Desilication of bamboo for pulp production

Abstract

Bamboo is one of the world’s fastest growing feedstocks. It is a promising nonwood resource that can be used in the pulp and paper industry. Among more than 1200 species of bamboo, the timber varieties can be processed much like trees, allowing current pulp mill logistical systems to be used. Bamboo can be difficult to pulp because of its high silica content, which creates issues for black liquor recovery. This study compares two methods of reducing the silica content of a common species of timber bamboo. Specifically, the dermis layer of Moso bamboo (Phyllostachys edulis) was removed through mechanical treatment and then chipped. The same species was also chipped without treatment. The two chipped materials were then alkali extracted and subjected to kraft pulping experiments. The pulps were bleached with an OD0(EP)D1 sequence. The material was then refined and formed into handsheets. The results indicate that 80% of the silica could be removed from the bamboo material through a combination of dermal mechanical treatment and caustic chip extraction. Caustic chip extraction removed a significant portion of hemicellulose materials, which in turn lowered cooking yields but had minimal effect on pulp properties.