The disclosure relates to a process for the preparation of a sugar product from lignocellulosic material, comprising the following steps: a) optionally, pretreatment of the lignocellulosic material; b) optionally, washing of the optionally pretreated lignocellulosic material; c) enzymatic hydrolysis of the optionally washed and/or optionally pretreated lignocellulosic material in a hydrolysis reactor using an enzyme composition comprising at least two cellulase; and d) optionally, recovery of a sugar product; wherein during the enzymatic hydrolysis oxygen-containing gas is added to the lignocellulosic material in the hydrolysis reactor and wherein part of the oxygen-containing gas, added to the lignocellulosic material, is gas originating from the headspace of the reactor, preferably during part of the time of the enzymatic hydrolysis less oxygen is added to the lignocellulosic material compared to the other part of the time of the enzymatic hydrolysis, or preferably during part of the time of the enzymatic hydrolysis no oxygen is added to the lignocellulosic material.

A bleached softwood kraft pulp fiber with high alpha cellulose content and improved anti-yellowing is provided. Methods for making the kraft pulp fiber and products made from it are also described.

A bleached softwood kraft pulp fiber with high alpha cellulose content and improved anti-yellowing is provided. Methods for making the kraft pulp fiber and products from it are also described.

A surfactant treated bleached softwood kraft pulp fiber, useful as a starting material in the production of cellulose derivatives including cellulose ether, cellulose esters and viscose, is disclosed. Methods for making the kraft pulp fiber and products made from it are also described.

The invention relates to a process for the preparation of a sugar product from lignocellulosic material, comprising the following steps: a) optionally, pretreatment of the lignocellulosic material; b) optionally, washing of the optionally pretreated lignocellulosic material; c) enzymatic hydrolysis of the optionally washed and/or optionally pretreated lignocellulosic material in a hydrolysis reactor using an enzyme composition comprising at least two cellulase; and d) optionally, recovery of a sugar product;
wherein during the enzymatic hydrolysis oxygen-containing gas is added to the lignocellulosic material in the hydrolysis reactor and wherein part of the oxygen-containing gas, added to the lignocellulosic material, is gas originating from the headspace of the reactor,
preferably during part of the time of the enzymatic hydrolysis less oxygen is added to the lignocellulosic material compared to the other part of the time of the enzymatic hydrolysis, or preferably during part of the time of the enzymatic hydrolysis no oxygen is added to the lignocellulosic material.

A surfactant treated bleached softwood kraft pulp fiber, useful as a starting material In the production of cellulose derivatives including cellulose ether, cellulose esters and viscose, is disclosed. Methods for making the kraft pulp fiber and products made from it are also described.