from the (iii) branched digestion additive and that comprises:
• wherein each A is at least one alkyleneoxy group and each alkyleneoxy group has from 2 to 3 carbon atoms, each m is independently an average value from 3 to 9, n is 1, and each B is independently a branched aliphatic hydrocarbon group having from 10 to 13 carbon atoms,
• wherein the caustic composition has a Draves Wetting Time of less than 10 seconds as determined using ASTM D2281, and
• wherein the caustic composition is free of a sulfide;
• and comprises less than 0.1 weight percent of additional additives;
• C. combining the lignocellulosic material and the caustic composition to form a mixture;
• and
• D. heating the lignocellulosic material and/or the caustic composition to digest the lignocellulosic material.