Patent ID: 9091022
Filing Date: 2015-07-28
Classification: B27N,C08H,D21C

Abstract:
1. A process for the preparation of a modified lignocellulosic material by contacting and reacting a lignocellulosic material with a modification agent, which contains acid anhydride, and stripping the modified lignocellulosic material to remove excess of modification agent and by-products, including the steps of a) introduction of the lignocellulosic material into a first activator zone and treatment of the lignocellulosic material in the first activator zone having an atmosphere of the modification agent, which contains one or more acid anhydrides, in vapour form in a gas at a gauge pressure of 0-50 kPag and a temperature of 100-160° C., b) transfer of the lignocellulosic material from the first activator zone into a second reactor zone and treatment of the lignocellulosic material in the second reactor zone having an atmosphere of a gas at a gauge pressure of 0-50 kPag and a temperature of 120-190° C., c) transfer of the lignocellulosic material from the second reactor zone into a stripper zone and stripping of the lignocellulosic material with steam or water in the stripper zone, d) optionally transfer to further processing, wherein the modification agent introduced into the first activator zone has a content of hydrated acids below 3% by weight.