Method for preparation of bio-filler for plastic and bio-filler for plastic prepared thereby

A method for preparing a bio-filler for a plastic, the method comprising the steps of:

• (a) pulverizing and drying lignocellulosic biomass;
• (b) adding a strong acid to the pulverized and dried lignocellulosic biomass;
• (c) adding a base to the reaction mixture obtained in step (b) to neutralize the residual acid;
• and
• (d) removing water-soluble substance from the reaction mixture neutralized in step (c) to obtain a solid particle.