What is the first step in the Kraft process of pulp production?

In the Kraft process of pulp production, the correct first step is cooking wood chips under pressure. This step takes place in a digester, where wood chips are mixed with a chemical solution, primarily composed of sodium hydroxide and sodium sulfide. The cooking process breaks down the lignin, which binds the cellulose fibers together in the wood. By applying heat and pressure, this step effectively dissolves the lignin, allowing for the separation of cellulose fibers and the creation of pulp.

This initial stage is crucial because it directly impacts the yield and quality of the final pulp product. The chemicals used in the cooking process not only assist in breaking down the lignin but also help in preserving the cellulose content, making the Kraft process efficient and suitable for producing strong paper products. Understanding the significance of this initial cooking process is essential in grasping the overall workflow of pulp production.