| abstract |
The invention discloses a method for mild acid-catalyzed depolymerization of lignosulfonate, which is characterized by comprising the following steps: a depolymerization liquid separation step: adding a composite inorganic acid catalyst to a phenol solvent and then adding the lignosulfonate , react at high temperature and normal pressure until solid precipitation is precipitated, and then transfer the upper layer solution to obtain a depolymerization solution; use acetone solvent to wash the solid precipitation and high-speed centrifugation to obtain a filter residue; the inorganic acid catalyst is a mixed catalyst of sulfuric acid and hydrochloric acid. In the present invention, by adopting a low-concentration composite inorganic acid catalytic system, under mild conditions (about 90° C., 0.5 hr), a one-step method is used to rapidly and efficiently depolymerize lignosulfonate, and a depolymerization efficiency of more than 95% is obtained. product. |