Process for the comminution of materials and plant for carrying out the process

A process for treating high consistency fibrous materials, which comprises

• contacting fibrous material, a reaction agent and a carrier gas in a comminuting zone under a closed system to separate said fibrous material into smaller segments and react with said reaction agent;
• passing said segmented fibrous material, reaction agent and carrier gas to a reaction zone for further reaction between said segmented fibrous material and said reaction agent;
• separating a gaseous fraction of said reaction agent and said carrier gas from said reaction zone and recycling said gaseous fraction to said comminuting zone for further reaction;
• and
• discharging reacted, segmented fibrous material from said reaction zone;
• wherein said reaction agent is NO.sub.x, with x being an integer between 1 and 3, inclusive, and said carrier gas is carbon dioxide.

A process for treating high consistency fibrous materials, the process comprising

• contacting fibrous material, a reaction agent and a carrier gas in a comminuting zone under a closed system to separate said fibrous material into smaller segments and react with said reaction agent;
• passing said segmented fibrous material, reaction agent and carrier gas to a reaction zone for further reaction between said segmented fibrous material and said reaction agent;
• separating a gaseous fraction of said reaction agent and said carrier gas from said reaction zone and recycling said gaseous fraction to said comminuting zone for further reaction;
• discharging reacted, segmented fibrous material from said reaction zone;
• and
• cooling said gaseous fraction in a heat exchange zone before recycling said gaseous fraction;
• wherein said reaction agent is separated in the liquid phase from said carrier gas to produce said gaseous fraction including vapors of said reaction agent.