Biofuels and Bioenergy

Bamboo is a fast-growing species that is widely distributed in many parts of the world, especially in Asia, with India and China leading in acreage. Moreover, over 1200 species of bamboo have been reported indicating the existence of

remarkable genetic diversity. Over the past decade or so there have been increased efforts to develop bamboo as a feedstock for conventional pulp and paper products, dissolving pulp, and cellulosic ethanol. However, its high silica content is a challenge for bamboo processing. Consequences of high silica such as scale build-up in evaporators are well acknowledged in the pulp and paper industry. Recently it was reported that silica also affects enzymatic hydrolysis during cellulosic ethanol production. We investigated alkali-and acid-based chemical methods and mechanical treatments to develop technologies for using bamboo as a feedstock in biorefinery applications. Treatment with NaOH at moderate temperatures led to the removal of more than 95% of silica in bamboo. We successfully integrated this method to a modified kraft pulping process scheme to co-produce dissolving grade pulp, lignin, cellulosic ethanol, and silica at 32%, 20%, 9%, and 1% (% wt. on input dry bamboo), respectively,

at lab-scale. Further studies have shown that NaOH treatment can be bolted-on as a unit operation in several approaches for cellulosic ethanol production from bamboo. On the acidic treatment front, we improved the conventional pre-hydrolysis kraft pulping process by incorporating mechanical refining and xylanase treatment to produce dissolving grade pulp. Collectively, these results demonstrate the feasibility of using bamboo as a promising feedstock for a biorefinery.