摘要 |
Processes for preparing pulp from lignin-containing cellulosic material are disclosed including a prehydrolysis step followed by neutralizing hydrolysate and the prehydrolyzed cellulosic material in the reactor with alkaline neutralizing liquor, removing the neutralized hydrolysate from the reactor and delignifying the neutralized prehydrolyzed cellulosic material with alkaline cooking liquor containing sodium sulfide and sodium hydroxide. |