Two vessel reactor system and method for hydrolysis and digestion of wood chips with chemical enhanced wash method

摘要

A reactor vessel system including: a first reactor vessel having a hydrolysate and liquid extraction screen, a first region above the extraction screen that is maintained at conditions promoting a hydrolysis reaction in the cellulosic material, a second region below the extraction screen in which the hydrolysis is substantially suppressed and a wash liquid inlet below the extraction screen providing wash liquid at a temperature below a hydrolysis temperature; a transport pipe having an inlet coupled to the first reactor vessel and an outlet coupled to a second reactor vessel, and the second reactor vessel includes a liquid discharge that extracts a portion of liquid from the second reactor vessel and directs the portion of liquid to the first reactor vessel or to the transport pipe.

主权项

1. A reactor vessel system comprising:
a first reactor vessel including a material input receiving cellulosic material and a material discharge for the cellulosic material, wherein the cellulosic material flows through the first reactor vessel from the material input to the material discharge; a hydrolysate and liquid extraction screen in the first reactor vessel; a first region of the first reactor vessel between the material input and the liquid extraction screen, wherein the first region is configured to be maintained at conditions promoting an autohydrolysis reaction in the cellulosic material; a second region of the first reactor vessel between the liquid extraction screen and the material discharge, wherein the second region is configured to operate at conditions that suppress hydrolysis of the cellulosic material; a source of wash liquid, wherein the wash liquid includes a mixture of water and at least one of sodium hydroxide and essentially sulfur free white liquor, and the wash liquid is at a temperature below a hydrolysis temperature of the cellulosic material; a wash liquid inlet port coupled to the source of wash liquid and positioned on a bottom region of the first reactor vessel and below the liquid extraction screen, wherein the wash liquid inlet port provides a conduit for introducing wash liquid from the source of wash liquid into the bottom region of the first reactor vessel below the extraction screen and flows through the second region to the liquid extraction screen; a transport pipe having an inlet coupled to the material discharge of the first reactor vessel and an outlet coupled to a second reactor vessel, wherein the transport pipe is configured to move cellulosic material from the material discharge to the second reactor vessel, and the second reactor vessel is configured to receive a cooking liquor and to receive the cellulosic material from the first reactor vessel from the transport pipe, and the second reactor vessel includes a liquid discharge configured to extract a portion of liquid from the second reactor vessel and direct the portion of liquid to a pipe providing a passage for the portion of the liquid to at least one of a lower inlet of the first reactor vessel or to the transport pipe.